yes would be good to know how old the current cap is
The Mystery of the Missing Heat
- Thread starter Dunnik
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- Thread starter
- #42
So after letting the vehicle rest with the front wheels up on blocks (about a 4 in. lift) for about 20 hours, here are the results:
- reserve tank level seems to be about the same, maybe a little lower (-1°C this morning, down to about -4 overnight)
- coolant is up to the level of the neck inside the radiator (picture)
- engine temps seemed to climb a little faster to operating temp, where it stayed
- once the engine warmed up a bit, tested the heat: it blows warm, which is actually an improvement, previously it would blow ice cold for much longer. Still not heat, though, just warm-ish air
- after a 15 minute run, still blows just warm air (imagine that had I drove for another 10-15 minutes, it would start producing heat, as before)
- reserve coolant tank hose is slightly bent (picture), but seems a normal flex considering its not made of the most rigid of rubber
- radiator cap and seals seem OK, unknown age but probably original
- hose running from reserve tank to the radiator seems well-secured
- as requested, picture of the engine bay, in all its coolant-encrusted glory
- reserve tank level seems to be about the same, maybe a little lower (-1°C this morning, down to about -4 overnight)
- coolant is up to the level of the neck inside the radiator (picture)
- engine temps seemed to climb a little faster to operating temp, where it stayed
- once the engine warmed up a bit, tested the heat: it blows warm, which is actually an improvement, previously it would blow ice cold for much longer. Still not heat, though, just warm-ish air
- after a 15 minute run, still blows just warm air (imagine that had I drove for another 10-15 minutes, it would start producing heat, as before)
- reserve coolant tank hose is slightly bent (picture), but seems a normal flex considering its not made of the most rigid of rubber
- radiator cap and seals seem OK, unknown age but probably original
- hose running from reserve tank to the radiator seems well-secured
- as requested, picture of the engine bay, in all its coolant-encrusted glory
Last edited:
2001LC
SILVER Star
I really was hoping to see level low, would have been case closed. Oh well!
Just a note: I did once have and air bubble in the front heater core. System look properly topped. But very low or no heat coming from cabin front heater (did not check rear). On a drive, I slammed on-brakes and heard a gurgling sound as I did. Then front heater then worked. I did need to re-top coolant system afterwards. But I'm thinking the odds of both your heater cores with a bubble, is unlikely. But I did want to throw that out there.
Also:
Make sure to double check the cabin sensor hose and wire are connected. You may be able to see with mirrors without pulling dash molding around IG switch. I pull sensor and connect, put dash together then snap sensor back in to install. Otherwise the hose falls off about halve the time.
forum.ih8mud.com
Observation of picture:
A) Reservoir tank hose looks good, it's not curved.
B) Coolant level to of neck under radiator cap, is proper level.
C) The pink crusty splatter, is mostly on radiator and adjacent areas, not on hood insulator. So looks like someone just began opening the radiator cap while hot, some coolant blew out. Not some leak or over-pressurized blow-off while driving, which would have likely gotten on underside of hood.
Recommendation:
1) I would replace the radiator cap, which I do very often. The coolant reservoir level should have changed after reaching operating temp of ~187 F (87 C) and then OAT of 24 F (-4 C) after cool down. It is not likely the radiator cap would keep your heaters from working, but it may be minor influence. I'm not a fluid engineer. So others here may have different and more educated opinion on how pressure effect the coolant flow within the system and through heater cores.
Cap controls pressure in coolant system. Pressure builds as coolant expands from heat. The cap release this pressure at ~13 PSI "IIRC". A stuck cap can cause over-pressurizing in the coolant systems. This can blowing plastic top off a weak old radiator, blow apart old rotten heater tees plastic or find some other weak spot to blow off pressure. If cap weak from age, which is very common. We release coolant into reservoir to easily, at lower pressure. System is not getting to designed pressure, and we don't get movement in or out of reservoir as designed.
