SpeedyWankel

Hello everyone, I have been on this board for a while but have not posted as of yet. I have searched and am fairly confident that my turbo seals are on their way out, but I am not sure. The car is a silver 93 touring. Here's what I know:

Rebuilt 13brewtt has approx. 14,000 miles on it. Rest of car has 60,000.

Car smokes heavily upon startup and moderately at any other time, esspecially at WOT. The smoke does subside somewhat once the car has warmed up, but it still puts out at WOT a little.

It does this mainly when temperatures drop below 60 outside. If it's warm out, I don't think I remember seeing much, if any, smoke at all.

Smoke is white with slight bluish hue(coolant, oil, both), except at WOT, when it appears black(fuel).

Smoke smells RANK. I'm talking about some truly ***-like smoke. It's not particularly "sweet." Just nasty. Smells "to me" like partially burnt fuel.

Modifications consist of full 3" exhaust system with a silencer to reduce spiking/creep. Factory intake.

Car runs very strong. 12.72 @ 108.87 strong.

Coolant overflow resevoir cannot hold coolant due to large crack. The car does gradually lose coolant, but I am fairly confident that it's due to the cracked overflow tank.

Car started overheating last May, but I stopped it before temp level needle rose too high. (AST popped the DAY I bought the car) That is the only case of overheating I have experienced.

Sorry for rambling on and on, but I have nowhere else to turn. The only rotary shop in town just moved to a different state, and the guys at Mazda are 'tards. It seems to me like a possible turbo seal problem. I have driven these guys to the bone, so I am not disappointed with them. I've been planning on going single anyway, so I really hope it is just the turbos signing off. If it were smoking white at startup and gradually going away, I would immediately point at the coolant seals in the engine, but that really isn't the case. Believe me, I have searched, asked, called, read, meditated, and even conjured the ghost of Felix himself to find out what is wrong. Any ideas would be greatly appreciated.

rynberg

what ecu are you using?

SpeedyWankel

Factory ECU. After doing some homework and talking to some people at different RX-7 shops, the stock ECU seemed an ok choice as long as I was using the factory intake and didn't allow the boost to spike (silencer).

SaulV

LOL, NO OFFENSE DUDE, But I hAVE nO iDEA ,....N wHAT *** SMELLS LIKE, I havent Had the chance to smell One and i dont think i ever will

SaulV

Now back to beeing serious, I have the same problem, i think is pretty normal to see that little but of smoke when you first start you car, Now mine doesnt smell like "***" but it does have this fuel like smell, nothing out of ordinary.
The smoke shouldnt be blue or black though, you sure have something goin on in there.
i have the same problem with the overflow tank leaking, it does it gradually though, you have to be careful it doesnt overheat. Any suggestions on what to do to override that Overflow tank"????

Snook

iTrader: (12)

so you are keeping your boost to 10 psi?
I don't see how you ran in the 12s with 10 psi.
Maybe with a 1.8 60 foot time and 10 psi.

doesn't sound like you have a boost controller or boost gauge or upgraded water temp gauge right?

This is not good.

SpeedyWankel

I do have a digital boost gauge. I am running 10-10.5 psi with it trailing off slightly at very high rpm. When I ran the 12.72, it was in the high 40s to low 50s outside. 1.9 60ft, 8.2 1/8. I didn't feel the need for a boost controller seeing as how the factory computer seems to be regulating it correctly, except for a 4700rpm spike instead of dip. It actually won't spike very hard during a drag race. It spikes mainly when I'm in a gear other than 1st at low rpm and floor it.

What a queer little car. Today, it is very cold out (cold for Memphis, anyway), around 34 this morning. I expected for it to smoke like hell, but it's not. Even on startup, it smoked, but not to the degree that it does sometimes. After warmed up, I don't see any smoke at all except some black fuel smoke when at WOT.

Again, I really appreciate the input. I won't be too discouraged if the motor is shot. I race at the local track a LOT, and that would be a good excuse to buy a ported, warrantied Pineapple.

Snook

iTrader: (12)

you know that when it is colder outside your boost goes up correct?

on that night that it was 40-50 degrees out you were not running 10 psi. You were probably running 13, it could be more or less but it was not 10 unless you really do have a boost controller.

I think it's kinda hard to pay attention to the boost gauge while drag racing.

so what is the problem?

get a new overflow tank for starters

you say your motor and turbos are running great but there is smoke. I don't think there is anything you can do so just ride it out. It could be anything or it could even be normal. If I were you I would just keep driving it the way you have and when the turbos go they go....
right?

Nathan Kwok

What I would do is moniter all your fluid levels, that should help you identify what is coming out the tailpipe. First, fix the overflow tank, so you can moniter your coolant level. You shouldn't burn any measurable amount of coolant once that is fixed. Also, moniter your oil levels. Obviously if you drive hard you'll burn more oil, but if you're burning a quart every 500 miles on the street then yeah, maybe its the turbos. Also, note that a boost leak can kill your turbos. What can happen is you get a leak somewhere, so the turbos have to work very hard to make boost. The wastegate won't open until it sees a certain psi (which goes up with an open exhaust), so all the exhaust gas goes through the turbos, overrevving them. Since you are only seeing 10.5 psi, this may be your problem (I know the silencer will help limit things but you could still have an intake leak). I suspect this is why I had to rebuild my turbos at only 40000 miles, I had a fat hole in the y-pipe coupler when I first got the car and didn't know about it, didn't have a boost gauge, so my wastegate was never opening.

SpeedyWankel

I will just keep rolling then, I suppose. I'm gonna go single towards the end of this winter. We'll see what kind of smoke it blows with a new turbo.

You'd be surprised how much that silencer actually limits boost. It's incredible. Even when it's hella cold outside, boost stays around .79 bar (about 11 psi) and drops down around the .55 bar (8 psi) level.

if the car were completely stock, would boost go above 10 psi on an extremely cold day? Enough to hurt anything?

Snook

iTrader: (12)

I can't exactly answer your question but I know that with a dp, stock main cat, catback, intake, streetport, and pettit ecu my boost stayed exactly at 10 psi on a normal day 75 degrees. When it got down to around 50 maybe a little less or little more my boost went to 12 psi with the same setup.