Ok, so I bought this 96 Jeep Cherokee. I noticed it would overheat after extended driving (at the tail end of the drive, and when pulling into the driveway). When I come to my final stop and idle for more than a minute the temp goes up and it will get into the red if I don't turn the heater on full blast.

So far I have put in a brand new 195 Stant Thermostat. A brand new radiator. I bought a new radiator cap, and found out yesterday it wasn't holding 16psi like it was supposed to. I bought a new rad cap, and thought I fixed my problem. Well turns out I didn't. I also burped the system very well.

So then I replaced that catalytic converter because it was rattling.

Oh and there's fresh coolant 50/50 with distilled water. The water pump looks brand new.

I also replaced the fan clutch, and the fan shroud. I had a mechanic do a pressure test on my cooling system, no leaks, and he said it didn't show any signs of cracked head, leaky head gasket, or warped head. Also bought a combustion leak tester and did it twice following directions to the tee. It didn't show any signs of combustion gasses in the coolant.

Is there anyone in Colorado Springs that would be willing to help me get this figured out, I would compensate..

otherwise please post any advice you might have.. Thanks.

I always drive to the store (about 5 miles away). The trip there is fine always stays at about 200. After coming back to the car after 30 mins of shopping, the drive home is where I run into trouble. This is consistent, happens every time.

 

You say the water pump looks brand new? It looks brand new on the outside? Have you had it off?

Since you've already sank this much in it you might as well swap out the water pump. They're cheap enough and it shouldn't take you more than an hour or so to swap.

 

check my Sig...

 

I have read this whole post, I verified my temps with a temp gun. I used all quality parts. I don't know what else to do.

 

IF you're not sure about it's condition, replace it. That goes for any part.

 

^^2X^^
Just because it looks new. The inside can be completely trashed. Like lowrange2 said you put that much money in to it you may as well replace the one thing you didn't change.

 

im guessing water pump cause going there it is cool heat soaks while there then doesn't flow enough going back to cool it back down.

 

i had a f150 blow both headgaskets and the water pump looked new. when i took it out the fins were rotted away

 

Do you think it could have a blown headgasket? Even though it passed both tests and the engine runs beautifully.. No oil in coolant and vice versa.. Nothing to lead me to believe its a head gasket other than overheating.

 

water pump
thermostat
clogged radiator
clogged block/head
air in coolant
too advanced ignition (???)
fan shroud
fan clutch
electrical fan
head gasket

What did I forget?
thertmostat can open half way.

 

If the cooling system pressure test and combustion gas test were both OK, I'd say probably not.

I agree with the others. At higher RPM your water pump might still be pushing enough water around to keep the temps in check, but when you drop back to idle...with a system full of hot water...it may not move enough coolant to avoid a "thermal event", lol. They can look wonderful from the outside, but inside the impellers are rotted away. Have a look.

 

Ok so I called the previous owner who's had it for A considerable amount of time. He said the waterpump never has been replaced. I don't know why it looks so New compared to the rest of the engine bay. Ill pull it out on Tuesday and let you guys know what I find.

 

Anymore suggestions?

 

change water pump, report results