weaping head

[lotharamc]

My 92 R/T is slowly loosing coolant from near the power steering pump.

I don't have a problem with doing the head gasket, but I don't want to take the engine out to clean up the surface. I rebuilt the engine 2 years ago, and did all the block work at home, so the surface probably isn't perfect.

What do you guys do to ensure sealing, when leaving the block in the car?
Any special prep work?

Cometic better than felpro? Copper coating?

Andy

[lotashelbys]

Well,if you dont want to deck the block I would just get it as flat as you can with a block and use a Mopar TIII HG with copper spray on that. I would get the head machined at least tho....

[rc91 Spirit R/T]

Unless you had the head milled, it's probably the head that is causing the leak at the front near the power steering pump. My car showed a leak there when I pulled the head gasket and had rusted out that corner head bolt. I never noticed any external leak from there. Just pull the head, measure with a steel ruler and see if the block or the head is flat. They you can decide how much you want to do from there. It turned out to be the head on mine, which is more likely to warp than a iron block.

Copper spray with a Cometic head gasket and ARP studs here, pretty much the norm for most TIIIs now.

[xtrempickup]

+1 on Cometic headgasket and copper gasket sealer

[lotharamc]

OK, I'm thinking I'll go with the cometic and copper.

Just some more info: When I rebuilt 2 years ago the head was a "new" one from FWD. So at least that was flat when it went on. It started leaking about a month after I got it running again. So, I'm thinking the block isn't quite flat.

Andy

[mopar2ya]

VERY IMPORTANT! When using the COmetic the head has to be surfaced to a RA25 or smoother. I would just scotch bright the block to make sure its clean and dry if your not going to deck it. Dont use anything grittier than 400 if you block it. ARP studs are a good addition.

[LowSL2]

Quote:

Originally Posted by mopar2ya VERY IMPORTANT! When using the COmetic the head has to be surfaced to a RA25 or smoother. I would just scotch bright the block to make sure its clean and dry if your not going to deck it. Dont use anything grittier than 400 if you block it. ARP studs are a good addition.

So if the block is nice and flat I could get away with doing a usual block sanding to smooth it out? Like when you wet sand when polishing something? I've done this with Saturn engines but those are a different animal than TD's.

How about the head?

(I can see it now, someone is going to wet sand their block and then use an orbital polisher to get a mirror shine. Haha.)

[mopar2ya]

The smoother the better. Id use a marker and color the top of the block and use a sanding block and lightly sand it to find any low spots, if you find one Id use a straight edge and feeler gauge and check it. Then switch to like a 800 and block it some more. Just like wet sanding.

As to the head take it to a shop and have it surfaced to RA25 or smoother. Its cheap enough to have done and you know its flat.

[rc91 Spirit R/T]

If you do get the head milled, make sure to plug that pesky 5/16" oil plug on the deck of the head with a small bolt. There is an oil galley behind the plug and it is known to leak oil; the area is not covered by the stock or Cometic head gasket. Hopefully the head was already properly plugged. You can search other posts on the details.

Actually, after rereading your post, there is a coolant line on the back of the engine near the powersteering pump that could be leaking. Much easier to change than the head gasket. Pop the air cleaner off along with it's base and you can get a look at it.

[lotashelbys]

Quote:

Originally Posted by rc91 Spirit R/T If you do get the head milled, make sure to plug that pesky 5/16" oil plug on the deck of the head with a small bolt. There is an oil galley behind the plug and it is known to leak oil; the area is not covered by the stock or Cometic head gasket. Hopefully the head was already properly plugged. You can search other posts on the details.

Actually if you go with the Cometic you dont have to plug that hole if you dont want to. That was a good fix when using a stock composite gasket that over time cold break down and start leaking there. A Cometic,being a steel gasket,wont have that problem.

Andy
If I were you I would really think about getting the block decked if you go with a Cometic. You will have alot better luck getting it to seal up. I have Cometics on three of my TIIIs and only two of them have been decked and milled and niether of those leak at all and the one that only had the head milled actually dont seal up 100%. What mods and how much boost do you plan on running?

[lotharamc]

I'm not looking to modify it too much.... Yet. For the forseeable future, it will just have a G valve set for 12-14 psi. Otherwise the previous owner did 2.5 exhaust out the back with no cat, and a K&N drop in filter.

I know it isn't the water return line on the back/side of the block.

I'm driving the car daily now, so when I do this it will be as quick as I can. I will check both surfaces incase one is really wavy. What I'm hoping for is a relatively flat head (because the amount of leaking hasn't changed since I put it on), and a block surface I can sand....smooth enough. Then use the MP gasket with copper spray. I think the composite gasket would do better with a surface that isn't perfect.

Anyway, thats just what I'm expecting/hoping for. I find out whats the real deal when I get it apart.

Thanks All