intermittent compressor surge?

[Joey Kaylor]

i got this weird sombitch coming in later this week, and want to get a little insight on it.

 

truck info:

2005 F450, 6.0 auto4x4. truck has 3600 miles on it (is our counties crash truck, ran on call a few times a month, but i make sure it is driven hard weekly to keep the carbon down).

 

this is the same truck that split a charge cooler at 1800 miles due to overboost, and after it went to the dealer four times with no fault found, i pulled the turbo and cleaned the vanes which were stuck hard with carbon. since then, it has not had any overboost issues.

 

the last two calls i worked it on (vol. firefighter, there are four of us in the county that can extricate, and only one of them is on the rescue squad.) the driver said that on the way back from the call, it would have a knocking sound that sounded like something smacking the truck. i drove it back from a rollover yesterday, and sure as shit, it was doing the noise he was saying.

 

it did it five times, and then stopped. when you accelerate, and then snap out of the throttle, you will hear a BAD compressor surge noise. you know when it will do it cause when you accelerate, it whines like its in full boost about to blow up, even in a part throttle low load situation. but the rest of the time it is not whining as loud, even in a WOT WFO situation.

 

i got a feeling the ring is sticking again, but want to verify to see if anyone else has seen this happen. i didnt have my IDS with me yesterday when driving it back from the call, so i didnt watch PIDs or anything, but will do that when i get the truck.

[DamageINC]

This sounds like the ones I've been seeing lately with cracked unison rings... the ring gets stuck to the housing, and the VGT pin grinds up the slot in the unison ring, and this usually results in some small cracks on the inside of the unison ring.

 

Dave

[Brad Clayton]

Ditto on that, I'm up to two dozen even on these now.

[Joey Kaylor]

so....ring or turbo? cause i got a feeling this will be me repairing it, unless they will do it at the local dealer under warr.

 

they could not get the charge cooler in under warranty unless we left them the truck for two weeks, and that was not an option for downtime. ditto on the turbo cleaning.

 

they say they are on a 3 week backlog now, with about 10 cars sitting on their lot as i rode by last night.

[Brad Clayton]

Tear it apart and look at the ring very closely, if the slot where the pin rides is whollered out then you'll need a turbo. If the ring looks ok no cracks ect. and the turbo is gummed up, then you can clean it. Most of the time what I see up here is alot of rust on the center section and the ring sticks to it requireing some prying to get it off, if that's the case then the center section can be replaced but it's only a couple of hundred dollars cheaper than just replacing the turbo altogether.

 

In either case if you have an old style drain tube be sure to replace it with 6C3Z-9T515-A, it is suppose to help out with oil coking problems in the future. Here is a picture of it on the left.

 

[Bruce Amacker]

 

In either case if you have an old style drain tube be sure to replace it with 6C3Z-9T515-A, it is suppose to help out with oil coking problems in the future.

OK, I'll bite. I'm not aware of this update and question how it will help a coking problem. Can you elaborate? Is there a TSB/SSM?

 

Thanks!

 

 

/forums/images/%%GRAEMLIN_URL%%/grin.gif

[Bruce Amacker]

Post deleted by Bruce Amacker (duplicate post)

[Jeff_]

TSB 08-4-7

 

Quote:

"VGT Solenoid replacement is no longer necessary. The new oil drain tube will resolve the coking issue."

 

"The oil drain tube has been revised for greater turbocharger oil flow."

 

Too bad 95% of mine have been rusted not coked /forums/images/%%GRAEMLIN_URL%%/rolleyes.gif

[Keith Browning]

Now that Bruce mentions it I would like clarification as to HOW the larger drain tube is supposed to affect coking. I think it has to do with coking of the turbine components rather than the bearing which is traditionally what coking is referring to.

[DamageINC]

It's actually pretty simple-a lot of turbos have been destroyed in the high-performance world because of similar concerns.

 

The issue is that the drain tube, becuase of the retarded angle (almost totally flat) that it drains back into the engine on, will "back up" with oil from the turbo. It can't drain faster than it's being fed.

 

This ultimately results in the compressor shaft seal blowing out. Alhough it's infrequent that these seals TOTALLY fail and cause severe oil consumption, they still have a tendency to never stop leaking once they've started. It doesn't usually creat enough of a leak to see oil in the exhaust (i.e. blue smoke) but what it will do is cause oil to collect and coke up in the turbine housing. The problem gets worse once the engine is shut off, as the residual oil isn't blown out of the exhaust and burnt, but it just sits on the components in the housing and cokes up from the heat and lack of airflow around it.

 

The new tube is just a little larger diameter and is supposed to aid in making sure the oil properly returns to the engine and doesn't 'clog itself' in the drain tube.

 

Ideally, any good turbo should have as much vertical drain back to the source as possible, and whatever horizontal parts may be necessary, should be VERY VERY short. Much shorter than the 6.0 design.

 

Dave

[Brad Clayton]

Quote:

Now that Bruce mentions it I would like clarification as to HOW the larger drain tube is supposed to affect coking.

Now Dave, not that your reply wasn't a technically accurate response but the true answer is that it's filled with "magic pixie dust" and should be handle with love and care during installation.

[DamageINC]

That too.

 

Dave

[Keith Browning]

/forums/images/%%GRAEMLIN_URL%%/rofl.gif

[Keith Browning]

Hmm, I do remember some mention about draining the oil more effectively. Back to the topic, I just took this shot of a worn unison ring slot causing hesitation on acceleration, surging at all speeds and smoke. The sad thing is that the tech working on the truck cleaned the turbo and reinstalled it and somehow never saw this... or the leaking EGR cooler. /forums/images/%%GRAEMLIN_URL%%/rolleyes.gif

 

[Torqued_Up]

WOW! Great picture. I havent seen that before but how the hell did somebody miss that????

[LARRY BRUDZYNSKI]

I/We have seen that here, just because we build these all the time. It's definitley going to become a more frequent issue. Hey by the way guy's have the CHRA's gotten any better quality wise from Mother (FORD)?

[Tony302600]

I haven't seen one that bad, but i saw one that you could tell. Keith you seem to get the worst case sceonario. LoL.

[DamageINC]

The last two I've had were right in line with the pic of the one that Keith posted, however I've had one other one that was so far bowled out (much worse than the pic) that the VGT pin itself was ground down to the point to where it looked like it was about to snap off.

 

That particular turbo failure resulted in blown head gaskets /forums/images/%%GRAEMLIN_URL%%/smile.gif

 

Dave

[Aaron]

Quote:

Now that Bruce mentions it I would like clarification as to HOW the larger drain tube is supposed to affect coking.

 

Now Dave, not that your reply wasn't a technically accurate response but the true answer is that it's filled with "magic pixie dust" and should be handle with love and care during installation.

YOU MEAN THE ONE I DROPPED IS NO GOOD?!?!?!?!!

[Brad Clayton]

It should still be ok if you picked it up within the 5 second rule, brushed it off, coddled it for a bit and whispered sweet nothings to it. A tsb will follow to reflect this update. /forums/images/%%GRAEMLIN_URL%%/grin.gif

[Aaron]

Is there a CX part number for this pixie dust? I'm worried some of it may have spilled during the accident. /forums/images/%%GRAEMLIN_URL%%/laugh.gif

[Brad Clayton]

No, I'm afraid your f*cked, it's a one shot deal.