We want the coolant system up to par. These caps get weak with time. You can test a cap. But really difficult to find a cap tester. New Toyota OEM cap is ~$15, and best bet and insure this part of system working as designed.
So what now?
We want to confirm engine coolant is indeed reaching operating temperature. The dash gauge indicated it did/is, but we need to make sure. This can be done with a simple IR temperature gun.
With IR temp gun, you'll be able to point at specific places on engine and read temperatures. First will be thermostat housing and water by pass joint where water temperature sending unit is threaded in and reads temperature.
It will be easier to take temp reading with engine (valley cover) off. Just remove the 2 nuts and 2 bolts seen on top of cover and un-clip the hose (fuel return hose) hung on back of cover near DS fire wall.
OBDII reader, will be a nice tool addition to aid in monitoring temperature:
If we find temperature is running low. Considering you've new OEM thermostats, that were installed. I'd then want to know fuel trim readings. A rich fuel mixture and cylinder heads run cooler than normal, and as such coolant temp is often on low side. You'd also likely have poor gas mileage also. So here the OBDII scaner would be valuable.
I've a OBD II bluetooth reader, that I brings up data on my smart phone. We don't need for the IR gun test, but would be helpful during and after. With it you can read engine temperature (coolant temp) through tech-stream. You'll see exact temperature, water temperature sending unit send to ECM and dash gauge. You 'd be able to drive around and log temperatures also, among many other data point. I use a lot for reading codes and monitoring fuel trims and CAT temps. You'll know if temperature staying in a normal range. The IR gun will confirm temp sending unit giving correct data, as read through tech stream. Than we'd just watch tech stream via and OBDII reader.
Verify engine at operating temp, and that water temperature sending unit is giving a good signal as read by dash gauge:
Once temperature gauge on dash is at normal. Verify with IR temp gun at various points, that water temp is about 187 F (~87 C).
Reading temp off the brass nut at base of water temp sending unit, is a good spot. The difference between the aluminium housing of front water bypass joint and brass threads of sending unit into it, will be about the same.
The thermostat housing is good place to rear temp of coolant, as shot off housing The temp will be very close to water temp within. This may be just slightly lower. How long engines been at operating temp and OAT temp will cause some variation in reading.
Temp shot off goose neck of upper radiator hose will be slightly higher, than that of thermostat housing which lower radiator hose connects to. Reason, hot water flows from engine into top of radiator through the upper hose. The water cools as it passes through engine radiator, then out lower hose to thermostat. Ref back to post #37 for coolant (water) flow.
This is a VVT engine like yours with air pipe from air filter box, throttle body and intake manifold removed removed. So yours will appear a little different. But you should find this helpful, if unfulfilled with parts.
So if coolant system is properly topped, no air bubble in system and temperature gauge is reading properly indicated we are indeed make proper operating temp..
Than what?
Well I've two theories.
1) Coolant is not flowing through heater core fast enough. That is to say; If coolant barely moving through the heater cores. The heat (energy) would be removed from water in core, as air passes over core. The energy is then to slowly replaced, as water not moving through heater core at acceptable rate to replace heat in cores.
This would presumably be either not enough flow pushing coolant in. Possible defective water pump or a blockage of flow in the passage before the heater tee's. This could be in down stream blockage also. Where water get to the heater tees and in heater cores, then is slowing exiting do to back pressure form blockage down stream.
Since cores where confirmed no blockage and neither front or rear working, the blockage, if one, would be on engine side of circulation.
A sign of this would be it takes a long time after engine reaches operating temp, for heater in cabin to blow hot. The cabin fan would need to remain off and vents set to circulating air as oppose to outside fresh air. This way no air is passing heater cores, remove energy/heat from water. So heat can build in them. Then turn cabin fans on high and heat will blow hot until heat (energy) pulled from water in heater cores. Then air blowing from vent would start cooling. This may indicate restricted water (coolant) flow, being to slow for recovery. Leaving fan off again for a certain amount of time, would give time for heat to build again. This should be repeatable, time and time again.
