Lots wrong...PLEASE HELP!!

A couple of months ago my 2000.5 XJ overheated. I removed the thermostat as a side-of-road fix but did not replace it until the first cold morning here in NE Texas. The morning was not freezing but very cold. I drove the XJ that morning then replaced the thermostat that evening. The jeep ran fine. About a couple of weeks ago, when it got cold again, the XJ started running funny, rough idle and the heater barely worked. Then, about a week ago, I overheated - I checked and I did have little coolant in my system (my fault, I'm sure). After that my heater did not work at all and I have started to overheat again and intermittently run higher than my thermostat rating. I have a rough idle too. I have always had a bit of oil seepage I think around my valve cover. The leak seems to giving more of an oil smell now every time I drive yet I have not lost any oil from my dipstick or on the ground.

This brings me to today. I started hearing a knock - maybe a tappit (sp?) - and my idle is real rough.
I removed my spark plugs and they do not have corrosion or buildup - just a bit of whiteness on 5 and 6, probably from overheating.

Have I likely blown my engine? Any think to look for when I remove my valve cover?

As always, I'm grateful for any advise.
~TerryDean

I forgot to mention that since my last over-heating I have felt a hesitation when first taking off.

You havent mentioned if you changed your oil immediately after overheating, either time...?

If you changed your oil, did you notice any water/antifreeze in the oil? any oil in your radiator?

sounds like your headed down the cracked head highway...

cracked head or blown head gasket is what i would be looking for.

Yup Head gasket for sure. After seeing your year prob head also. My .02. The dead give away is the whiteness on your spark plugs. Antifreeze turns your plugs white. Good luck post pics.

Same thing happened to me. I opted for a rebuilt long block, but I know now that I could have just remanned the head, decked the block and stuck it all back together with a few new parts. Jump on this project now if you can! Dont let it wait!

Never let engine work sit-- I blew my headgasket, and waited almost 8 months to fix it. The problems got much worse just from sitting for so long-- if I just replaced the gasket when it blew.. I would have been fine.

Aside from some time in the garage, and 30$ for a new gasket.. you should be fine if you havn't cracked/warped the block or the head.

After the first overheat I did change the oil within the week. These recent overheats I have not. I drained it out a little while ago, and it's black as night but looks like 100% oil, no moisture. I installed one of those Prestone radiator flush kits but in doing so I found that I have 0 coolant in the radiator, which is odd because I just filled it last week and I have not noticed obvious leaking.

I will admit to one problem that I have not fixed and could probably be considered the root of some issues - my overflow outlet on my radiator was broke when I bought this Jeep. I have always just stayed on top of keeping water in it because I can not find a way to tap a new one in without removing the fan/shroud and maybe the whole radiator. I've searched this forum to no avail.

Should my overflow outlet REALLY be able to drain my radiator down to a few drips of water within a week?

p.s. Tomorrow I am going to do whatever it takes to fix the overflow, then put new oil/Restore, flush my radiator and see what God has in store for my engine past that. Wish me luck.

Well, 2000-2001 had the cracked head problems. Since you're probably going to want to remove the head anyway to check the head gasket, you'll be able to tell how the head is at the same time.

Yesterday I started the morning working on the Jeep. I put the new oil in and flushed my coolant system a few times. I had a LOT of rusty sludge in my system but once I got it out the heater began to work very well so I had hope. I went to the parts store and got a fitting to fix my broken overflow spout, some Lucas gas and Lucas oil treatment and a new valve cover gasket. The whole drive there and back was good, no strange noises and good power. I had hope, so I changed my gasket then checked my dipstick to see how much oil I needed to drain in order to add the Lucas - I have seen coffee creamer look less milky than my oil. I drained the pan and sure enough it drained milky all the way through. Coolant in my oil!!

I removed the head, which is a helluva chore. Upon inspection:
-There is nothing visually and apparently wrong with the gasket.
-The head has one stress mark between CYL 3&4 but it doens't appear to be a crack.
-More milky substance in my block where the coolant runs.
-The head surface appears smooth when running a smooth edge level across it. Same with the block.
-All of the lines in the head/block where the oil passes through have rust buildup - some of them nearly closed with rust.
-Pistons/cylinder walls/valves all have no apparent defects.

I will be finding a machine shop to look at my head/gasket this week to determine what my next step is. Anyone around East Texas have a suggestion of where to go?

p.s. To brighten my day, while talking to my Dad he said "Well, if the head does turn out to be bad let me know because I have been needing a new boat anchor". Thanks Dad.