No Boost

[Sekred]

No matter what the map the minimum boost should be wastegate spring pressure. The fact that you had boost the previous day and now you have near zero probably eliminates a mechanical failure of the turbo. Do you still have the whirring noise from the turbo?. Going back to the Diverter valve I assume the solenoid is powered to close and not powered to open?.
Looking at Boomba racings "boost operated blow off valve" seems to confirm this. Are you getting any voltage signal at the diverter valve?.

http://www.fiestastforum.com/forum/threads/10114-Boost-Operated-Blow-Off-Valve-Boomba-Racing

 

[Sourskittle]

Kevin, text me, I don't have your phone number, I changed phones and lost my contacts.
Really sounds like a hard to find charge pipe rip or leak. But text me anyway.


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[Siestarider]

No matter what the map the minimum boost should be wastegate spring pressure. The fact that you had boost the previous day and now you have near zero probably eliminates a mechanical failure of the turbo. Do you still have the whirring noise from the turbo?. Going back to the Diverter valve I assume the solenoid is powered to close and not powered to open?.
Looking at Boomba racings "boost operated blow off valve" seems to confirm this. Are you getting any voltage signal at the diverter valve?.

http://www.fiestastforum.com/forum/threads/10114-Boost-Operated-Blow-Off-Valve-Boomba-Racing

Yes, I am kicking myself for not disconnecting the diverter lead and trying it. If the lead is hot the bypass would be opened, and if it stays hot, would be consistent with my problem. Oh well, back to jackstands to disconnect the find out.

I noticed today that I am emitting smoke from tailpipe under deceleration, not a good sign. Looks more white than black, but hard to say in rearview mirror glimpse.

Checked oil, no loss or gain. Coolant looks maybe slightly down but could just be paranoia.

 

[Siestarider]

I already tried compressed air into the compressor outlet to listen for boost leaks. The only thing I could hear was noise at compressor. Bypass valve is closed when ignition is off, as it only opens by signal, and I pressure tested with ignition off.

So, no need to try disconnecting lead, I already know air is leaking past compressor wheel into intake plumbing. Guess my question is whether this leakage is normal. Maybe I have some sort of compressor seal failure?

 

[Sekred]

This is growing more intriguing by the minute and must be frustrating for you. The obvious answer would be a charge hose has blow off. The fact that you had boost at the track day and no boost the next morning knocks that out. This is what made me think it was the diverter/bypass valve held open.
Other reasons could be wastegate open, spring failure, breakage, flap disk failure. Turbine delaminated from the shaft, compressor wheel failure, compressor wheel nut loose. These problems I have all seen but generally not overnight

 

[Siestarider]

Thanks Sekred, did you see my additional information of 'smoke' out tail pipe? Looks like the only thing left is to pull the turbo and inspect, I already checked the WG tension, its good, so I should spool to at least EFR WGA pre-load of 10 psi or so. WG flap valve might be disconnected from WG arm, no way to tell from outside turbo.

Light color of tailpipe smoke suggests coolant. Turbo is heat wrapped so I cannot see cracks if there are any. But no indication of coolant leaking outside the turbo housing.

I am going to pull the compressor elbow coupling and try compressed air on it separated from turbo just for one final system check for leaks downstream, but am already convinced that is not the problem.

Yes frustrating. On the other hand, a good mystery is fun. On the other foot, I would rather read about it than own it. On the other other foot, better me than Ford shop.

 

[Sekred]

Thanks Sekred, did you see my additional information of 'smoke' out tail pipe? Looks like the only thing left is to pull the turbo and inspect, I already checked the WG tension, its good, so I should spool to at least EFR WGA pre-load of 10 psi or so. WG flap valve might be disconnected from WG arm, no way to tell from outside turbo.

Light color of tailpipe smoke suggests coolant. Turbo is heat wrapped so I cannot see cracks if there are any. But no indication of coolant leaking outside the turbo housing.

I am going to pull the compressor elbow coupling and try compressed air on it separated from turbo just for one final system check for leaks downstream, but am already convinced that is not the problem.

Yes frustrating. On the other hand, a good mystery is fun. On the other foot, I would rather read about it than own it. On the other other foot, better me than Ford shop.

Yes I saw smoke out the tail pipe. If you have done a seal (very rare) then you will get lots of smoke as oil gets pumped into the intake or exhaust side.
It is looking like you will have to pull the turbo and inspect. The only other thing I would do is manually power up the diverter valve, connect straight to the battery (use a inline fuse).
Its the sudden boost loss overnight not while driving is the weird thing.

 

[Sourskittle]

Kevin I'll give you an extra BOV as well, just to double make sure that's not an issue


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[Siestarider]

Update: Pressure tested every piece of the compressor piping and its all tight. Mounted stock turbo with BOV disconnected from electric and I have boost. Makes a funny sigh sound after boost. Still have to reconnect BOV and see if boost fails.

Update: Reconnected BOV electric lead, boost continues to work fine, sigh sound gone.

Turbo sent off for inspection, have to believe a seal failed, but seal failure happened after boost loss. Hot side charge pipe had 4-6 oz oil in it when pulled off turbo. Will update again when turbo diagnosis is made. Still not clear to me how turbo could fail to make boost. Compressor side not firmly connected to exhaust side? 'Bought the only option left.

 

[Sekred]

What turbo are you running by the way?.
If the compressor nut has comes loose then it will spin on the shaft.

 

[BiigMe]

What turbo are you running by the way?.
If the compressor nut has come loose then it will spin on the shaft.

That's what I'm thinking might be his problem, if there's no boost leak in the piping it might be the shaft that connects the turbine to the compressor.

 

[Siestarider]

Sorry guys, I did not get a notice of thread replies.

