I know the timing belt was done, but my friend does not recall if they did the water pump then… I wish there was a way to test the water pump flow before undertaking that job…
Since other bases have been covered, what about the the thermostat? For lack of a better phrase, maybe it’s dazed and confused due to a defect and elevated RPMs is affecting it. Odd I admit, but stranger things have happened.
A clogged catalytic converter can also cause overheating but generally this is noticeable with decreased engine performance if the clogging is severe enough.
Why not try a leakdown test with the engine cold. While each cylinder is under pressure, check the radiator for bubbles, or put a balloon over the neck of the radiator and see if it blows up.
Today’s update is as follows… After testing the clutch fan, I found it failed almost every test… Replaced it today, and it made a difference… However the truck is still running hot. It now took much longer to get warm (230 on my OBD scanner reading live data)… I drove it about 5 miles around my development before it got to the point I put on the heat and pulled back in the drive…
I noticed the following, the air coming off the fan (with my hand behind the fan) was cool, and not warm or hot at all. The lower radiator house was cool as well, and the upper was warm but not to what I would call hot. The heat in the car was very hot.
I’m thinking the tstat may not be opening all the way at this point. Or the water pump is weak, but I really hope that’s not it…
Thanks again, and if you have any more input please let me know…
It sounds like there is no circulation, reaching 230F in five miles and the upper hose is not hot. If the cooling system is full the thermostat is a good place to start.
BTW in general a clutch fan should engage when the air temperature passing over it is about 160F. Until you achieve good circulation and a hot radiator it is difficult to condemn the performance of the fans clutch.
Did I tell the story about a guy at the Saturn site that replaced his radiator and started having overheat problems? Turned out that there was a plug in one of the outlets that he did not see, after he found it and removed it, no more problems. Just saying…
@keith yes I saw that in an earlier post… However I’m not sure what you mean? I know sometimes new radiators have plastic caps on the inlets and out lets, but you could not get a hose on with them on… Even if you did you would have zero flow. What was on the saturn guys rad??
@navada_545 I can hear and feel the difference with the new clutch… When I pulled the old one I tried getting it to manually engage by turning the shaft with pliers and there was no change at all… It’s defiantly better with the new clutch, but still far from fixed
Thanks again for all of your guys help !!.
I don’t know the details. someone suggested that he pull the hoses and look for one that had collapsed internally, thats when he found something inside the radiator. Like you, I have never seen an internal plug, only exterior caps, but who knows.
The thing is that the vehicle didn’t have an overheating problem until the radiator got replaced due to a crack. I always go back to the last maintenance on something like this.
So apparently to get to the tstat on this motor the upper intake has to come off (who designs these things !!!)… The water pump is a timing belt job…
I was hoping to just throw in a new tstat and then see what happens, but now I’m wondering if that plan still makes sence since its so labor intensive.
I believe we have a circulation issue, but is there a way to tell if its the water pump or tstat ?? Or is it purely a guessing game??
I will also check the radiator for an internal cap maybe restricting flow.
Yeah, it’s a PITA, but if a new tstat and/or water pump saves the engine, it’s worth the effort.
Here’s a guy who made some videos for replacing his Passport tstat and water pump:
If you want to see if it is pumping remove a haeter hose and start the engine. You said that the heater is working so the results are predictable.
@keith well I forgot to check the hoses like you suggested when I took the whole intake off for the tstat over a week ago… Today I finally had the chance to work on the truck again today, and it noticed the lower hose still had antifreeze in it. Odd as the plug has been pulled for over a week. Put my rubber gloved hand over the open side and squeezed the hose… Suction at my glove, crap… Pulled the hose and bingo bango there was a rubber plug in the hose compleatly blocking it… You were 100% right and I’m halfway through a job I should not have had to do in the first place. To say I’m agrivated at myself is an under statement… Just thight you would want to know your advice was dead on !
Glad I could help. Thanks for the feedback. This is the second time in as many months that I have heard of this. I changed the radiator in our Honda and I never thought to look for a plug, guess I got lucky.
Well, the good news is you saved your friend an unnecessary head gasket job. And you can stop by the mechanic who “diagnosed” a bad head gasket and tell him what the real problem was.
Hope your friend at least buys you dinner!