Maybe is placed in wrong direction?

 

Maybe is placed in wrong direction?

Spring side is towards the engine just like direction of the OEM.

I think the problem is, now thermostat is almost a foot away from the original position. Coolant heat is going to be transferred to the thermostat by conduction only instead of convection when thermostat is in the initial closed position. OEN is right in the engine and in the path of hot coolant flow. Drilled holes in the new thermostat are only going to push cooler coolant from radiator to engine not helping raise the coolant temperature. Eventually it might get hot coolant but by that time engine is going to overheat. I don't want to try that. :lol:

That is just my theory. All reviews for this product are great therefore I am not sure what I am doing wrong.

It looks like on some cars thermostat is on the top radiator side. I can see how it can work better moving thermostat on the top radiator hose.

I am thinking if I get a lower temperature thermostat then that might solve the problem. I don't want to do that until I am certain I didn't miss anything.

 

My fear with a lower temperature thermostat is you could end up back where you were with the temp too low.

I've had a few Troops with 6VE1. Swapped manifold gaskets but didn't change the OEM thermostat. I understand the gripe with the factory thermostat location but balanced that with having several trucks well over 100k on factory thermostat. Is tough to get to but was so rare to need to change it I was not willing to change to an external fitting.

Barring I could find someone with the install you have with it working on a 6VE1 I'd give at least some consideration to getting an OEM thermostat from JLEMOND and moving back to original location. If you do go that route please do get an OEM thermostat as many of the aftermarket ones are awful. I replaced a few on 6VD1 trucks and every aftermarket one stuck open. Swapped the OEM back in and they were fine 50k miles later.

I don't mean to be party pooper and I hope the external device works. Best of luck.

 

I did this based on some others with Isuzu engines doing it and recommendations from some members on this board. Only thing I am guessing that they all installed it on the upper radiator hose. It just can't work on the lower.

I am sure putting the inline thermostat/housing on the upper radiator hose will work. It has to because now that is getting really hot.

I have already taken out intake manifold twice and put it back. I have no desire to do it again. Having inline thermostat has really helped me experiment without too much hassle.

I will have to order the lower radiator hose though because I can reconnect the cut hose again.

I am open to ideas but until then this is going to be the plan.

 

Yep...The inline thermostat should go on the Upper hose (outlet). That is the only way to get the hot coolant to open the thermostat. Otherwise, the "cool" water from the radiator is always pushing against the thermosatat. I installed mine this way and it worked perfectly for 2 years, until I finally pulled everything apart an replaced the original thermostat.

 

Maybe need a small hole in the thermostat or housing to allow at least a small amount of flow regardless of thermostat position?

Thin extreme example where your housing was 10 feet out from the outlet on the engine. Even though the engine is hot the coolant way down at the thermostat never gets hot as a lot of heat is lost along the way.

Even a tiny hole (ideally at the top) would allow air to bleed if needed and also allow some coolant flow to make sure the hot water is making all the way to the thermostat.

 

Thanks guys!

Now, what should be the direction of thermostat when installed inline with the upper radiator hose? Spring on engine side or radiator side?

 

Spring toward the engine. Drill a 3/32" hole in the outer ring below the gasket to allow some coolant flow. Place the hole at the top.

This is the hose I installed. It worked flawlessly for 2 years.

 

I moved the housing to upper hose close to the engine just like in the picture above.
Now thermostat appears to be opening/closing fine.
Average coolant temperature was 170 degree in a 5 mile drive with speeds up to 45 mph. Coolant temperature on Torque app was ranging from 167.5 and 172.4 degrees. Manual says normal operating temperature of engine is 176-212 degrees.
Is this good enough or do I need to get a higher temperature thermostat? Maybe 195?/180?
I think the stock thermostat is 170 because it is before coolant goes to the engine. As this is after, it needs to account for temperature of heated coolant.

All in all, very happy with the end result although I spent awful lot of time dealing with the whole thing. :shock: I treat this as a hobby therefore no complains.

 

When I had the inline thermostat installed, I was using a stock 170 degree thermostat. If I remember correctly, I typically read 176-182 and never had any issues.

With the regular setup, I am currently running 178-185, weather and driving dependent.

 

Mine is a 2002 Trooper if that makes any difference.
It is also cold now but not as much. Yesterday it was even around 60 degrees outside and coolant temperature was in the same range regardless of local or highway driving. At traffic lights it climbed as high as 174.2 but that is about it.
I am going to wait until summer and see what it does when it is 100 degrees outside.
I don't want to worry about it as long as 167+ degrees temperatures are acceptable, engine is not stuck in the open loop, and doesn't throw code P0128.

