ullbsorry

Yes I did use the search button and yes I did find a few threads about it and yes Im gonna try chainging out the t-stat this weekend with a dealership t-stat.

2000 XJ. 2 door, 4x4, I6, 260k miles.

Noticed late last week that my temp guage liked to dance a little. It would go up to 210 then start to bounce back and forth slowly. Go a little past the 210 mark then go back down below it a little and repeat. Checked my coolant level and it was fine. Looked at my overflow tank and noticed it was empty. So I filled it up to the full level with coolant and with on my way. Yesterday I checked it again and saw that the coolant level on the tank was at the "add" line. This morning I popped the hood and looked and it was well below the "add" line so I filled it up again.

I dont see any leaks and cant find any leaks. I dont have any power loss or white smoke coming out my exhaust (assuming a head gasket) like whats to be expected with that problem.

When I first picked the Jeep up a few weeks ago it did have a small leak in the radiator and I did put some of that stop leak stuff (forgot the name) in the radiator to stop it until I get a new radiator so the coolant is a little "dirty" and not green but it doesnt have the oily look to it like it is an oil mix.

Figure Id see if anyone current has had an issue like this or close to it plus any other insight would be helpful.

I did take a vid of the temp guage this morning that Ill try and upload tonight so you all can see.

fishtaconc

http://jeepsunlimited.com/forums/sho...d.php?t=391831

Required reading for '00-01 XJ owners, with your description, you pointing out the #1 symptom of a cracked head Unexplained Coolant Loss, as for the dancing gauge it could be a result of the former, or water pump failing, etc.

tjwalker

fishtaconc beat me to it. It always worries me when there is "unexplained coolant loss" on an 00-01, as that is often related to a cracked 0331 cylinder head. There is a known casting defect between cylinders 3-4 on that head.

Read the J.U thread that he linked to. I am a moderator on the J.U forum, and instead of detailing all of the specifics about the 0331 issue, it is much easier for you to read about it.

Good luck and post back what you find!

ullbsorry

I have read a little about the cracked head problem but it never really caught my attn b/c it has 260k miles. I figured that it would of been a problem way before this b/c of the mileage....maybe Im wrong.


ahhhhh...clicked the link and majority said it happened to them 100k+ miles. ***** fugger!

tjwalker

I'd follow the suggestions in that thread on how to "verify" if you indeed do have a cracked head.

Many times, you can visually see the cracks with a thorough inspection between cylinders 3 and 4. Some have been able to see the cracks right through the oil filler cap. Otherwise, pull the valve cover for the best look. Not seeing cracks visually doesn't rule out a crack as small cracks are obviously tougher to see, but it is what I recommend you try first.

Keep us posted on what you find.....

ullbsorry

I will. Im gonna shoot for popping the VC off this weekend and seeing if I can find anything along with changing out the t-stat tomorrow to see if that fixes any problems.

ullbsorry

i need to pop off the valve cover to be able to see the stamp for the casting right? along with the possible crack or etc....

fishtaconc

Casting # is visible with VC on, may have to clean grease/grime off. Take off the oil filler cap, shine a light down, look for crusty green or white residue. Like stated earlier, smaller cracks may not be visible just looking at it.

ullbsorry

well i do have the 0331 stamp but the coolant level hasnt gone down at all since I filled the tank a week ago. Im still going to replace the valve cover gasket this weekend and take a better look to see if i can see anything with the naked eye. dont have any milky residue under the oil cap or inside or signs of coolant in the head so far....

fishtaconc

The milky residue, can be misleading if your vehicle sits for extended periods of time or you only take short trips. An oil analysis is good way to determine if coolant is making its way into your oil. FWIW

ullbsorry

i just ordered a sample kit online and once i get it ill be sending it back in to be tested....JUST to make sure

tjwalker

Wise move.

I use Blackstone Labs for my oil analysis.

Good data = good decisions

In the meantime, keep an "eagle eye" on that coolant level.

ullbsorry

thats who i ordered the kit from. should get it in 1-2 weeks they said and i only pay the $25 when I send the kit back in to get tested.

ullbsorry

Well I popped off the valve cover and replaced the gasket along with the t-stat and gasket. Couldnt see any cracks with the naked eye and didnt see any visible signs off coolant or etc...

The previous week didnt show any signs of coolant loss through the overflow tank so idk...

The new t-stat keep the engine temp a tad below 210 and i noticed if im stopped or waiting for a light and start driving the temp drops a little...but never goes below the first line to the left of the 210 mark...but usually hovers right below the 210 mark...weird