Engine checks after turbo failure?

[Big Daz]

I had suspected turbo failure at a trackday last month
Turbo Dynamics now have the Turbo stripped and found this -

So they are recommending a new one :doh:
Thats bad enough, but the report also says
"the turbine wheel has suffered major foreign object damage. See attached image. This damage can only occur when a foreign body enters the turbocharger via the exhaust side (i.e. from the engine).
An unrelated issue is cracking in the turbine housing. This is not uncommon, and occurs during the turbochargers many heat cycles (expansion and contraction results in hairline cracks). However in this particular case the cracking has exceeded what we deem as acceptable. "
I have compression tested the Engine, and its at 160, 160, 162 & 161 PSI across the cylinders. Which looks fine to me.

So my question is - what else can I check on the engine to find out what the "foreign object was and if its old damage or not? Dont know if this damage may have come from a previous engine as this Turbo was on the car when I bought it, but no idea if it was fitted new or not. Looking at it, I suspect not.
The engine started / ticked over and rev'd fine before turbo removal.
Last thing i want is to get a brand new tubby and have it happen again. :shock:
Cheers
Daz

 

[RO_SUNNY]

Check the manifold gasket.....maybe a piece of it broke apart and entered the turbocharger.

 

[bensmith907]

thats some nasty damage there mate sorry to see it.

 

[skiddusmarkus]

Sparkplug tip?

 

[PobodY]

Sparkplug tip?

Especially if it was precious metal? - They've been known to break off like that because they are essentially welded onto the central electrode as opposed to being part of it.

 

[Fast Guy]

What does the compressor wheel look like? I'd pull the plugs and boroscope the engine if you can.

 

[bensmith907]

I would think its something bigger than just a spark plug tip that's quite a lot of damage and a spark plug tip would just pass through. Although I have seen it many times on gas turbines where the initial fod impact takes off a bigger part of the turbine and that then does the real damage.

 

[skiddusmarkus]

Well it's about the eaisest thing for him to check, especially if he has a fmic.On my old engine it detted and the tips of the plugs disentegrated.Needed 3 new valves from what I remember.

 

[MarkTurbo]

What state were the bearings in and was it a roller bearing turbo or normal journal bearing?

If they have failed i'd get the sump off for a look and check the oil pickup whilst you're at it as i found this little lot in my sump after a bearing failure!

 

[Big Daz]

Ok, just been out to the garage and pulled the plugs - All good there
I doubt its valve damage as the compression would not be within 2 PSI of each other.
Inlet compressor looked fine - I could see this fully before send off.
Manifold gasket in fine fettle too, not damage or sealant used.

Background - car was check on RR 6 weeks ago, AFR all good and held boost fine too
1 trackday completed with no issues at all - track car only
2nd trackday, smoke from exhaust from the off, 4 slow laps later and it was loads of smoke, but turbo still spooling fine.

Could the Turbo have held boost with that damage to the compressor and just hard use caused a seal to go?

Cheers

Daz

 

[skiddusmarkus]

What oil drain have you got on it?If you just use the standard one it can back up the oil causing low pressure through the turbo.Mine was cut a bit to fit and hoping to improve it a bit more next week.

 

[bensmith907]

I reckon the turbo would still hold boost if the damage has been there a while and maybe the ineffiency of the turbine has ment the turbo has got hotter which in turn has killed your bearings and wastegate. I might add I'm not an expert in turbos all my experience is a totaly different field of turbines but I reckon its been like that for a while maybe failure from a previous engine. Deffo boroscope the cylinders before fitting a new turbo or fit a standard turbo for a while just incase it does it again (wouldn't want to break another £900 tubby)

 

[Fast Guy]

It looks like your bearing has gone and then the turbine has contacted the exhaust housing wall. I think with that damage, your boost would be down as the exhaust gases could leak around the blades.


The chances of something going through the engine and not causing internal damage is remote.