1. 2001 Nissan Pathfinder
2. 190,000 and some change miles.
3. Model LE
4. No engine light comes on.
5. Coolant levels stays same.
6. Oil level as recommended.
7. Vehicle seems to idle well.
8. My simple 3030 code reader finds nothing wrong.
9. A year ago my wife said that the codes said catalytic converter problem but those codes are not coming up now.
10. Automatic
Vehicle overheated on hill initially going between 30-45 mph so I changed front thermostat and cover. Also changed fan as it was cracked. I was able to drive 20 minutes, when I turned AC on it immediately started to overheat even though I was going down hill at 45 mph. On way back home 20 min. mostly up hill did not heat up but did if AC was turned on.
Things replaced or fairly new:
1. Radiator 6 months old.
2. Cooling fan NEW
3. Thermostat and housing new (one piece) OEM
4. Radiator Cap NEW OEM
Things I have checked:
1. Inlet hose to radiator gets hot.
2. Clutch fan seems good as no wobble and fan doesn't spin freely. I check with magazine to see if it would slow down and it did not.
3. AC blows cold
4. Does not heat up when idling and turning AC on.
5. Did visual inspection of condenser and although some of the fins are bent no major gunk or damage to it. Shows no leaking or rust anywhere.
6. Not losing antifreeze and no leaks at hoses or radiator.
I know it has internal water pump and I don't know if I would see leaking even if it was leaking based on it being internal.
I did not change second thermostat because it requires taking off intake manifold and is at back of engine(Nissan engineering nightmare).
There was a mouse house in the air cleaner box and I changed that out and put new air filter in. (don't know how that would affect anything regarding over heating).
Thank you for any help in advance.
If I use a head gasket sealer (Bar leak)
That stuff is a temporary bandaid at best and may lead to more problems, like a clogged-up cooling system.
Well since you changed all the other stuff I would assume the water pumps going bad. I know sometimes this stupid impellers either fall off or start to go bad because of the use of plastic crap.
Do you think it could be thermostat on back of engine possibly? Easier in your opinion to change water pump first or second thermostat? Thanks in advance.
Hey Scotty,
Hope you are surviving the blizzard. Still on that 2001 Nissan pathfinder with the thermostat at front of engine and a thermostat that is referred to as "water valve" on back of engine that requires removal of intake. If I use a head gasket sealer (Bar leak) would I need to remove not only front but rear thermostat and would I be able to run it for 30 minutes without intake on. Rear thermostat is 210 degree one where front is 170 degree. Stay warm and look forward to hearing your response.
A little more information.
1. The vehicle now does not heat up on regular highway or idle but does in fact heat up when the AC is turned on (this was when we had warmer weather) and moving. I ordered gas test kit you demo'd and will receive tomorrow via amazon to see if it is blown head gasket.
a. no white gunk under oil cap or in area a top of engine.
b. oil is clean and not milkshakey
c. no white smoke out of tail pipe
d. no bubbles in radiator when cap off and idling.
e. radiator fluid clean and in correct proportions per owners manual
Thanks,
Chris
Since you did all these work I would replace the other thermostat that you didn't replace and also I would replace the water pump. Before you replace the thermostat you can rest them to see if It works or by putting it in boiling water and when the temperature reached 180 to 195°F the thermostat should start top open. If it opens then it works perfectly fine. If those still doesn't fix your issue. I would go to a honest mechanic or go to a Nissan dealer and have them diagnose your car and go from there.
Also do you think it could be a bad coolant temperature sensor?