Exhause Leak While Cold....

[Frozen001]

My truck has recently developed a small exhaust leak after the truck sits for a while.. ie when it is cold. It sound like possible a manifold leak, but I have not investigated it much. Any one else experience this?

 

Thanks,

 

Lou

KC2RVD

 

EDIT: Read the post on the Exhause manifold bolts... could be my problem.... How can I tell if this is it??

[Kodiak450]

Look at the bolt heads carefully, see if any are broke off. Look to see if any black deposit around manifold, the engine will make a clicking type sound when running. Also will intensify the longer it is not fixed. Look for cracks in manifolds "usually small in size". You could also experience worse mileage and slight loss of power depending on how bad it's leaking. Most common bols to break off are bolts next to firewall. In my case both sides. When excellerating you will hear a knockng type noise if they are leaking.

[Kodiak450]

Finally got my new manifold installed on DS. Only one bolt head was broke off but came out quickly with vise grips. The stock manifold uses two SS gaskets, so I had to get two new SS gaskets. Truck runs great now and sounds alot better! The revised bolts GM uses now have a little bigger head on them and are coated and have some type of lock tite already on the center of the bolt. Hopefully this will be the last time I will have to replace that side manifold again. Gonna get the PS done in a month or tow from now, one of the bolts head is broken off like the DS was. Gonna get the warranty to cover an entire new manifold like they did on DS. Only had to shell out $100.00 for new manifold. Gotta love those extended warranties!

[pennzoil29]

Exhaust leaks can drive you up the wall. I've developed one on my '99 5.7. It's really annoying.

[Frozen001]

Welll found atleast one broken one on the DS.... it is ofcource the one hear the firewall... looks like fun to get it apart....

[Kodiak450]

If you do decide to replace the manifold (That is if warranty will cover it) makes sure you have your mechanic order the revised set of manifold bolts. Sometime in 2004 GM revised the manifold bolts, the new ones have a slightly bigger bolt head and are coated and have this lock tite substance around center of bolts. You also need 2 SS gaskets that go with the manifold. Also make sure you get the manifold that has the SS cover on it, it should come with it. You most likely will also need 3 new bolts where they attach the manifold to the exhaust, mine wouldn't come out easy and needed to be replaced with new ones.

[swillia2]

has anyone done this thmslvs? How bad is it? I tink mine has just started leaking but looks like my bolts are still intact... Are you guys just having prob with the bolts or are the manifolds themslvs cracked?

[Kodiak450]

My manifold develpoed a crack in it, most likely after the bolts broke and the road salt in winter from plowing. When the bolts are broke off the manifold itself will not have a snug fit, therefor the temperatures fluctuating from cold to hott and so on, will most likely develope a crack in time in the manifold.