Leaking valve covers causing exhaust leaks?

[cramezl]

I had a decent exhaust leak from my passenger side manifold that was there when I bought the truck. Dropped by the parts store and got new gaskets and swapped them out real quick. No leak all the way home and then back to the restaurant to eat supper. When we went out to leave, I can hear a little bit of a leak. They lasted about 3 hours. Both of my valve covers are leaking. Will the oil cause my exhaust manifold gaskets to leak prematurely? I'm planning on fixing the valve covers this weekend.

 

[Tyger13us]

I had a decent exhaust leak from my passenger side manifold that was there when I bought the truck. Dropped by the parts store and got new gaskets and swapped them out real quick. No leak all the way home and then back to the restaurant to eat supper. When we went out to leave, I can hear a little bit of a leak. They lasted about 3 hours. Both of my valve covers are leaking. Will the oil cause my exhaust manifold gaskets to leak prematurely? I'm planning on fixing the valve covers this weekend.

I never use gaskets for exhaust "cast iron manifolds" to heads...they usually always leak...

with headers i use the ole fashioned tin coated OEM,, but i double them up with the tin on the out side of both,materiel facing each other, that is a good header trick without paying big bucks for b.s. header gaskets.........

 

[cramezl]

So you just metal on metal with cast iron manifolds?

 

[skysurfer]

Valve cover leaks have no affect on the exhaust manifolds. It's common to have to retighten the exhaust bolts after the new gaskets have gone through a couple of heat/cool cycles.

 

[cramezl]

Valve cover leaks have no affect on the exhaust manifolds. It's common to have to retighten the exhaust bolts after the new gaskets have gone through a couple of heat/cool cycles.

Thanks. I'll crank on them and see if that helps.

 

[Tyger13us]

So you just metal on metal with cast iron manifolds?

yup,, just make sure the surfaces are clean/ no left over gasket crap,, then torque um to 35 ft lbs and they will never leak..... unless there cracked someplace...... ive seen that also.......

i and many gave up on gaskets for cast iron to cast ion long time ago.....

if they are aluminum head? ehhhh, some say yes some say no...

i still would bolt um up without,, i figure a leak will try and torch a grove in the head where the gasket is ******......

 

[cramezl]

Hey I'll give it a shot. I've never had good luck with those gaskets anyway. Used to have a 92 Blazer with a 350 and it leaked all the time.

 

[MrMarty51]

Clean them surfaces up real good.
Use a sanding block with 80 grit to remove any excess material, carbon, old gasket and whatever else might be stuck toum.