Taylorsquad

I have a 1998 Jeep Grand Cherokee Orvis 4.0 that has been really problematic getting it to run without misfires. However, recent work has now got it running totally free from misfires. It has been running very well for the past week or so but has started overheating through the radiator filler cap. I’ve replaced the cap though to no avail. Any guidance on what might be adrift would be really useful. I’m not very mechanically minded though I am happy to do the more simple tasks. The radiator is not leaking, the coolant sensor warning comes on intermittently. I’m aiming to replace the latter. Would I be right in assuming that my overheating issues most likely the result of a faulty water pump and/or thermostat?

Any useful suggestions would be welcome.

97grand4.0

What you need is a radiator pressure tester to test the whole system for leaks. They loan them at the stores. Put it on the radiator and pump it till it says whatever the radiator is supposed to hold probly around 15-16 lbs. Then wait. If it drops, there is a leak. Finding it can be hard, eliminate all that you can see on the outside, water pump etc. They make dye you can add and check with an ultraviolet light if you have a hard time finding it otherwise. If you do all that and cant find anything leaking, start to suspect the head gasket leaking or even the head itself is cracked.

Mike Morris

I have the same problem on my 96 Grand Cherokee limited 5.2 with the 18 inch electric fan I put in some of that bars sealer now on these and get hot without the fan on stuff is wonders and no I don't have a cracked head gasket or block

jon-d

The motor could be running lean, which in turn makes it run hot. Other consideration is the rad could be partially clogged.