Head Gaskets

[jahorns95]

I have been having this problem for a while. I started getting the "Low Coolant" message on my 2000 Jeep Grand Cherokee. After filling the reservoir bottle, it happened again. I took into a dealership and they told me it was my thermostat gasket and they had it replaced. A couple of weeks go by and the message came back. I took back in and they told me it was the clamp from the reservoir bottlet to the radiator. More time passed by and it went off again. Well, this time the repair got more expensive when they told me it was the water pump that needed to be replaced. Well, guess what I happened again that I noticed my reservoir bottle get low. I do not see any major leakage spots in my garage, but the limit goes from the "full" line to the "add" line in about 2 to 3 weeks. Last time I took it to the dealership, they couldn't find anything. So I just took it back home. Well, I took it back yesterday (same problem) and now they say it might be a crack in my head gasket. My only problem with this is I don't see any mixture of oil in my radiator or any mixture of coolant in my oil? Wouldn't these be symptoms of a crack in my head gasket? Has anyone had a similar problem or can someone tell me if it can be another problem besides a crack in my head gasket?

[JDPascal]

That is a lot of coolant gone west on you. I presume they have pressure tested the cooling system for you.

They can use the pressure tester to detect a head gasket problem if they know what to do.

There are also special kits that will detect combustion gasses in the coolant.

A head gasket or cracked head won't necessarily give you oil in the antifreeze or antifreeze in the oil.

Often, when the head gasket is a problem or there is a cracked head, the vehicle will overheat.

It could be that the gasket is leaking externally to. Have you parked the vehicle over a sheet of cardboard to check for drips.

let us know what you find out.

by the way... What engine is it??


JD

[jahorns95]

Thanks JD,

It is the 4.0L 6 cylinder engine. They did do a pressure test and could not find anything, but they did another special combustion test that told them this was the problem. The thing is I have not noticed any significant leaks (because what I lose from the coolant reservoir is not a small amount) on my garage floor. The vehicle hasn't overheated, but there is always some coolant in reservoir at all times I don't let it empty out. The guy at the service department at the dealership told me the coolant gets burned off in the engine, so that is why I don't see coolant in the oil. Because that is one of my questions if there is a crack and the coolant leaks into the engine, shouldn't there be signs of coolant in the oil or vice versa? I will still be researching before I decide what to do, because it is a pretty expensive fix not be sure about.

Thanks,

[JDPascal]

If they did the test that detects combustion gasses in the coolant, you can be sure that there is a problem either with the gasket or a cracked head.

They are right about the coolant not necessarily showing up in the oil.

from the time line you gave, it is a small leak that will get bigger. Then it will show up in the oil or on the ground.

When you consider how far you drive and how much makeup liquid is required over that time period, you are really loosing a minute amount every mile you travel.

let us know what else you find out about this and what you decide to do.

JD

[jeep mechanic]

do you have steam coming from exaust?sign of cylinder leak

[jeep mechanic]

if the low coolant sensor is in the resivour bottle,check the coolant bottle for cracks my 95 has ben cracked and i patched it with silicone,also is sensor itself bad?
my wind shield washer bottle sensor went bad and said it was low all the time even though it was full

[CU Ballin 803]

I have the same problem with my 99: "Coolant Low" came on about once per week or two weeks, even after refilling; but it never runs hot, and the radiator level was always fine. Couldn't tell where the leak was coming from. It only leaked if the car had been running; didn't look like a cracked reservoir. Oil looked fine as well. That went on for a few months, but recently it started draining a lot faster; I found it dripping from underneath the center, rougly 6 inches from the back of the front bumper - just behind the front belt there. This just happened this morning, and I haven't had any more time to look at it closely to see what it's coming from - I wish I had a diagram or something to look at...
Thanks for any advice!

[JDPascal]

being in the center it would seem to be the water pump but check for leakage above that too.

JD