A further clue would be using IR temp gun to obtain temp readings at heater tees, or better may be the metal tube (heater core aluminium tubes rubber hose connect to) coming through the fire wall at tees. If you can see them.
Test these temps, when engine has reach operating temp. Do this after enough time has passed, as it takes to get your heater in cabin to work. But do not turn on cabin fan and keep air set circulating, not allowing air movement pass the heaters cores. The temp reading should be the same on DS (driver side) which is hot water from engine, as PS (passenger side) which is water returning to engine for front heater core. The lower hoses & pipes, warping down firewall from tees, are to and from rear heater core.
Then turn on cabin fan to high, we'll see a drop temp on PS pipe near heater tee, as heater energy is take from core with fan on.
Here we need to know what the acceptable drop in heater core temp is. Either look-up or someone can check their's and report back here. I've got to run now. But if I remember I shoot my temps and report back when I can.
If flow restricted, the temp will drop in cabin to warm rather than hot as fan runs. Then after some time with fan off, temperature will recover in core to give heat in cabin again.
Scored 2006LC w/194K GrayBeard this link has pictures of tees removed, may help you locate where heater tees are.
If temp is recovering in heater cores and holding properly, then this is not likely a coolant temperature or flow restriction issue.
2) In which case we're left with electronic problem or serves controlled by. Either a signal not being properly read by HVAC systems. Or the doors of HVAC are not working properly. Since both heater, this would indicate a central area short, or control signal like ground signal control.
This is why I asked about windshield. I've found so many issue from water entry into cabin. Most those being from improper windshield install.
So why can't your Dealership find cause:
The likely reason the shops can't find, is they will not take the time require. They're given a book time to do diagnosis. If they can't find in that time, they just move to next job that came in the door 8 out of 10 times.
I had one in-op AC diagnosis, that many Toyota Dealerships try to get AC working and failed. Independents shops and owner who was a mechanic himself, could not get it working. They brought to me.
forum.ih8mud.com
It heat worked before and will work again. It just takes patient and time to root out the cause.
Just a note: I did once have and air bubble in the front heater core. System look properly topped. But very low or no heat coming from cabin front heater (did not check rear). On a drive, I slammed on-brakes and heard a gurgling sound as I did. Then front heater then worked. I did need to re-top coolant system afterwards. But I'm thinking the odds of both your heater cores with a bubble, is unlikely. But I did want to throw that out there.
Also:
Make sure to double check the cabin sensor hose and wire are connected. You may be able to see with mirrors without pulling dash molding around IG switch. I pull sensor and connect, put dash together then snap sensor back in to install. Otherwise the hose falls off about halve the time.
Scored 2006 LC w/194K AHC (untouched Jewell restoration)
I finished cleaning the paint with my porter-cable DA buffer using a 5" micro fiber medium cut pad with cutting compound. I had to adjust my timing to catch early mornings while the ambient temperature was cool. Much above 72 deg and the cutting compound just worked me to death. The paint looks...
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Observation of picture:
A) Reservoir tank hose looks good, it's not curved.
B) Coolant level to of neck under radiator cap, is proper level.
C) The pink crusty splatter, is mostly on radiator and adjacent areas, not on hood insulator. So looks like someone just began opening the radiator cap while hot, some coolant blew out. Not some leak or over-pressurized blow-off while driving, which would have likely gotten on underside of hood.
Recommendation:
1) I would replace the radiator cap, which I do very often. The coolant reservoir level should have changed after reaching operating temp of ~187 F (87 C) and then OAT of 24 F (-4 C) after cool down. It is not likely the radiator cap would keep your heaters from working, but it may be minor influence. I'm not a fluid engineer. So others here may have different and more educated opinion on how pressure effect the coolant flow within the system and through heater cores.
