Holy Turbocharger Meltdown!!!

[kapnklug]

Putting a turbo on my M1009 has definitely been the best mod ever, but things got a little rough this weekend. My girlfriend & I set out on a 4-hour road trip to a camping party. We were about 2 hours into it on I-86, with the truck loaded to the ceilling with our camping gear, pulling a 4X8 trailer loaded 3' deep with band equipment, doing about 65mph when the engine started surging. I looked down and the boost gauge, which normally tops out at 7psi and stays there, is vibrating like a hummingbird's wing between 0 and 15psi. So i pull the whole circus onto the shoulder and pop the hood. Smoke is pouring off the turbo and there's a noise coming from it like a beer can in a blender.
I shut it off & considered our options -- getting a tow truck seemed unlikely in the middle of F*****G Nowhere, and they're not gonna tow it with the trailer attached; can't leave the trailer on the shoulder with thousands of dollars of our friends' gear in it; we are completely screwed. Finally in desperation I wired the wastegate wide open with a coat hanger to at least slow the turbo down, then removed the rubber coupler between turbo and intake manifold and duct taped over the turbo outlet, to keep the disintegrating turbo from throwing metal into the engine. I started back up, pulled a U-turn across the median & began heading back. The boost gauge was now at zero, but without the airflow from the turbo the engine was getting way too much fuel and i couldn't push the gas down more than halfway without the pyrometer hitting 1000deg. So we're chuggin back down the interstate at 45mph with big-rigs whipping past blowing their horns and smoke rolling out from the hood AND exhaust, i've gotta run the heater to keep the engine from over-heating but it's 90degs outside so we have to keep the windows open and we're choking on the burning-oil smoke. We started out at 9am and didn't get back til after dark. I'm still not sure of the situation with the engine, but i spent $700 this morning on a new turbocharger & associated parts. Reeeely hoping the engine didn't swallow anything sharp, but i'll be doing a compression test after pulling the bad turbo. (((
Moral: Money saved on a used turbo with unknown mileage is not money saved.

 

[BigWill1985]

That's one heck of a rough day!

I'm curious to see what happened. My only thought is maybe the turbo was starved for oil and the bearings overheated. If that happens, the impeller starts bouncing around in the housing and chews the fins apart.

Hard to tell how much damage was done until you start tearing it apart. The extent of your search is dependent on just how much time and money you have. Honestly, if it were me, I'd just change the oil, determine the cause to the shelled turbo, fix the issue, replace the turbo, and drive her. After another 100 miles or so, change the oil again. Continue to do so until you don't have any metal coming up in the oil. Worst comes to worst you'll wind up have a shelled engine. Best case scenario you'll run her and get another few hundred thousand miles. Really, for the price that you can pick up a good military take-out, it's not worth tearing one of these motors down in my opinion.

~Will Courtier~

 

[Skinny]

Nice roadside MacGuyver fix!!!

Just think how much more expensive that day would have been if you couldn't limp it home...

 

[cpf240]

Um....



Sorry, had to be said...

 

[MarcusOReallyus]

Nice roadside MacGuyver fix!!!

Just think how much more expensive that day would have been if you couldn't limp it home...

Yeah, might even have been a quarter of the price of a new engine!

 

[Mainsail]

Back in the 80s on my E3 salary I decided to turbo my Mustang II, so I bought something called a Turbo Pre-Luber. The theory of operation goes like this- Dry starts damage the engine, especially the turbo. The turbo is spinning at some six-figure speed at shutdown when the oil pump stops, causing coking of the oil on the bearings. The Pre-Luber prevents these issues by pre pressurizing the oil system before start, and pumping oil to the turbo bearings after you turn the key off. The pump is pretty serious looking, like it comes off an airplane or something. I never got around to the turbo, but the pump ran great on the engine without it.

Now it's sitting in the garage waiting to do duty as a WMO pump. Someday....

