Diesel question!! maybe... ;-/

[tj98gmc]

Hey guys.. im still having problems with the boost in my 6.5l... sometimes it works but most of the time it dont.. (the turbo doesnt always spool) ive changed the wastegate soileniod 4 times with brand new ones from GM..they usually work fir a couple of days they slow quit... So now im guessing its the vaccum pump.. but i noticed that its been getting wet on top of the intake.. so im guessing i need to change this gasket... do you think that this is where my boost problem is?? Here is a pic..

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[95chev]

Hey guys.. im still having problems with the boost in my 6.5l... sometimes it works but most of the time it dont.. (the turbo doesnt always spool) ive changed the wastegate soileniod 4 times with brand new ones from GM..they usually work fir a couple of days they slow quit... So now im guessing its the vaccum pump.. but i noticed that its been getting wet on top of the intake.. so im guessing i need to change this gasket... do you think that this is where my boost problem is?? Here is a pic..

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If Your intake gasket is leaking, which is what appears to be happening in that picture then you are most definitely loosing some of your boost pressure there.

 

[great white]

There should be no oil in that area. Gasket is very likely bad or going.

However, changing the solenoid and getting boost then having it slowly fail would have nothing to do with the gasket.

Test your vacuum pump. It should pull somewhere around 20 in/hg.

Test your vacuum pot on the turbo with something like a mightvac. It should pull vacuum, stay closed and not bleed off until you release the pump bleed.

Check your vacuum lines for cracking and splits. I see a big goof of silicone on your vacuum lines which makes me suspicious of them. The plastic lines are great until the get old. They can become brittle and crack over time and need replacement.

I see your engine is an L65, so no egr gaskets to work about down inside the intake.

There's not much more left in the system.

You also have the option of a mechanical wastegate control. Basically, it's set by spring pressure and does away with all the vacuum and computer controls. Heath diesel sells them or you can google for a DIY solution.

Personally, I prefer a well tuned vacuum system. But spring wastegates work fine also.

 

[tj98gmc]

If Your intake gasket is leaking, which is what appears to be happening in that picture then you are most definitely loosing some of your boost pressure there.

Thats what i figured.... i guess i just needed someone elses opinion... im going to replace the gasket and go from there... maybe check to see if there are any other vacuum leaks while im at it... thanks gor your input!!!

 

[tj98gmc]

Thanks great white for all of the info!! I thought about doing a turbo master... but $119i just seems so much for all that it is... i am going to go out and do all the checks and see if i can figure this thing out today...

 

[tanman_2006]

you should be able to order new Vac Lines if you need them. With that much oil leaking out of the gasket I would think of adding a CDR to my list of parts.

 

[great white]

you should be able to order new Vac Lines if you need them. With that much oil leaking out of the gasket I would think of adding a CDR to my list of parts.

Nah, 99% of the time that much oil in the intake is indicative of a worn engine or one with a lot of miles on it.

Changing the CDR is just a waste of 50 bucks in that case. Very little to go wrong with a CDR anyways except "gumming up", which also indicates a worn or high mileage engine.

The CDR gets blamed far too much on these engines for oil problems.

Contrary to popular opinion, that much oil indicates it's being blown out not sucked out.

Mine for example: it barfed oil like no tomorrow with the old engine. CDR was blamed by several "experts".

Then, the engine popped.

New engine in, same CDR, no more oil barfing. Clean as a whistle.

Once you get up around 200-300,000 on a 6.5, it's going to have excessive blowby and that's where the oil comes from.

Whether it still runs good or not....

 

[tanman_2006]

Good thing I never spent money on a CDR lol. Not sure how many miles are his truck but I've never seen that much oil on any of my trucks.

 

[great white]

Good thing I never spent money on a CDR lol. Not sure how many miles are his truck but I've never seen that much oil on any of my trucks.

Oil blowing out there would be a cumulative thing. Mix in some dirt and road grime and voila;

Instant mess.

 

[tj98gmc]

**Update** problem solved

I ended up taking the top of the intake apart and cleaning it up.. i put some rvt silicon on it and put it all back together... i them checked all the vacuum lines and i couldnt find any issues.. i then playing with the soleniod a little and noticed that as i wiggled it, it would work and then stop and then work again... i played with the wires to that plug and the pink one broke off... i cut that plug off and put on a new one.. the truck has been running great since yesterday...

Tha ks everyone for your info and help!!