temp gauge started climbing on slow hills. What to check? (1 Viewer)

[Mig]

Maybe this will help a little.

Koso slim water temp gauge install

Yes, I was thinking about doing something like this. Granted I was considering doing it more with the transmission and just setting up the stock temp gauge to show actual temps. In all the testing that I've done, the stock gauge has barely moved from the center. I really wonder who thought it would be a good idea to cripple a gauge so that it is no better than a idiot light.

Mig

 

[Tools R Us]

I understand that cooling will not be consistent but I would think it would have a hard time getting hot with the coolant free flowing. Can you elaborate? Please, treat me like the slow kid. I've never claimed to be the great guru of all things mechanical.

Mig

The bypass goes directly from the thermostat to the suction side of the water pump, a short, low restriction, circulation path. When that option is open, little coolant is taking the longer, more restrictive path through the radiator. The thermostat controls the mix of bypass/radiator flow as needed, depending on conditions.

 

[Tools R Us]

The thermostat has two functions, open the path to the radiator (blue) and close the bypass (red).

The red path is the bypass, the blue is the radiator, with no control the path of least restriction is the bypass, so most of the coolant will go that route. The bypass is what 6" vs several feet for the radiator, not a contest.

 

[Mig]

Ok everyone. What i have done so far:
1. New 180 thermostat (later replaced with a 170 thermostat)
2. Block tester indicates no exhaust in the Rad.
3. New blue hub fan clutch (stock oil, yes it roars when I start the engine)
4. New OEM water pump.
5. New ecu temp sensor.
6. New upper and lower rad hoses.
7. New silicone PHH
8. I show about 16 deg differential between the upper and lower rad hoses.
9. Temp measurements on the exhaust dropping from about 520 to about 440 from the engine side to the exhaust side of the cats. Removed cats and put in a straight pipe as a test to see if i was getting heat soak back up to the cooling system.
10. Replaced the trans filter (still need to just flush the whole thing)
11. Removed and clean the trans cooler.

The problem, is that i can now drive this on the open road just fine without any temp issues. As soon as i start going slow or loading the engine the temp starts to climb. And of course the idea of putting this in 4L, well lets just say that the truck thinks the L stands for Laughable.
Open road 60 - 65 temp holds at 194 - 203. Generally climbs when slowing to a stop. I expect this.
Get off the open road and start hitting 2 lane twisties with minor inclines, temp runs 208 - 213.
Get home and drive it out to my barn in 4L, and the temp hits 226 in a heartbeat.

This is better than it was and i still need to install the unbroken fan shroud, but im running out of thoughts. I didn't buy this to use as a mall Crawler, I bought it to use off road and so far my subaru is kicking its butt.

 

[69vortec]

[QUOTE="Mig, post: 11081231, member: 131147" i still need to install the unbroken fan shroud,[/QUOTE]

Without the shroud installed it will have a hard time pulling air through the radiator.

 

[Mig]

Without the shroud installed it will have a hard time pulling air through the radiator.

It actually has a fan shroud on it. The top of it was broken, and someone tried to 'fix' it by attaching a piece of plastic that the fan promptly tried to eat. Yes, the fan is fine. The repair is just a little chewed up. I have a replacement, i just haven't installed it yet.

I do have a correction though. I just checked the temps at the upper and lower hoses on the Rad. I'm now showing about a 20 deg difference. Am I due for a new radiator?

Mig

 

[SmokingRocks]

What % mix are you using? If you are running a 50% glycol / 50% water mix (standard 50/50 antifreeze) then you have way too much glycol in your system for summer use.

I would suggest buying a coolant hydrometer to measure the freezing point of your fluid. If you measure it and it says its good to -35 to -40 F (about 50/50) then you need to dilute way down. Glycol does not transfer heat as efficiently as distilled water but it does help raise the boil point so its key to have some.

I run a 15/85 glycol/water mix in the summer with water wetter (its a surface tension reducer which dissipates bubbles fast and increases the cooling capacity of the fluid)

a 15/85 fluid has a boiling temp of 218, but our systems are designed to run under pressure and water's boiling temp raises about 2.5 degrees per PSI. Our caps vent at about 13-14psi which brings the boiling point of my 15/85 solution to about 250 degrees while also providing me the better heat transfer coefficient of that a water biased mix has.

 

[SmokingRocks]

geeky cool reading about glycol vs water here:
Things you should know about coolant | hellafunctional

Beyond that I'd say you need to service your fan clutch but I'm 100% sure thats been mentioned before

 

[Mig]

Very good info smokingrock. With all of the changes I've made recently I'm currently running straight water in the radiator. I figured i would go back to toyota red when I stopped blowing hoses and changing parts. And yes, when all is said and done, i don't see any reason i should be looking at a 50/50 mix as it just doesnt get that cold here.

Mig

 

[Dave 2000]

Just flicked through this and saw that @Tools R Us mentioned radiator condition, has that been followed up? Radiator removed and checked for bugs/leaves and other crap cleared between the rad and AC condenser, light shone threw rad and condenser to check for crumbling fins which collapse in on themselves and blocks airflow?

Hoses getting hot and as they soften collapsing in blocking or restricting flow?

Baffle across the gap between chassis rails near steering damper in place?

Don't get drawn into the Red versus Green debate unless you do not use distilled water, if you use faucet flow in your mix then check the 'type' of water you have in your area, IME this is more important, then choose the coolant to suit.

And yes there is a deionised water versus distilled versus osmosis debate, something else to not be distracted by.

Regards

Dave

 

[Mig]

Just flicked through this and saw that @Tools R Us mentioned radiator condition, has that been followed up? Radiator removed and checked for bugs/leaves and other crap cleared between the rad and AC condenser, light shone threw rad and condenser to check for crumbling fins which collapse in on themselves and blocks airflow?

Hoses getting hot and as they soften collapsing in blocking or restricting flow?

Baffle across the gap between chassis rails near steering damper in place?

Radiator has not been removed. I cleaned in between and around as much as i could. There really wasn't that much to clean. And yes i can shine a light thru it.

I thought of the hoses getting hot, etc. They were replaced with new hoses.

The baffle that you mention is missing. I've considered that it would cause some issue with the air flow, and have determined that i will replace it, just as soon as i can find one. I seem to be having an issue finding the right terminology to find one online and there doesn't seem to be an over abundance of these in the salvage yards around Memphis. I've also considered getting a piece of conveyor belt from tractor supply and fashioning one out of that. I wouldn't mind if someone were to send some pictures or measurements to assist with the redneck engineering.

Concerning the red -vs- green discussion or the distilled -vs- DI -vs- well -vs- city water discussions, I'm not intending to get wrapped up in all that. I figure if this vehicle is that delicate, it is probably not the right vehicle for me. I just figured i would go back to toyota red just to go back to original. Although I could also make an argument for green based on the fact that it is available EVERYWHERE. Someone had put the green in there, and it would still be in there if i weren't having a cooling issue. And yes, i know i shouldn't mix them.

So here is a specific question. What are your thoughts on the chemical radiator flushes? I figured i would head that direction before replacing the radiator, but wasn't sure how rough the chemicals would be on the gaskets etc. In the block.

Mig

 

[Dave 2000]

Radiator has not been removed. I cleaned in between and around as much as i could. There really wasn't that much to clean. And yes i can shine a light thru it.

I thought of the hoses getting hot, etc. They were replaced with new hoses.

The baffle that you mention is missing. I've considered that it would cause some issue with the air flow, and have determined that i will replace it, just as soon as i can find one. I seem to be having an issue finding the right terminology to find one online and there doesn't seem to be an over abundance of these in the salvage yards around Memphis. I've also considered getting a piece of conveyor belt from tractor supply and fashioning one out of that. I wouldn't mind if someone were to send some pictures or measurements to assist with the redneck engineering.

Concerning the red -vs- green discussion or the distilled -vs- DI -vs- well -vs- city water discussions, I'm not intending to get wrapped up in all that. I figure if this vehicle is that delicate, it is probably not the right vehicle for me. I just figured i would go back to toyota red just to go back to original. Although I could also make an argument for green based on the fact that it is available EVERYWHERE. Someone had put the green in there, and it would still be in there if i weren't having a cooling issue. And yes, i know i shouldn't mix them.

So here is a specific question. What are your thoughts on the chemical radiator flushes? I figured i would head that direction before replacing the radiator, but wasn't sure how rough the chemicals would be on the gaskets etc. In the block.

Mig

The line 'cleaned around and in between as best as I could' with respect lacks commitment, when looking for problems you need to really get in there.

Re the hoses, I did shortcut here once, a new copy failed (pulled in when cold), and this prevents the radiator maintaining full capacity, never gave me any issues and if I had not seen it when the hood was up, I am unsure how long before it would have given grief.

Re the baffle, I can pull mine off at a moments notice, any further problems locating one let me know, and I will remove and photo for you with measurements.

Re chemical flushes, if a radiator tube us blocked they will not clear it, if partial then the chemicals will pass through and dissolve a lot of the crud...........normally dumping it in a pile around your transmission cooler, and also leaves crud around the bottom of the cylinder liners. TBH if you are suspecting/considering this then change out the radiator.

