derick195

Ok guys I'm lost on what direction to go here. I've got a 2001 Cherokee and at low speeds and idle the jeep runs hot 220 plus if I let it idle don't start driving it. it does it without the a.c. on but does it much faster with it on. when it gets this warm it pushes the coolant into the over flow and eventually leaks, if I shut it off at 220 it pukes coolant out the over flow real bad

I be tried everything I could think of I have flushed the system twice and both times it has flowed good and no trash came out, I've replaced the following parts also.

I put a 3 core aluminum radiator in it
new fan clutch
new electric fan
new fa n shroud
2 new water pumps
new 180 degree thermostat
all new coolant hoses
moved the catylictic convertor to the back instead of in the engine bay

none of the above has fixed my problem and I don't know what else to do at this point, it's only at idkd and low speeds. driving down the road pulling mountains ect it stays at 180, no milk in my oil or water and no abnormal pressure build up in my cooling system. I'm at a loss anDrd don't know what to do it's my old lady's daily currently and I can't continue having this issue with my children in the vehicle any help would be greatly appreciated

XJeepCheep

Possible cracked head?
warm it up, shut it off and do a radiator pressure test and see if it leaks down over a period of time. You could also check for exhaust gas in the cooling system. Maybe even pull the valve cover and inspect for signs of a crack.

dans98xj

It looks like you did a lot of work on it so far. You should change the thermostat back to a 195 that is what the factory called for. It could make the engine run hotter with the 180. The 195 Thermostat will open later letting the coolant stay in the radiator longer to cool it down. I have read a few articles about the 3 row radiators and they have a tendency to less efficient then the factory single row.

here is a shot of a 2 row radiator and you can see the width of the tubes is less for the 2 rows then it is for the single. There is also a gap between the 2 rows this is could be a hot spot of dead air. As the air blows over one row it goes onto the next row with hot air on a hot tube and can't release more heat into the environment. The radiator will be come heat soaked and cause an over heat situation.

derick195

I have done all the above, no change in dye color, no excessive pressure, and just replaced motors thinking that it may have been a head after replacing the head gasket in the original motor it did this exact same thing so I figured there may have been a problem with the German head I installed or a problem in the block so I just swapped a 100k motor in it. before pulling the new motor out of its original xj I let it run at idle for 2 hours and it never passed up 210 but as soon as I installed it in my jeep it started do the same thing my original motor done. it's the craziest crap I've ever seen

Martlor13

What do you mean by this?

derick195

the thermostat, and radiator make sense to me but at the same I put 2 new single row radiators in it from autozone with worse results then the 3 row, and as far as the thermostat I will try it I thought it had a 195 in it so I bought a 180 hoping it would help but when I pulled it apart it already had the 180 in it so I'll try the 195 thermostat. but for example my electric fan does not come on until 212 and when it gets that hot that single electric fan just isn't going to be able to cool it and maintain it at 212 on its own and at idle the fan clutch isn't doing a whole lot so I almost feel like the fan needs to come on sooner then that but I'm not sure I've tried everything, today im going to swap thermostats out and try bypassing the heater core to.see what happens even though when I put the water hose to it it flowed out of the heater core just fine im running out of ideas

derick195

what part ard you not understanding, I will explain in more detail just not sure what part your questioning

Martlor13

Someone gave thebidea to do a pressure test, and you said there's not excessive pressure. But that's not really how a pressure test works? How did you come to that conclusion?

derick195

I put a pressure test on the cooling system and I was in tolerance I wasn't building more pressure then recommended

Martlor13

ok but I think the one you should do is the pressure test where you pump the system up with pressure, 16 psi I think, and if that pressure drops you have a leak. If it remains constant you are good? Is that the test you did?

extrashaky

That's a pic of a single row and a two row radiator of the same core thickness. The heavy duty two and three row radiators like Champion and CSF still often work better than the stock unit because they are not the same core thickness, but are considerably thicker, providing more surface area for cooling even with the gaps between the rows. The Mopar heavy duty radiator for the XJ is actually just as thick as those multiple row radiators, but with a single row.

I'm running a CSF three row in mine, and it does seem to have more cooling capacity than the little thin stock radiators. But it's so thick the mechanical fan barely fits behind it. If I ever have to replace it, I'm going to go with the Mopar HD radiator, which is 5/8" thicker than stock.

That 3 row you installed is probably thick, like I said above. If so, it should be working better than the thin parts store radiators.

Considering everything you've tried so far, at this point I think I would be looking at the A/C and the transmission, both of which dump heat into the radiator and can raise the coolant temperature. Have you checked your transmission fluid lately?

tech

Do you have a/c because the a/c condenser could be stopping air flow from getting to the radiator the fins can get plugged up or damaged . you should be able to see though the a/c condenser .

BlueRidgeMark

Get over the idea that the number of rows is a big deal. It isn't. Some 4 row radiators are better than some single row radiators, and some single row radiators are better than some 4 row radiators.

There is a lot more to cooling efficiency than the number of rows.

Since the problem wasn't there when the engine was in the other vehicle, and when it's in this vehicle there's a problem, the problem is in the vehicle.


Air flow? Radiator? Hoses? Heater core? What's in the problem vehicle that is not in the other vehicle?