XJEnthusiast

OK, I've spent this summer trying to resolve an issue. I thought it was a simple problem but despite all my efforts it still remains. In an effort to finally solve this damn problem I'm not dicking around anymore and just laying it all out there in the hopes that someone can help me out.

I've got a ’97 Cherokee Sport, 4WD, 4.0L, with A/C, and no block heater.

So it started out as two seemingly separate problems:

1) I was constantly loosing coolant, despite that fact that I was always resupplying through the overflow reservoir, it would always end up empty. There was no readily apparent leak, and I never saw any pools of coolant under the car.
2) During the cold season my engine would tick. It’s not a clunking, or knocking, and it isn't always around. It’s a very distinct “tick” and it’s very clearly is coming from the engine. The tick wasn't immediate, I’d start the car and about ¼ to ½ my way to work (about 2 city miles) the clicking would begin. During the spring and summer however the clicking wouldn't be apparent.

So because of the constantly empty coolant my car began running hot. I thought this was the most immediate problem so I took it to the dealership for a diagnostic. They said that a broken radiator was the culprit. I asked why I never saw any leaks under the car; they explained that it’s probably because the leak would start when the system was brought up to pressure during driving, which is when I would be losing coolant. When the engine was shut off and pressure removed the leak would seal. Not being an automotive expert, and from what others had told me, I was suspicious of this explanation.

Then a few weeks later I took a short road trip to visit family. Not too far, about 120 miles. To assure I didn't kill my engine during the drive I took spare coolant and checked the coolant levels any chance I had. Then, on the way home, while stopping for gas, I saw it: a pool of coolant under the car. I took some pics and did some research, finally an expert I spoke with said the water pump was shot. Hallelujah, finally a line on the problem.

After this I set about replacing the pump, I figured while I was in there I’d replace a lot of the other aging parts. As I popped the trunk and dove in I discovered a leaking radiator, feeling stupid that I hadn't listened to the dealerships mechanic, I set about replacing that too.

A couple weeks later I now have a new thermostat, thermostat housing, temp sensor, serp. belt, water pump, radiator, rad cap, and coolant outflow and inflow hoses. I started the car and low and behold it worked! The engine was running cool, the seals appeared to be holding, no leaks, and all the hoses were warm in the right places. But alas two more problems have appeared over the course of driving it the past few days:

1, 2.0) I’m still losing coolant, with, again, no visible leaks under the car or from the engine, or strange noises from the engine. This is indicated by a vanishing supply in my reservoir tank. After all the trouble I had before I wanted to monitor the level to make sure the seals were holding. I set a line on the reservoir, and every day I drive it sinks a little lower from that mark.
3) I now have a widely varying oil pressure. When I start the car, and for the first 10 minutes of driving, it’s at about 40-45 after which it drops down to practically 0 and my "Check Gauge" light comes on. However when I accelerate rapidly it jumps up back into that sweet spot around 40, but if I accelerate moderately, or remain at a constant RPM, it remains down at the bottom.

I got an oil change about a week ago, and after doing some research I feared it might be a cracked head. So I started checking the oil, and it doesn't look like peanut butter, but I don’t have the expertise to know if there are other signs to look for in the oil if there’s coolant present. It doesn't look like there is oil in the coolant. I checked this thread (https://www.cherokeeforum.com/f2/00-...erview-118922/) and although I have some of the symptoms (1 & 2) my heaters working fine, and aside from the tick (which hasn't reappeared since replacing the parts, but its still warm out) the engine isn't running poorly, in fact despite the problems mentioned above the car feels like it’s running great, its runs smoother than it used to and its running cooler (I upgraded to a 2 channel rad).

Based on the thread above I’m going to start monitoring my oil and coolant levels, check for bubbles in the coolant, and run an oil sample test in a week or so. Based on the model/year of my XJ, and on the symptoms I've mentioned, am I just over reacting? How strongly does all this point to a cracked head? If I am over reacting where the hell does my coolant keep disappearing too?!?! As I test and get more info I'll post it, thanks for any help or suggestions.

black2000xj

well you got yourself a heck of a problem

i would suggest looking at a cracked head. 0331 heads are known to do that and that would loose coolant without a visible leak

or check head gasket.....

good news is...if it is the head, you get a new gasket anyway!

djb383

Guess a cracked head/head gasket could be an issue but I didn't think '97 XJs got a 0331 head.

It's always best to check coolant level when the motor is cold.

Troyboy

Ok water pump & radiator replaced! 1. check every coolant hose 2. dont pay any attention to reservoir tank. Pay attention to the radiator and make sure no oil in coolant and no coolant in oil top them off but make sure no air pocket in coolant! 3. check heater coil and hoses 4. check freeze out plugs. sounds like your losing coolant only under pressure oh and always check your radiator plug. keep your eyes on exhaust if steaming it may be burning it off fast then we got a head problem but thats in mostly in high mileage 4.0

CCKen

Do you have a factory service manual (FSM)?

There are several tests of the cooling system for internal leaks using different testing tools, outlined in section 7 of the FSM. The testing tools can be borrowed from parts stores like O'reilly and Advance auto parts.

What do your spark plugs look like? Pull all of them and examine them. Let us know what they smell and look like. Pics would help.

Rockville

First of all, if you cannot repair cars, you shouldn't have 15 years old car. Mechanics will suck your money and you'll spend for repairs more than value of your car.

Whenever mechanic is diagnosing your car, ask him to show you. If your radiator is leaking, you'll see it. Mechanics lie pretty often to get your money.

Firestorm500

He doesn't have the 0331 head.

Unexplained coolant loss is one sign of a blown head gasket and/or cracked head.

If it is blown between cylinders, it doesn't contaminate the coolant or oil. It just burns coolant.

Compression check might help isolate what is going on.

Lostfisher1

they can teat for exhaust in the radiator that would tell you right away if ur gasket is bad.

belvedere

This is one good way. Another is a used oil analysis (UOA) to check for coolant. Years ago, I had a Triumph Adventurer that started to slowly lose coolant. Nothing appeared abnormal when looking at the oil, but I sent a sample to be tested. The lab called me to say it had tested positive for coolant in the oil.

blinkbears

I had no idea you could do that.