Dusty said:
Preventing overheating
- Thread starter Dusty
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
You need either a new radiator or a new fan clutch or perhaps both. If your fan clutch hub is not navy blue start by replacing that with a 16210-66020.
Rich said:
I'll have to watch it in the Cruiser (only had it a year), but no problems out of my 1/2 Cab Bronco (been running it that way at least 8 yrs.), or my Full Size Bronco (running 70/30 about 4 yrs.). Of course, neither of these have alumimum heads, and only one has an aluminum radiator.
I'll keep my eye on it though....its certainly a valid point if indeed 50/50 is the minimum level to provide corrosion protection, which I doubt.
Good observation.
My understanding is that mixes with less than 50% antifreeze transfer heat more efficently.
To expand, I have also heard that one should not run any more than is absolutely necessary to prevent freezing. Cummins markets a corrosion inhibitor to use in engines that are not exposed to freezing temperatures.
To expand, I have also heard that one should not run any more than is absolutely necessary to prevent freezing. Cummins markets a corrosion inhibitor to use in engines that are not exposed to freezing temperatures.
- Thread starter
- #26
Thanks all
So perhaps my cooling system isn't as effective as it could be. On the other hand these recent hot spells while climbing passes are isolated occurances and my digital temp guage hasn't been over 210 since the I15 baker/Vag pass (and not above 200 cruising around town). Im not worried about roasting the HG as the guage is right in my face and I always know if the truck is hot (thats why I installed the guage in the first place). If I see any AC cut outs or hot temps while on flats Ill start getting humble but I dont see temps over 210 on flats while driving here in CO and I have yet to have the AC quit going over the I70.
In the meantime I think I may get a new thermastat (not a cooler one of course) and an oil cooler plumbed into a sandwhich adapter. Im even thinking of a coupler though the fan hold test says im good there. The only problem with fixing things that aint broke is that I may not be running up any more passes this summer so I may not get to test stuff.
Im still currious to know if all the supercharged rigs out there can run up passees as well as MTNRAT can.
So perhaps my cooling system isn't as effective as it could be. On the other hand these recent hot spells while climbing passes are isolated occurances and my digital temp guage hasn't been over 210 since the I15 baker/Vag pass (and not above 200 cruising around town). Im not worried about roasting the HG as the guage is right in my face and I always know if the truck is hot (thats why I installed the guage in the first place). If I see any AC cut outs or hot temps while on flats Ill start getting humble but I dont see temps over 210 on flats while driving here in CO and I have yet to have the AC quit going over the I70.
In the meantime I think I may get a new thermastat (not a cooler one of course) and an oil cooler plumbed into a sandwhich adapter. Im even thinking of a coupler though the fan hold test says im good there. The only problem with fixing things that aint broke is that I may not be running up any more passes this summer so I may not get to test stuff.
Im still currious to know if all the supercharged rigs out there can run up passees as well as MTNRAT can.
DOES YOUR FAN CLUTCH HAVE A NAVY BLUE BASE?
Dusty,
I think it would be a good idea to check the color of your fan clutch - this is highly relevant.
I completely agree with Sean's two consecutive posts, and will answer your key question whether you can overheat an 80 with a properly functioning cooling system. No.
I tow a 6000lb trailer all summer. You can't go anywhere in Idaho without hitting a pass, and with my family and gear aboard I've weighed over 12,000lbs on truck scales. When you're whizzing along at 80 on a high mountain pass there are two key differences between the heat load your truck is experiencing and the what I am about to tell you my truck can withstand. First, you're going 80 and getting lots of airflow. Second, you're at higher altitudes on some passes you describe, which means there's less air density and therefore your engine is not putting out full horsepower and the attendant heat that output would generate.
Contrast that with this heatfest.
There's a pass on one of the rural highways we regularly traverse that is WAY steeper than the interstate passes, which is simply because interstates have to minimize the steepness for trucks, etc. One particularly memorable day, it was in the high 90s and we had the A/C on and were pulling the trailer. My foot was flat on the floor for at least 3 minutes, and barely off it for another 2 or so and the vehicle speed hovered around 24mph. As I recall, the temp guage went up a needle width, and the oil pressure went down several needle widths, but the A/C kept going full blast and everything was fine. I'll guarantee I was generating considerably more heat than the situations described above, but my cooling system handled it fine. I've owned the 93 since new and the cooling system has been personally maintained by me specifically because I know that I am an extremely demanding user.
