cherokee_99

Hey everyone,

I'm new to the community but have used the helpful information from the site in the past regarding other issues with my Jeep Cherokee.

A few weeks ago my wife was driving the cherokee and it overheated (all the way to 260) and she continue to drive it for about 5-6 miles before pulling over. She wasn't aware of the damage that could be done by doing this.

By the time she pulled over it was missing. I had it towed home since it wouldn't run right. I replaced the thermostat but believe the first issue was due to a cracked lower radiator hose. I replaced this as well.

After starting it back up, it was still missing so I assumed a head gasket had blown. This past week with the help of a friend, we got the head off and replaced head gaskets (it actually looked normal). We also took the head to a machine shop and it was actually warped a little (17/1000 inch). They found no cracks or anything like that and they fixed the warp.

The Haynes manual mentioned using a sealant on the gasket cover. We thought this sealant was the silicone liquid (high temp) and applied a very small amount to the gasket. It still missed when complete so we started thinking maybe the sealant wasn't supposed to be on there.

We then bought another head gasket, cleaned off the sealant from the head, and replaced the 2nd gasket. We still get a leak in the back cylinder and I'm wondering now if there's something wrong with the block or something deeper.

Anyone ever change head gaskets and still have cylinder leaks, even after taking the head to a machine shop? If the block is messed up, would it still leak?

By leak, I mean you can see water after removing the valve cover. You can see it where it's mixed with the oil after you run it a minute. It also misses and there was white smoke coming out of the tailpipe for the first few minutes after changing the head gasket the first time.

partsguyct

Did you use rtv on the head bolt threads?

EZEARL

+1 Some of those bolts go into the water jacket. But then again her driving it that much longer after it had overheated to that extent could mean some major damage. Here's HOPING for the best for ya.

cherokee_99

Thanks for the replies. No, we just torqued those head bolts according to the specs in the Haynes manual -- no sealant on them. We removed all the silicone sealant and put the new 2nd head gasket on as well so it still misses with the silicone sealant removed and a new head gasket.

I'm guessing at this point it's a bigger issue in the engine than the head gasket.

partsguyct

Like someone said the bolts go through a couple water jackets in the block if you pull them out again and put a little black rtv on the ends of the threads then reinstall and torque to factory specs you might solve your problem. What's the worst that can happen if you do it? Your out a few bucks and minimal labor time.

cherokee_99

Oh thanks for clearing it up..I thought you meant if I did that it wouldn't be good. I'll give that a try -- worth a shot!

EZEARL

Found this:

...here is the tightening sequence (start at 1 and work your way out)

front 12 8 4 1 5 9 13 rear
" 11 7 3 2 6 10 14 "

step 1...tighten all bolts to 22ft/lbs
step 2....tighten all bolts to 45 ft/lbs
step 3....recheck all bolts at 45ft/lbs
step 4...tighten all bolts except #11 to 110ft/lbs, then tighten #11 to 100ft/lbs...

Only #11 goes into the water jacket so should have sealant on it.

cherokee_99

Yea we got the torque specs from Haynes. We also put lock-tite on the bolt #11 as specified by the Haynes manual. I assume this is in place of the sealant mentioned in above posts, right? Lock-tite should be just as good as sealant for bolt #11?

We put nothing on the other bolts but I guess that's ok now b/c it looks like they don't go through water jackets?

partsguyct

I didn't use loctite when I did a head gasket on a 95 I just used rtv on all the bolts with no issues

cherokee_99

So if I put RTV on the bolts and it still misses and leaks, I assume it's something in the engine block? What all could mess up in the block itself? I just always assumed the head would be the thing that took the lick from something like this.

cherokee_99

One more thing to note -- I'm beginning to wonder if this could be the issue -- I reused the head bolts not knowing that this would be a problem. I've never done anything as large as a head gasket replacement but figured it was worth a shot since it wasn't working anyway.

Could the head bolts just be too old and stretched?

cherokee_99

Would a small leak like this in the head cause it to overheat like it's still doing? The thing still overheats. I assume it'd make it miss like this but would it cause an overheat?

The oil is milky looking when I take off the valve cover. Kinda frothy w/ bubbles. This is towards the rear of the valve cover most. Taking out the spark plugs though I see no coolant.

The jeep still overheats and has a miss.

I'm wondering if I should also mention that the heat in the car doesn't blow hot air....is this typical with coolant issues?

Kalali

The head bolts can only be used twice and the original factory install accounts for one. As for bolt #11, you need to use a thread sealer not thread locker. Also remember Loc-tite is a brand name and they make both. The first thing to check is see if your head is the 0331 casting. Some late '99 model year XJs came with that casting and I'm willing to bet your head cracked if you have that casting. Even with the older more reliable casting 0630 heads, given your extreme overheating and the current symptoms, you probably still cracked the head. Those cracks are sometimes very hard to detect even with magnafluxing and close inspection. If it were me I would take the head off again and have it checked again for cracks. You need to replace the head bolts anyway so might as well have it doublechecked for cracks by a competent shop and magnufluxing. And finally, I've never heard of using RTV on the head gaskets, at least on the newer XJs. Do it right and do it once. Good luck.

Turbo X_J

Apparently Autozone loans a cooling system pressure tester, go borrow it. Ensure the cooling system is full & install the tester & pump it up to 16 psi with the valve cover off. See what happens. I'll bet the head leaks like a sieve, as far as the miss, a serious overheat can take out a piston. What did the cylinders look like when you had the head off? In closing, nothing magic about the 0331 cylinder head, an engine can run for a day without oil, only a couple of minutes with no coolant.

OleBlue

if you have the 0331 head and overheated it that bad, you can pretty much guarantee a crack in it.