Hi Guys and Gals,

My stepson’s 2000 Cherokee, 6 cylinder, Auto, 2WD, seems to have a hearty thirst for coolant. I only see the vehicle on occasion (when it needs work), but every time it is low on coolant. The last check it was down about 6 quarts. It is not showing up in the oil or ATF, and I do not see any visible leaks, so I am wondering if the cylinder head or gasket could be cracked, and the coolant is getting sucked into the intake ports or combustion chamber and exiting with the exhaust.

Are there any checks that will detect a cracked head or gasket? He will be coming by today for a complete set of fluids and filter changes, and I would like to identify the issue before putting more Prestone “down the drain”.

I understand that this year is prone to problems (0331 cylinder head). If it cracked, are there any other model year cylinder heads that will bolt in and hold up better? What else should be replaced if we go down this path (besides gaskets and head bolts)?

Thank you in advance for your help and suggestions,
David

 

the 2002 and newer heads were fine so it could be replaced with one of those. Also, there are remans you can get with the defect strengthened. Supposedly if you take off the valve cover, if the head is cracked you can see it

 

ive replaced 2 that were loosing coolant at about 1 pt a week.........
it was going into the oil and did not have it milky or show up as you would expect it would.

you can have a oil analysis done to ck for the presence of coolant in oil.... it runs about $12 to have it done.
if ya let it go too long it will wipe out the bearings and at a hot idle your oil pressure will be low = rebuild time.

 

I have a 1994 Jeep Cherokee Country (High Output) And I'm very worried about it having a cracked head. Every time I exit the vehicle I smell burning coolant, and I've checked every day (multiple times) to see where/if it's dripping from somewhere. All hoses look good in my coolant system, all valves intact, and there are NO drops visible under the engine compartment. I hear kind of a screeching noise from the engine area when I'm driving sometimes, and I think it may be burning through bearings. I'm not sure at all though, just wondering if this is what it sounds like. Also, eats through a lot of coolant, and oil pressure has been drooping a little lower then rises back up when I'm idling/driving sometimes. No milky oil, coolant looks clean, pretty worried I'm gonna have to rebuild or do huge maintenance. Hoping the jeep isn't lost if it is that.

I'm not trying at all to Hijack your thread at all, just maybe the people viewing your thread would have some input for both of us!

 

If a 2000 4.0 is down six quarts on coolant, you either have a nasty leak (which should be visible) or you very possibly have a cracked 0331 head.

First, perform a comprehensive search for a leak. Don't want to assume anything here.

In the absence of any leak, you should pull the valve cover and have a look with a good light between cylinders 3-4, which is where all of the 0331 heads crack. Most people can see these cracks with the valve cover off.

And as mentioned, if run long enough with this cracked head, the engine bearings will take the hit. Then you have bigger fish to try. Dropping the oil pan and sampling some bearing clearances with some plastigage is not a bad idea.

If you do need a head, Clearwater Cylinder Head and Alabama Cylinder Head are good sources. Also consider 2003 and newer heads from the Grand/Wrangler. They were sourced from the Brazilian foundry TUPY. Some late 02 heads are TUPY, but some early 02 heads are NOT. These heads will have the word TUPY stamped on the head between cylinders 3-4. Be sure to check!

 

Thanks for the tips. I will check the head next time I get near it.

Tonight we changed oil and filter and did two more transmission pan drain and dumps with a new filter on the second dump. When we started the vehicle, I noticed water comming out the tailpipe and from a pinhole in the muffler. The temp was ~70 degrees with medium humidity so it seemed odd to be seeing so much water.

To Cherokee Country: No promlem on the tag-a-long. Watch your water pump to see if it is wobbling. The screech could de metal to metal grinding when the WP bearing gets sloppy. This could also lead to coolant bypassing the seal