Truck is a 2003 with 147,000

The last few days I have noticed blue/white smoke coming from under the hood area on a cold start. It appears to be on the driver side but cant quite pin point it. It only smokes for a very short period of time (5-10 seconds) and only when it is cold and I dont let my glow plugs run the full cycle. (I do have the glow plug LED so I know when the relay shuts off).

It seems after research that up pipes are prone to failure but what are the odds its a manifold gasket or that the manifold is cracked?? What should I be looking for to pin point the problem before I tear into it??

This is currently my DD (since im in the process of rebuilding the motor on my regular DD!! ), so little down time as possible would be great!!

 

KH85, It sounds like an exhaust leak from the up-pipes.

Have the manifolds been off in the past? If the manifolds haven't been removed in the past there shouldn't be any gaskets. (some add them later if the manifolds warp after removal.)

Do you hear a clicking or tapping sound when you're accelerating? Do you have soot around the firewall between the up pipes and manifolds?

I had a bad exhaust leak and had to do the up pipes.

The soot wasn't that bad imo but the up pipes were so loose they fell off the collector when I removed my turbo.

 

As far as I know the manifolds have never been off. I have only owned it since 120k. I havent noticed any noises out of the norm when driving it as far as popping or clicking type exhaust leak noises go. And I can not see any soot on the firewall either.

Other than the smoke from under the hood on a cold start everything seems to be working just fine. Havent lost any boost or anything like that either.

 

It doesn't sound so much like an exhaust leak now with the additional info.

I'm guessing here but have you checked your intercooler hoses and clamps. Maybe some leak on the IC side and it's showing up under the hood when you first start the truck on cold days?

 

I'll give my advice on the subject. The reason it's leaking when cold but acts fine when warm is simple.

The gasket on your uppipe is bad. But not totally blown. So when the metal is cold it shrinks and on start up allows exhaust thru. Then the metal warms up and expands and seals.

You will be find for the moment, but I would recommend that Uppipes go on your to do list.

 

I'd recommend building an exhaust leak tester. I'm doing one this weekend if my plans go right. I'm going to use a rubber union to fit over the tailpipe, a PVC cap in the other end of the union, drilled and tapped with an air chuck so I can add regulated pressure from a compressor. Add about 10 psi, and listen and feel for leaks. I'm going to check it cold, then check it again hot.

There's also a similar boost leak tester that goes in the intake tube.

 

I have been thinking about building an exhaust leak tester too. I'm getting between 15-17 psi max with out a load. Most often I'm seeing between 5-10 psi at normal acceleration.

In case anyone is interested, here is a video on how to build one.

 

Good ole Spooner pulling through with another great how to.

 

Yeah, Trey does great work.
Good luck on the exhaust checker. Wish I was still at the dealer I worked at, we had a smoke detector for finding fuel vent leaks around the tank area. Used veg oil. Maybe cap the tailpipe after throwing a smoke bomb in the pipe??
I can hear a light ticking still, but no soot since I did the drivers side manifold. Probably moved the up pipe! Another reason to do bellows.

 

Well, still worth it to build the leak detector, but I don't think you are too far off on the boost, if it's stock. Try taking the red line off and see what happens.

 

lol Nah stick a tator in there and fire her up... then wait a few mins.... or in some cases an watermelon for those really large exhaust guys....lol


p.s. this is a joke

 

https://www.google.com/shopping/prod...#hsec:overview

 

Smoke in a Can? I was also thinking about something that would fit into the pyro hole? Hmm.

 

Thanks for the replys guys. Does sound like it is my up pipes, I dont think its an IC boot. I looked at them an see no signs of soot or loose connections and have not lost any boost.

So now the question is.....do I just replace the gaskets on the up pipes or replace them all together, maybe bellowed up pipes??

 

Bellowed. I've questioned all the others, trying to pinch a penny, but as soon as I can afford it, bellowed it is.

The best is International ceramic coated (riffraff in my sig) and then the non ceramic coated is a little cheaper. Dorman makes the bellowed now for less than 200, but quality has been in question. There are a few threads on it.