Cap controls pressure in coolant system. Pressure builds as coolant expands from heat. The cap release this pressure at ~13 PSI "IIRC". A stuck cap can cause over-pressurizing in the coolant systems. This can blowing plastic top off a weak old radiator, blow apart old rotten heater tees plastic or find some other weak spot to blow off pressure. If cap weak from age, which is very common. We release coolant into reservoir to easily, at lower pressure. System is not getting to designed pressure, and we don't get movement in or out of reservoir as designed.
We want the coolant system up to par. These caps get weak with time. You can test a cap. But really difficult to find a cap tester. New Toyota OEM cap is ~$15, and best bet and insure this part of system working as designed.
So what now?
We want to confirm engine coolant is indeed reaching operating temperature. The dash gauge indicated it did/is, but we need to make sure. This can be done with a simple IR temperature gun.
With IR temp gun, you'll be able to point at specific places on engine and read temperatures. First will be thermostat housing and water by pass joint where water temperature sending unit is threaded in and reads temperature.
It will be easier to take temp reading with engine (valley cover) off. Just remove the 2 nuts and 2 bolts seen on top of cover and un-clip the hose (fuel return hose) hung on back of cover near DS fire wall.
OBDII reader, will be a nice tool addition to aid in monitoring temperature:
If we find temperature is running low. Considering you've new OEM thermostats, that were installed. I'd then want to know fuel trim readings. A rich fuel mixture and cylinder heads run cooler than normal, and as such coolant temp is often on low side. You'd also likely have poor gas mileage also. So here the OBDII scaner would be valuable.
I've a OBD II bluetooth reader, that I brings up data on my smart phone. We don't need for the IR gun test, but would be helpful during and after. With it you can read engine temperature (coolant temp) through tech-stream. You'll see exact temperature, water temperature sending unit send to ECM and dash gauge. You 'd be able to drive around and log temperatures also, among many other data point. I use a lot for reading codes and monitoring fuel trims and CAT temps. You'll know if temperature staying in a normal range. The IR gun will confirm temp sending unit giving correct data, as read through tech stream. Than we'd just watch tech stream via and OBDII reader.
Verify engine at operating temp, and that water temperature sending unit is giving a good signal as read by dash gauge:
Once temperature gauge on dash is at normal. Verify with IR temp gun at various points, that water temp is about 187 F (~87 C).
Reading temp off the brass nut at base of water temp sending unit, is a good spot. The difference between the aluminium housing of front water bypass joint and brass threads of sending unit into it, will be about the same.
The thermostat housing is good place to rear temp of coolant, as shot off housing The temp will be very close to water temp within. This may be just slightly lower. How long engines been at operating temp and OAT temp will cause some variation in reading.
Temp shot off goose neck of upper radiator hose will be slightly higher, than that of thermostat housing which lower radiator hose connects to. Reason, hot water flows from engine into top of radiator through the upper hose. The water cools as it passes through engine radiator, then out lower hose to thermostat. Ref back to post #37 for coolant (water) flow.
This is a VVT engine like yours with air pipe from air filter box, throttle body and intake manifold removed removed. So yours will appear a little different. But you should find this helpful, if unfulfilled with parts.
So if coolant system is properly topped, no air bubble in system and temperature gauge is reading properly indicated we are indeed make proper operating temp..
Than what?
Well I've two theories.
1) Coolant is not flowing through heater core fast enough. That is to say; If coolant barely moving through the heater cores. The heat (energy) would be removed from water in core, as air passes over core. The energy is then to slowly replaced, as water not moving through heater core at acceptable rate to replace heat in cores.
This would presumably be either not enough flow pushing coolant in. Possible defective water pump or a blockage of flow in the passage before the heater tee's. This could be in down stream blockage also. Where water get to the heater tees and in heater cores, then is slowing exiting do to back pressure form blockage down stream.
Since cores where confirmed no blockage and neither front or rear working, the blockage, if one, would be on engine side of circulation.
