Turbo Diagnostic

[SixBuy]

Filter was/is clean as we replaced it just to be sure. Also ran the engine with the intake disconnected from the turbo inlet - no change. Have not watched the vanes turn while running yet but have turned the air side manually. Turns smooth but has some drag sort of like tight seals. Will not freewheel or coast.
The cloud of smoke definitely stinks of fuel and will drift for a couple of blocks stinking up the neighborhood. The neighbors call it 'ol Smokey for now - worse if I don't get it fixed!
I thought I could isolate a cylinder by cracking the injector lines one at a time and look for an rpm drop but apparently the governor does a good job of compensating!
Turbo whine is basically non-existant (it's a -1D) and I can't say I can hear it spooling down after shutoff.
Starts very easy every time - it's running before you can get your finger off the button.
And I've never seen any black smoke.
We'll look some more in the daylight.

 

[jwaller]

you should not be able to feel "ANY" drag on the compressor wheel whatsoever, esp if this is done when its cold. getting it hot only makes the bearings tighter and thus the drag more. take a look at it with the eng running, sounds to me like you've got a turbo on the way out.

you should be ale to spin the entire turbo assembly with the flick of the fingers and have it continue to turn for 5-8 sec or so. any less and you have a problem, and if this turbo totally craps out on you. you risk damaging the motor when it pukes it's guts down the turbo oil drain line into your crankcase and into the eng oil pump then gets sent into your motor.

take a look at my sig pic, I deal with very high hp turbo motos every day and I've seen more than my share of turbos wipe out good motors from this.

 

[SixBuy]

OK, took the air intake off the turbo and verified the wheel will turn freely. Cranked 'er up and the turbo is spinning. Shut 'er down and watched the turbo coast to a stop. At idle everything is fine - just a wisp of thin blue smoke as it warms up. AT 1100 RPM throttle setting oil is streaming out the stack , dripping off the rim of the pipe and coating everything in a 20ft radius. When I wipe it up it's got a distinctive fuel smell. Still get the clouds of grey/white on acceleration with the air intake open on the turbo.

 

[G744]

Maybe not the culprit, but take a look at the master cvlinder vent system. I've seen them go goofy and pump BF into the engine intake system, with a lot of white smoke. Usually caused by a problem in the air-pac.

dg

 

[SixBuy]

Currently, the Master Cylinder vent is disconnected from the MC cap. There is what appears to be a vent tube that tees into the road draft tube (crankcase vent); is that what you're referring to?

 

[G744]

No, it is just the vent system occasionally gives grief. Seldom. Just a thought. Fuel gets into the MC. Brake fluid gets into the engine. I've even seen gas in an M37 distributor 'cause the owner didn't capiche how the plumbing was supposed to go, and the thing burst open.

Recently we had a post here from a gent with supposedly gear oil dripping out of his transfer switch on the dashboard. Just a little weirdness for you.

You might also pull the injectors and give them a once-over by eye. Duece injectors have two peewee holes on the tip. Use a good magnifier to check.

If a tip is split open, it will really dump fuel. This usually happens from water in the fuel whilst running. It turns into steam and there goes the tip.

You can do an ersatz test by pulling them and reconnecting the metal lines, facing up into the air. Have someone crank the engine with the throttle pulled out and you should see each and every one giving a sharp misting in the firing order. (NO SMOKING!) A bad one will usually just squirt a stream at an odd angle.

The injectors are not particular about placement, so don't worry about mixing them up. Just be careful with the return line jumpers as they are always fragile. (A good idea is to keep a bit of 1/4" plastic line and extra ferrules on hand).

dg

 

[cranetruck]

I mentioned this on a different post/thread, but the flame heater nozzle may be leaking fuel into the air intake manifold adapter....

 

[m35a2cowner]

turbo problem

I agree with Crane truck. If the nozzle is just dumping fuel into the intake it wouldn't atomize properly and thus wouldn't burn well at all (fuel smell from liquid exiting stack) and might just pass right through for the most part. Abundance of fuel would tend to make truck start easier. Its worth a try and cheap test. If this is or isn't it I would keep an eye on the engine oil to make sure its not getting contaminated with diesel fuel.

 

[SixBuy]

Good idea (s). I'll check out the flame heater today. I've never switched it on so it shouldn't be leaking but wierdness seems to be the order... I guess at this point about all that's left is pump timing and the pump itself. All this would be much easier if I were getting black smoke!

