whatcha think? This is after it sat for 2 days, I let it idle for 15 mins...It has had a slow coolant leak for ehh...5 years now or so

recently though, the coolant seems to be lost fast. But I only drive it occasionally now, and its colder here. Oil has no water in it when I change da oil.

cleaned all the gunk, ran it again, all perfectly clean.

 

I see a dirty dipstick and aerated oil on the cap due to condensation.

Amiwrongorwhut?

 

Functioning crankcase ventilation, along with modern, (high detergent) oil, seems to about eliminate sludge buildup. Also water vapor is vented out. One large tube from the VC should be free to vent to the air cleaner, then the other smaller with the CCV orifice goes to the intake manifold.

"back in the day", I've seen valve covers completely full of sludge with just space where the rockers kept it mashed back.

 

areyourightorwhut? amirite?

No I figured that...I just cannot figure out this coolant loss deal.

 

Do you mean abnormal fluctuation in the coolant reservoir bottle? Or are you actually losing coolant?

 

actually losing coolant. Compression is good, plugs are clean, no oil/bubbles in coolant, no sweet/white exhaust, normal mpg's, no knocks or ticks, clean oil. I havent pressure checked the system, but there are no visible leaks. Its been a problem for 5 years now...I keep up with it well, but now im ready to finally bite the bullet and stop this. I dont really drive it much anymore so I can afford the ability to tear into it. Should I pull the head? I can, but I dont want to unless I need to!

 

Yeah the oil cap is from not driving it long enough.The lose of coolant could be a lot of things.Are you sure you have no leaks in the coolant system?

 

Drive it around for a while and when you park, shut it off, pop your hood and look for a pinhole leak. It may only happen when then motor is hot so look while its hot. Look for steam or wet spots.

 

That's a '00? Unexplained loss of coolant? Milk looking crap on your oil filler cap? What is the oil pressure at a very hot idle? Sounds like all the symptoms of a cracked 0331 head.

 

Didn't catch the year. If so, I would say cracked head as well. Common problem with the 00-01 xj

 

Cracked head. Search the board and find all you never wanted to know about the 0331 head.

The coolant is probably going into your oil and out through your tail pipe. You can't see it in the oil because the detergents in motor oil have gotten so good now that the oil doesn't get cloudy like it used to. You can verify it by taking an oil sample (when the engine has been driven for about 20 minutes) and sending it off to Blackstone for analysis for $28.

If you're at the point where coolant is disappearing rapidly, you may be able to actually see the crack by shining a light down into the oil filler hole. They crack between the #3 and #4 cylinder. Sometimes you can see coolant weeping up from the crack.

Don't let this go. As soon as you have coolant in your oil, you're doing damage to the bearings. You can get a replacement head from Clearwater Cylinder Heads for under $500. If you wait until you start having oil pressure problems, you'll be pulling the whole motor instead.

 

Having the problem for 5 years without bearing damage seems highly unlikely to me. It all sounds very suspicious regardless.

 

yeah i agree with you on this. If I were losing coolant, at any rate, into the oil for 5+ years...there would be bottom end damage...I just changed my oil today and have a magnetic plug, nothing of concern. Cannot see a crack through the oil fill hole, I've been looking for one since I bought it!!!

I work at lab, I could have them analyze my oil for water, but Im confident theres none in there. I've put over 80k miles on this engine in 5 years and its never missed a beat, aside from the occasional heat soak miss

I suspect its going out through my exhaust somewhere and causing no damage to the engine. I have boiled this engine over once and the problem existed before and after that, no change. Do you think sealant would be a good idea or bad idea?

180k miles on the motor, body is "great" shape!

edit: oil pressure is 15-16 psi at hot idle on both dash and mechanical gauge.

 

That's awful low... I'm pretty new and all but I feel like this is another clue leading toward a cracked head.

If you're talking about Bars Leaks or something like that, the main complaint I've heard is that it tends to clog the oil ports themselves and creates a bigger problem. That, or it works and you drive it for another 100k.

 

Note, I have a F250 that's had a cracked head for... about five years now. Still runs fine, you just have to feed it coolant constantly and eye the hell out of the temperature gauge. Dipstick even comes up clean.