Cracked Exhaust Manifold
 

Saturday night driving home I noticed a loud ticking noise only while I was accelerating. Turned out the driver's side stock ram type exhaust manifold is cracked almost completely around the base down tube section. Any thoughts on how or why this happened?

Re: Cracked Exhaust Manifold
 

Age would be my guess. I need to replace the passenger side on my K2500 for the same reason.

Re: Cracked Exhaust Manifold
 

It's a common issue.

Re: Cracked Exhaust Manifold
 

the constant heat and cool cycle over time will cause some of these to crack.
Vic

Re: Cracked Exhaust Manifold
 

yep, it's the heat. it sucks. good excuse for headers ;)
but, i'd just replace it (headers have enough of their own issues..) cast iron manifolds last a long time before they get to this point. unfortunately, they're all old by now!

Re: Cracked Exhaust Manifold
 

It's metal fatigue... age. Unfortunately Chinese cast iron sucks at this point. Let's hope the new ones last half as long as originals.

Re: Cracked Exhaust Manifold
 

That's why I didn't want to replace it with an old one, hope the new one lasts as long as the old ones did.

Re: Cracked Exhaust Manifold
 

I have had zero issues with my Dorman knock-off 2.5 inch center dump cast iron manifolds on my 4x4 Blazer. Its been about 10 years now. However, it should be noted that if you wrap your cast iron manifolds to reduce under hood temps or to just look cool, they will not be able to dissipate heat and will become very brittle very quickly. Ask me how I know!