 

[cranetruck]

Oh, about the flame heater nozzle, it's not the pressure side, it's the return fuel side which is pressurized from the engine operation at all time. The return from the flame heater is common to the injector returns.
The 5-ton flame heater installations feature shut off solenoid valves, one in each line, so there must be a reason. I'll look for pictures...

EDIT: Image below

 

[ken]

Do you let it idle before shutting it down? It sounds like the thrust bearing it the turbo may have some coke on it. Witch will let it spin by hand but when it's under a load from gas expansion it's thrusting forward and slowing down. Try grabbing the turbine shaft and moving it back and forth in the housing. It should move about .015 if a inch. If not or it moves a mile. It needs a rebuild.

 

[SixBuy]

Ken, As I recall there was no end play on the turbine shaft, but I'll check it again when I get the time.
Put Dad in the hosp. with CHF at age 97 so things are a bit busy right now. Still need to follow up on Bjorn's suggestion of checking the flame heater. Thanks for the help.

 

[ken]

6by. It has to have some play in both thrust and radial movement. Some of this clearence goes away as it heats up. Do you have a dial indicator?

 

[SixBuy]

Believe I do - haven't used it in a while. If push comes to shove I can always improvise. Could that be a source of oil coming past the seal on the exhaust side? If it turns out the turbo needs work is it reasonable to have it done or just toss it? I watched it the other day after shut down; I had time to walk around to the right side and the turbo stopped after about 5 seconds. Does that seem reasonable?

 

[ken]

There isn't a seal like one would think. It's too hot there for a rubber seal. They use a laberynth to stop oil from bleeding over into the exaust. As the rotor increases speed it thrusts forward witch brings the grooves closer together. Since you mentioned you don't have any thrust movement i would check the thrust bearing for coking. If you shut it down with out letting it idle a couple of minutes oil will bake in the bearing housing and bearings. If so it could deposit on the oil passages and oil drain. If the oil can't get out then it bleeds over into the exaust and sometimes into the compressor side. Check the inside of the air intake after the turbo and look for oil. If so it's time to overhaul or replace it.

 

[SixBuy]

We've been careful to follow the 5 minute idle regimen on start/stop but who knows what was done before we got it. Thanks for the good info; it really makes sense. I'll check it out and report back.

 

[mobileauto2000]

If the turbo is seized it's the same as having pluged exhaust and restricted intake. power will be way way down. It will also create vacuum as you now have an intake restriction. At least that's what happens on Ford power strokes. I love them, lots of money to be made.

Ps come to think of it on the ford if the turbo is seized it almost imposable to start. are you having trouble starting?

 

[pegasus55]

SixBuy, for what it's worth, I just installed a boost gauge, fuel pressure gauge, and a pyro on my M35. My truck, sitting still shows no boost pressure regardless of whether it's idling or wound up. BUT, once you get it out on the road, and the engine is pulling the truck through the gears, the turbo makes boost. The boost pressure and the EGT respond together it seems and it looks like if the exhaust isn't making good heat say from about 1500 rpm up, you're not creating enough expanding exhaust gases to make noticeable boost pressure. These engines are higher compression than most diesels and therefore you're not gonna see a lot of boost even under max output conditions. My guess is your truck shouldn't be blowin' white smoke even if the turbo is locked up....it'll just make a ton of black smoke. They put the turbos on these things primarily to clean up their emissions. I'm leaning towards an injector issue causing you to dump a ton of fuel in a cylinder. I would think if you were dumping engine oil into the exhaust side of the turbo, you'd see clouds of BLUE smoke. Please let us know what you find! Just my to consider.

 

[tm america]

Excessive slobering and white smoke? You probably have bad rings or a melted piston letting alot of oil into the cylinders.. Head gaskets won't make it slobber oil out the slobber tube and exhaust.. You would smell the anifreeze burning.. It smells sweet.How does it start ? low compression can cause low boost levels to . You might have a few things happening at one time ... bad rings and plugged fuel filters..If the turbo was dumping oil you would most likely have a run away situation.. Or it would burn it and you wouldn't notice till it got real bad .These motors are are made to run on waist oil

 

[JxxxOxxxE]

Did anything ever come of this? I believe i may be having a similar low/no boost issue...