I just bought a used 97 a couple months ago. Because I know it too will be towing, within the first month I bought a new copper/brass radiator spec'd for the 93/94 models and installed it after properly flushing the block (have you done this, btw?), and backflushing the heater cores among other cooling oriented PM steps. If I were you, this is what I'd do because I suspect your original radiator has sludge in it from a previous owner mixing green with the Toyota Red it came with. Dealers do this routinely as well - they're clueless about this issue believe me (used to work for Lexus).
So, my stock well maintained cooling system cannot be overheated by conditions that go well beyond what you describe. Naturally, I keep everything else overmaintained as well, but it's all stock - just fresh and synthetics for heavy use.
DougM
I think it would be a good idea to check the color of your fan clutch - this is highly relevant.
I completely agree with Sean's two consecutive posts, and will answer your key question whether you can overheat an 80 with a properly functioning cooling system. No.
I tow a 6000lb trailer all summer. You can't go anywhere in Idaho without hitting a pass, and with my family and gear aboard I've weighed over 12,000lbs on truck scales. When you're whizzing along at 80 on a high mountain pass there are two key differences between the heat load your truck is experiencing and the what I am about to tell you my truck can withstand. First, you're going 80 and getting lots of airflow. Second, you're at higher altitudes on some passes you describe, which means there's less air density and therefore your engine is not putting out full horsepower and the attendant heat that output would generate.
Contrast that with this heatfest.
There's a pass on one of the rural highways we regularly traverse that is WAY steeper than the interstate passes, which is simply because interstates have to minimize the steepness for trucks, etc. One particularly memorable day, it was in the high 90s and we had the A/C on and were pulling the trailer. My foot was flat on the floor for at least 3 minutes, and barely off it for another 2 or so and the vehicle speed hovered around 24mph. As I recall, the temp guage went up a needle width, and the oil pressure went down several needle widths, but the A/C kept going full blast and everything was fine. I'll guarantee I was generating considerably more heat than the situations described above, but my cooling system handled it fine. I've owned the 93 since new and the cooling system has been personally maintained by me specifically because I know that I am an extremely demanding user.
I just bought a used 97 a couple months ago. Because I know it too will be towing, within the first month I bought a new copper/brass radiator spec'd for the 93/94 models and installed it after properly flushing the block (have you done this, btw?), and backflushing the heater cores among other cooling oriented PM steps. If I were you, this is what I'd do because I suspect your original radiator has sludge in it from a previous owner mixing green with the Toyota Red it came with. Dealers do this routinely as well - they're clueless about this issue believe me (used to work for Lexus).
So, my stock well maintained cooling system cannot be overheated by conditions that go well beyond what you describe. Naturally, I keep everything else overmaintained as well, but it's all stock - just fresh and synthetics for heavy use.
DougM
- Thread starter
- #30
thanks Dan thanks Idaho D
well well my coupler aint blue at all-its aluminum silver color...im calling Cdan today for new one.
I have flushed my motor with the prestone stuff 2 times and just stuck a garden hose in the top with my last "flush" and let the water run for 30min with the motor running and heater on.
well well my coupler aint blue at all-its aluminum silver color...im calling Cdan today for new one.
I have flushed my motor with the prestone stuff 2 times and just stuck a garden hose in the top with my last "flush" and let the water run for 30min with the motor running and heater on.
IIRC the blue one is a 3 stage Aisin, my originl one was a 2 stage eaton
CJF said:
That is the newest part number for the 1FZ engine. It is not specified for the 3FE.
Dusty did you follow this method? Beowulf posted it on the old SOR forum.
Its all in the details.
Cheers,
Sean
Re:Radiator Flush
--------------------------------------------------------------------------------
Kenton,
Your friend would be well advised to do a good heater core and block flush in the near future. The FZJ80 cooling system is one of the areas where good maintenance pays off in the long run. An annual flush and fill is strongly recommended even though that is more than the factory recommends. There have been far too many people that have posted their horror stories due to cooling system problems.
The only "reventative" that the experts (Christo, Robbie, C-Dan, et al.) have offered the 80 community is to be anal regarding the cooling system.
Since this is an important maintenance item and we haven't covered the details since our arrival on ih8mud, I am copying the thread that I remember from the SOR archives into this thread. The subject line in this thread is appropriate so here goes:
==================================
Copied & edited from SOR Rad Flush Procedure
==================================
Jim,
Since I did this last weekend here are a few tips. If you're using the Prestone kit as someone else suggested, you can install it on the hose going into the heater valve. The hose has a 90 degree bend so placement is critical. You may need about 2" of a flexible 5/8" heater hose that goes between the heater valve and the garden hose connection. You'll also need 2 or 3 gallons of distilled water (under $1 ea at the grocery store.) Get 2 gallons of Toyota coolant (the red stuff.)
