Jeep Plaftforms

FredoinSF · #1 05-12-2011, 07:14 PM

A couple of days ago the coolant low warning came on again. Last time was around Christmas and the problem quickly became clear: the Jeep had a pretty good leak from the radiator.

One new radiator and 8,000 miles or so later, the warning is back and indeed, the expansion tank is right at the low level. I am not seeing any obvious leaks at the hoses, radiator, or water pump. I am not seeing white smoke or anything unusual with the oil.

Since I am not seeing any visible sign of where the coolant went, I am puzzled and concerned it may be the very start of a head gasket leak. I am taking the car to my mechanic tomorrow for a leak test, but in the mean time any thoughts from this group would be appreciated. I hope it's not anything major and that it can be fixed fast cuz this thing has to get me from Reno to the Bay Area on Sunday.

**Chaoul1** · #2 05-12-2011, 07:25 PM

Check your Freeze Plugs and your Oil!

**Frango100** · #3 05-12-2011, 09:08 PM

When the coolant gets into a combustion chamber, you normally can tell it by the special smell from the exhaust. If it took 8000 miles to get from the max level to the low level, it is a very small leak and therefore not so easy to detect. It can be something new and that it is a bigger leak, but i would start by refilling the expansion reservoir and keep a close look at it the next days.

FredoinSF · #4 05-16-2011, 05:01 PM

Thanks for the replies guys. Here's what happened since I first posted.

On Friday I went to have the Jeep tested. They did a hydrocarbon test and it came back positive which would mean I have a failed head gasket. This shop does not do the head gasket work on the 4.7L, so I went to couple of other shops to get quotes for that repair. Ouch... Every place I went to said the 4.7L is known for weak head gaskets and it is not unusual for them to fail at my mileage. They suggested having the work done ASAP - big surprise, huh? At one of the shops, the mechanic said anyone having the Jeep with the crappy 4.7L Mercedes Benz engine deserves what they get. I left...

Since the shops did not inspire high levels of confidence, I decided to do as Frango suggested and take a wait and monitor approach. So far so good but does anyone know a reputable Jeep shop either in the Bay Area or in Reno in case my coolant drops again? Are head gasket failures a common item on the 4.7L if they have not overheated and had regular coolant changes?

**Frango100** · #5 05-16-2011, 06:19 PM

What seems to be a more or less common problem is that corrosion on the head can create pitting and finally the head gasket can not seal anymore. Has to do with the different types of metal used for head and block and the different electrical potencial they have, causing the less potencial metal to "eat"away and causing the pitting. Don't say that this is your problem, but i found it already several times on the net.

Amelie · #6 05-16-2011, 06:21 PM

@Frango: An irrelevant question but Why on several of your posts does your font alternate between 2 different ones? Which looks to jump back and forth from Comic Sans MS to Times New Roman and so forth lol