Regards

Dave

 

[riffman12]

Hey guys wanted to give an update on the original post here:

I've had the new blue clutch in for a few weeks now. We had a heat wave in northern California and it was 103+ out for a few days. Temp was fine in stop and go traffic. Never got above 202 or so.

This weekend we went up to Lake Tahoe and drove the long climb up highway 80 to about 6000 feet. Any of you from around here know its pretty steep for extended periods.

It was about 85 out and my coolant temp kept creeping up on the climbs. I had to really baby it at 45mph and it still peaked at 221 for a brief period. Stock temp gauge was moving by this point

I'm guessing this isn't normal. The fan clutch is brand new and the radiator was placed less than 20k miles ago by the previous owner. Recent coolant flush.

Will new fluid in the clutch fix this? I just don't want to use it as a bandaid if i have a different underlying issue.

 

[baldilocks]

Hey guys wanted to give an update on the original post here:

I've had the new blue clutch in for a few weeks now. We had a heat wave in northern California and it was 103+ out for a few days. Temp was fine in stop and go traffic. Never got above 202 or so.

This weekend we went up to Lake Tahoe and drove the long climb up highway 80 to about 6000 feet. Any of you from around here know its pretty steep for extended periods.

It was about 85 out and my coolant temp kept creeping up on the climbs. I had to really baby it at 45mph and it still peaked at 221 for a brief period. Stock temp gauge was moving by this point

I'm guessing this isn't normal. The fan clutch is brand new and the radiator was placed less than 20k miles ago by the previous owner. Recent coolant flush.

Will new fluid in the clutch fix this? I just don't want to use it as a bandaid if i have a different underlying issue.

In the spring of 2016 I did a complete and I do mean complete overhaul of my 1993 cooling system, which was more PM than problem solving.

My first trip up Donner Summit on 80 at about the same 85* with a moderate load developed 214* water temps with the AC off maintaining 65mph. My black hub fan clutch was set to start opening at 100* and has 10k oil in it per info here on Mud pertaining to my particular clutch (have a second clutch now loaded with 15k oil that I will install very soon).

I would say that what you posted here is normal based on my experience.

We on Mud fear the head gasket so much that temps over 200F worry most of us. I have to ask myself, why did toyota choose to shut the AC off at 226f???

On my way home that same weekend my gauge read 219 at 70mph on the flat down in the valley at 100f ambient temps with AC on. If I slowed down 10mph, temps started decreasing.

If my AC isn't shutting down I'm gonna keep on truck'n. I'm over it.

 

[Mig]

Re the baffle, I can pull mine off at a moments notice, any further problems locating one let me know, and I will remove and photo for you with measurements.

OK, i found it. It helps to know that they call it an 'engine under cover'.

Thanks for the push Dave. I'm not sure it will be the end all be all solution but logically it makes sense that it will help. If it does end up being 'the' fix then i owe you a beer.

Mig

 

[Dave 2000]

Engine under cover, well you learn something new everyday! I am sure I read on here that it's absence can be a factor, as can many other parts not working or even missing from your vehicle.

The VC seems to get more stick than any other component but I am not convinced this is the case.

Without doubt shedloads of people have gone with the Purple and Green with spots fan clutch, and had no more problems would indicate the now over driven fan is keeping the symptoms at bay, not fixing an underlying problem.

The original spec VC allowed for towing around 3000kgs, so why are owners having issues, even unladen?

A recent thread on MUD had an owner complaining his motor was running hot, one mudder suggested a new OEM fan clutch, the owner followed these instructions but alas still had running hot issues, another member advised such and such modified VC, and this worked great!

Thoughts?

Original OEM VC faulty, new OEM VC faulty, or modified (enter colour /silicone weight here) VC disguising a problem?

One thing that is certain, is that the cooling system operates as a whole, any component/s having any weaknesses will contribute to overheating, if the seemingly insignificant 'under engine cover' works or even helps that would be great

BTW, feel free to keep the beer, but a decent straight Whisky or Bourbon and you will be talking my language.

Stay cool guys and girls.

Regards

Dave

 

[riffman12]

Hey guys wanted to give an update on the original post here:

I've had the new blue clutch in for a few weeks now. We had a heat wave in northern California and it was 103+ out for a few days. Temp was fine in stop and go traffic. Never got above 202 or so.

This weekend we went up to Lake Tahoe and drove the long climb up highway 80 to about 6000 feet. Any of you from around here know its pretty steep for extended periods.