A sign of this would be it takes a long time after engine reaches operating temp, for heater in cabin to blow hot. The cabin fan would need to remain off and vents set to circulating air as oppose to outside fresh air. This way no air is passing heater cores, remove energy/heat from water. So heat can build in them. Then turn cabin fans on high and heat will blow hot until heat (energy) pulled from water in heater cores. Then air blowing from vent would start cooling. This may indicate restricted water (coolant) flow, being to slow for recovery. Leaving fan off again for a certain amount of time, would give time for heat to build again. This should be repeatable, time and time again.
A further clue would be using IR temp gun to obtain temp readings at heater tees, or better may be the metal tube (heater core aluminium tubes rubber hose connect to) coming through the fire wall at tees. If you can see them.
Test these temps, when engine has reach operating temp. Do this after enough time has passed, as it takes to get your heater in cabin to work. But do not turn on cabin fan and keep air set circulating, not allowing air movement pass the heaters cores. The temp reading should be the same on DS (driver side) which is hot water from engine, as PS (passenger side) which is water returning to engine for front heater core. The lower hoses & pipes, warping down firewall from tees, are to and from rear heater core.
Then turn on cabin fan to high, we'll see a drop temp on PS pipe near heater tee, as heater energy is take from core with fan on.
Here we need to know what the acceptable drop in heater core temp is. Either look-up or someone can check their's and report back here. I've got to run now. But if I remember I shoot my temps and report back when I can.
If flow restricted, the temp will drop in cabin to warm rather than hot as fan runs. Then after some time with fan off, temperature will recover in core to give heat in cabin again.
Scored 2006LC w/194K GrayBeard this link has pictures of tees removed, may help you locate where heater tees are.
If temp is recovering in heater cores and holding properly, then this is not likely a coolant temperature or flow restriction issue.
2) In which case we're left with electronic problem or serves controlled by. Either a signal not being properly read by HVAC systems. Or the doors of HVAC are not working properly. Since both heater, this would indicate a central area short, or control signal like ground signal control.
This is why I asked about windshield. I've found so many issue from water entry into cabin. Most those being from improper windshield install.
So why can't your Dealership find cause:
The likely reason the shops can't find, is they will not take the time require. They're given a book time to do diagnosis. If they can't find in that time, they just move to next job that came in the door 8 out of 10 times.
I had one in-op AC diagnosis, that many Toyota Dealerships try to get AC working and failed. Independents shops and owner who was a mechanic himself, could not get it working. They brought to me.
AC Inoperable, collective wisdom of mud help
So a local mud member (a mechanic) brought me his clean 04LC w/157K miles, for diagnostic of inoperable AC. He had it at Toyota Dealership which told him to start by replace AMP ((NAV unit). He declined as he's done that! In researching Toyota Service History, he found PO had it in Toyota...
forum.ih8mud.com
It heat worked before and will work again. It just takes patient and time to root out the cause.
- Thread starter
- #45
Thanks very much @2001LC I'll get on that. And now that you mention it, fuel economy does seem a little worse than I expected. I haven't been tracking it closely, but I will now.
I presume the radiator cap is a Toyota part? Can anyone help with the part number? I can't seem to find it on the website or a local OEM parts supplier.
The (non-IR) windshield has an OEM mark on it, but also a curious sticker in the upper left edge that says something like "Made in Indonesia, sticker only to be removed by owner" if that's a clue.
I presume the radiator cap is a Toyota part? Can anyone help with the part number? I can't seem to find it on the website or a local OEM parts supplier.
The (non-IR) windshield has an OEM mark on it, but also a curious sticker in the upper left edge that says something like "Made in Indonesia, sticker only to be removed by owner" if that's a clue.
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+1 on replacing rad cap. its not the rubber seals so much as its ability to open mechanically when the pressure gets to that magic number.