Now its getting more expensive than interesting. Another turbo failed this weekend. No boost, after previous day boosting just fine and I have the logs to prove it.

The original failure was on Cyborg turbo, now stock turbo failed too. Just pulled the oil supply line, it had dirty oil in it but was not obstructed. So maybe either obstructed gravity drain or excessive crankcase pressure preventing gravity drainage.

SS says bearings and compressor wheel/housing all destroyed on Cyborg. So I am taking no chances with stock turbo, limped home and now on stands while I ponder how I could have possibly messed up this badly.

I am troubled by the apparent boost failure sequence. I figured ruining a bearing seal would cause some boost loss, but not total. Definitely same symptoms as first failure though. And having done it to two turbos, I am confident its me, not the turbo.

So will pull water lines and check them to make sure both are open. Then check oil pressure to turbo feed the old fashioned way, crank over with throttle pressed to floor and inspect mess. Then pull gravity drainage line and inspect that.

 

[jeffreylyon]

You'd have to have a very noticeable amount of blow-by to cause enough back pressure on the drain line to keep the turbo from draining. You said the supply line had dirty oil in - does it look burned like there's poor flow through the turbo and it's just sitting in housing and cooking? I had a twin turbo Mustang that would eat turbo bearings until I improved the flow back into the sump (not water cooled so it needed a lot of oil).

You said that you see smoke when you rev. the engine. Maybe that's oil being pushed past the seal into the exhaust side because it can't freely drain. This sure does sound like my Mustang before I fixed the drainage problem. A restriction in the drain hose or port into the sump?

 

[Siestarider]

You'd have to have a very noticeable amount of blow-by to cause enough back pressure on the drain line to keep the turbo from draining. You said the supply line had dirty oil in - does it look burned like there's poor flow through the turbo and it's just sitting in housing and cooking? I had a twin turbo Mustang that would eat turbo bearings until I improved the flow back into the sump (not water cooled so it needed a lot of oil).

You said that you see smoke when you rev. the engine. Maybe that's oil being pushed past the seal into the exhaust side because it can't freely drain. This sure does sound like my Mustang before I fixed the drainage problem. A restriction in the drain hose or port into the sump?

I drove the first failure with no boost (actually it would make about .5 lb according to AP) until it started smoking badly at tailpipe. When I pulled turbo, the hot charge pipe had 4 oz oil in it, and the way engine ran, I am sure I was getting oil into the intake. So I am sure oil was being passed into compressor side. Not so sure about turbine side. There may still be data coming from teardown and rebuild, might get another clue or two.

I have to pull the turbo in any case, so will carefully examine gravity tube. But its pretty good diameter, cannot imagine how it could be blocked except if excess crankcase pressure was causing blockage. I am running a Mishi CC, but no other mods to PCV system.

 

[Hijinx]

Sorry guys, I did not get a notice of thread replies.

Now its getting more expensive than interesting. Another turbo failed this weekend. No boost, after previous day boosting just fine and I have the logs to prove it.

The original failure was on Cyborg turbo, now stock turbo failed too. Just pulled the oil supply line, it had dirty oil in it but was not obstructed. So maybe either obstructed gravity drain or excessive crankcase pressure preventing gravity drainage.

SS says bearings and compressor wheel/housing all destroyed on Cyborg. So I am taking no chances with stock turbo, limped home and now on stands while I ponder how I could have possibly messed up this badly.

I am troubled by the apparent boost failure sequence. I figured ruining a bearing seal would cause some boost loss, but not total. Definitely same symptoms as first failure though. And having done it to two turbos, I am confident its me, not the turbo.

So will pull water lines and check them to make sure both are open. Then check oil pressure to turbo feed the old fashioned way, crank over with throttle pressed to floor and inspect mess. Then pull gravity drainage line and inspect that.

What's your oil level at?


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[Sekred]

Wow, things have gone from bad to worse for you. Sorry to hear that.
If the bearings have failed it sounds like the turbo(s) has lost oil pressure for some reason. Check your supply hose to see it has not collapsed internally and restricted/stopped oil flow. (Ok, I see you did that).
A leaking PVC valve can cause high crankcase pressure but it usually creates a hell of a mess, blows oil pass seals, blows out the dip stick, pumps oil into the intake and stuff like that.
Also have a look at the hot side of the IC and check for alloy from the compressor wheel and housing.

 

[Hijinx]

If your oil level is too high, it would prevent oil drainage from the turbo. It happened to my first Cyborg. My oil level was almost an inch ABOVE the full level.


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[Siestarider]

Thanks guys, oil level is perfect on the second turbo failure but it was maybe 1/4 inch high during first failure. Not a strong candidate for the failures, but could be contributory to first one.

When I removed the oil feed line last night, it was tight in feed hole but the nut securing the tab to block was loose enough to remove by hand. Not having any idea how that line is fed, maybe with securing bolt worked slightly loose it pops out a little during operations and fails to feed? If it gradually loosened, that might explain how Cyborg lasted a month before failing, and stock turbo lasted 10 days before failing. Maybe intermittent oil supply getting less reliable over time as bolt loosened.

But no sign of any oil leakage in that location, so maybe I am reaching. And I will use a new oil feed line in case something wrong that visual and blowing through does not reveal.

SS is coming to my rescue with another stock turbo to get me by while I correct everything I can think of and try again. Better to trash another stock unit if I fail than the restored Cyborg he is building for me.

Good news is I am a lot faster at turbo replacement than I was on first change out. Bad news is I still am not confident I have found the problem. More as I find out.

 

[BronxBomber]

Good luck and keep us posted.

 

[Hijinx]

Another long shot here: pull the axle and peep into the oil return. Maybe take something and poke around in there to make sure there isn't a blockage.


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