Considering 2 pc. exhaust manifold... have some basic Q's...

[fkovalski]

I reading many threads on problems similar to what I am experiencing, I came across this topic: https://www.turbodieselregister.com/forums/showthread.php?244137-pinging-noise-from-front-passenger-area-turbo-wastegate



I checked mine and it does in fact have some leaking from the exhaust manifold. I do not know if this issue is the end-all to my drivability problems, but I am sure it is not helping. I need to have the gaskets changed and am considering going to a 2-piece manifold. But I have some reservations that I hope folks can chime in and answer some concerns:

• I assume that since the manifild is "2-piece" that the connection of the two parts is some sort of an "interference fit. " Is there the possibility that a leak can occur at this connection point?
  

• I assume that aftermarket 2-piece manifolds are more performance oriented when compared to a stock, factory manifold. I assume it will flow better as a result. I have a totally stock truck. Will the increased exhaust flow cause the turbo to spin up sooner? If so, will it cause an increase in overall boost pressure? I ask this because my truck has the plastic end caps on the intercooler and have read of issues on this type due to increased PSI.
  

• What parts should the shop include other than the gaskets and manifold? Is there a gasket where the turbo meets the manifold that should be replaced? ... Are there any other clamps, bolts or other hardware that should be standard as part of this R&R?
  

I am going to start spraying some Liquid Wrench on the exhaust studs to hope that it will help prevent anyone from breaking. Any other comments/ recommendations are appreciated.

 

[WCPoe]

The 2 piece manifolds just allow for better heat expansion. The OEM one piece over time tends to shrink and warp, sometimes breaking the studs.

On a stock truck you shouldn't notice any difference or any increased boost pressures. The two piece may spool a little quicker because they are more free flow oriented and are supposed to help with the temperatures on number 5 and 6 cylinders.

When I installed my BD 2 piece I did but new gaskets and I added a stud kit from Geno's which I used anti-seize on. Just a thought.

 

[jelag]

I installed a 2 piece manifold because my stock manifold was warped and broke the back two studs... . the broken studs were easy to remove... the exhaust leak around the joint sealed up in a couple of weeks... heat from expansion and later contraction sealed it up... . the ATS unit I purchased had a web cast into the manifold so that would hold it's shape better and it has worked well for 70K miles...

 

[WCPoe]

I forgot to add that due to the thermal expansion the "slip-joint" area where the 2 piece units join do not leak. At least mine never has. The joint is a precise taper fit and the thermal expansion as the manifold heats up keeps it sealed.
An added bonus is that the manifold is already tapped for 2 EGT probes, (at least my BD was).

 

[AMink]

Mine is a BD and was easy to install. No leak from the joint. Make sure the prove port brass plugs are in good. They will back out a little and I've had to snug them down a few times. I can't get the manifold to turbo joint to stop leaking. Used a new gasket (twice) and it still leaks. Also at the turbo/exhaust brake. I need a new v-clamp for that. As for added power it feels like the turbo spools a little quicker but nothing earth shaking.

 

[rscurtis]

The BD manifold is a slip fit- it can be assembled on the truck if that makes your life easier. Be sure you have all the hardware to connect the turbo to the manifold- when I did mine 4 years ago, that was an omission by BD that has allegedly been corrected by now. The supplied hardware would connect their manifold to the stock turbo, or their turbo to the stock manifold, but not their manifold to their turbo.

 

[Shadrach]

Parts you will need are:
6 exhaust manifold to head gaskets
1 turbo to exhaust manifold gasket
2 turbo to exhaust manifold studs - the other two are in the turbo
It's up to you if you want to replace the bolts that hold the manifold to the head but I recommend you use the long bolts and spacers on the new manifold as it helps dissipate the heat better
use a high temp anti seize compound on all threads

There are also some very good ONE piece after market manifolds. They are much stronger than the stock one and won't shrink or crack. I chose an AFE stainless steel one for my truck.
David

 

[AMink]

You may want to grab two manifold to turbo gaskets. They're cheap. My first one leaked. My second one also leaks. Maybe I should have got three! I don't know why they leak. I'm guessing either the BD manifold isn't flat or the turbo isn't flat. Either way, I'll live with the leak. You may also want to get a new v-clamp for the turbo to exhaust brake if you have an eb. Mine leaks there too and I read somewhere the v-clamps are one time only.

 

[AMink]

So, here we are several years later and I STILL have the leak around the manifold/turbo interface. I think I'm on my 5th gasket and the last two were put in by a reputable shop. Unfortunately they didn't check their work last week so it goes in again. To top it off the manifold is now leaking at the joint. I don't know if this is because it's cold or if time warps all things. Between the suspension pops that are addressed in a different thread and this I'm getting ready to start walking. I get a wicked cicada-sounding noise under load that I hope is just the gasket vibrating since most everything else that goes around on the front of the engine has been replaced.

 

[Tuesdak]

They need to check the turbo and manifold for flatness. Like they do for cylinder heads and the block. Something is off causing it not to seal up.

 

[AMink]

They need to check the turbo and manifold for flatness. Like they do for cylinder heads and the block. Something is off causing it not to seal up.

Since the manifold itself was also leaking at the slip joint I contacted BD. The rep there gave me his info and I went to Summit Racing. Summit was able to provide a good price break on a new one since the one I have is out of warranty. Great service by both BD and Summit. Hopefully this will address both leaks since I don't know what you'd do with the slip joint leak other than replace. $$$$ 150K on the truck, lot's of towing. I need to get gauges to see if I'm getting too hot. You'd think there would be some type of fail-safe built in to not allow it to get too hot if that's actually what happened. I love my truck I love my truck I love my truck...