tsi keeps killing turbos!!!

[insanedsm2403]

Ok so I have a 90 tsi awd.some of you may remember my post about a month ago asking why I may have smoked my new evo 3 16g.well I got another 16g,great condition,barely used,minimual shaft play.(also I took apart my blown 16g completely.although I am not an experienced turbo rebuilder,I see no blue shaft to indicate lack of oil,nor is there oil everywhere to indicate blown seals so I still have no clue why it died.chewed up compressor blades is all I found)now,I used new oil feed line,new a/n return line.I get plenty of oil out of the feed port.650 miles on the replacement 16g now and it has so much shaft play I give it a week of use left.now once again,could anyone give me any pointers as to why this may be happening?I ran this replacement at no more then 18psi?(current mods are in profile)compressor surge maybe?I'm out of ideas and can't keep replacing turbos every 1k miles.any help is greatly appreciated.

 

[insanedsm2403]

Ok did some reading up on flutter and surge and what not.my plan for next turbo is two bov's.one dodge modded and one stock.would this setup work well?if so can anyone tell me how I would run them recirculated.maybe the stock one to atmosphere and dodge modded back to intake?any suggestions would help on this setup as I couldn't find much info on it

 

[Demon33]

Ok did some reading up on flutter and surge and what not.my plan for next turbo is two bov's.one dodge modded and one stock.would this setup work well?if so can anyone tell me how I would run them recirculated.maybe the stock one to atmosphere and dodge modded back to intake?any suggestions would help on this setup as I couldn't find much info on it

The response of the system using two BOVs would tend to follow the weakest link which would be the stock BOV. I don't see how adding another BOV, especially a stock one would help in this situation.

You're getting flutter because the modded BOV has the bottom of the diphragm vented to atmosphere instead of to a pressure source like the unmodded BOV. This mod helps the BOV hold higher boost pressure but it also reduces the response time of the BOV when the throttle plate closes. This happens because the top of the BOV diphragm sees vacuum when the throttle plate closes (this is how it normally happens regardless of whether the BOV is modded or not) but the bottom of the diaphragm is seeing atmosphere and not the boost pressure in the intake like an unmodded one does. Without the boost pressure at the bottom of the diphragm, the BOV can only move as a result of the vacuum at the top which causes it to move slower and probably with less travel. With the boost pressure present at the bottom of the diphragm, as in a stock BOV, it assists the vacuum in opening the BOV quickly and completely. Does this make sense?

I used to have a flutter problem after I modded my stock BOV and the solution I used to fix it was to install a Dejon stop leak kit. It's an air actuated 3-way valve that vents the bottom of the diaphragm of a modded BOV to atmosphere only under high boost and switches to intake pressure under lower boost/normal driving. This allows the BOV to function as originally designed (like stock) and also to hold more boost as it was intendedly modded. I've taken it to 26 psi with no problems and it doesn't flutter one bit.

 

[insanedsm2403]

Makes sense ill have to read that post a few more times though.I have a blitz dd bov that I can't recirculate so I don't use.dodge mod bov and blitz? would this help my problem.this turbo b/s plus I purchased a brand new harmonic balancer this morning,plus a turbo rebuild has left me dry on funds.so I have to look away from the fancy parts right now and work with what I have.

 

[JEFFREYCASTGSX]

You cant blame the turbo dying on surge, unless its the real conmpressor surge. There are people running turbos WITHOUT bovs, and many drifters dont even run bovs, diesel dont run bovs and they do it for years. Maybe some pics of the internals would help us determine the real problem.

 

[insanedsm2403]

Well I have no way of posting pics sorry.but my compressor blade was chewed up only on the outter edge.I can tell that it was grinding on the inside of the compressor wheel.the shaft shows no blue marks at all.upon dissasembly there was no excessive oil on the components at all.I barely got dirty taking it apart.the bronze bushings have slight scoring on them as well as the trust plate.

 

[Demon33]

You cant blame the turbo dying on surge, unless its the real conmpressor surge. There are people running turbos WITHOUT bovs, and many drifters dont even run bovs, diesel dont run bovs and they do it for years. Maybe some pics of the internals would help us determine the real problem.

What is the purpose of the BOV (aka compressor bypass valve) on our cars?

What is "the real compressor surge"?

 

[JEFFREYCASTGSX]

What is the purpose of the BOV (aka compressor bypass valve) on our cars?

