Any way to tell if manifold is warped or just gasket need replaced?

[endlink]

So I know I have a vac leak at the intake manifold on my 2000 yuk 5.3 when the motor is cold. I was wondering if I should order a whole new intake manifold or just the gaskets to replace? Any advice? FYI the truck has 107k easily driven miles in it.
Thanks,
- Ed

 

[bkboatnsleds]

Just do the gaskets.. very common problem on our motors.

be sure you get the METAL ones - they are an update version..

 

[ATL]

vac leak when cold, do u mean it sounds like it has a cam on cold start up? i need to do this myself

 

[endlink]

Just do the gaskets.. very common problem on our motors.

be sure you get the METAL ones - they are an update version..

Ok I'll give the gaskets a shot. I thought the one piece manifolds only have rubber gaskets?

vac leak when cold, do u mean it sounds like it has a cam on cold start up? i need to do this myself

Yes, violent shaking and random missfires until warmed up. Edit: also a little coolant consumption.

 

[Rivieraracing]

Have you tried spraying carb cleaner on and all around the base of the intake for air leaks while the truck is running? Does indeed sound like a bad gasket but that will tell you for sure!

 

[endlink]

Have you tried spraying carb cleaner on and all around the base of the intake for air leaks while the truck is running? Does indeed sound like a bad gasket but that will tell you for sure!

Yes, but that doesn't differentiate between a warped intake manifold or a bad gasket.

 

[Rivieraracing]

Yes, but that doesn't differentiate between a warped intake manifold or a bad gasket.

I was just telling you how to know for sure if it's even the intake at all (which sounds like you have already done that but since you didn't mention that procedure I thought I'd throw that out there!! ).

As for the warped intake, you can take a straight edge to the mounting surface of the intake and see if it's all evenly flat, but more than likely you have a bad gasket since that's a common problem with our trucks!

---------- Post added at 10:57 AM ---------- Previous post was at 10:54 AM ----------

Just noticed that you say there is some coolant consumption, have you checked your oil for any contamination?

 

[endlink]

I was just telling you how to know for sure if it's even the intake at all (which sounds like you have already done that but since you didn't mention that procedure I thought I'd throw that out there!! ).

As for the warped intake, you can take a straight edge to the mounting surface of the intake and see if it's all evenly flat, but more than likely you have a bad gasket since that's a common problem with our trucks!

---------- Post added at 10:57 AM ---------- Previous post was at 10:54 AM ----------

Just noticed that you say there is some coolant consumption, have you checked your oil for any contamination?

No contamination at this point.

 

[Rivieraracing]

No contamination at this point.

Well, that's good!!

 

[bkboatnsleds]

Well, that's good!!

But these motors have a dry intake... so there wouldnt be any coolant loss with a bad intake