[muddstopper]

My 6.5 td is sick, sick, sick. Low on power and blowing black smoke. I read the faq's section but want to make sure I haven't missed anything before I purchase a new vacuum pump.

I haven't really diagnosed anything, just haven't had the time, but heres what I have checked. Wastegate actuator seems to be free but no vacuum at this point. I checked the wastgate solenoid fuse and have power at the solenoid, verified by volt meter at solenoid. I checked vacuum from solenoid, no guage, but no noticeable suction either. I Checked for vacuum going to solenoid and no noticeable suction here either. I also decided to tie a string to the wastegate actuator and pull it open. I was driving the truck loaded and about to pull a long grade and decided that maybe manually working the wastegate might help me get across the hill, or at least tell me if the turbo was working. Problem is, I couldnt really tell a difference with the wastegate open or closed, still no power and lots of black smoke. This leads me to think I might have more than one problem. Any suggestions before I replace the vacuum pump. I havent checked the codes yet, but service engine lite is on.

I guess I also need to add, air cleaner is new. Also black smoke coming up from around underside of turbo at high idle, smokes up whole engine compartment. Clogged exhaust or bad gasket on exhaust pipe????? Both?????

 

[DavidPhillips]

Don't do anything until you check the codes and post them.

Do you have a boost gauge and egt gauge? Don't run it with black smoke.

Check the vacuum at the pump. plastic lines break.

 

[muddstopper]

no guages of any kind in my shop. Plenty of wrenches and welders and cutting tools. I will post codes first chance I get. Working 6-7 days a week right now. I am just trying to narrow down the possibilties for when I get a chance to work on the truck. I aint even in the same part of the state the truck is in right now. Well, maybe I am in the same state as the truck, I think we are both worn down and tired and in need of a fixer-upper.

 

[DavidPhillips]

Also the turbo has no gasket at the manifold. The downpipe is clamped on with no gasket.

Take the downpipe loose and check it out.

 

[edzzed]

wastegate actuator should be very difficult to move while truck is running. i think buddy up above might be asking if you have a boost gauge in the truck and not in the shop. that would tell you if the turbo is working. if it is the vacuum pump you can dget a shorter belt and remove the pump completely. then do a homemade turbo master. but make sure you have the boost gauge first and peferably a pyro second.

 

[muddstopper]

There has to be something loose on the exhaust, probably is the downpipe. I'll check it out. You mentioned checking for cracked vacuum hoses, I did check next to the pump for vacuum, not with a guage, but by placing my finger over the hose, doesnt seem to be any suction there, shouldnt there be enough vacuum to feel some suction on my finger? I dont own a guage, but can probably borrow one, but if its obvious I cant feel any vacuum, is there any point in checking with a guage. Or is the amount of vacuum so low that i couldnt feel it by covering the tube with my finger?

 

[edzzed]

try moving the wastgate while the truck is running and see what happens

 

[Dieseldad97]

great thread going here.........keep it up, I'm learning. Thanks.

 

[jifaire]

OK. Simple stuff.

#1: check the vacuum after the pump. The outlet line is right on top of the pump, and runs to the wastegate solenoid. You should have about 25" of vacuum (lots ... will suck really hard on your finger)

#2: if you have lots of vacuum above the pump, check it out at the wastegate solenoid. You should have vacuum coming in (about 25"), and some vacuum coming out (about 12") at idle. You can't test the thing with a voltmeter... the way it works is, there is 12v runnng to one side all the time, and the PMC grounds the other side on a duty cycle. That means it is ALWAYS open part of the time, and closed part of the time. When the duty cycle frequency increases, it it closed more than it is open, and vice-versa.

SO... if you see power to one side, that's normal. What you need to measure is the number of cycles per second that the GROUND side closes.

OK, just measure the vacuum.

#3 - your turbo is run by exhaust pressure. The exhaust comes from the engine (both sides) collects, spins your turbo, and your turbo pumps air into your engine from the intake.

When your turbo wastegate is open, the exhaust flows through the turbo and straight out your tailpipe, without pumping air. You need it to be closed (more than it's open), hence the "duty cycle" on the wastegate controller, above.

You mentioned that you wanted to use a string to pull the wastegate controller OPEN. This is a bad idea. For the turbo to work, you have to pull the Wastegate control CLOSED. When it is CLOSED, the turbo pumps air into the intake.

Obviously, your turbo isn't pumping air. SO- either you have a wastegate problem or an exhaust problem. If your duty cycle is high enough to read vacuum on the outlet side, and if your wastegate solenoid is working, then you have exhaust issues. (which is also plausible, as you have exhaust in the engine compartment)

#1 - check your cross-over pipe. It must be whole (no leaks) and connect the driver's side with the turbo. These things die every so often... if they let the pressure out somewhere under the engine, your turbo won't have enough pressure to turn. If it doesn't turn, it can't pump air.