What is "the real compressor surge"?

To make ricer noises . Im not saying that we dont need bovs, but under LOW LOAD conditions the flutter created by a imperfect bov will NOT cause damage. Many cars that were in production never had a bov. There is two types of "surge", the flutter created by the air not exiting the bov and backing out the turbo, and the REAL surge, the one where you start cross the surge line on a compressor map, the kind that will DESTROY turbos.

Heres a vid

http://www.youtube.com/watch?v=nCj6Spwl1CU

 

[insanedsm2403]

Well how would I know if I have this REAL surge because all I know is my turbos keep REALLY fuc**** up and it needs to stop asap

 

[JEFFREYCASTGSX]

Well how would I know if I have this REAL surge because all I know is my turbos keep REALLY fuc**** up and it needs to stop asap

You dont have that, dont consider the surge the reason why there is another reason for it, maybe just bad luck.

 

[insanedsm2403]

Oh yea and I can't see that video until I get on a REAL computer .

 

[Demon33]

To make ricer noises . Im not saying that we dont need bovs, but under LOW LOAD conditions the flutter created by a imperfect bov will NOT cause damage. Many cars that were in production never had a bov. There is two types of "surge", the flutter created by the air not exiting the bov and backing out the turbo, and the REAL surge, the one where you start cross the surge line on a compressor map, the kind that will DESTROY turbos.

I agree that under "low load" the flutter has little to no affect. But where do you draw the line between low and high load? 5, 10, 15, 20 psi? A properly functioning BOV should not flutter at all.

The OP is running about 18 psi spiking to above 20 psi. Is this considered low load? At this boost level could the air pressure wave bouncing off the closed throttle plate back towards the compressor damage the turbo over time if adequate bypass of this wave is not provided such as in a partially opened or slow-to-open BOV? I think the OP needs to consider this and try to eliminate the flutter. At least it will be one less variable in the troubleshooting process.

While I do understand what you are talking about the "real surge", at only 20 psi on the OP's 16g I don't think that is the case here. I've run my 16g up to 26 psi on my daily driver for thousands for miles and it hasn't skipped a beat yet.

 

[JusMX141]

diesel dont run bovs and they do it for years.

That's because diesel engines don't have throttle plates which would stop airflow.

You're comparing apples to oranges.

under LOW LOAD conditions the flutter created by a imperfect bov will NOT cause damage.

Whew, that's a relief. I'll be sure to call my buddy Jeff and let him know the shaft play and howling that his turbo made at the track after he drove around for a week without the BOV line hooked up (BOV inoperable aside from the boost pressure forcing the valve open on it's own) was nothing to worry about after all.

 

[insanedsm2403]

So is the compressor surge theory down the toilet on my setup?

 

[Demon33]

So is the compressor surge theory down the toilet on my setup?

No, I don't think it's out of the question. Justin (jusmx141) was being sarcastic in his reply about low load. No tests have been done to eliminate it as a possibility. You pretty much eliminated oil starvation, as you used a new stock OEM oil feed line fed from the head and you also inspected the damaged turbo's shaft for bluing which would indicate oil starvation and found no indication of oil starvation. What's next?

Check for boost leaks which would cause the turbo to have to run at higher rpm's to maintain a set boost pressure, eliminate the possibility of compressor surge caused by the fluttering BOV and (unlikely, but on a long shot) verify that you boost gauge is reading correctly. It may be malfunctioning- indicating a lower pressure than what it actually is, possibly taking the turbo past its surge line. That's what I would do.

 

[insanedsm2403]

Boost leak test holds to 28psi no problem.by the way my authentic 16g howled really loud when it died that's how I knew something was horribly wrong.idk if this helps I'm my search for surge

 

[JusMX141]

Well keep in mind I've seen knockoff 16G's fail for no reason at all, so you can't really take the failure of yours in account to the case. I would be more curious to figure out what killed the new Genuine MHI turbo over anything else.

If you suspect the BOV being too stiff you can do one of two things....find another stock 1G BOV for cheap and replace it, or you can run an external boost source from the compressor cover (tee'd into the wastegate line is ideal) to the lower nipple on your Dodge Garage 1G BOV while you're doing low-boost street driving then unhook the line to disable the quick-release feature for high-boosting.

