Head Gasket
05-21-2013 | 07:59 PM
#16
CF Veteran
Joined: Sep 2011
Posts: 4,172
Likes: 4
From: Riviera, Texas
Year: 1998 Sport
Model: Cherokee
Engine: 4.0
If you fill the radator to the brim and power/brake it with the cap off, and get steady bubbles, a bad HG can do that. That test won't tell you if it's good, but it can be pretty clear if it's bad. Once I had a geyser shoot up and hammer the hood!
In my experience if the HG lets 2000* gasses into the coolant, the Jeep overheats. I suppose a small enough leak might not. X2 on the "sniffer", I guess a smog machine can detect hydrocarbon in the coolant also.
Was me I might do a wet/dry compression test. Handy to know those numbers anyway for down the road.
Consider a new cap?
In my experience if the HG lets 2000* gasses into the coolant, the Jeep overheats. I suppose a small enough leak might not. X2 on the "sniffer", I guess a smog machine can detect hydrocarbon in the coolant also.
Was me I might do a wet/dry compression test. Handy to know those numbers anyway for down the road.
Consider a new cap?
If you plan on driving it Make sure that you have NO water in the oil. If you do you will cause a lot more problems then just a head gasket if you keep running it with water in the oil. You can end up having to rebuild the entire engine.
05-21-2013 | 09:31 PM
#17
Thread Starter
Member
Joined: Oct 2012
Posts: 111
Likes: 1
From: Fairmont WV
Year: 1996
Model: Cherokee
Engine: 4.0
Its not going into the oil the oil is dark as i need to change it but i don't about into the exhaust but i will get it pressurized and everything else to make sure it is not blown
05-22-2013 | 03:44 PM
#19
Member
Joined: Apr 2013
Posts: 126
Likes: 0
From: Sonoma County Ca
Year: 2000
Model: Cherokee
Engine: 4.0L inline six
Well ill be replacing my head gasket. After all this talk about it and putting my two cents in, I went out to check all my fluids antifreeze ect.. power steering ok.. trans fluid ok.... antifreeze ok... oil up to level but milky! Wtf I check last week and it was fine }:/ very maddd..
05-22-2013 | 04:30 PM
#22
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 19
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Oops..Yea, there is a little one way valve in the cap. While drawing coolant from the overflow, it might have sucked in a piece of crud...That could let it vent air and blow bubbles....
05-22-2013 | 09:51 PM
#26
Senior Member
Joined: Mar 2013
Posts: 691
Likes: 2
From: Texas
Year: 1993
Model: Cherokee
Engine: 4.0L
Don't forget that the system is bleeding air for the first couple of heat/cool cycles after the coolant fill which may account for some bubbles in the over flow bottle.
I've never paid that close attention but will the next time I service the system just out of curiosity.
I've never paid that close attention but will the next time I service the system just out of curiosity.
05-22-2013 | 10:42 PM
#27
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 19
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
The big seal you see has a spring and lets coolant go to the tank if it's over something like 16 Lbs. Later, parked and cooling the air in the system contracts as it cools. That slight vacuum lets it pull coolant back from the tank, past a small check valve in the cap, about the diameter of a dime in the middle, into the radiator. That tank outlet needs to be at the bottom. If it were to suck in a bit of something that holds that open, next time it warms up it would start blowing bubbles in the tank. Just a thought. Or it just got done burping!
Last edited by DFlintstone; 05-23-2013 at 03:27 AM. Reason: into the radiator----that open
05-23-2013 | 07:10 AM
#30
Senior Member
Joined: Apr 2012
Posts: 578
Likes: 4
From: Ocean, New Jersey
Year: 2000
Model: Cherokee
Engine: 4.0
Well ill be replacing my head gasket. After all this talk about it and putting my two cents in, I went out to check all my fluids antifreeze ect.. power steering ok.. trans fluid ok.... antifreeze ok... oil up to level but milky! Wtf I check last week and it was fine }:/ very maddd..