It was about 85 out and my coolant temp kept creeping up on the climbs. I had to really baby it at 45mph and it still peaked at 221 for a brief period. Stock temp gauge was moving by this point

I'm guessing this isn't normal. The fan clutch is brand new and the radiator was placed less than 20k miles ago by the previous owner. Recent coolant flush.

Will new fluid in the clutch fix this? I just don't want to use it as a bandaid if i have a different underlying issue.

Does anyone else have any insight on this? I appreciate baldilocks's response, but I can't help thinking that Toyota designed the dummy temp gauge to where if it moved at all, it's probably not ideal. I also can't help thinking that the car was most likely designed to easily climb mountain passes without overheating, especially without towing anything.

I'm tempted to go ahead and do the fan clutch mod, but I'm worried I'm masking the symptoms rather than fixing the underlying problem.

I'm not sure if this is related, but the last day I was up in the mountains I tried to use my heater and the heat was pretty weak. Much colder than it is at sea level. Then when I got down the mountain my heater got pretty hot. How could altitude be affecting my heater performance??

 

[flintknapper]

I'm tempted to go ahead and do the fan clutch mod, but I'm worried I'm masking the symptoms rather than fixing the underlying problem.

Yes, definitely do the fan clutch mod. The cooling system works very much in conjunction, so ALL aspects of it need to be in tip-top shape and where 'improvements' are possible, it only makes sense to do so, especially since it is such an inexpensive and easy modification to do.

'Improving' the performance of your fan clutch eliminates THAT aspect of your cooling systems performance issue(s).

So rather than think of it as "masking" the symptoms, approach it differently and regard the mod as a process of elimination that is being done thoughtfully and with purpose (not just throwing parts at it). Our advice will always be offered with the benefit of much experience and proven techniques.

It might well be that no single element will prove to be the solution to your problem, but we will start with the most 'likely' components/procedures based on the information you give us.

 

[82much]

Hi guys,

I've been doing some searching and can't seem to find an answer. My plan is to get a scangauge in the near future to keep a closer eye on engine temp, but hoping someone can point me in the right direction in the mean time.

Car is a '97 FZJ80 with 159k on the clock

GF and I were driving to Prewitt Ridge near Big Sur. It's abut a 3 hour drive with the last hour being a steep climb on a mix of asphalt and dirt roads.

It was a hot day, had the A/C going for the most of the drive with no issues. As we started to climb I figured I would turn the A/C off and open the windows.

The road started to get very steep with lots of switchbacks so we weren't getting above 15 - 20 mph. It was paved so I was in normal hi range in first and second gears as to not lock the center diff.

My temp gauge normally sits about 45% of the way up once the car is warmed up. It has never once gone above this in my 6,000 miles of ownership.

This time it started creeping to about 60%. I panicked and pulled over as I know once these gauges move it's getting pretty hot. Once I pulled over and let it cool off for 5 minutes, I started it and let it idle and it went back to normal.

I did this a couple of times until I got to the dirt section, then changed into 4-Lo. After I did that the temp gauge never climbed past it's normal position and was fine for the rest of the climb as well as the 3 hour drive home with the A/C on.

Recent maintenance I've done:
1) new thermostat
2) coolant flush with red Toyota coolant
3) new long hose PHH

The previous owner had a service record for a fan clutch service at about 110k miles, but I have no idea who did it or what parts were used.

I'm not seeing any head gasket symptoms (losing coolant, foamy oil, white smoke). I also had a shop check for hydrocarbons in my coolant and there were none. This was his quick and dirty way to check for a leaking HG.

I don't know exactly how the fan clutch works, but could this be a symptom of that?

Does anyone have any ideas? Sorry for the long-winded post.

So I had an issue like this very recently. I would overheat going up hills. It was a vacuum hose going to my EGR that had a hole/crack in it. This was causing my engine to run rich, lose power and overheat. Go figure right!

 

[baldilocks]

Does anyone else have any insight on this? I appreciate baldilocks's response, but I can't help thinking that Toyota designed the dummy temp gauge to where if it moved at all, it's probably not ideal. I also can't help thinking that the car was most likely designed to easily climb mountain passes without overheating, especially without towing anything.

I'm tempted to go ahead and do the fan clutch mod, but I'm worried I'm masking the symptoms rather than fixing the underlying problem.

I'm not sure if this is related, but the last day I was up in the mountains I tried to use my heater and the heat was pretty weak. Much colder than it is at sea level. Then when I got down the mountain my heater got pretty hot. How could altitude be affecting my heater performance??

Has your 80 actually over heated? As in, steam, an erupting recovery tank, and you were forced to pull over? Or is it simply running warmer than you think it should?