Coolant leak @ #11 head bolt

See this video I took. You can clearly see the leak when I rev it up. I've sealed the heck out of the bolt using permatex high temp thread sealant. Why would this just keep leaking?

https://youtu.be/4dTl6PHEy4w

Are you getting the threads clean and dry?
Are you letting it cure?

They are as clean as I could get them. It was leaking, so I gooped the HECK out of the bolt (after the first application failed). The permatex seems to cure when heated. I let it sit for 24 hours and the white part that squeezed out around the bolt head was still a little gooey. It dry now. I cleaned the bolt threads really well before I put it back in.

This leak is bad enough that on a warm day, i'll lose enough coolant to drain my overflow tank and need more in the radiator.

CarComp said:

the white part that squeezed out around the bolt head was still a little gooey.

Click to expand...

That doesn't make sense, the sealant has to be on the threads! The block should be drained and the threads in the block should be "clean and dry". Permatex advertises 72hrs to properly cure.

This is really strange. Some years ago I had a mechanic do a cylinder head job on my Jeep and when I had to pull it off years ago I didn't even see that he used sealer on that bolt and I never had any problems.

The sealer goes on the threads. Basically you just make a line down the bolt threads with the thread sealer and that's all you need. Loctite / Permatex 592 "high temp thread sealer"

Where exactly did you put the sealer?

If you packed the cavity with it, oh, I bet you trashed your head gasket.

I know the sealer goes on the threads. I used so much sealer on the threads, some of it scraped off when i put the bolt in the hole.

I want to update this thread...

When I take the torque off the bolt, the leak is dramatically reduced. I have had the bolt at 60 ft/lbs and the leak is manageable... I understand that isn't the rated torque, but we're using it as a grocery getter right now, so it should be fine until I can fix it permanently. At least its no longer dripping on the ground, but it still bugs me that its leaking. You can smell it.

Its a 0630 head, junkyard pull, and i also installed it myself with a new felpro "Print-O-Seal" gasket, new head bolts.

Why would loosening the bolt cause it to stop leaking? Also, if i torque to 100 ft/lbs, it SPRAYS OUT when I rev it. If I back the torque off to 60 or so, it just dribbles ever so slowly when I rev it, like in the video.

I've also tried to use different types of RTV, I've cleaned the bolt. I've tried installing it without coolant, and with coolant. I've tried using an old / different bolt. I've tried using RIDICULOUS amounts of sealant.

The only thing I haven't done is buy a boiler brush and clean the threads in the block out real good. But how in the heck is coolant getting out from between the head and block, especially when its torqued TIGHTER? So weird.

Sounds like a cracked head.

A manageable leak, no such thing! It could a lot of things, but it sounds like you need to start again with a new head gasket. Besides draining the block, I always chase the threads and make sure they are clean and dry. You want to coat the threads in the block before installing the gasket(making sure no compound is on the head surface). Place the compound on the bolt threads evenly and let it cure after it's been torqued!

It looks like it's leaking from that lower exhaust manifold attach stud. The threaded hole for that stud goes into the passage for #11 bolt. The leak is probably coming from there.

That nut/stud does not look like the OEM configuration. Someone may have replaced the OEM stud with an off the shelf stud. In any case, you should remove that stud and apply sealant to it.

That is a good idea. For some reason I thought the stud went into the #11 bolt hole.. like this...

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But what you are saying is it goes into the water jacket in the head? I could probably get that stud out of there without removing everything. I do know that the head I took off and the head I pulled had that same stud on it. There is one at each end, somewhat like they are there so you have something to perch the intake / exhaust on while you put in all the bolts.

I suppose it would help to mention its a 1998. I think earlier models used a bolt there.

md21722 said:

This is really strange. Some years ago I had a mechanic do a cylinder head job on my Jeep and when I had to pull it off years ago I didn't even see that he used sealer on that bolt and I never had any problems.

The sealer goes on the threads. Basically you just make a line down the bolt threads with the thread sealer and that's all you need. Loctite / Permatex 592 "high temp thread sealer"

Where exactly did you put the sealer?

If you packed the cavity with it, oh, I bet you trashed your head gasket.

Click to expand...

I first just put it on the bolt threads. I used a enough to cover all of them. Also, i'll note that when I pulled the bolt out, the white sealant was all black and crumbly, like it had been contaminated.

