Inspecting a Turbo Car

I am going to look at an '04 Mazdaspeed Miata on Sunday. I'm familiar with Miatas enough to know where to look for chassis issues. I've never worked on a turbo car before. Any special things to do in regards to inspecting the turbocharger?

I would take the intake boot off of it and check it for play. Just grab the center of the compressor wheel and move it in and out and side to side. A little play is OK, but if it seems excessive, it probably is. Also, if it's really oily in there it's probably got problems.

Except that it's a Mazdaspeed, which means that the oil separator hose has been puking oil into the entire intake system. It's not super-easy to get to the turbo compressor wheel on one of these, unfortunately.

Listen for a whirr from the turbo. Think "unmuffled redneck Cummins" whirr. That's not a good sign. But they usually fail pretty hard when they go.

Yeah that reminds me... I need to get rid of that piece of crap oil catch can halfassed thing.

Or put in a check valve so it works as intended.

Keith Tanner wrote: Except that it's a Mazdaspeed, which means that the oil separator hose has been puking oil into the entire intake system. It's not super-easy to get to the turbo compressor wheel on one of these, unfortunately. Listen for a whirr from the turbo. Think "unmuffled redneck Cummins" whirr. That's not a good sign. But they usually fail pretty hard when they go.

Are you saying expect this to be bad? Or look for this as a potential issue?

How bad is the damage if it has this issue and how expensive to fix?

Preventative maintenance to tackle ASAP if I do buy?

It's unlikely the turbo is bad. If it is, then it's a matter of a rebuild or a new one. That noise is indicative of damaged blades, usually. You can get salvage parts. There's no preventative maintenance other than making sure there is an air filter. For some reason, every car I buy from California is missing the air filter.

But you asked about how to inspect it, so I told you!

Smoke out the exhaust is obviously a concern as well.

I drove my MSM today for the first time since October (eventhough we have gotten snow the past two days, it is no longer sticking) and my first impressions are that I wish it had the power and gearing that my WRX has.

Mine is an '05 with about 76k miles. Never had any issues with the turbo. Also never checked it for shaft play.

There were a few failures when the cars were pretty new - around 2006-07, I'd guess. But I haven't heard of many recently.

So basically check for weird sounds, bad smells, and smoke. Yup. Can do.

In reply to Beer Baron:

In general, modern turbos are much more durable the those of the past. Better materials and better oil means lots of stock turbos live long and happy lives. That said, I recommend diving more then one example of the car you are looking at. If you are not familiar with the car, it would be tough to tell if it's performing as designed.

Especially since these cars kindof perform not so well to begin with...

The spool is real weird for such a tiny turbo. If you don't expect it to feel weird you might think something is broken.

Swank Force One wrote: Especially since these cars kindof perform not so well to begin with...

Are they really that underwhelming?

For a group of folks who love Miatas so much, I would expect more love for a factory turbo one.

I should also mention this car already has installed a series of upgrades comparable to the FM "Little Enchilada". (Not the FM brand, but same upgrade path.) No O2 signal modifier or down-pipe, probably for CARB reasons.

When I drove one a few years ago I was underwhelmed.

Before I picked up my current NC, I thought seriously about looking for one, but realized I would immediately need to drop a few grand to get it where it should have been stock. I don't really want to mod my DD.

Although I've already been looking at full exhaust/intake/tune and suspensions for the NC.

Well, my very generalized reaction to MSM is "if you put a turbo on and gained all of 25 hp, you're doing it wrong".

Ive heard people grumble about mazdaspeed proteges just as much, but i dont know if any of the complaints are related. All my turbo cars came from the factory with 400whp bottom ends, so this complaining thing is sorta foreign to me.

Beer Baron wrote:

Swank Force One wrote: Especially since these cars kindof perform not so well to begin with...

Are they really that underwhelming? For a group of folks who love Miatas so much, I would expect more love for a factory turbo one. I should also mention this car already has installed a series of upgrades comparable to the FM "Little Enchilada". (Not the FM brand, but same upgrade path.) No O2 signal modifier or down-pipe, probably for CARB reasons.

Yeah they aren't great. You can get some decent improvements with the current upgrades, but the downpipe is a big one.

But end game, that stock ECU just needs to go, it's awful. And then the turbo. It's silly how something so small and capable of so little power spools slower with a crappier powerband than the 2560 that commonly comes with the FM2 kit.

The MSM makes for a good blank canvas. It's the "cream of the crop" of NBs for other reasons besides the motor as well. Reasons that may or may not matter to you personally depending on how deep you'd plan on going with the car.

I don't hate my MSM, despite it being a huge pain in my ass. But if i were to do it all over again, i'd buy a "normal" NB and boost it myself.

I really am just looking for a newer, fresher replacement for the NA Miata I had to serve DD duties. Should I just pass on the MSM and pony up the extra cash for an AP2 S2000?

Beer Baron wrote: I really am just looking for a newer, fresher replacement for the NA Miata I had to serve DD duties. Should I just pass on the MSM and pony up the extra cash for an AP2 S2000?

Won't be able to get a real answer to that unless you drive both.

I would personally pony up the cash for an S2000, but you should probably drive both and see what you feel. I find the S2000 more comfortable, probably faster, just as cheap if not cheaper to maintain, quieter, and has a bigger trunk.

Any reason why an 01-05 NB isn't on the list? They're certainly newer, fresher NAs.

Swank Force One wrote: Any reason why an 01-05 NB isn't on the list? They're certainly newer, fresher NAs.

No reason. Probably should be. I could do an NC with the suspension already sorted.

I guess I kind of want something with a touch of wow factor.