16401-67150 this worked for my 2000
could it be that the radiator is clogged somewhat?
i would be pulling the T's and sticking a garden hose to one side of each core pipe and watch the flow come out the other side. the cores still could have a lot of air in them from the previous flushes.
and yes it is def time to get some real temp readings from the ECU. get a code reader or scangauge and monitor water temps while driving. cant trust those needle gauges.
16401-67150 this worked for my 2000
could it be that the radiator is clogged somewhat?
i would be pulling the T's and sticking a garden hose to one side of each core pipe and watch the flow come out the other side. the cores still could have a lot of air in them from the previous flushes.
and yes it is def time to get some real temp readings from the ECU. get a code reader or scangauge and monitor water temps while driving. cant trust those needle gauges.
Probably good idea to wash off the coolant residue in the engine bay so you monitor for leaks going forward.
Toyota/Lexus OEM replacement windshields have a sticker like that. Below is one from an OEM LS windshield. Does yours look like this one ? That is evidence that the windshield has been replaced. These stickers do stay on pretty long, but eventually come off. So the windshield was probably replaced in the last 2 years or so, depending on the frequency of car washing. Maybe it was replaced for the sale?
I'm north of GTA. Feel free to PM me if you need help looking at possible error codes / engine temperatures. I have Techstream running.
Toyota/Lexus OEM replacement windshields have a sticker like that. Below is one from an OEM LS windshield. Does yours look like this one ? That is evidence that the windshield has been replaced. These stickers do stay on pretty long, but eventually come off. So the windshield was probably replaced in the last 2 years or so, depending on the frequency of car washing. Maybe it was replaced for the sale?
I'm north of GTA. Feel free to PM me if you need help looking at possible error codes / engine temperatures. I have Techstream running.
Your glass is 'AGC automotive', which is Asahi Glass Company which is the OEM. But the fact that it has the sticker on it, indicates that it was replaced. No immediate red flags as the PO/dealer was careful enough to replace it with OEM glass.
2001LC
SILVER Star
I look for various clues first being a Toyota or Lexus. Second I look at molding. Side molding, which is almost always installed wrong. In your case I can only see sticker and top molding. That does not look like correct top molding. But not sure due to angle of shot. Sticker as said, indicates replacement.
If you read the link about on inop AC, I posted above. Then you know the inop AC, was caused by improper install. Water was leaking down the A pillars, long before it came to me. By the time I inspected, the owner had corrected and stopped the leaks. So it was dry, but damaged remained.
Here's a shot that was just text to me of a few days ago, with side molding removed. This was windshield install improperly years earlier. I inspected the vehicle pre purchased and told buyer "I would not buy" as I saw minor paint bubble along side windshield molding. I said it has rust. Whether bad or not, I could not say with molding on, but I was sure it had rust. He got a deal, so savings is going into rust repair.
This water entry traveling down "A" pillar is a big deal, and has totaled 100 and 200 series, after dealerships could not corrected electronic issues.
This one, was done through Denver's top Lexus Dealership. Like most all Dealership they contract out windshield work. With the Lexus LX470. If it has heads up display, they use OEM glass.
Here we see a cracked windshield, with crack coming from rust spot. Rust growing caused the crack in glass.
Here is factory installed molding or a perfect subsequent install.
Look at bye bye to The King, for more on windshield install.
forum.ih8mud.com
If you read the link about on inop AC, I posted above. Then you know the inop AC, was caused by improper install. Water was leaking down the A pillars, long before it came to me. By the time I inspected, the owner had corrected and stopped the leaks. So it was dry, but damaged remained.
Here's a shot that was just text to me of a few days ago, with side molding removed. This was windshield install improperly years earlier. I inspected the vehicle pre purchased and told buyer "I would not buy" as I saw minor paint bubble along side windshield molding. I said it has rust. Whether bad or not, I could not say with molding on, but I was sure it had rust. He got a deal, so savings is going into rust repair.
This water entry traveling down "A" pillar is a big deal, and has totaled 100 and 200 series, after dealerships could not corrected electronic issues.
