Yet another heat issue thread... (3 Viewers)

[Nikwho]

I've run aftermarket/NAPA thermostats in my vehicles for over 20 years without issues with a single one. I'm curious why you reccomend running an OEM thermostat? Is there a specific known issue with other than OEM thermostats?

 

[Nikwho]

At this point, I'm not worried about the factory temperature gauge, or sending unit. I know that the truck is running too cold. I can feel it, by holding my hand continuously on the thermostat housing. The truck is sticking mostly around 145°, according to my IR thermometer, with peak of about 166°! This isn't after pulling a long hill, but it doesn't need to be checked after pulling a long hill. The engine needs to get up to it's normal operating temperature during normal driving, not only in the most extreme conditions. The upper thermostat gasket almost certainly got dislodged during installation, I'm thinking. Or, at least coolant is bypassing the thermostat somehow. The temperature of the housing, hose and radiator slowly creeps up, as the engine warms up. Its circulating enough water to stay cool and the thermostat is ultimately not doing, or not able to do its job. So, the heater is blowing air that roughly correlates to the engine temp. I'll pull the t-stat housing off and carefully re-assemble. Its seems as though it's almost certainly that upper thermostat gasket that is the culprit.

 

[Seth S]

did you put the higher temp T stat in yet?

 

[OSS]

While an aftermarket NAPA thermostat may work fine in other engines, that doesn't mean that the one they sell for the 2F works correctly. Replace it with a TOYOTA 190° thermostat and TOYOTA T-stat upper gasket.

The 180° thermostat isn't the correct one to use for this engine. Aftermarket or Toyota. Its not a smog thing either.
Then reassess the cooling system.

This is how a properly functioning thermostat and cooling system should work on a FJ60 2F:

1. Start engine and let it idle fast at 1200 rpm (use choke to hold fast idle)
2. Within 10 minutes (at 1200 rpm) the engine temp should be near mid gauge and the upper radiator hose should be too hot to touch.
3. Turning on the heater (after 10 minutes) should blow HOT air in the cab. Not warm.
4. Temperature in front of radiator directly across from inlet hose should read at least 190° F with an infrared heat gun.

 

[Nikwho]

did you put the higher temp T stat in yet?

No. It's not getting hot enough to open the lower temp thermostat, plus, I've never head a compelling reason to run a hotter thermostat. If it gets up to 180°, that should be plenty warm.

 

[Nikwho]

While an aftermarket NAPA thermostat may work fine in other engines, that doesn't mean that the one they sell for the 2F works correctly. Replace it with a TOYOTA 190° thermostat and TOYOTA T-stat upper gasket.

The 180° thermostat isn't the correct one to use for this engine. Aftermarket or Toyota. Its not a smog thing either.
View attachment 2128153

Why do you say this? I'm not saying that you're wrong, I'm just asking why you make this statement? I totally agree regarding the Toyota upper gasket. But, Toyota doesn't make their own thermostats. They have a thermostat manufacturer make them for them. If another thermostat is built to the same exact dimension and specification, why would it not work? I'll buy a 190° Toyota thermostat, I just have never heard a compelling reason other than "because", or its "reccomended". Water is. Bypassing the thermostat, which may be due to not using the correct gasket, but my engine running at 145° has nothing to do with running a 180° or 190° thermostat. I like to understand why I do something, not just "because". definitely going to pull the t-stat housing off and carefully reassemble, ensuring proper placement of the upper gasket. I'll report back when that is done. Hopefully that keeps the coolant from bypassing the thermostat!

 

[OSS]

Because aftermarket parts can't be trusted. Toyota parts can. Yes, Toyota doesn't make a lot of its parts, but Denso, Aisin, etc do - for them. The NAPA part may be fine, but you've run into strange problems that normally never happen (when using Toyota parts). So to rule out unknown variables (aftermarket parts) that might be the culprit, the general consensus here is to use the Toyota part. Then that's one thing that can be taken off the "suspicious" list.
New Toyota parts can be counted on working correctly 100% of the time. That assurance can't be assumed from inexpensive aftermarket parts. Maybe they will, maybe not

 

[60 toy ota]

I may have missed this but are you carbed? Seems it's worth mentioning that a rich running engine will run cold. Is your mixture level correct?

 

[Seth S]

Id go to the dealer and get a fresh 195 or 198 t stat....whatever the actual number is. Put it in and go for a drive. When I first got my truck and changed the t stat I forgot the top gasket and the truck would never really warm up. Opened it back up and put the gasket in and no problems since.

 

[Nikwho]

I may have missed this but are you carbed? Seems it's worth mentioning that a rich running engine will run cold. Is your mixture level correct?

That's a REALLY good point!! I live at 6,800' ASL! So, I would assume that it's running fat! Fat enough to run THIS cool? I don't think that's the only culprit, but a definite variable! Coolant is 100% bypassing the thermostat. By using my IR thermometer this morning, I have determined that with certainty. Now I just need to pull it apart to see why.

 

[Nikwho]

Id go to the dealer and get a fresh 195 or 198 t stat....whatever the actual number is. Put it in and go for a drive. When I first got my truck and changed the t stat I forgot the top gasket and the truck would never really warm up. Opened it back up and put the gasket in and no problems since.

They are cheap parts, and worth running the highest possible quality, I would definitely agree on that! I also agree that Toyota is likely to have far better quality control standards! What I don't buy, is that vehicles run better on 190° thermostat's vs. 180° thermostats. Its 100% not that 10° difference in temp rating that is causing my issue. Other than "general consensus", "because a toyota rep/parts geek told me to", or just "because" isn't a good enough reason (in my opinion) to purposefully run an engine hotter! PARTICULARLY on a straight six, that intermingles the carb/intake manifold/exhaust manifold, and is already so prone to carb heat soak, that the manufacturer had to install a fan in the engine compartment to cool the carburetor! I think that these old engines are more likely to pass a smog test with a 190°/195° t-stat, and THAT alone is why they are recommended! Purposefully running the engine hotter than it needs to doesn't make sense to me. May sound odd, coming from a guy that cannot get his FJ to run warmer than 166° at the moment, but the slow, even heat rise of the engine, t-stat housing and radiator, up to a temp that is too low is an issue of coolant always flowing past the thermostat, not an issue of the thermostat being rated incorrectly. That's just my take on the matter, though. I'll be right back. Gonna pull the thermostat, ensure that its properly installed, and check its operating/opening temp while I'm at it! Will be interesting if it is indeed sealed correctly, and just opening at the wrong (very low) temp! Though, I do not think.thats what is going on.

 

[Nikwho]

Here it is! This is exactly how the gasket looked when I pulled the housing off. Wasn't careful enough! Gonna go grab at least the Toyota gaskets, MAYBE the Toyota thermostat, too.

 

[Nikwho]

Thermostat opening and closing correctly. I also learned that my laser thermometer is not all that accurate!

 

[g-man]

Here it is! This is exactly how the gasket looked when I pulled the housing off. Wasn't careful enough! Gonna go grab at least the Toyota gaskets, MAYBE the Toyota thermostat, too.

View attachment 2128277

I don't see a gasket here. Looks like the lower t'stat housing. can you explain what I'm looking at.

 

[Elbert]

FJ60 Thermostat removal and replacement. Step by step with pictures.

Ok guys I had some problems with my current setup as you can see here: https://forum.ih8mud.com/threads/problem-with-thermostat-or-super-efficient-cooling-system.778689/ I purchased OE T-stat, upper and lower gaskets. T-stat is 88C or 190F. First off, I have been hitting the bolts which hold...

forum.ih8mud.com

IN the case of the thermostat I do believe the OEM item is the better product, on this specific engine. Many people do screw up the replacement of the thermostat and leave off the top large rubber o-ring/gasket (that sits on top of the thermostat. This is a wierd design by Toyota but it is that way so you have to ensure the right combination of parts are there. Also the aftermarket o-ring/gasket in my view don't fit correctly. I no longer have the stock engine, but the couple of times I screwed with this I only used OEM thermostat, and OEM rubber o-ring and then the gasket at the bottom or you could use silicone of some type there without issue. I like the gasket with something like the read fast-tack stuff on it.

I don't test thermostats, I just replace them over time, if I take off the water neck it gets a new thermostat. The same with other cooling components. A 30 year old water pump just gets replaced...and any hoses that would be rather old too.

if that top o ring is not right or totally missing the thermostat is getting bypassed due to that weird design....which would make the truck run cold in the winter.

I like a real temp gauge, so I run autometer stuff, which tells me the the temp vs hot/cold range.

If the truck is not running around 180F once the truck warms up and is in "normal" mode then presumbly you have a thermostat issue. As long as you have gotten the air pockets out of the cooling system and its full of coolant.

do yourself a favor and get the OEM thermostat and OEM related parts if avaliable, if not avaliable get whatever works. in the case of this specific part combination the OEM parts do make a difference...no reason to debate that.... if you want to buy something else then at least someone has shared that with you...you make the call.

The "brain" for how hot or cold the engine runs is the thermostat, given all other cooling components are functioning properly and they are in good shape.... and there are no other issues in play (head gasket/cracked head/cracked block).

 

[OSS]

What I don't buy, is that vehicles run better on 190° thermostat's vs. 180° thermostats. ....

I think that these old engines are more likely to pass a smog test with a 190°/195° t-stat, and THAT alone is why they are recommended!

.....Purposefully running the engine hotter than it needs to doesn't make sense to me.

It's not really about "what makes sense", rather what actually happens in real life.
Since most people are not ignition and combustion experts with Ph.D.'s, we are not qualified to assume we know more about what's best for the engine than the engineers & scientists at Toyota (or GM or Ford etc).

When it comes to engine temperature specifically, intuition is not a good guide. Cooler than "ideal" isn't better.
Toyota makes (and made) gasoline engines for land cruisers and other vehicles that are destined for other countries that are not required to pass smog tests. Those vehicles have no smog equipment and the engine is tuned for maximum efficiency and durability.
The carbureted 3F used in the land cruiser that replaced the 2F, which was destined for other countries which had no smog equipment installed, - ran a 190° thermostat.
A 190° thermostat isn't a smog tweak workaround, it's the ideal temperature for the engine to run its best.

Thermostats a long time ago in the 70's & earlier were 180°, 175° jobs, but engines, lubricants, fuel and combustion knowledge has advanced since then.

 

[3_puppies]

I don't see a gasket here. Looks like the lower t'stat housing. can you explain what I'm looking at.

looks like the upper part of the housing, the rubber gasket is up inside the opening, you can see it inside the opening at 6 oclock

 

[g-man]

looks like the upper part of the housing, the rubber gasket is up inside the opening, you can see it inside the opening at 6 oclock

ahh! now I see it. stuffed up in the passage.

 

[g-man]

Do you think overheating and subsequent steam can do this? And if so, maybe need to resolve an overheating issue first?

 

[Nikwho]

Do you think overheating and subsequent steam can do this? And if so, maybe need to resolve an overheating issue first?

Where did the assertion of over heating come from? There has been no signs of overheating.