PLS HELP! Getting 200KM or less after changing Thermostat!!

If it was in backwards it would be overheating

 

Not possible to install an OEM like t-stat backwards, on these engines. Only if installing something like the URD t-stat kit, could that be possible.

 

I agree with most on here. It probably is not getting up to temp due to being stuck open partially. Which is causing it to remain in Open Loop Fuel Control, run rich and get poor mileage.

Lots of good suggestions above. My 2TR-FE 4 banger drops into closed loop control at 130 degrees. You should be able to tell from the idle when it goes into closed loop.

It is possible that the Temperature sending unit or wiring has an issue sending inaccurate temperature reading to the ECU, less likely. Coolant levels can also effect this, if it is low it will be exposing the temperature sensor to an air pocket which would cause erratic readings.

 

Have you tried buying another stat (maybe paying more to know its legit) and swapped that one in?

 

It was leaking around the housing. I think I threw it away in the excitement of that camping trip I was headed to that day that was 4.5 hours away. I can't imagine that I'd toss a part like that but perhaps I did. I'm totally considering reusing it. Gota find it first. It's kind of hard to install it in the wrong orientation. I doubt I'd do that. Are you able to post a pic here of the correct way it should go on?

 

I'm lucky if I'm getting 190KM on a full tank and remember, it's either Mobil 1 Premium or Shell Power Nitro+. If I was to use regular gas, I'd probably get 140km.
I was clocking 490 to 650km prior to that. Still think it's not the thermostat? What else could it be?

 

I don't think I'll ever order online again for certain mechanical parts. I tested the other thermostat. Will be posting my findings soon.

 

Can you show me a pic of how it would look if it was on backwards as you say? I'm a pretty intelligent guy. I'm sure I installed it as the other old one unless it's easy to install it backwards...

 

It can’t be installed backwards.
If you did, you really accomplished something.

It won’t fit.

 

Could you post a pic of it put on backwards? I remember installing mine pipe downwards but I'll take a pic to check.

Coolant is full both on reservoir and radiator.

I have a spare thermostat. Did the boiling test and need to do it again as I didn't see it open at 82 degrees celsius. Both stats are new.

Could it be possible that my spark plugs have gone bad? Could that be why my mileage is less than 200km per full tank??

 

Do you have a pic of how it look in the engine bay when on correctly?

 

You can’t install it backwards. It has a hose fitting on one side.

Take a few deep breaths, then put an OEM one back in and go from there …..

 

Here is a screen shot from youtube.
Too dark out for me to go take a picture.
I didn't link the video because he uses RTV with the gasket. And I don't advise that.

 

Spring side toward engine

 

You can't get it in wrong.
The space in between the 2 "holders" is too small.
Plus, the spring is too long to go in the other way, it will hit the "bend" in the neck.

It's not happening.

 

Have you cleaned you MAF sensor lately?

 

So your truck was getting 490 to 650km. All the way to the one day you changed the thermostat. Immediately after changing the thermostat it started getting 200km. There was nothing else done mechanically between that time frame which could have also contributed to the loss in mileage, correct?

If so, the thermostat is the culprit.

Regardless, check your spark plugs. Check the ends of your vacuum hoses for splits. As well as any other engine bay maintenance checks that should be done. Check your air filter even.

 

Thermostat is what, $30? Easy to replace. Much as I’d hate for a newly installed part to be bad, if that’s all that’s changed why not replace it.

my MPG is low. Not that low. I attribute it to drag add ons, lift, 35’s, armor, stock gears (for now), depending on city vs highway. City is more fuel burned for less distance.

disclaimer I have done other things though to try and make sure the truck is good. O2 sensors replaced, TB cleaned, MAF cleaned

debating throwing a RockAuto FPR at it. Downside is the best they list is Delphi; while OEM is Denso. Not sure if that’s an issue or not.
Was recently a thread here where someone’s FPR went bad.

 

So, from a low of 14.5mpg down to 6mpg on a changed thermostat?

Did you also swap to 37" tires and start pulling a 8 ton trailer?

 

It did open though, or change positions?