This one, was done through Denver's top Lexus Dealership. Like most all Dealership they contract out windshield work. With the Lexus LX470. If it has heads up display, they use OEM glass.
Here we see a cracked windshield, with crack coming from rust spot. Rust growing caused the crack in glass.
Here is factory installed molding or a perfect subsequent install.
Look at bye bye to The King, for more on windshield install.
Bye Bye to The King: Windshield rust repair ++
Well I can't believe I sold The King (2001LC Thunder Cloud NO NAV ), He's be with me near 14 years and has been the most reliable vehicle I've ever had the pleasure of owning & driving. When I bought it, I ask at the Toyota parts counter; "what part or parts are you seeing purchased the most...
forum.ih8mud.com
Last edited:
2001LC
SILVER Star
I tried the IR temp gun test I outlined above, after a 30 minute drive. OAT was 37 F and heater set to hot, fan off
I found back of thermostat housing away from fan, gave best reading at 187 F.
I could not see heater core aluminium tubes at fire wall. So I shot off top on clamps just rear of heater tees. 172 DS, 171 PS
Turn heater fan blower fan on high. I watched temp drop and stabilize after ~5 minutes
Thermostat 158 F
DS tee clamp 165 F
PS tee clamp 158 F
It was hard to get a good reading and hit the same spot with IR gun. But what I saw; is water temp drops in engine, as does water into core with only 7 F difference through the core, as fan pulling heat from water in heater core.
You said 41 F (5 c) from dealership report, which I said sound high.
The dealership measured a 5°C temperature difference. That is a 9°F delta. Your observations 165°F-158°F=7°F. Pretty close, indicating the problem could be on the air-side of things.
2001LC
SILVER Star
How do you get 9f
0c Celsius = 32f (Fahrenheit). 5c = 41f.
www.worldwidemetric.com
°F = °C * 1.8 + 32
Example: 20 °C = 68 °F
20 * 1.8 = 36
36 + 32 = 68
0c Celsius = 32f (Fahrenheit). 5c = 41f.
Reference Tools | World Wide Metric
Check out World Wide Metric's quick reference guide for flanges, piping, valves, and more.
www.worldwidemetric.com
Example: 20 °C = 68 °F
20 * 1.8 = 36
36 + 32 = 68
The multiplier between °F and °C is 1.8. So 5C delta is 5°Cx1.8=9°F difference.
Another way of looking at it: Assume a temperature delta of 5°C as measured by the dealer. Lets say 75°C (167°F) inlet, 70°C (158°F) outlet. It shows that 75-70=5°C temperature delta is equivalent to a 167-158=9°F temperature delta.
The conversion of 5°C to °F is 41°F. But that is the converion of 5°C absolute temperature, not the temperature difference.
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2001LC
SILVER Star
DUH, you're right. ~9 f difference at operating temp of 187f
Still, need to verify 5c that was reported by Dealership and in two condition..
What we need to see:
Engine water temp with cabin fan off ~187 f. matching what dash gauge indicates.
Then differences while heat working good with fan blowing on high a normal drop.
Then while heat not blowing hot while fan still blowing on high.
If while not blowing hot, difference isn't lower than normal, we can than assume this is not coolant temp or flow issue.
We also need confirmed the cabin air sensor wire and hose are on. I've found that hose falls off often, when dash molding remove and reinstalled.
Then move on to electrical.
Still, need to verify 5c that was reported by Dealership and in two condition..
What we need to see:
Engine water temp with cabin fan off ~187 f. matching what dash gauge indicates.
Then differences while heat working good with fan blowing on high a normal drop.
Then while heat not blowing hot while fan still blowing on high.
If while not blowing hot, difference isn't lower than normal, we can than assume this is not coolant temp or flow issue.
We also need confirmed the cabin air sensor wire and hose are on. I've found that hose falls off often, when dash molding remove and reinstalled.
Then move on to electrical.