#2 - check your downpipe (passenger side)... it must be tight to the manifold (turbo outlet), have no leaks, and allow echaust to flor away from the engine. Look for leaky turbo gaskets at this stage, also.

#3 - make sure your catalytic converter isn't plugged. If it is, it will prevent the exhaust from flowing though your system properly, and since it can't escape through the tailpipe, it will get out where it can (probably through the gaskets or at the turbo).

Exhaust flow is the key here... to make your turbo turn properly, and hence pump air properly, the exhaust HAS to flow properly.

So ... your 2 things to test area;

- the turbo wastegate/vacuum pump (vacuum)
- the exhaust system (exhaust leaks)

Let us know what you find out, OK?

SO -

 

[muddstopper]

The truck was running when i tied the string to the wastegate and it moved quite easily, in fact it seemed to be almost centered. I will double check to make sure I aint miss-remembering anything, but thats the way I remember it. I did this last week on a spur of the moment thought while in a hurry, on the side of the road, as ususal.

This is a great site, I have been reading the faq;s section for the last hour or so and Man! oh Man!, I think my truck might run in the low 10's if i fix everything I found that could be wrong with it.

 

[DavidPhillips]

Go easy on it till you get the vacuum fixed. Black smoke is bad on the engine. The EGT's go way up when your getting black smoke.

 

[muddstopper]

jifaire , I think I probably have at least three problems.
1.No vacuum pressure(suction) at the pump, I certainly couldnt feel any.
2. Definate exhaust leaks
3. possible cat plugged or partially blocked.
Suspect leaking exhaust has caused vacuum pump to fail, could this happen? Suspect exhaust leak caused by plugged cat. Truck has ran farm fuel in past, would this cause cat failure.

Took intake hose off turbo and it is spinnin freely by hand with engine off. Blades can be stopped with a pencil at engine idle, dont know if that means anything or not. At least there doesnt seem to be any bearing or bushings bad in the turbo.

Also suspect possible lift pump problems just from reading the faq's and having already put three on this truck over the years. Also suspect glow plugs need replaceing, has originals at 172,000 miles. Thing is hard to start, especally when cold.

Truck is 95 3500hd. manual tranny

 

[DavidPhillips]

looks like your on the right road.

 

[muddstopper]

I know exhaust leaking in the engine compartment is bad for a lot of things, but can that leaking exhaust cause a vacuum pump failure? If so, would the failure be due to the excess heat or from dirty air? I know the dirty air cloggs the air filter fast.

 

[jifaire]

I doubt that the exhaust issue would affect the vacuum pump.

If there really is a failure of the vacuum pump, you're probably better off to get yourself a turboMaster (mechanical wastegate controller) than to replace the pump. Lots of guys on here made their own, but I bought mine from Heath. Didn't trust myself and worried about overboost, I guess.

If you do go with a turbomaster, the next time you change the serpentine belt, get the one that's a little shorter (designed to fit with the vacuum pump removed) and take off the vacuum pump before it dies and causes you grief. If you aren't using it, might as well get rid of it, right?

Get the exhaust leak fixed, especially if it's in the crossover or turbo gaskets. Until you do that, you'll have black smoke and crappy performance.

I would gut the cat, if I was you. It's old enough to be pretty much useless anyway. If your state requires it, then punch the ceramic honeycomb out of it and run a 3" pipe right through the thing so it LOOKS like it's still there.

Let us know how your fixing goes.

 

[GregAbell]

He didn't mention if he had the "F" or the "S" engine. If it's the "S", the vacuum pump would still be needed for the EGR stuff, right?

 

[jifaire]

Ugh ... good point, Greg. All of the '93's i've seen are 'F' engines, but I should have checked anyway.

The EGR ain't working now, that's for sure.

 

[GregAbell]

He didn't mention where he's from, but if he's near Chicago, there's a parts place called Parts City Auto Parts - they sold me a new vacuum pump for under $70

 

[muddstopper]

Truck is a 95 not a 93, but i think it is a F model, it only has the wastegate solenoid on the right side of the engine. looking front to back. I seem to remember reading the S engines had two more solenoids mounted beside the wastegate solenoid. Give me another way to tell which engine it might be and I will check it out

Greg, I could use the number for the autoparts store you mentioned, in Western NC they want $146 for the pump at Carquest. How does the $70 compare in cost to the turbomaster mechanical wastegate controller. Also, everybody drives this truck, if the mechanical controller involves pulling cables and such, probably not a good ideal.

Cat will probably be gone soon, I will just straight pipe it.

 

[jifaire]

If you only have the 1 solenoid, it's an F. You cal also look under the Turbo-Power cover and see if there's an EGR mounted on top of the engine. only S engines have EGR.

Price on Turbo-Master? $109 on Heath's website.
Lots of guys build their own for like $10. You just gotta get it right, and then you never touch it again.

There are no cables or wires involved. It's a spring or 2 and a couple of brackets. Once it's in place and set, you're done with it.