And yet another over heating/head gasket thread...

The other day my brother picked up a '96 XJ 4.0L with 126k on the clock. When we went to look at it everything checked out, it was clean and it seemed to be a smooth runner. Before purchasing it we drove it around for 20 minutes or so with no issues.

The next day it over heats (gets up to 260). Upon inspection there is a HEAVY coolant leak right from the block. It was literally pouring out. It seemed to be pouring out near the exhaust manifold right by the coolant drain plug. Possibly a freeze plug?? Would a leaking freeze plug cause a little white smoke in the exhaust?

Would a bad head gasket actually cause coolant to leak from the side of the block? There is a little white smoke coming from the exhuast, but there doesn't seem to be any coolant in the oil, or vise versa.

Also, the upper and lower radiator hoses don't feel like the have any flow through them at all.

I wish I knew more about the Jeep, the PO only had it for a month or so (which I know is a red flag for a lemon), but he seemed to have a legitimate reason for selling it.

Any help or input is much appreciated!! I will provide more information as it becomes available. Thanks!

 

well ill start off by saying that if there is a massive leak somewhere in the cooling system pressure will not build making it feel like their is no flow.

but it sounds like you may have a couple different cooling system issues.

and no a leaking freeze plug will not cause smoke out of the tailpipe.

do a compression test and see what the readings are..

 

Yeah there are definitely some cooling system issues. I just don't know where to start. Keep the input rolling in!

 

Along these lines, I shall add some advice and delve into my own problem along these lines.

Advice, yes, the freeze plug will cause leaking along the side of the block. But so will a cracked block in cerian areas.

An inspection mirror helps look under the manifold and see the 4 plug on the side of the block. I just replaced mine for the same reason you stated. I recommend placing the new freeze plugs in the freezer over night, as it shrinks them just enough that gentle taps are all it takes to get the new ones in. You're welcome in advance for that tip. Ha.

Besides the freeze plugs, the job calls for a $40 manifold gasket as it needs to be removed to access the freeze plugs more frreely. Id say, go ahead and get a gasket for the water pump as well, and pull it off to see if its worn down or not. Also check to see that the electric fan on the drivers side of the radiator is running when the engine gets warm. That can cause problems if its not running when it should. Try also replacing thermostat and radiator cap.

After all that, if like me, you still have over heats... well, then its scratch head time.

4 different jeep owners said the map censor was the fix, for some reason. So I tried that today, no luck. Still random over heating. Many times I can pop it in nutral and turn off the engine as I coast. Restart it to find it cools back to normal, and some times she just keeps on blowing out all my coolant. Im stuck. Even the pros are stumped on my ordeal.

I will search for other over heat posts on here... surely this isnt just my luck kicking in. Its bound to have struck another jeep owner or 2.

 

Just wanted to follow up on this post. I hate leaving posts 'unfinished'. Anyways after doing some tests at the shop we found hydrocarbons in the exhaust. So the head was removed and taken to the trusty machine shop. Upon inspection the head was cracked in three different places, and wapred overall .0033. The head and all gaskets were replaced and everything is running fine now. I ran into a small road block you can read about here
https://www.cherokeeforum.com/showth...254&styleid=14.

 

[QUOTE="The91XJ;2576218"] ... Upon inspection the head was cracked in three different places, and wapred overall .0033. The head and all gaskets were replaced and everything is running fine now...

I think I am about to replace my 0331 head in my '01 XJ, do you mind sharing how many labor hours it took the shop to remove the old head and replace it? Trying to gauge pricing. Thanks!

 

All the work was done by me and my brother (its his jeep). It took probably 10 hours total. If you have basic mechanical skills you should be able to do it no problem. It will save you roughly $1,000 in labor.

 

And by the way, the coolant leaking from the block ended up being 3 failed factory freeze plugs, which were extremely easy to replace with the manifolds off.