After you install the kit, drain the engine block and the radiator. There is a 14mm brass plug on the left side of the engine block. You can get to it through the left front wheelwell. Use about 2' of extension to get to the plug (torque at 22ft/lbs). The radiator drain c0ck can be accessed after you remove the front skid plate (4 bolts.) If you remove the radiator cap the coolant will spray everywhere. If you leave it on the coolant will drain slowly and can be drained into a bucket. I would remove the block plug first, let it drain, then remove the radiator drain plug (white).
Install the block plug and follow the directions on the Prestone flush kit. Basically, you will hook up the garden hose and get it flowing. When the water starts coming out the top of the radiator, start the engine. Push the heater control to full hot and let the engine run about 5 minutes with the water flowing. Eventually it will run clear. Turn off the engine and let the radiator drain. Remove the block plug again and let the water drain. Put the cap on the Prestone fitting. Remove the overflow bottle and empty it because it will be full of old coolant and tap water.
Reinstall the block plug and the radiator plug. Pour 1 gallon of anti-freeze in the radiator. Pour 1 gal of distilled water in the radiator. Pour 1/2 of the 2nd coolant jug into the empty water jug. Use the remaining distilled water to mix up a 50/50 mixture of coolant and distilled water. Fill the radiator with the 50/50. Check for leaks. Fill the overflow bottle with 50/50. Loosely install the radiator cap and start the engine, again checking for leaks. Let the engine run for a few minutes and top up the radiator as necessary with the 50/50.
If you're in to preemptive maintenance like I am, this would be a good time to put in a new thermostat and gasket (when the coolant is drained of course.) Check all hoses when it is drained and replace as necessary. You will probably get coolant sprayed on the engine so be prepared to clean the engine with Simple Green or similar.
Antifreeze is toxic to dogs so clean up any spills. Some communities approve flushing the old coolant down the toilet for disposal. If you're concerned then check it out first, otherwise just flush the old stuff and you're done.
-B-
Jim,
After the radiator is drained you can look down the filler and see the top portion of your radiator tubes. Mine looked good as new but if you are seeing rust, or a silvery paste-like substance then you should plan on getting the radiator professionally cleaned/rodded. It's been reported that mixing coolant brands has been causing some radiator failures in the 80 series. The main thing is to get a good flush and remove all of the old coolant (remember the heater valve!) before filling it with new.
Keep us posted on the job and good luck.
-B-
Jim,
FSM calls for a "good brand" of coolant. You will be OK with the something like Prestone or whatever is considered a good brand in the UK. There is a very strong link between mixing red & green and clogged radiators; not just in cruisers. There is also strong evidence of problems caused by the so-called "long life" coolants. These work OK in cars that were designed for the long-life stuff, but not so well in those that were not designed for it.
You will be OK since you did a good flush of the old coolant. The concensus seems to be that the coolant in our cruisers should be changed every 2 yrs max. This is shorter than Toyota's recommendation, but now that you've done it you can see that it's not a big deal and well worth the peace of mind.
How did your radiator look when you checked it?
-B-
Beowulf,
Thanks for the detailed post! Did the flush and fill this weekend (first time on any vehicle I've had). All went good with your instructions. It took me about 3-1/2 hours, of which most of the time was spent waiting for everything to drain. I did as suggested and left the radiator cap on so things would drain in a slow controlled way to keep the mess down. It would have gone much quicker to just open things up and let it go, but the mess would have been much more. I would say knowing how things work now, and having one under my belt this would take less than 2 hours next time, easy. Anyway, just wanted to say thanks for the good info. to all who had input.
Todd / '95 FZJ80
Beowulf
I attepted the job this weekend, but I could not located the block plug. Could you please explain US / DS? (I got that DS is "Drivers Side" Do you have to take the wheel off to access the plug?
Thanks
stacker,
I believe the plug is located near the oil filter towards the rear of the engine. You should be able to see it from underneath. I actually removed mine, stuck a pipe in there and connected that to my plugin heater.
