coolant gremlin

hey all

just finished swapping a new (to me) engine into my 1990 XJ. the donor was a 1990 MJ so the swap was pretty straight forward.

the engine has good idle and good oil psi, but even when sitting it weeps coolant. i have been tracing the leak and it seems to be coming from just above the freeze plug, maybe 1/4"-1/2" up, and it is leaking down around the freeze plug and down the block. its not actually coming from the freeze plug, and it doesnt seem to be coming from the head.

any ideas would be helpful

-Tim

Could be your head gasket has a slight leak.

Check the coolant in your radiator. If it appears at all muddy, your problem is definately your head gasket. Drive it as little as ppossible, if you have to. Fix it right away.

Sounds like a head gasket. It's pretty rare for one to leak externally, but it can happen.

hey guys,

i filled up the coolant again back to full and ran it, this time it was dripping pretty heavily (musta been almost drained before). i could see where it was coming from just above the freeze plug, i dont think its coming from the head gasket.... its a camera phone pic, but my phone takes pretty good pics. please lemme know what you think

you are looking at the 1st freeze plug to the top left is the exhaust header flange thing where it connects to the head

It looks like either your head gasket or intake manifold gasket. Either one means serious work.

I wouldn't run it any more.

Check you engine oil for water and your coolant for oil. Oil will rise to the top in the radiator, and your dipstick will show water on it.

pabloconrad said:

It looks like either your head gasket or intake manifold gasket. Either one means serious work.

I wouldn't run it any more.

Check you engine oil for water and your coolant for oil. Oil will rise to the top in the radiator, and your dipstick will show water on it.

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Well there's no coolant in the intake manifold so you can rule that out.

It looks like it's dripping down from your head gasket. (Or else you managed to crack your block)

Dave4.0 said:

Well there's no coolant in the intake manifold so you can rule that out.

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Not always. It can leak without going into the intake manifold. I've seen that a few times.

Dave4.0 said:

It looks like it's dripping down from your head gasket. (Or else you managed to crack your block)

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Sounds like a lot of work is in order so you can find it.

Dave4.0 said:

(Or else you managed to crack your block)

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would it be possible to weld the leak up assuming it is cracked, and that one was using proper cast iron welding techniques with the pre-heating and stuff?

Oizarod115 said:

would it be possible to weld the leak up assuming it is cracked, and that one was using proper cast iron welding techniques with the pre-heating and stuff?

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I'm not too sure. I know that if I had a cracked block, I'd want to figure out what made it crack in the first place.

Here's a picture of my head/ block to maybe give you a better idea where the leak might be coming from.

hey guys,

i was really thinking that i had a small crack in the block just above the freeze plug, but after removing the power steering bracket and looking closer, it really looks like it is coming from behind the exhaust header bolts, which indicated head gasket most likely.

few questions before i start

where do i get new head bolts?, how do i get the old ones out (are they studs?), why does god hate me?

-tim

Hold on, not to try to hijack, but over the summer my coolant was all brownish, and I had about an inch thick layer of gunk in my overflow bottle. My radiator is clogged and I drained it by pulling the bottom hose. I check it again after I refilled it and an offroad trip and it was brown again, I thought it was just because there was still some left in my block that was all disgusting. Does this mean I have a leaky head gasket on my '99?

God must hate all Tim's. I am doing one on my 91 right now. Not all that bad, just alot of nuts and bolts. Try NAPA for head bolts but I re-used mine as they were not painted. (can be used twice, no more) Oh and they are all bolts the ones on the driver side have threads above the bolt head but is not a nut.
Have a buddy help you put it back on it's heavy and make sure the rear driver side bolt is in the hole in the head before you put the head on. It wont go in after.
Good luck!:tears:

Begster. I think brown is rust 'cause oil in water usually is a milky white. Stick your finger in the top rad hose and see if there is any white thick gunk in there. Also check your oil and see if the same thing is in there. If either is, then most likely a head gasket.

A few other things, while you have the exhaust off and the head off I would recommend you pull the other freeze plugs and replace them with brass ones. Put a dab of indian head gasket cement around each plug just before you set them in. Use brass not steel. Remember to paint or mark those headbolts too once you reuse them.
As for begster, FLUSH THAT SYSTEM, you outta be ashamed
Now that winters pretty well over, drain it, refill with water, dump the 7 hour prestone flush in and drive it, don't even think about that 15 minute crap. Remember to turn your heat on hot and drive with it like that so the cleaner gets in the heater core too. The do the drain again, and refill and drain it a couple of more times to get all the cleaner out.
Don't forget to remove the overflow bottle and give that a good cleaning too.
Then do the 50/50 mix of prestone and DISTILLED water mix.
It might be a good time to replace the heater hoses too, remove the probably factory clamps then slice the hose with an exacto or razor knife lengthwise and peel off the hoses from the heater core bungs, don't pull it, break or crack one of those you you are going to cussing up a blue streak. I'd use dealer OEM hoses for this, they are already prebent and come with new clamps. While you have the hoses off take a garden hose and manually flush the core out [make sure the heater controls are on hot when you start so the core is open to the cooling system]. I use one of those twist type hose nozzles and alternate between the two two bungs. Don't connect and seal the garden hose in any way, remember the cooling system normally sits at ~17psi, your house water pressure could be as high as 60psi or more and you don't want to end up flushing your carpet or interior out by blowing up the core. Finish up by replacing the pressure cap with a new 17lb cap.

Thanks Rich, I flushed my radiator with a garden hose for a while last time, and I thought I had gotten most out. I was surprised to look in the overfill again and find it was brown again. I'll have to do that when I get home for summer. Now, how much is that going to cost me with the hoses and what not...

Begster said:

Thanks Rich, I flushed my radiator with a garden hose for a while last time, and I thought I had gotten most out. I was surprised to look in the overfill again and find it was brown again. I'll have to do that when I get home for summer. Now, how much is that going to cost me with the hoses and what not...

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I seem to remember the dealer OEM hoses will run about $20 for the two. Not real expensive considering they are not generic fit. When I did all three jeeps couple of summers ago I think all the hoses, 2 tj's and 1xj were under $75 and that included caps.