Dustin Boyle

Hello, I'm hoping someone from here can point me in the right direct direction. I have a 1998 Jeep Grand Cherokee 5.2L V8, It has the 318cc in it. It keeps overheating at idle. I have replaced everything.

It has had a new radiator put in, water pump, belt tensioner, upper and lower radiator hoses, new thermostat (195°F), new thermostat housing, new clutch fan, new fan shroud. This fan is mechanically driven.

I have no idea why it keeps overheating, I don't know if the head gasket is blown, it runs great, sounds wonderful, no squeeks, or squeals on cold start or anything. There is plenty of fluid in radiator and plenty of fluid in reservoir. No clear smoke from the exhaust,

Please someone point me in the direction to get this overheating issue fixed. When driving down the road, a/c blows ice cold, heater works just fine nice and hot. Temps are about 180ish when driving 60mph+ on interstates but when I hit traffic and sit about 5-10 minutes the temperature keeps creeping up. If anyone has had this problem please let me know how to fix this issue.

dt750

could it be the temp sensor? try a compression test on the cylinders, that should let ya know if the head gasket is bad. you might also need the system flushed as I've seen in other vehicles were the water journals were plugged full of stop leak and other crap in the heads.

BlueRidgeMark

Well, first of all, you don't have a Cherokee (XJ) as your profile says. You have a Grand Cherokee, which, for a 98, is a WJ. Ergo, you are in the wrong forum. No worries, I've reported your post and a mod will probably move it in the not-too-distant future.

Also, I'm pretty sure your engine is bigger than 318cc. That would be tiny even for a motorcycle. (It might be 318 ci, but I don't know your engine.)

You need to find out. One good way to verify that is an exhaust gas test. It's easy to do. If it shows exhaust gasses in your coolant, it's time to pull the head.




That usually points to a fan clutch (for mechanical fans) or an inoperative electrical fan (for vehicles so equipped).

I'm not familiar with the V8 setup. Are you sure you have a mechanical fan, and are you sure you do not also have an electrical fan?

Noah911

The overheating happening like that only when the Jeep is sitting still and is idling sounds like a fan issue to me too. It certainly makes the most sense. The fan does the primary work of keeping the engine running cool when there is not another source of air flowing over everything like how there will be when you are driving and moving down the road.

Do you know how, or have you spun the mechanical fan as a test indicator for seeing if it is showing as being faulty or not?

97grand4.0

First step to any cooling issue is to use a radiator pressure tester to see if the system is leaking coolant, either internally or externally.

dave1123

OR not holding pressure. How hot is it getting? It could get up to 220* without doing any harm, but not too much over that. 180* is too cold, seems to me. Check it with an infrared thermometer to see if it's reading the same as your dash gauge. It should be running close to 195* with that thermostat.

97grand4.0

Um well if it's not holding pressure that would be because it is what...? Leaking. thank you

Noah911

When using a radiator/coolant system pressure tester to look for leaks (or, pressure being lost somehow). You will be using the radiator filler neck spot to plug into and hook up the pressure tester (a mini bicycle pump looking thing), for when you are pressurizing the system to get the readings. Doing it this way makes it impossible to know wether or not you are losing pressure via the radiator cap though..

If it is testing fine and holds pressure when you test it like this? Another thing to consider doing at this point is to just go ahead and try replacing the radiator cap next. A radiator cap only runs around five dollars new from the parts store. They should almost always have the right cap in stock at all times. I would still verify any new radiator cap is actually stamped as being the correct level of PSI called for by the stock specifications. A parts store radiator cap will probably not be an OEM piece.. Even so, it will most likely still do a much better job than any original radiator cap that may still be on these old Jeeps anymore right now though, or any other older radiator cap.

dave1123

A good radiator pressure test kit has a sleeve that you put the cap on and the tester on the other end, pump it up, and it should blow off at the specified pressure. When I said "not holding pressure" I meant the cap.

BlueRidgeMark

Aaaannnd it's been two weeks with no response from the OP. Another one-post wonder. I guess he didn't get spoon fed quite as much as he wanted.

Or maybe he died. Dunno.

Noah911

I don't think he died? I'll ask him... Did you die?

dt750

LOL!!!!

Noah911

I'm sure he would have let us know. I can only conclude that he is still alive. Otherwise.. 'how rude'

dave1123

Some people don't realize this ain't Facebook where you can get an instant response! Don't come here if that's what you want. Pay the price and ask an on-line mechanic!

Noah911

I honestly do not even have a Facebook account. This is actually a lie... My ex set me up with a Facebook account probably it was back in around 2010 or something.

How many times have I used it..? Only once on the day she initially set it up for me.

When was the last time I was on this Facebook account..? That same day it was set up for me.

I don't really know why? This is just how it happens to be for some reason. I have no plans to open a new one, or start using this other one either.. I just don't

Merry Christmas