Yomama
For the block drain bolt, remove your front DS tire, then pry off the last little mud skirt thing on the right, and look straight ahead. You'll see a bolt in the block that doesn't connect to anything. I think its 12 or 14 mm. Just get about 5 ratchet extension and pull that thing out. One word of caution, make sure you keep the radiator cap on while doing this or it will shoot out pretty fast. Takes longer to drain with the cap on, but its a lot less messy.
HTH
aaron
Stacker,
"There is a 14mm brass plug on the US DS of the engine block. You can get to it through the DS front wheelwell. Use about 2' of extension to get to the plug (torque at 22ft/lbs)."
1. It's 14mm
2. US DS = US Driver Side = Left Side = Port = same side as the oil filter.
3. I didn't have to remove the tire but mine is lifted. Pull back the flap, shine a light in there, and you'll see the brass plug.
4. Use a 14mm socket with a long extension, about 2ft should do it.
5. When reinstalling, torque to 22ft/lbs.
-B-
======================== End of edited SOR Copy =================
Its all in the details.
Cheers,
Sean
Re:Radiator Flush
--------------------------------------------------------------------------------
Kenton,
Your friend would be well advised to do a good heater core and block flush in the near future. The FZJ80 cooling system is one of the areas where good maintenance pays off in the long run. An annual flush and fill is strongly recommended even though that is more than the factory recommends. There have been far too many people that have posted their horror stories due to cooling system problems.
The only "reventative" that the experts (Christo, Robbie, C-Dan, et al.) have offered the 80 community is to be anal regarding the cooling system.
Since this is an important maintenance item and we haven't covered the details since our arrival on ih8mud, I am copying the thread that I remember from the SOR archives into this thread. The subject line in this thread is appropriate so here goes:
==================================
Copied & edited from SOR Rad Flush Procedure
==================================
Jim,
Since I did this last weekend here are a few tips. If you're using the Prestone kit as someone else suggested, you can install it on the hose going into the heater valve. The hose has a 90 degree bend so placement is critical. You may need about 2" of a flexible 5/8" heater hose that goes between the heater valve and the garden hose connection. You'll also need 2 or 3 gallons of distilled water (under $1 ea at the grocery store.) Get 2 gallons of Toyota coolant (the red stuff.)
After you install the kit, drain the engine block and the radiator. There is a 14mm brass plug on the left side of the engine block. You can get to it through the left front wheelwell. Use about 2' of extension to get to the plug (torque at 22ft/lbs). The radiator drain c0ck can be accessed after you remove the front skid plate (4 bolts.) If you remove the radiator cap the coolant will spray everywhere. If you leave it on the coolant will drain slowly and can be drained into a bucket. I would remove the block plug first, let it drain, then remove the radiator drain plug (white).
Install the block plug and follow the directions on the Prestone flush kit. Basically, you will hook up the garden hose and get it flowing. When the water starts coming out the top of the radiator, start the engine. Push the heater control to full hot and let the engine run about 5 minutes with the water flowing. Eventually it will run clear. Turn off the engine and let the radiator drain. Remove the block plug again and let the water drain. Put the cap on the Prestone fitting. Remove the overflow bottle and empty it because it will be full of old coolant and tap water.
Reinstall the block plug and the radiator plug. Pour 1 gallon of anti-freeze in the radiator. Pour 1 gal of distilled water in the radiator. Pour 1/2 of the 2nd coolant jug into the empty water jug. Use the remaining distilled water to mix up a 50/50 mixture of coolant and distilled water. Fill the radiator with the 50/50. Check for leaks. Fill the overflow bottle with 50/50. Loosely install the radiator cap and start the engine, again checking for leaks. Let the engine run for a few minutes and top up the radiator as necessary with the 50/50.
If you're in to preemptive maintenance like I am, this would be a good time to put in a new thermostat and gasket (when the coolant is drained of course.) Check all hoses when it is drained and replace as necessary. You will probably get coolant sprayed on the engine so be prepared to clean the engine with Simple Green or similar.
Antifreeze is toxic to dogs so clean up any spills. Some communities approve flushing the old coolant down the toilet for disposal. If you're concerned then check it out first, otherwise just flush the old stuff and you're done.
-B-
Jim,
After the radiator is drained you can look down the filler and see the top portion of your radiator tubes. Mine looked good as new but if you are seeing rust, or a silvery paste-like substance then you should plan on getting the radiator professionally cleaned/rodded. It's been reported that mixing coolant brands has been causing some radiator failures in the 80 series. The main thing is to get a good flush and remove all of the old coolant (remember the heater valve!) before filling it with new.