 

Hahahaha! I just went through the exact same thing. I just found your thread today. I had to sort it out on my own but ended up in the same place you did. Mine is on the upper hose now too. I'm running a 180 temp thermostat. So weird how this engine cools!
-Jack

 

It escapes me why you simply did not simply install a new thermostat in the factory location.
anyhow...moving on
Do you have proper coolant circulation?
Is the new t-stat installed with the spring facing the engine?
Have you tried elevating the new t stat housing above the height of the original?.

 

Yeah what's the point of an inline? It takes like 10 minutes to do the swap of the factory one.

 

Hey guys. I don't have the thermostat on the top front of the engine like is stock for this year truck of 1998. Someone swapped the engine at some point and I think parts off an engine for another year were used on this one. The thermostat is buried under the intake. It would take at least two full days to do the job and I have two kids that are still virtual. I'd need something like 16 hours straight to get it torn down and put back together. This was a 100 buck fix that took 20 minutes and it gets me down the road a few months. My immediate plans are to yank the plant and rebuild almost the whole thing. I'll fix all those typical issues. I'll probably even do the timing belt. Ugh... All the seals and gaskets but nothing below the heads. I might figure out how to fix a few issues like the cam shims that I am dreading getting into. This thing may head to the machine shop. Not sure how much that will cost. I might build one while I drive this one around and slowly get it ready than just swap them so the truck is only down for a day or two. I need to see what performance mods are out there if any... Headers maybe. Get rid of this stock exhaust. It's so noisy in the cab. Any way
It's about as ******* of a fix as you can get around here for sure. I can say that cause I'm a *******, or at least I was raised by some. I get it's a dumb fix but it works great. I imagine this older version is why they eventually ended up on the front of the engine. I like how simple a design this truck is for the most part. They made something easy to work on that does a lot but like others before they had some bone headed ideas like the early thermostat under the plenum. I cant wait to get this thing like new and get it off road. One piece at a time.
-Jack

 

The thermostat is located under the throttle body, not the intake. It takes 1.5 hours to replace, not 16 hours. you do not need to remove the intake manifold, only the throttle body

 

The thermostat is located under the throttle body, not the intake. It takes 1.5 hours to replace, not 16 hours. you do not need to remove the intake manifold, only the throttle body

The pipe attached to the lower radiator hose has the thermostat underneath it. That pipe leads to a valley below the intake. I'm literally reading the words- "Remove the intake manifold assembly" in the book. Not all 3.2L Engines were set up the same way.
As for my time estimate, have you ever removed the plenum without pulling the engine? I haven't, but I have heard tell and I have watched hours of ridiculous attempts to work on this engine with it still in the vehicle. There is no way it will take less than two full days to disconnect and remove the plenum and then reinstall everything. (I don't tare these down and back up again for a living and I don't have parts left over after a rushed job) All while not breaking any of the hoses, wires, and connectors on a 23 year old truck. I understand the confusion though. I am trying to figure out which engine set up I have. I see pieces of it here and there but none of them are set up the same way mine is. The references to removing the assembly is a footnote in the manual. This truck is straight up Frankenstein's Bride.

 

Straight out of the book.

 

Didn't you wonder why this thread even exists before you started commenting? Why do you think we went through all this with the inline thermostat? Do you think we would have gone through all this if it were that easy? Come on. Why do you assume you are the only person that knows what they are doing. The finality of your message, like I know what I'm talking about and you don't! Jeez. What is it with some folks on here set out to make people feel inferior?

 

You are confused, please allow me to clarify. My commit is not to boast or to belittle as I am not that kind of person. My commit is to inform and educate for next time around & for others who maybe reading. Also keep in mind that shop manuals are not always correct, accurate or up to date. Me personally would never pull a engine if its not necessary. In 30 years of professorially turning wrenches on all different kinds of vehicles I've found it best to take apart as little as possible when making repairs. In my eye, I see no reason to remove the engine to R&R the intake parts, cylinder heads or anything on top of the engine and this holds true for may other make and models of vehicles, not just Isuzu. I truly home you find this helpful in some way. in the future if you have any questions about anything please don't be shy.

 

As a test to circumvent a stuck Tstat in my 98 amigo I used a chev 185 deg in the upper hose. I trimmed off the flange and placed it in the top rad hose against the top tank neck and tightened the clamp. I sold it years later and ran without issue. I did drill two small bleeder hole on the edge of the Tstat to allow a small flow of water.

 

I installed this inline thermo not long ago. Working Great.
Thx for the thread.
Super helpful

 

Ok I got one for you. A related problem with my 99 trooper which NOW has a 2002 Axiom engine in it. Ehgine started over heating several weeks ago. I pulled the Plenum (twice) to replace the thermostat (with Slide to the Rear) but there seems to be NO hat water returning to the radiator? ( by the way 1st time to do this Im not a mechanic it took 5.5 hour to do pull and replace everthing, the 2nd time only 2.5 hours)