the_saint

Hello,

I have a huge problem. Yesterday the primary turbo packed it in.

Symptoms
1) Over the day decreasing boost on the first turbo.

2) Eventually no boost. As per gauge and seat of the pants performance.

3) Tore down the front intake section and the compressor on the primary turbo did not spin

Today, pulled the turbos and saw the following.
1) Primary turbine is toasted.
2) Piece of metal in the housing. From where? From a sleeve in the exhaust port of the front rotor.
3) Secondary turbo looks fine visually.

Questions.

1) Can this sleeve be replaced without tearing the engine apart? I assume it get puts in from the inside, but have no idea.

2) what happens if I drive without this piece?

3) Wear can I get aftermarket exhaust manifolds? i.e. for a T4?

4) How did this piece break off, has this happened to anybody before?


Thanks

thesaint

the_saint

Picture of the piece of metal that toasted the turbine.

thesaint

the_saint

That piece came from here.

atihun

HOLY CRAP!

That is a big piece of sleeve that broke off!

It is possible that a piece of an apex seal broke off and it then broke the sleeve.

I think that you can get it rebuilt, but you should send it to a place that will balance them as well.

Good luck.

the_saint

I guess my questions are:

1) is it possible that the sleeve broke without a apex seal packing it in? The car still ran smoothly and pulled normal vacuum at idle.

2) how much work is needed to replace that sleeve?

thesaint

p.s. yes it is a HUGE piece that broke off.

BATMAN

god damn never seen anything like it.

ilike2eatricers

i agree that piece is frickin humongous.

were the symptoms you described only over one day or were there additional previous warnings or signs that you may have noticed?

the_saint

Everything happened over one day.

Here is the timeline:

May 15th.

New spark plugs, 9s all around.

The car is running like a champ.

On 10 lbs, the car breaks the tires loose in 2nd gear above 40 mph at will

Pulls like a banshee up to 100 mph and then some. Never pushed it harder.

Normal boost pattern 10-9-10.

At 12 lbs same deal but I am scared at how fast it is.

At 14 lbs of boost I can't get traction in 3rd.

I beat up on Mustangs and Camaros at will.

May 16th.
Car runs perfectly fine, even better than the 15th.

May 17th.
I hear a small rattling coming from the turbo area. I initially thought it was a loose heat shield.

I notice that car only makes 8 lbs of boost on the primary turbo, but fine on the second.

Over the course of the day the rattling comes and goes.

The amount of boost I can make on the primary decreases to 7. I think I have a wastegate solenoid problem or a boost leak. I check all the couplings and tighten a few here and there. There never was any sounds of a boost leak. I have had those before and know what a boost leak can sound like.

Still making the same amount of boost with the secondary turbo.

Less power though, can't spin the tires in third on 14lbs of boost, and not in 2nd at all.

1st gear seems less powerful as well.

Overall the car is slower. I was wondering if the spark plugs were fouled.

Power below 4500 rpm on the primary turbo is definitely down. The car has very little low end power

Suddenly while driving down a "highway" at 70 mph, I pulled out to pass and there was no power at all.

I looked at the boost gauge and noticed that the car made no boost at all. 0 psi. No audible evidence of a boost leak.

Even less power than when I had a boost leak. The car doesn't rev up that easily. As if there is some huge obstruction in the exhaust system.

Free revving doesn't make any boost. nothing above 4500 rpm.

Pull off the intake, intake tubing, turbo inlet elbow and notice that the compressor wheel doesn't spin/move at all. Very bad feeling about the whole situation.

May 18th
Pull the turbos off the car.

Tear the turbos apart, notice the primary turbo compressor is chipped up. A piece of metal falls out of the housing.

Very very bad feeling arises

Take of the exhaust manifold. Everything is fine with it.

Very very very bad feeling
Look at the exhaust ports and notice that the sleeve is busted.


btw the car was pulling -17 mm Hg with a perfectly normal idle pattern. The car ran smoothly and no hiccups (although with no boost).

Checked the apex seals and nothing missing at all that you can see with the block intact.

Any suggestions?

thesaint

atihun

If your engine idles normally and you are pulling the same vacuum as before then you may not have internal engine damage.

