Wolfmann

my 2000 xj likes to run warm and takes along time to cool down sometimes. it has 227k on it currently and it is on its 3rd radiator. the newest rad is a CSF full brass triple pass, it keeps it cool most of the time but if i wheel or take a long drive on big hills it will creep up slightly above 210 and stay there. a few months ago i flushed my system 4 times in a month and my heater core was clogged every time, this was right before the csf, and i flushed once more after the new rad. another item to mention is my head gasket is ever so slightly seeping on the low pressure side, what could be the cause of this? beat water pump, clogged system again, issues due to seeping head gasket? anyone have any ideas? thanks

Wolfmann

another item to add is i have a decreased pressure radiator cap, its a 7.5psi cap , was thinking of increasing back up to 12 or 13 psi cap, could this also be the reason?

00jeepXJ

If i remember it right the radiator cap should be an 18 lb cap. Have you replaced your thermostat? The head gasket could affect the temp of the engine but it would also cause other issues.

RTorrez1

Rad cap 16lbs is what is recommended. Also If you know that you have a leak in head you best bet would be to change it before you really overheat and crack the head if not already. The main reason I say that is your year has the crappy 0331 head that are known for cracking rally easy. You should do a compression test on it and make sure you don't have coolant in your oil before you cause damage to the engine.

Wolfmann

Yeah i knew that it was a 16psi cap from factory, i was recommended to lower it to relieve pressure from the old gaskets. Ive checked coolant and oil for any exchanging, but they are both clean, if i decide to look into doing a new head gasket then id definitely pick up a different year head then the 00-01 head.

Wolfmann

Ill definitely look into checking my t-stat that could very well be the issue, also everyone i know that has a grand or a cherokee has a slightly seeping head gasket, ive heard its normal for these engines... Who knows

moparnj

Are your fans working properly

moparnj

You could have a fan clutch problem. When your engine is off it should have a little resistance when you try and turn it. I would also ohm out your temp sensor and make sure that's good before you make more work for yourself. Also un plug the sensor and the temp guage should sit on one side of the guage. Jump the two terminals with a small diamerter paper clip and the guage should go all the way to the other side of the guage. That will check your sensor and circuit. It sholdnt take more than a few min and it will ensure your not chasing the wroung things

Wolfmann

Thanks for the good ideas and cheap alternatives ill definitely try the temp gauge checks... Tonight just driving around it was fine, it likes to run lower with the new rad, (one mark to the left of the 210 mark) but im just not sure why on some days even in 35 degree days it likes to run hot with the aux fan on quite often

Wolfmann

Ohh and my fan clutch is fine, slight resistance when off, seems to work properly

RTorrez1

It is NOT normal. You shouldn't have any coolant leaking from the head. The main reason for a leaking head would be a blown head gasket or crack head. I am on my fourth JX and none of mine ever leaked anything from the head.

bigbadon

2 things you mentioned are red flags:
1. Clogged heater
2. leaking head gasket
If you have been using OAT antifreeze and have not maintained it or mixed IAT coolant with it you have created a corrosive brown sludge that will clog heater cores & radiators AND will EAT gaskets and water pump impellers. A normal flush will not clean the system you have to use harsh chemicals (available at GM dealers for cleaning Dexcool systems). If you flush ASAP,use fresh antifreeze (OAT or HOAT) and add the CORRECT amount of Bars pellets (also available at GM) you might save it.

Wolfmann

There is no coolant leaking from anywhere, just a small oil residue between the head and block, who knows, there is oil everywhere from a leaking valve cover i changed a few months ago. I know when we had put the second rad in it it was because of the sludge and we flushed it multiple times with harsh chemicals, it just has become clogged again

Wolfmann

What is the difference these different types of antifreeze, i wasnt aware that there was such a problem like this. I knew that the anti freeze was the cause of the sludge thow

bigbadon

OAT & HOAT are organic LONG LIFE coolants. Good stuff if system is maintained and not neglected (leaks or low coolant level). IAT had to be changed every 2 years but it is more forgiving and does not harm the system if left in too long. The downside to IAT is that it contains silicates which is an issue with the 0331 head....any IAT mixing with crankcase oil will wipe out bearings.