 

[cdm_sd02]

sounds like a surge issue, but the one thing I have found with the "cheaper" turbos is there not even close to being balanced right.

 

[insanedsm2403]

Well ebay turbo aside because that was a gamble from the start,my mhi 16 I can't seem to find the cause of failure.maybe I'm overlooking something but from what I see,I'm not able to pinpoint the cause of failure.

 

[jrohner]

You cant blame the turbo dying on surge, unless its the real conmpressor surge. There are people running turbos WITHOUT bovs, and many drifters dont even run bovs, diesel dont run bovs and they do it for years. Maybe some pics of the internals would help us determine the real problem.

WTF You obviously don't know how diesels run or work.

 

[shadohc]

it sounds like something in the oil line is blocking oil to get to the turbo

 

[JEFFREYCASTGSX]

I was giving examples, of cars that dont have throttle bodies. I mean low load conditions as in just driving around town, under wide open throttle i can see damage being done. What happens to all of us that have dodge modded 1g bovs? They flutter, A LOT. What about all those with tial bovs, they flutter to hell and back. For you to be blaming your dying turbo on surge is ridiculous, run it with no bov and then you can blame it.

Look at what i found:
http://www.youtube.com/watch?v=b5YboYGt5U0

No bov for months. Oh yeah, yall are welcome to look at my profile and look at where i work(jhroner).

So maybe I was pushing the authentic 16g too far?I got maybe 1500 miles on it,but it had horrible creep,and would always spike past 20 psi any time I got on it.also does anyone know if the mitsubishi td05 "20g" compressor wheel on ebay wil fit in my 16g housing?

Ebay? There is your reason.

BTW, some diesels DO HAVE throttles plates, and they even make aftermarket spacers for them.

 

[JusMX141]

Look at what i found:

Do we know if this is a ball-bearing or journal-bearing turbo on the car in the video? Obviously you're not going to cause bearing wear on a ball-bearing turbo no matter how much it surges.

This video actually demonstrates the exact sound my buddy's car made when the line blew off the top of the valve which was later followed by a nice "howl" from the turbo at the dragstrip after we had repaired the BOV line issue.

BTW, some diesels DO HAVE throttles plates, and they even make aftermarket spacers for them.

Some good info from a Diesel Tech:

"A blow-off valve is designed to prevent compressor surge on turbo-charged engines. Compressor Surge occurs when the engine's THROTTLE PLATE is suddenly closed, giving the Charge from the Turbo compressor, no where to go. So the blow-off is plumbed in somewhere between the Compressor's outlet and the Engine's Throttle body, allow unwanted Boost Pressure to be vented to Atmosphere or Intake stream before Compressor inlet.

So, that being said, it should be obvious why most modern Turbo-charged, direct-injected Diesel Engines would have no need for a "blow off valve". A diesel engine is controlled by fuel, thus not requiring it to have a "intake air throttle plate".

In a diesel engine, all mixing of FUEL/AIR occurs in the Combustion Chamber, by design the Diesel operates in EXCESS AIR situations, it can pump up to 600X times more air than it needs @ low idle. A Diesel builds peak power and Manifold Boost when UNDER-LOAD, so when you cut fuel to that engine while under load, the Manifold boost still has a place to go since the engine is still pumping air.

The manifold boost tends to drop off quickly since it is being displaced by the cylinders, and since the turbine drive pressure will be less as well. This is why diesels do not provide "engine braking" without the use of devices, (i.e. Jake Brake, Exhaust Brake.), where as a gas engine provides said "engine braking" ability."

 

[JEFFREYCASTGSX]

You need to re-read what I just stated justin, if your buddies bov was stuck closed, then yes it CAN cause damage. I was stating that just because his bov flutters, doesn't mean that it caused the demise of his turbo. Look at a 7.3 powerstroke, it has a throttle plate, its there, I never stated what it did, its there for emissions purposes. Diesel engines just use input from the foot of the driver to control the injectors, the more the foot goes, the more fuel is being sprayed into the engine.

 

[insanedsm2403]

Well if this helps my bov flutters and as it flutters the car starts bucking pretty bad.I have to end up letting off the gas for a sec.

 

[JEFFREYCASTGSX]

Well if this helps my bov flutters and as it flutters the car starts bucking pretty bad.I have to end up letting off the gas for a sec.

Does it? Can you check your bov,