[4doorTAHOE6.5TD]

That is what I have at the cyl head to Turbo manifold on sig truck. This is a very hi mile engine & all the bolts are in place . I did not check for loosness though but appears to be on the top side as there is some exhaust particle coating there. Prevous to this I discovered a missing turbo cartridge bolt & replaced it & it was depositing exhaust particles also & could be what I'm observing.The engine looks like it is a hundred years old with the coating. : This leak is audible when accelerating thru the gears from low RPM & by open steth scope. It is not the crossover or headpipe as those are recent new Stans parts. Has never been apart. My question is are these manifolds prone to warping on a proper/fueling/ running engine ? If so can they be surfaced ? Are the bolts likely to be stuck & how, if so how do you get them out ? Any body have exact problem ? What was wrong & solution ? Thanks,Joe

 

[Scrufdog]

could just be a worn manifold to head gasket

 

[4doorTAHOE6.5TD]

I think your right, just a minute. OK, I just looked closely from the top & front. There is a double layer of thin metal coming up from the manifold & cyl head parting line. None like it on the LH side. so isuspect the external metal is a heat shield for the fuel return hoses & etc. in that area I suspect that is the gasket also. Is it double thickness between the manifold & cyl head also ? Do you know if it can be replaced with out taking the turbo mount exhaust manifold completely out. If not it will be an opportunity to drill & tap for the EGT sensor, HUH ? I will replace the Fuel return hoses and any thing brittle in the area also. Thanks a lot & tell me if I should be doing any thing other than what I mentioned.

 

[Senotext]

i dont know about on a diesel, but I have put many manifolds on gas engines, with cast iron heads and manifolds, without any gasket, my old boss showed me that, never had a problem, no gasket to go bad, but I dont know if that would work on a diesel with the higher exhaust pressure between the turbo and the manifolds.

 

[nickg]

I never put gaskets in mine when I rebuilt it as well, I learned the same thing years ago, with no gasket it cant burn thru. 40,000KMs and still no leaks!

 

[DavidPhillips]

Mine did not have a gasket on it from the factory.

 

[Senotext]

sounds like you should take the manifold off, I know it sucks, and make sure the head and the manifold are clean and slap it back together with the new blow proof gasket... none.

 

[4doorTAHOE6.5TD]

What about the EM/TM bolts?

Are they prone to being stuck? If you have expirence with this please inform me of your solutions. I have my 2000 6.5 engine on a stand to rob emergency parts from but no way do I want to be drilling / tapping out broken bolts . Thanks

 

[Senotext]

most of the time they dont break, i'm not saying they wont but just take it easy with them, if they feel tight, work the bolt in and out, loosen it a quarter turn then tighten it and keep lots of penetrating oil on the bolts, dont try to force them out or they will break, but sometimes they just come right out.

 

[4doorTAHOE6.5TD]

Well I have that general knowledge ,but I'm dealing with a 443k 10 year engine. I just replaced the original starter!!! Now this truck has less cycles on it than most will aquire in a 100.000 mi. as it was a fulltime trailer puller. It has no history of running hot so I don't expect to find changed composition of the bolts. I'm looking for 6.5 specific situation of someone having done this job. Can someone name a penetrating substance that can migrate up hill for the 8 bolts thru the exhaust manifold into the cyl head ? I have till Saturday to get it soaked. Thanks

 

[DavidPhillips]

No problem at all on mine.

Just screwed right out(unscrewed). I used PBlaster.

 

[4doorTAHOE6.5TD]

D. P. Was it necessary to use the penetrating chemical & were the bolts rusty ? Would you pls give me info on the name of the company, etc. so I can source the Pblaster. sp?.

 

[DavidPhillips]

I got it at Wal-Mart just sprayed it on the threads.

I probably could have used WD-40 as well but PBlaster is much better.

They look a lot worse than they actually are, I used an open end wrench on the drivers side except the drivers side rear I used a ratchet. They are not very tight.

Without anything they may be a bit more likely to give you a fight.

 

[4doorTAHOE6.5TD]

OK,Thanks DP. I put a rachet & socket on the front four & broke them loose dry. The rear four bolt & stud combo are obstructed by the down pipe so I'm going to leave them for the mechanic who is going to knock this out Saturday. I'm going to remove & replace the inner fender as it is damaged so it will be out of the way when this work is being done. I'm going to go with the gasket / heatshield as I will not put many future miles on it. Thank s every body for your help. Joe

 

[notbob]

Does the downpipe need to come off or anything else for this job?

As my passenger side manifold gasket is leaking as well

 

[DavidPhillips]

The down pipe gets in the way, but does not have to come off. You should be able to loosen all of the manifold bolts and change the gasket by just moving the manifold away from the head a little bit.

Mine does not use exhaust gaskets.

Easy to get at if the inner fender is removed.

Be careful with the glow plug wires.

 

[notbob]

Should I omit the gasket and just pull the old one out and retorque?

Is there a set torque spec on the exhaust manifold nuts or just crazy tight?

I'm guessing it'd be a good idea to do a new exhaust / downpipe at that time so can just get the downpipe out of there

 

[DavidPhillips]

You don't want the bolts very tight.

About 26 ft/lb on the right, and 25 ft/lb on the left.

Not sure about the gasket. I don't have gaskets on mine. I guess at some point they decided to put one in. If it came with one I'd put one in, if it did not I wouldn't.