Shaft Play on K04

[furinax]

Anyone know of how to measure shaft play on the stock k04? And how much is too much?

I saw some rebuild kits as well and was wondering if anyone had any advice/suggestions for it. Is it possible to do a rebuild yourself or can the someone like the dealer or an 3rd party vendor take care of that for you?

[MSMS3]

I don't know how much is too much in terms of maximum allowable shaft deviation.

I can say that I know one way to tell, but it's not a good one: wait until the compressor wheel starts scraping the turbo inlet! That's what happened to me. I noticed that the turbo was making some extra noise, just a slight change in pitch on light throttle changes. Upon inspection, I caught several things:

1. The shaft play was very noticeable.

2. The compressor vanes were actually scraping the side of the compressor housing at the point where they contact the snail, leaving little score marks.

3. Upon closer inspection, one of the compressor vanes was actually chipped.

I've done turbo rebuilds before on T4 turbos on Saabs and feel confident in doing that. In this case, however, with an obviously damaged wheel on the compressor side, that was not even a remote option.

I had my turbo rebuilt be Work Turbochargers (turborepair.com) in Pelham Alabama, a suburb of Birmingham. Because the compressor wheel had to be replaced, I opted to have them install a new CHRA inside a rebuilt housing. Even then, it was a reasonable $600, if I recall. A normal rebuild is about $350 if I recall. They did a great job, turn around was fast, and it is performing just like a new K04.

Mazdaspeed 3

I'm sure there are other companies that do good work, but I had heard good things about them and am happy with what they did.

[sheston]

@MSMS3; you had all that and no smoke?

I was going to answer, that the play doesn't matter, just fix it when it smokes

[MSMS3]

Originally Posted by sheston @MSMS3; you had all that and no smoke? I was going to answer, that the play doesn't matter, just fix it when it smokes

It never smoked, not in over 100,000 miles. I have always run synthetic oil, and exclusively Shell Rotella T-6 after it became popular here, and have had idle up +200 for about the last 6 years or so. The catless dp/rp exhaust does produce bit of black fog for a second or two on initial WOT, due to going rich, but that is normal, sort of like a diesel. Never smoked at idle. Never any oil related smoke.

When a CHRA is spinning at over 100,000 rpm under boost, eventually any shaft and bearings will wear enough to fail. The seals held.

[furinax]

Originally Posted by MSMS3 and have had idle up +200 for about the last 6 years or so.

What does that mean? I'm on Rotella T6 btw... great oil but then again I'm not really sure what makes it so great.

Also, at what mileage did you end up having to do the rebuild? I'm thinking if all is okay at 90k miles I can just do it there but I'm at 50k now..... may just do it ASAP for peace of mind.

[MSMS3]

Originally Posted by furinax What does that mean? I'm on Rotella T6 btw... great oil but then again I'm not really sure what makes it so great. Also, at what mileage did you end up having to do the rebuild? I'm thinking if all is okay at 90k miles I can just do it there but I'm at 50k now..... may just do it ASAP for peace of mind.

The rebuilt turbo went in earlier this year at about 105,000 miles. But you can't go by someone else's experience totally. Some wear out sooner, some later. A lot of WOT and frequent driving under high boost will put more load on the bearings. Also, dirty oil, even if synthetic, accelerates wear. I change the T6 every 5,000 miles. I would not replace the turbo at 50,000 miles unless smoking badly, not reaching and holding target boost, or making noise.

The +200 is idle rpm. I raised it up 200 over stock. It is now about 900. You have to have some form of aftermarket tune to adjust idle rpm. It really helps relieve the gen 1 positive crankcase pressure effect on the turbo oil flow.

[furinax]

Originally Posted by MSMS3 It really helps relieve the gen 1 positive crankcase pressure effect on the turbo oil flow.

Ah I see. I have my idle set at 1100 due to tune. I'm not sure what you mean by the above quote but I'm assuming higher idle is safer for flow? Also, I turn my car off at stoplights at times to save gas. Is this a good idea?

Looking at the cost (~$400) I am less inclined to do this as a preventative measure... maybe at a major service interval like 90k miles or so, but until the turbo starts smoking or making noise I think it's safe to just leave it. How would I know if it was not reaching/holding target boost?

Also, k04 is billet right?

[broda]

Turning your car off at stoplights sounds like an accident waiting to happen

[sheston]

I would think that turning the car off at stoplights wouldn't save any gas. On startup, it runs rich, probably negating any benefits.

As far as worried about your turbo, turning the car off at lights would accelerate wear on the turbo. Especially if you had been getting on it at all. It would heat soak everytime

[furinax]

Originally Posted by sheston I would think that turning the car off at stoplights wouldn't save any gas. On startup, it runs rich, probably negating any benefits. As far as worried about your turbo, turning the car off at lights would accelerate wear on the turbo. Especially if you had been getting on it at all. It would heat soak everytime

Hmm good idea about the heat soak. I don't think the car runs rich though because then I would be moving right after right? It only runs rich on idle?

I've only done it a few times anyway. A lot of modern cars shut off when stopped actually- they turn back on when you press gas... but I guess this doesn't apply to turbo cars.

[broda]

^ That too. If you beat on it and then don't let the car idle at all you're asking for bad things to happen.

[MSMS3]

The stock tune on this car is pig rich. Very rich AFR, not merely at idle. It is a characteristic of turbos, and especially with high compression direct injection. It is protective and the cylinder cooling effect permits more timing advance for better power at higher rpm.

Don't shut off and on at stop lights. No fuel saving. Starter will wear out sooner, and with a manual transmission on hills . . . just no.