Bri Bro

Last day of the last track event of the year and ran into a problem. Running at VIR and all was fine on the back straight but the car made a sound like a cat growing going into the roller coaster. I though I had damaged something in the drive train but it happened only under acceleration. I was close to the pits so I got off and drove around on the paddock. All gears were OK, clutch grabbed well so I tried to get a little boost. Again, the sound and it was in the engine area. As soon as boost went away so did the sound. I looked at the Turbo and it had a bit of side to side play on the shaft. This Turbo is a Lindsey Sport and has worked well up to this point. I am guessing I lost the bearing in the middle section.

So my question is how much play should you measure in the Turbo shaft and how would one confirm that this is the problem?

Ian Carr

a little play is ok. give or take 1-2mm play. any thing more than that there is probably a seal or worn out bearing.

if there is any play, it should only be a small nudge each way. Check your intercooler pipes (the boots) for leaks, does the turbine spin freely? exhaust leak?

Bri Bro

Tubo spins freely, all inter cooler pipes are tight. I would say it has 1mm play side to side. The sound doesn't sound like an exhaust leak, just a growling sound ONLY under boost. The car is on the trailer now (visiting folks for turkey day) but I will have it back home this weekend. I just don't want to R&R the Tubo and find out it isn't the problem.

Ian Carr

can you see inside the inlet? did u suck some thing in and clip part of the blades?

try pressurizing the system (turbo to intake), doesn't sound like the turbo failed but more so a vacuum leak some where.

blown 944

can you feel a slight vibration on the clutch pedal??

try to put diagonal movement to it. the rear bearing is harder to feel.

VOoDOoGTX

if it sounds like a moaning hooker your ****ed.

HansB

Should it not read: Tuba making a new sound?

951jamie

Are you still getting good boost? Mine wqas making a wied noise but no boost. I have since found out that the down pipe has an inner wall in it and that had colapsed.
jamie@944online.com

Bri Bro

Thanks guys, no vibration and it still makes boost but I am not sure how much, the noise make me lift rather quickly. The compressor blade looked good, all the blades were in place and appeared to be true. The shaft would spin freely by hand.

I looked and didn't see a tuba or a hooker.

VOoDOoGTX

jackin this thread....

hans can you send me more pictures of the car in your sig? that car looks absolutely sexy. mainly the hood.

Bri Bro

WTF, Can I get this back to a technical discussion. I was hoping for some constructive feedback after a long road trip.

Tom M'Guinn

You might call LR to see how much play they call normal. Hard to diagnose sounds over the internet -- any chance the sound is boost leaking somewhere? Bad blow off valves and ripped hoses can become kazoos.

Bri Bro

Thanks Tom, I will be getting it off the trailer shortly and will pull all the hoses to look for leaks. Your point is well taken, I was a little lost on what in the turbo could be making that noise since the shaft still spins freely.

Chris White

I vote of a boost leak. Check all hoses (and I mean all) and the blow off valve

hp18racer

Definitely start looking for a boost leak. When I had a damaged turbo hot side, I couldn't feel play until I pulled the exhaust and could get at the hot side directly, the cold side felt fine.