Yet another heat issue thread... (1 Viewer)

[Seth S]

Let us know if everything is back to par once the gaskets are in correct. That one gasket off could easily prevent the truck from ever warming up.

 

[Nikwho]

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.

There's a lot more to than a one size fits all thermostat temperature rating! A 195° thermostat will allow for higher oil temperatures, which can be of some benefit in high humidity areas, to get rid of moisture inside of an engine. What Toyota engineers were doing is specifying the best thermostat temperature for the masses. The vast majority of Toyota vehicles are stock, and used to commute to and from work, short distances. Most people also don't allow their vehicles to properly warm up properly. A modified vehicle, used in extreme conditions, in low range (lower low range than stock), traveling long distances at very low speeds, with 35" tires and mechanical lockers is NOT the conditions for which Toyota engineers were specifying a thermostat for. The conditions in which MANY folks that frequent this forum operate their Cruisers in, tax the cooling system much more than they were designed to be. There are a LOT of factors, that with some thought, can help lengthen the life of your engine. The people that jump on the "don't second guess the Toyota engineers" bandwagon drive me nuts. Sorry, but they do. There are too many factors to simply say that there is a one size fits all solution. Toyota engineers also specified the stock tire size! I hope that the Toyota engineer thermostat rating nazi's are also strictly adhering to stock recommended tire sizes!

Anyway, I digress. Back to the topic. I disassembled and discovered the misplaced upper gasket. I reassembled, and tested yesterday evening. My 'Cruiser quickly came up to what I have determined to be the ideal operating temperature, and is now blowing hot air from the heaters, and it's cooling system is ready for the winter.

I will say that if I were up for seasonal thermostat changes, I would run the 190° t-stat in the winter and the 180° in the summer. But, I want to set my cooling system up for success on the trail all spring/summer/fall, and I am okay with the compromise made during the winter. The only foreseeable downfall that I see is the need for more frequent need for oil changes, by 180° thermostats not being quite as effective in evaporating moisture (water and fuel) out of my oil.

It was FoMoCo that first began using the 192° thermostat's, and they were the first to come out with the 6,000 mile oil change recommendation. FoMoCo attributed this longer oil change interval much to the change to the 192° thermostat! But, there are more factors than oil change interval, and people that are willing to think about what is best for their application will need to make this determination for themselves. I have put more thought into thermostat temperature ratings than the vast majority of folks. The cookie cutter answer of "because they said so" doesn't cut it for me.

I do appreciate everyone's help with regard to my issue! I certainly wouldn't have thought that my gasket would have been dislodged during installation, but it sure did! I also found a great port in the lower thermostat housing that allowed my aftermarket Auto Meter temperature sending unit to thread right in! Just need to mount some gauges now! I'm going to run temperature, volt and oil pressure gauges. I like the redundancy, particularly out on remote trails, where the factory "dummy" lights and gauges don't provide as accurate of information.

Thanks again to all that helped! I really appreciate everyone's help!!

Nik

 

[Nikwho]

Let us know if everything is back to par once the gaskets are in correct. That one gasket off could easily prevent the truck from ever warming up.

Everything is GREAT now! I really appreciate the help! I'm still going to go pick up some Toyota parts! I've read about gaskets being different thicknesses, etc. Heck, I may even pick up a Toyota thermostat, even if just for the winter!!

Thanks much,
Nik

 

[g-man]

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

I replaced my t-stat top seal this summer. The original seal got pinched during install and coolant was bypassing it causing lower temps at the gauge. After replacement my gauge read normal. But I noticed on a few long trips that when I got off the highway and was idling at a light the temps starting creeping closer to the red. Like 3/4 up the gauge. Also puking a little coolant from the overflow when parked. I may have an old semi clogged radiator not sure what's causing it. Anyway ...recently my temp gauge is reading about 1/4 not the 1/3 to 1/2 that it usually is. So I'm thinking that steam from over heating has caused the seal to be pushed out of position again. And wondered if that was why your's was out of position. If steam or overheat can cause the upper seal to dislodge. I've got another seal on order but repairing the seal won't fix the overheating problem.