EDIT to add: This is the thing: http://www.marinemanifold.com/partspages/Pre-luber/preluber1.htm

 

[kapnklug]

Well I wrestled the old turbo off -- it's toast alright, noticeable side-side play in the main shaft, but no obvious missing pieces. Looking down the inlet, the compressor housing doesn't show any signs of contact, so hopefully the problem was on the impeller (exhaust) side. I won't have time to disassemble it, since the new turbo arrives tomorrow & there is a core charge I need back ASAP (as well as needing the truck running ASAP, this is my daily driver). While waiting for the new turbo I'm gonna check the turbo oil supply flow by cranking it over, then change the oil & filter and purge the oil cooler lines. Was thinking about doing a compression test but I'll probably just put the new turbo on and see what happens.
The turbo oil supply is coming from the oil pressure port on the top of the driver's side of the block, which probably produces less flow than the port near the oil cooler lines. Still, I've read about others using this oil port without the problems I'm having. One SS member (was it Southdave?) reported oil starvation problems to the cam-bearings when running his turbo oil supply from the cooler-line port, that's why I used the smaller port on the top. I'm inclined to blame the used, unknown-mileage turbo rather than the plumbing setup.
CPF240: if you want some pix, see my thread "M1009 lift/turbo buildup" & imagine a wad of duct tape in place of the manifold connector!

 

[kapnklug]

Was thinking about investing in an oil accumulator, plumbed in between the engine and turbo:
http://www.summitracing.com/parts/mor-23930/overview/

Anyone have any experience with these?

 

[MarcusOReallyus]

Hmmm. How long would that last?

I recall seeing something similar years ago, but it had a solenoid-actuated valve that kept the pressure in the reservoir when the engine shut down. Then, when you start up, as soon as the key is turned, the valve opens and you have instant oil pressure before the engine even turns over. The idea was to reduce dry bearings at start up.

 

[Mainsail]

Hmmm. How long would that last?

I recall seeing something similar years ago, but it had a solenoid-actuated valve that kept the pressure in the reservoir when the engine shut down. Then, when you start up, as soon as the key is turned, the valve opens and you have instant oil pressure before the engine even turns over. The idea was to reduce dry bearings at start up.

Those will help with the dry start-up, but are useless for the spool-down of the turbo after engine shutdown. I think more damage happens when the engine stops and the oil pressure drops to zero, but the turbo is still spinning. The Turbo-PreLuber I mentioned could be set to run for up to five minutes after the engine shut off, so it kept the bearings lubed and cooled until the thing stopped.

The only thing I didn't like about the system, and wonder if it was the issue that put them out of business, is that the pump pulled oil from the bottom of the oil pan- so unfiltered. Probably not the best oil to use, but easily remedied.

 

[kapnklug]

Oh I think it will help with the spool down of the turbo:
Oil comes out of engine supply port thru a one-way check valve to a T-connector. One branch of the T goes to the turbo oil inlet. Other branch goes to the accumulator. While the engine is running, turbo gets oil and accumulator is pressurized. When engine shuts off, accumulator discharges thru the turbo since it can't flow back thru the check valve. No electric valves required.

 

[MarcusOReallyus]

The point of the electric valves is to make sure there is pressurized oil when you start up.

You could do it with check valves instead, in the right area, to oil the turbo after shutdown.

Better yet, you could use one that way to oil the turbo, and one in stock config for start up.

 

[Brett09]

Just an FYI for the future. You can just buy the center section of the turbo and save a few bucks, its called a CHRA cartridge. Its all the parts from turbine to compressor. I saved about 200-300 going this route. I used http://baeturbosystems.com/ and was happy with the product I received (I have no business interest with them just a happy customer, your results may very) .

 

[Mainsail]

Oh I think it will help with the spool down of the turbo:
Oil comes out of engine supply port thru a one-way check valve to a T-connector. One branch of the T goes to the turbo oil inlet. Other branch goes to the accumulator. While the engine is running, turbo gets oil and accumulator is pressurized. When engine shuts off, accumulator discharges thru the turbo since it can't flow back thru the check valve. No electric valves required.