I would recommend a new/used housing instead of trying to replace the sleeve.

However, to replace that sleeve, if it is possible as with older rotaries, you will be pulling the engine. At this point, you might as well do a rebuild since you have the engine out.

Resource

Could have easily sucked in some debri.

BI State Customs rebuild and balances them. They also do upgraded twins.

Here is there number.

618-234-0069

the_saint

I am waiting for a call from my rebuilder. I sent him the lowdown and the pictures.


Pulling the motor and shipping it out isn't a problem, just a hassle. It only has 15k miles on it just got it rebuilt 2 summers ago, and the guy that did it is very good. Oh well.

As for the turbos, not sure what to do. Thanks for all the suggestions and help.

thesaint

Cheers!

your only pulling -17 mmHG?

i'm getting around -34 to -40 mmHG at with a stock 89 TII.

with original engine and turbos and intercooler

the_saint

As far as I understand -17 mmHg on a street ported motor is not unsual, if anything maybe -14 to -16 mmHg.

My car was running very very strong until yesterday.

thesaint

p.s. my mods are listed below

AUM

Sorry to hear about the car, that really sucks.

My car is actually still in the shop. Having the lower intake manifold gasket replaced and there were some large cracks in the exhaust manifold at the exhaust port. Mazda is replacing the entire exhaust manifold with turbos and all. The only problem is that the one one they received also had a small crack in it so I am waiting for a new one. Still have the compression problem to deal with as well. The warranty company is covering all the other work right now and are saying that after this work is done the compression will be better, we will have to see? I will most likely be pushing for a new engine.

Who is your rebuilder, the guy in Edmonton?

Keep me updated on what happens.

ilike2eatricers

What warranty are you referring to? A factory warranty?

vudoodoodoo

es

You must mean 17"Hg (Inches of Merc vs: Millimeters). if your car pulled less then 100mmHg it wouldn't idle.
-17mmHg is only .7 Inches of Merc...

the_saint

My bad

thesaint


AUM: I don't think that the compression will improve by replacing the exhaust manifold, turbos and gaskets. When do you expect to get it back?

The exhaust manifold looks fine on my car, and there is one small crack in the turbo manifold which hasn't changed in the last 25000 km (since my rebuild).

I am not sure what to do, but there are many possibilities, one being just putting everything back together and expect to replace the turbos in a while, but at least run the car as is. I figure if I put a new turbo on i will have to tear down the motor and get a new sleeve put in. I wouldn't wan to risk having another piece of that sleeve break off and toast a new turbo.

Oh well.

thesaint

AUM

I agree with you about the compression, in fact so do the guys at Mazda, but all they can do is what the warranty companmy tells them. The warranty company claims to have spoken to a couple of RX7 specialty shops that told them the compression should be fine after this work is done. All I know is that after Mazda has the car back together and tunned they are doing another compression test. The warranty company figures all they have to do is get the car running smoothly and pulling good and their work is done, we will see about that. Their adjuster drove my car before Mazda started work on it and said that it had lots of power, it was also the only time he ever drove an FD so go figure.

They should recieve the exhaust manifold by Tuesday so hopefull it is running by Friday.

So you are going to put your motor back together and run it till the turbos are toasted. Not a bad plan, you don't want to tear the engine open to quickly and if you plan on going with a single turbo soon why not. Let me know when you get it back on the road.

the_saint

Well, when the compression is still low, i guess you will be waiting for a new motor then

Get a street ported motor

I am not sure what to do. I am waiting to hear from the guy that rebuilt it. I figure the possible situations that might arise from running it are:

1) The busted sleeve leads to a complete nuclear melt down of the motor.

2) More pieces will fly off the sleeve and toast the turbos some more.

3) The turbos will self destruct b/c they are not balanced.

4) 1, 2 and 3 will all occur

5) Nothing will happen for a while.

When I go single turbo I will get the motor torn apart and rebuilt, as I would not want to jepordize a new turbo with a sleeve that has demonstrated that it has the ability to disintegrate. Why I have no idea.

I can understand the thermal stress that piece of metal must withstand, but to break in that manner is beyond me.

Oh well.

Does anybody know the purpose of the sleeve? Is it to do with emissions? Thermal barrier? Sound restriction?

thesaint