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2000 Jeep Gr Cherokee - 4.7L Cooling System Mud FIXED

Posted: Mon Dec 13, 2010 4:56 am
by Tim Martin
I just got in a 2000 Jeep Grand Cherokee LTD with a 4.7 engine and the coolant looks like gold colored mud. Is about the consistency of slushy ice. The owner says nothing has been done underhood recently except for a radiator about 2 years ago. It has 135,000 on the clock and otherwise the engine runs fine, drives nice and the vehicle is in very nice condition. What I am asking is what makes this brown sludge in this engine and what is the best way to get rid of the stuff. Owner reports slight coolant leak although he assures me no stop leak stuff has been added to the cooling system.

Re: 2000 Jeep Cooling System Mud

Posted: Mon Dec 13, 2010 5:24 am
by wbuxton
No help from me. Did you check the transmission fluid for cross contamination?

Re: 2000 Jeep Cooling System Mud

Posted: Mon Dec 13, 2010 7:12 am
by steven kiser
i see that in jeeps a lot. i want to say that bad grounding causes electrolysis in the block causing the sealant to wear off and allowing rust build up. there is no proof of that but i know it was an issue with fords and the ground was the culprit. i will add that if you decide to clean it out by flushing it warn the customer that be doing that it will probably cause a series of leaks. you're in a catch 22. leave it alone and it's going to cause overheating issues as well as low interior temperature issues. flush it out and probably you'll be replacing the water pump, heater core, and most of the freeze plugs. the rust probably has attached itself to the inside of the heater and radiator hoses. good luck and be careful how you approach it.

Re: 2000 Jeep Cooling System Mud

Posted: Mon Dec 13, 2010 7:36 am
by Tim Martin
Houston! We got us a problem!

I checked this Jeep out more and we come to discover a head gasket leaking compression into the cooling system. As soon as the engine is started, bubbles come out a the radiator cap and compression builds in the cooling system. Now we really gots us an issue. I think what steve predicted is beginning to become reality. Do i really want this? On a Monday? This early in the year?

Would I be wise to remove the engine from the vehicle and do an expansion plug replacement as well as water pump?

So. . . . . . . . . . Customer. Yer gonna get an unwanted call from me on a cold blustery Monday morning.

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 8:12 am
by liljoe
Could be worse, you could be getting the call instead of making it.......

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 8:34 am
by Tim Martin
liljoe wrote:Could be worse, you could be getting the call instead of making it.......
You don't say?

The lady called and wants a price for repairs. Soooooooo.

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 8:38 am
by liljoe
Just had an elderly lady that had a timing belt and w/p put on her PT over the summer at another shop, came in today with overheating and no heater. Yup, no antifreeze installed at time of repairs. Was told not to worry about it till fall and she forgot. Hated to have to break that bad news to her......

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 8:41 am
by brianp87
I would quote a flush And then let it be known there may be problems as a result. Stress that fact. In fact I would also let them know it may need to be flushed a few times. AND note on the ticket how bad the condition of the coolant was in

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 8:56 am
by Tim Martin
brianp87 wrote:I would quote a flush And then let it be known there may be problems as a result. Stress that fact. In fact I would also let them know it may need to be flushed a few times. AND note on the ticket how bad the condition of the coolant was in
Are you indicating a flush as opposed to a head gasket replacement? Or in conjunction with? We plan to totally flush out the engine before putting the engine back together.

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 9:42 am
by liljoe
I would put some Dawn dish liquid in and run it a while before tare down. I have found it to work wonders on cooling systems, just make sure to flush all of it out after wards....

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 9:48 am
by Tim Martin
I have heard of the Dawn soap treatment before. How much does it take to do the job? A tablespoon? A 1/2 cup? Entire 8 oz bottle?

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 9:53 am
by steven kiser
all things considered yanking the engine may be wise. head gasket, expansion plugs, water pump, etc. wouldn't be real shocked if a head bolt snaps.

Re: 2000 Jeep GR Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 9:58 am
by liljoe
Tim Martin wrote:I have heard of the Dawn soap treatment before. How much does it take to do the job? A tablespoon? A 1/2 cup? Entire 8 oz bottle?
I usually put about two ounces, unless it is an oil/trans fluid contamination problem, they tend to take a little more. Have tried the flushes that they sell at the parts places and not had the results that Dawn gives, cheap too.....

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:00 am
by steven kiser
dawn work great but, and it's a big but, be prepared for other issues, although not caused by you were unmasked by the flushing. therefore it's your fault, isn't it?

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:08 am
by brianp87
I dont use dawn it suds to much. I have a floor soap I will use after a head gasket leak that doenst suds and it gets the oil out pretty good.

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:29 am
by Tim Martin
brianp87 wrote:I dont use dawn it suds to much. I have a floor soap I will use after a head gasket leak that doenst suds and it gets the oil out pretty good.
Name of it?

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:33 am
by brianp87
Its from zep. Its like an orange powder and when mixed with water turns green.

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:51 am
by wbuxton
brianp87 wrote:Its from zep. Its like an orange powder and when mixed with water turns green.
Same here! I learned it here on the forum. Looks like anti-freeze when disolved.

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Mon Dec 13, 2010 10:52 am
by liljoe
brianp87 wrote:Its from zep. Its like an orange powder and when mixed with water turns green.
Super flash, I have that too, never thought to use it for that, bet it does work great.

Re: 2000 Jeep Gr Cherokee - 4.7L Cooling System Mud

Posted: Tue Dec 14, 2010 2:45 am
by steven kiser
just a tip on cleaners. many years ago i used zep on my floors. it worked great and i have no issue with the product. back then the warnings on the can caused a bit of concern because it was during the big eco friendly movement. there were inspectors for the e.p.a. everywhere and the knowledge back then was in question. no one really had a grip on what was going on. the inspectors had less of a clue than we did. some were down right idiots and i swear were put into that department because no one else wanted them. i had one that was a forestry worker before he became an inspector. couldn't understand how my water separator worked and wanted me to seal all the floor drains. well we decided to get away from as many toxic chemicals as we could. since they were so concerned with what was going into the sewer system and handing out fines for anything they could even though they had no idea what they were doing we started using tide for the floors. it was an accident. there was a dry cleaner behind us and i wanted the sunday crew to was the bay floors and there was no zep left. the dry cleaner also had washing machines on sight and had a few damaged boxes of tide that he gave me. it worked great and that's what i use to this day. i figure if i'm going to get fined for using tide then the line of people going to court for using it would be so long they would never get to me. it was a heck of a lot cheaper as well.