Keep us posted on the job and good luck.
-B-
Jim,
FSM calls for a "good brand" of coolant. You will be OK with the something like Prestone or whatever is considered a good brand in the UK. There is a very strong link between mixing red & green and clogged radiators; not just in cruisers. There is also strong evidence of problems caused by the so-called "long life" coolants. These work OK in cars that were designed for the long-life stuff, but not so well in those that were not designed for it.
You will be OK since you did a good flush of the old coolant. The concensus seems to be that the coolant in our cruisers should be changed every 2 yrs max. This is shorter than Toyota's recommendation, but now that you've done it you can see that it's not a big deal and well worth the peace of mind.
How did your radiator look when you checked it?
-B-
Beowulf,
Thanks for the detailed post! Did the flush and fill this weekend (first time on any vehicle I've had). All went good with your instructions. It took me about 3-1/2 hours, of which most of the time was spent waiting for everything to drain. I did as suggested and left the radiator cap on so things would drain in a slow controlled way to keep the mess down. It would have gone much quicker to just open things up and let it go, but the mess would have been much more. I would say knowing how things work now, and having one under my belt this would take less than 2 hours next time, easy. Anyway, just wanted to say thanks for the good info. to all who had input.
Todd / '95 FZJ80
Beowulf
I attepted the job this weekend, but I could not located the block plug. Could you please explain US / DS? (I got that DS is "Drivers Side" Do you have to take the wheel off to access the plug?
Thanks
stacker,
I believe the plug is located near the oil filter towards the rear of the engine. You should be able to see it from underneath. I actually removed mine, stuck a pipe in there and connected that to my plugin heater.
Yomama
For the block drain bolt, remove your front DS tire, then pry off the last little mud skirt thing on the right, and look straight ahead. You'll see a bolt in the block that doesn't connect to anything. I think its 12 or 14 mm. Just get about 5 ratchet extension and pull that thing out. One word of caution, make sure you keep the radiator cap on while doing this or it will shoot out pretty fast. Takes longer to drain with the cap on, but its a lot less messy.
HTH
aaron
Stacker,
"There is a 14mm brass plug on the US DS of the engine block. You can get to it through the DS front wheelwell. Use about 2' of extension to get to the plug (torque at 22ft/lbs)."
1. It's 14mm
2. US DS = US Driver Side = Left Side = Port = same side as the oil filter.
3. I didn't have to remove the tire but mine is lifted. Pull back the flap, shine a light in there, and you'll see the brass plug.
4. Use a 14mm socket with a long extension, about 2ft should do it.
5. When reinstalling, torque to 22ft/lbs.
-B-
======================== End of edited SOR Copy =================
- Thread starter
- #35
MTNRAT
I didn't use the Beowulf method though I read it and considered it. I also considered the Idaho Dough post. I finally just pulled the block plug, opened the peacock and drained it. i replaced the plugs, refilled with water, let the motor run a while with the heater on and redrained it again. I did this fill and drain method a few times before opening all the drains and just letting the hose run in the radiator fill while the motor ran for 30min. i then let 5 gallons of distilled water run through before closing the plug/peacock and filling the radiator with 50/50 prestone and distilled (demineralized) water. of course I also cleaned out the overflow tank.
I didn't use the Beowulf method though I read it and considered it. I also considered the Idaho Dough post. I finally just pulled the block plug, opened the peacock and drained it. i replaced the plugs, refilled with water, let the motor run a while with the heater on and redrained it again. I did this fill and drain method a few times before opening all the drains and just letting the hose run in the radiator fill while the motor ran for 30min. i then let 5 gallons of distilled water run through before closing the plug/peacock and filling the radiator with 50/50 prestone and distilled (demineralized) water. of course I also cleaned out the overflow tank.
semlin
curmudgeon
As well as looking at cooling system issues I would look at heating up issues. There has been speculation before that the 97s may have more h/g failures because they run hotter than the earlier trucks because the hot wire airflow system and the more sophisticated ecu allowed for better fuel efficiency (e.g., running closer to a lean condition). Anytime you engineer closer to the line, the system must function properly. I would consider what engine components might be making you run hotter as well as what parts are not cooling you down.
- Thread starter
- #40
so i ordered fan clutch a couple days ago from the Cdan and will install it soon. whats the easiest way to do this? is it necesary to remove the shroud? do you have to remove the the metal base that bolts with four bolts to the waterpump from the fan or is there just some magical button you push to make it all better?