The exhaust stud is drilled into the #11 head bolt hole, but the water is only stopped from getting in there by the threads in the block.

Facepalm.

I put the old head gasket on. Found the new one in the garage in the box still. How the heck I did that I have no idea. I don't remember putting a dirty looking gasket on, but somehow its on there. In fact I don't remember ever removing the gasket from the engine. I mean, wouldn't that explain the pinhole leak? The used gasket has been crushed there before obviously, and now it can't conform to the new head.

Its probably leaking through the head gasket from the coolant passage, and just happens to be right there by the #11 head bolt, or its just not sealing right for some other reason.

Thank god its a pushrod engine. I can have the head off in an hour. For some reason it usually takes 2 to 3 to get it back on though. I think being tired plays into it. You start dropping things a lot more.


Edit: I might just try a tablespoon of bars leak, until i can pull it all apart again. Winter is coming up, and i don't want to risk making the vehicle un-driveable if it decides to be nasty.

Warped or cracked head if the gasket isn't bad.

Sounds to me like you block is cracked, not the head.

How you used a used gasket is beyond me.............

Jeep Driver said:

Sounds to me like you block is cracked, not the head.

How you used a used gasket is beyond me.............

Click to expand...

I actually chuckled out loud at what you said. Ya I'm honestly pretty good at fixing things. Must be getting old. In a strange twist of events, the tablespoon (roughly eyeballed) of whatever is in alumapro radiator stop leak (brown dust) has not only plugged the leak, but cured the misfire...

Whaaaaaaaaaaaaa? Yes, it sounded like it had a cam. Now it just purrs and there is no slight shake at idle.

I might have cracked the block. It was overheated to the point that the piston melted and galled over a ring. On the interstate. I lost all coolant in the radiator from the bottom, so there was no warning before it started total meltdown. The #1 cylinder valves got so hot they warped out of round.

It has all new Pistons, rings, rod bearings, water pump, haha, and a new intake gasket at least.

Idk. It's like the one time I use stop leak to temp fix a tiny problem, it fixed a major one. Go figure.

You put all that work into your XJ and now don't want to fix it????
I would never use a stop leak product on a new motor!

I've removed the head like 3 times now maybe 4, each time its been something else.

Started off not knowing anything about this engine. I have worked mostly on DOHC V6 engines, and I'm used to all aluminum everything.

I replaced the head gasket originally thinking it was blown after overheating.. Cross flow between cyl 1 and 2. Replaced the head gasket. After reinstalling the head, still had low compression on cyl #1. Removed the head again. That's when I noticed a tiny booger on the side of piston 1. Turned out to be galled badly. Removed the piston and found destroyed rings. All new pistons and rings. Reinstalled the head. Still low compression cyl #1. Removed the head again and found that I had a burnt warped valve in cyl #1. Thats when I learned to test the valve seals using kerosene and watch for leaks. Grabbed a head from the junkyard, did a good lap job on the valves, and seal was tight on. Reinstalled the head. Ran pretty good, but you could tell one of the cylinders was not working as hard as the rest, some of the time. I chalked it up to one of the valves was rotating and sometimes it sealed good, and sometimes it didn't. I expected as much from a $50 u-pull-it head.

Then it started leaking. After trying again and again to seal the #11 head bolt, and going through bottle after bottle of coolant, at that point I was like to hell with it.

Oh, and new water pump, thermostat radiator, thermostat, A/C system vac/fill, new tires, repaired the broken sending unit. I'm just done. If a little crap in the system takes it to 'hardly anything seems wrong' at this point, so be it.

I've gone from barely runs, no heat, unreliable to I've driven it to towns hours away to doctor appointments and I trust it to do what it needs to do.

The 4 wheel drive system seems to be the most robust components on the thing.

Now it needs new shocks, new front wheel bearings, new front brakes, new front rotors, upper and lower ball joints, tie rod ends, new rear wheel bearings, new head liner, console fixed, A/C drain leak fixed, door lock actuators fixed, rear lift gate window pistons, probably a new turn signal bulb (it works only sometimes), replace the transmission filter and fluid, replace the fluid on both differentials, fix the flickering dash lights,.

Ya... i'm not too worried about a tablespoon of leak fix. :roflmao: