The Nissan Path

2007 pathfinder 4x4 SE
230k miles

went on a 500 mile trip with no issues, started overheating the second in pulled into my driveway.

history:
timing chain and water pump replaced < 5000 miles ago due to the popular rattle

new coolant added at the same time.

i noticed that when it was overheating the fan wasnt spinning. could easily stop it with a rolled up newspaper so I replaced the fan clutch with an OEM one. STILL OVERHEATED.

next, i drained the coolant, replaced the tstat STILL OVERHEATING

now what? going to try to burp it again just in case. when it overheats its super slow getting there. like i can have it running for 5-10 minutes before it gets to about 210 degrees (checked via torque app)

I shut it down at 240 to prevent more damage.

when i drained the coolant there wasnt any oil in it. seemed super clean. hopefully it isnt a HG.

if it is a HG, time to toss some water wetter and trade it in for something else.

i dont really wanna throw parts at this anymore. thoughts?

I have a few questions to get a clear picture on what your dealing with.
Are you losing any coolant? Meaning the level slowly is going down over time and you need to add.
Do you overheat no matter what your doing or only when not going highway speeds?
I would check the hoses when you first start up and while running at operating temp to see if any are collapsing.
Did you have overheating issue before you replaced the water pump?
Does the fan spin without being easily stopped like before?

My theory is based on what you have said so far:
1. Bad thermostat.
2. Bad water pump. (even though replaced, you could have gotten a defective unit based upon if you had this issue before first replacement)
3. Collapsing hose.
4. Air trapped somewhere.
5. Blockage somewhere.

tstat replaced yesterday.

fan spins much better now.

no overheating issues at all until this week. ever.
i replaced the heater hose stupid arrangement (like 300 bux) about a year ago cuz it was leaking.

Ive pressure tested the system and i have no leaks. it held 20 psi for about 15 minutes losing 2-3 psi to a bad radiator cap that ive since replaced.


i got 2 theories:

1. fan clutch was going bad but wasnt the root cause. Tstat was the issue and i now have air in the line which is causing the new overheating.

2. radiator is clogged. will test using a noncontact later.

Is it the original Rad? That would be my prime suspect at this point. I know a lot of Titan owners have had similar issues with overheating (including me) and replacing the rad was the solution.

From what you've answered then I would say either the radiator has gone bad or the replaced water pump is defective.

well, went out and replaced the radiator, still overheating.

decided to take it to a shop to check out and after fussing with it for a few hours he said

"i got all the air out i think but its still overheating. i THINK the head gaskets are blown"

now mind you it will idle relatively ok but once you put a load on it, the temp starts to go up

this makes little sense to me for the following reasons:

no coolant in oil
no oil in coolant
no visual leaks
no smoke in exhaust even on first start up


thoughts? maybe i should just throw some goop in it and make it someone elses problem...

You could always do a cylinder leakdown test to confirm the head gasket.