Cometic Head Gasket

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bobscuda67

bobscuda67

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I got my car going after a taking it apart over the winter. I finally got to drive it for about 20 miles yesterday, after breaking in the new cam. It runs ok but it has a small coolant leak from the pass cylinder head by #8 cylinder, at least that's what it looks like. After I parked it, there was a small puddle of antifreeze under the car, 4 or 5 drops. I had the block and heads cut so I could use a Cometic head gasket. First time I used a MLS gasket and was wondering if it will seal itself after a few heat cycles or do I need to torque the heads again. I installed them dry after wiping them down with brake clean.
Looks like the oil filter adapter plate is leaking too, but that is another issue.
 
I would try the heat cycles first, I sprayed mine with copper coat gasketsealant just enough to turn them copper color and it worked great, hopefully yours will seal with heat cycle:D
 
By #8, are you sure it's the head gasket?

When you installed the exhaust did you seal the end bolts/studs? They do go into water.
 
Is this a 273? Mine had a porosity in the head casting near #8 plug. Coolant would just bead up and drip off the surface -- crack wasn't really visible to the naked eye. When I pulled the heads and took them to the shop, both showed a crack in the same region. One of these heads was a replacement for the original, which had been replaced because of a coolant leak in the same area. So I woud say that this is a problem endemic to these 920 heads. If sealing the stud doesn't do it, I'd look at it
 
I have magnum heads and the studs were installed with teflon tape. The drivers side head is leak free. I can't really see exactly where the coolant is coming out so I just assumed it was the head gasket. I plan on driving it tonight for a while so I'll see if it stops. Thanks for all the suggestions.
 
You might borrow a rad pump tool & pump it up to 15 lbs when hot to pinpoint where it's coming from. Speedway mtrs has a 6" long 1&3/4" metal hose extension for cheap and drill a hole in it & add a valve stem and a pair of junk rad hoses cut to length & sub it in for your top hose and air chuck pump it up to 15 lbs.
 
Rapid Robert said:
You might borrow a rad pump tool & pump it up to 15 lbs when hot to pinpoint where it's coming from. Speedway mtrs has a 6" long 1&3/4" metal hose extension for cheap and drill a hole in it & add a valve stem and a pair of junk rad hoses cut to length & sub it in for your top hose and air chuck pump it up to 15 lbs.
Click to expand...

Hey, I was just thinking about doing something like that. I drove the car Saturday for 40 miles and I had a bigger puddle of coolant under it. I noticed that my upper hose was really swollen when I parked it. I had to replace my radiator cap this year as the old one came apart. I bought a 16 pound stock style for a replacement. The new cap does not leak any coolant out of the overflow. But the car runs cool and doesn't overheat.
 
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