how many miles on stock exhaust manifold before forced replacement?

[RonA]

I am curious to hear how many miles people have put on their stock exhaust manifold before it needed to be replaced. And if anyone has proof of performance or mileage gain from non-ported ATS manifold.

RonA

 

[Partyat33]

110 k plus with no signs of a problem



Dennis

 

[datablitz]

i've never heard of a exhaust manifold failing..... maybe the exhaust pipes/mufflers but never the manifold

 

[Forrest Nearing]

eventually, they'll shrink so much that they'll snap the bolts!



I think lifespan is shortened considerably by heat... my old 1st gen was barely turned up and with a few hundred thousand, it wasn't as shrunk as the one on my 2nd gen that's got quite a bit of fuel going through it w/ a little over 200k



Forrest

 

[KB0OU]

377,000 Just rolled over today, stock exhaust manifold.

 

[aggieLR]

My old man's '98 had around 120K when his cracked. I think it was where the front and rear meet, but I'm not positive. But now he has 200K and no problems since. I had 230K on a '93 back in school, and it was stock.

 

[Bob4x4]

Is that question for 12 or 24 v ? Two separate issues... ... ... ... ... crack or shrink.



Bob

 

[Doubleclutch]

12v manifolds shrink a lot when bombing, look at the front manifold bolt/port gap. My bolts were bent due to shrinkage. There are a lot of 24v engines with exhaust cracks at the center confluence. Look for soot tracks.

What about you '03 guys with miles and bombs... ?

Greg

 

[bmoeller]

12v manifolds shrink a lot when bombing

It doesn't have to be BOMBed, for it to shrink. Mine was starting to shrink before I bought my truck w/139k on it. Will probably have an ATS on it before the end of the year.

 

[Bob4x4]

I see a lot of 3rd gen trucks,no cracking issues yet,but I have upgraded about a dozen or so to the ATS manifolds... ... ..... I don't like the stock design with the siamesed passages on #4&5.



Bob

 

[kentdiesel]

At 86,000 miles the stock exhaust manifold on my 12V was bending the bolts on cylinders 1&6 . This was before any hp increases.



Kent

 

[Joe G.]

231K. It looks ok.

 

[willyslover]

115K and no sign of shrinking or cracking yet

 

[tile man]

98 24valve, 94000mi. crack at center, welded and has been fine since. 10600mi. and still ok.

 

[WDaniels]

184,000 and no problems for me either. I go from extream cold to extream hot and I figured that would cause problems. But I guess not.

WD

 

[1dslram]

I just worked on a truck with over 200,000 easy miles and the manifold looked new no shrinkage to be seen, I also have a customer that at 38,000 on a 98 12V I warned him about the manifold as it had shrunk a lot and now at 50,000 is about to break the head ears on the head, but he thinks all is OK. Some people ignore the obvious and worry about something that will never happen.

Bruce

 

[pwknapp]

Over 450k.

 

[DEickhoff]

86k and all is fine



dawna

 

[TMWeber]

Over 200,000 and going strong!