Blown Head Gasket -

LinkBack Thread Tools
post #1 of 7 Old 08-26-2013, 03:37 PM Thread Starter
Registered User
1998 ZJ 
Join Date: Aug 2010
Location: Los Angeles
Posts: 192
Blown Head Gasket

Ive been having overheating issues for awhile now. originally, i had a mechanic install a thermostat in a pinch and they installed it backwards. I was running warm (around 220-225) for awhile and overheated a couple times before i found the problem.

Yesterday when i checked my fluids i noticed my coolant reservoir was brown with a bit of red/tan. the coolant feels like it has oil in it. from what everyone has been telling me, it looks like i have a bad head gasket.

will a compression test confirm this? And if i have a blown head gasket, what are my options?

Its a 98 4.0 2wd with 152000 miles.

dean477 is offline  
Sponsored Links
post #2 of 7 Old 08-26-2013, 03:56 PM
Registered User
1993 ZJ 
Join Date: Apr 2013
Location: Cape Coral
Posts: 1,078
Compression test could. Also pull the oil dipstick. Does the oil look like chocolate milk? If so there's coolant in it. I'd be after the "mechanic" who put the thermostat in backwards for starters.
zj97ltd is offline  
post #3 of 7 Old 08-28-2013, 02:06 AM Thread Starter
Registered User
1998 ZJ 
Join Date: Aug 2010
Location: Los Angeles
Posts: 192
Cant do anything about the mechanic. I threw out a lot of things when i moved back to Los Angeles, including my receipt.

So far, my oil looks and smells normal but is at the add mark now. It looks like my coolant is the only thing with oil in it.

At WOT, it misfires(maybe stutters) above 4000 rpm half the time.

If im only getting oil in my coolant, what tests can i do to see if this is the head gasket. Im hoping there is another reason for this.

dean477 is offline  
post #4 of 7 Old 08-28-2013, 02:23 AM
Registered User
2007 WK 
Join Date: Feb 2008
Location: Louisiana/Texas
Posts: 5,092
Has anyone ever put stop-leak in your cooling system? If so, it sometimes has a brown oily look and feel to it.

2007 5.7 Hemi, Ltd. QD II -
1997 ZJ, 4,0 select trac, Up country, track lok.
Oldfrog is offline  
post #5 of 7 Old 08-28-2013, 06:24 AM
Web Wheeler
Uniblurb's Avatar
1996 ZJ 
Join Date: Jan 2012
Location: Central
Posts: 7,252
Agree Oldfrog and it's not unusual for the coolant reservoir to be reddish/brown from rust from the engine anyhow. Believe I'd be flushing the whole cooling system, including back-flushing the heater core, and installing new coolant at a 50/50 mix with distilled water. Flush the heater core from the hoses towards the front of the engine and don't remove them from the core itself or you may damage the tubes.

If you want to see if oil is in your coolant before doing this buy some UV dye like below (not the AC UV dye type). Then add a small amount to your engine oil and let it run for a while until thermostat opens. Then use an ultraviolet light to inspect the coolant to see if the UV dye's in it. I bought a UV pen light with the yellow glasses kit at Autozone for $11. Looks like it's up to $16 now and they also sell the dye.

NAPA UV dye:

UV penlight/yellow glasses from Autozone:

UV dye from Autozone:

Often a an engine temp of 220-225 isn't enough to blow a head gasket. But this is the coolant temp where the heads may have become a whole lot hotter with the T-stat in backwards and no coolant flowing through the system. The miss at WOT may be a whole other problem but it's worth checking the coolant using UV dye. Good luck.
Uniblurb is online now  
post #6 of 7 Old 08-28-2013, 07:33 AM
Registered User
1993 ZJ 
Join Date: Aug 2010
Location: Austin
Posts: 2,094
You can also buy or rent a kit to test for combustion gases in your cooling system. It's a syringe-like apparatus that you fill with a special blue liquid. Then you run the engine, wait for it to cool, open the radiator cap, and suck some of the air from the radiator into the syringe. It bubbles up through the blue liquid and turns the blue to yellow if any combustion gases are present. It's possible for the head gasket to fail just between a coolant passage and an oil passage and this test can't detect that but otherwise it's handy.
zjosh93 is offline  
post #7 of 7 Old 08-28-2013, 04:34 PM Thread Starter
Registered User
1998 ZJ 
Join Date: Aug 2010
Location: Los Angeles
Posts: 192
Ill try these tests on friday when im off. Then flush the coolant.

Thanks for your help guys
dean477 is offline  

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome