95 Gmc 6.5 no power

[Fordsandguns]

A friend of mine has a 95 GMC with the 6.5 in it. He just recently bought it. I'm not sure of the mileage. Starts easy, runs fine empty. He has a bumper pull TT that weighs less than 7,000, but he says it won't hit better that 60 on flat road. Less on hills. And it has a lot of clatter now, compared to when he bought it. Any ideas? Also the IP was supposed to have been replaced not long before he got it.

 

[chrisk1500]

SES codes?

 

[Fordsandguns]

He hasn't had any pulled. I don't have a scanner for this system. Would the average dealership be able to read them? I would think they would but you never know. I've heard of dealerships not being hot on touching diesels.

 

[chrisk1500]

The average joe-blow with a paperclip can read codes on a 95.....read about how on troublecodes.net

 

[Fordsandguns]

The average joe-blow with a paperclip can read codes on a 95.....read about how on troublecodes.net

Cool, thanks.

 

[Fordsandguns]

Should the wastegate be movable by hand on the 6.5? Running or not on his engine I could move the linkage for it. I found his clatter I think. It sounded like the vacuum pump is making all the extra noise. It takes a while to start doing it after truck is started. Other than that it sounds good. He has had the codes read and one was the electronic switch for the wg. At least that is what he understood they told him it was. It was replaced. I forget the other, but I believe he said it was fixed too.

 

[Matt C]

I'll bet the code for the WG was a 78. You should not be able to move the wastegate arm with the engine running. Take the vacuum line off, Does it have vaccum? If not go to the wastegate solenoid at the back of the intake on the drivers side, Is there vacuum there? If not check at the vaccum pump. My guess is the vacuum pump is shot since you said it rattles. With no vaccum the wastegate will not allow the motor to get boost, causing black smoke and no power.

You could either replace the vacuum system, or get gauges and a turbomaster and remove the vacuum pump.

 

[Fordsandguns]

Thanks for explaining how that system works, Matt. I'm gonna bet that vacuum pump is the cause. It was making a lot of racket. This is the first time I've looked under the hood of a 6.5. I like how they mounted the turbo to the side. I wish I could fabricate a setup like that for the Banks when I put it on on my 7.3. It might save having to have a special down pipe. Btw, What is a turbomaster? From the context I believe it controls the wg?

 

[chrisk1500]

Remove the vac pump completely and fab up a manual boost controller (or buy one from Heath if you don't know EXACTLY what you are doing)....cheaper to do this then to buy a vac pump...need to run a shorter belt (get one that ends in 010)

 

[Matt C]

Turbomaster is what Chris was explaining, a manual wastegate controller. Can be made fairly easily or bought.

 

[Fordsandguns]

Ok. So you just keep an eye on the boost yourself then? The pump was bad, but it wasn't the source of the noise. The crankshaft balancer was the cause of the noise. He is replacing both. Hopefully this will cure the problem.

 

[chrisk1500]

Need a boost gauge to watch the boost.....unless you buy Heath's turbomaster....

 

[Fordsandguns]

Ok, Carlton said he replaced the dampener and the pump. All seems to be well now. He hasn't put a load on it yet but he said there is definitely a difference in the way it pulls itself. I'd say we have it whipped. Thanks for the help guys.

 

[Matt C]

Thats good. Let us know when he hooks up to something.

 

[slideordie]

i was going to say the to check the vacuum pump but yall already beat me there. ive had to work on my step dads 95 k1500 with a 6.5. just like the others have suggested id do the manual boost controller. the wastegate these engines is controlled by vacuum unfortunately and when that pump goes u have no power at all and the pump makes all kinds of noise but i wish u luck and glad that he has it fixed.