I suppose an accumulator could be set to discharge at any time; at start-up or at shut-down. However once it’s discharged that’s it until the engine is running and the oil pump can repressurize it. So if you have it set to discharge when you turn off the engine, it will be empty when you restart the engine later. So now you’d need two accumulators, one for shut-down and one for starts.

 

[albersondh]

Dry starts will never hurt the turbo assuming you get oil pressure to it within a few seconds. At the very most I would opt for a turbo-timer, idles the engine for x amount of time post key-off, to allow the turbine time to slow down, so your not spinning the shaft on dry bearings. The one in my car doubles as a boost gauge, uses load/boost vs on-time, to determine amount of idle time post shut down. Down side is it reads in HKpa (pretty close to BAR).

What is the OE reccomended oil pressure at the CHRA inlet? You can verify this with a mechanical gauge and T-fitting. Did you fab the header/flange to the turbo yourself? Turbo OEM's have a spec for allowable deg away from turbine shaft parrallel to the deck. Fall to far outside this spec and you will eat up thrust bearings and see dramaticaly increased axial end play, which will lead to turbine or compressor contact....

 

[kapnklug]

Well, here's an update:
New turbo installed, changed oil & went for a test drive. Don't need a compression gauge to tell me it's only hitting on 7 cylinders so i've got alot of work ahead of me. Further inspection of the old turbo revealed alot of play in the wastegate pivot-shaft, which allowed it to jam in an almost closed position, over-center like a Vice-grip. I believe this created the rapid fluctuation of the boost gauge and the chatter from the turbo housing. Since i can't see any pieces missing from the compressor wheel to cause the loss of compression, i'm guessing the excess boost (which peaked at 15psi) blew a head gasket, even though i'm using 6.5TD head gaskets. Compression test is next, when it stops raining.

 

[kapnklug]

Further update:
Compression test revealed zero compression in #1 cylinder, normal in all others (and it was a real barrel of laughs testing the cylinders under the turbo). At least the bad cylinder isn't on the side with the turbo, then I'd be pulling the engine. Gonna remove the driver's side head and check for damage, maybe I'll get lucky.

 

[ajsmith184]

Just curious, how did this ever turn out?

 

[kapnklug]

Oh ya, the truck's been down for so long I forgot I started a thread about it.
Pulled the driver's side cylinder head. The intake valve on the #1 cylinder was loose in the valve guide, you could rattle it by hand. The valve had made contact with the pistion, leaving a scuff mark .06" deep in the crown. I smoothed off the edges with a dremel tool; we'll have to see how that goes. Both heads were supposedly rebuilt a year ago by Cylinder Heads International, a terrible company who sent me two sets of leaking heads before finally giving me something that would hold compression. The head is currently at my trusted local machine shop, getting all the guides replaced.
Not sure if the valve problem was caused by the fault in the turbo (now replaced), or an unrelated disaster. I'm thinking the excess boost pressure caused the incorrectly installed valve to hang open, the piston hit it and knocked the guide loose. Either way, it sucks bigtime and the truck has been down for months.

 

[kapnklug]

Further update:
Trusted local machinist determined it would be prohibitively expensive to rebuild the bad cylinder head, which was supposedly rebuilt only 18 months ago by Cylinder Heads International (HEADSONLY sellername on FleaBay). Did I mention how much these guys suck? I can't believe how much money and wasted time they have cost me. Anyway, they are done screwing me now, because I bought a pair of brand new 6.5 heads from SSD (total with shipping around $900).
The 6.5 heads fit just fine on the 6.2 with slight modifications to the injector-line support brackets. Turns out it is indeed possible to install the turbo-side exhaust manifold without removing the pass. side fender or lifting the engine. It is JUST BARELY possible, and a huge PITA, but it can be done. Also had to replace the pushrod on the #1 intake (slightly bent), and rocker arm (wear pattern).
Compression test with the new heads still reads low in the #1 cylinder which has the damaged piston (250 vs. around 350 in the others) but I'm going with it. Gonna test fire the engine without the turbo or intake manifold this week and see how it sounds before going any further.