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-   -   verify my Thoguhts so i dont waste money please (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/verify-my-thoguhts-so-i-dont-waste-money-please-898283/)

BigJim 04-15-10 11:58 AM

verify my Thoguhts so i dont waste money please
 
So ever since i got my car out for the summer its been smoking. i didnt notice it doing this before winter so my first idea was the PCV. I checked and it seemed fine but i drove without the oil cap (screened of course) for like a week and a half to see if it would clear up. no dice.

No, it smokes on startup more than it should. itll clear up for the most part but u can always see some blue smoke comn out of the exhaust when idling. At about 5k rpm on it will smoke heavily. Under full boost it usually doesnt smoke until i let off the gas.

Now, i started pulling stuff apart and when i removed the Y pipe i found a quarter sized pool of oil. this was on the rear turbo, and the pool was just outside of the turbo in the y pipe down by the downpipe.

So my assumption is, since there is a pool of oil there that a seal MUST be bad in my turbo because if it was a seal in my motor the oil would be being burn and not collection on the cold side of the turbo.

Im just looking for some reassurance before i send these out to BNR to get them rebuilt for a grand.

and on that note, anyone here have any experiences with BNR rebuilding their turbos?

mrgne 04-15-10 07:22 PM

A quick way to verify would be to purchase a used set of twins for like 2-3 hundred and then see if your car still smokes. The previous owner should be able to tell you if the twins he sold you smoked before. If that fixes your problem rebuild yours and then resell the used set when your done.

94touringFD 04-15-10 08:17 PM

I had BNR rebuilt twins last year that only lasted 1200 miles before I had the exact problem you're describing. I just went ahead and bought a single. They had been sitting around for a while before I got them. My car didn't smoke until things warmed up though. I was under the impression that if it smoked all the time it was burning in the combustion chamber from seals.

BigJim 04-15-10 09:54 PM

Ive had the car for a few years. The turbo's on it are a used set i bought for a hundred dollars from someone on here. Maybe ill pick up another set though and give ur idea a shot

Maybe its blowing oil through at both places then though 94touringfd. I just feel that oil coming from seals inside the engine wouldnt be pooling in the y pipe.

Montego 04-16-10 11:08 AM

I had that issue as well (SEVERAL TIMES), my vote goes to the twins. As seals go bad they leak.

The twins are great when they are still in good condition. Meanig only new. Used: you never know how much abuse they have endured, given the age of these cars MOST are rather beat. Rebuilt = suck (I can verify this multiple times as when I bought my car it had a warranty and my turbos where replaced multiple times). Buy new as buying used you take a chance that they are actually in good condition (not rebuilt) but dont be surpised when in just a few months you are right back where you started.

Now I'm single and no more blue smoke :).

dgeesaman 04-16-10 12:17 PM

I wonder if the turbos are not very tolerant of sitting for long periods of time without being rotated or fresh oil circulation.

Generally that is an issue with ball and roller bearings - after a long enough time the film of oil completely drains away, leaving metal/metal contact. On first startup the surfaces adhere in places and tear off, leaving a rough surface that no longer seals properly. Wherever possible it's recommended in industrial machines to rotate moving parts by hand to refresh the oil films. On a car with oil pump, you either need to run the oil pump manually or run the engine for a little while.

Dave

BigJim 05-18-10 10:57 AM

Got my turbo's out finally.

They both have up/down shaft play as they should, but the front has minor scuffing on the housing. When moving by hand the fin's dont touch the housing but there was definitely contact at some point. Probably still is as the scuffs do look fresh

There is almost no in/out play.

The downpipe has a lot of carbon buildup, but no liquid oil in it.

The manifold also has a lot of carbon buildup but no liquid oil in.

Intercooler piping has minimal oil buildup

Intercooler has been sitting upside down for a week and no oil has came out of it.

Still sounding like a turbo problem?

Obviously the scuffing on the housing is a bad sign, but the lack of liquid oil is making me think its not the turbos after all.


Thanks in advance

RENESISFD 05-18-10 11:20 AM

I think what you can do is get a non turbo exhaust manifold and run the car and see if it smokes. If it still does then you will have your answer. search WIDEBODYSEVEN he is a forum member but changed forum names to something different. he ran without turbos for a few months because he didnt have enough money to replace them.

John

DaleClark 05-18-10 02:17 PM

To pitch in, I had a talk with Bryan at BNR Supercars a while back about what to do to prolong turbo life.

He said one of the biggest problems he sees are cars that sit for a long time (like over a long winter) and then they're started up in the good weather. Sitting for so long, the turbo bearings dry up, and then you start the car and load the turbos with little to no lubrication. This is even worse on cars that still have the 3000 RPM startup. This also holds true for installing a used set of turbos - it's quite possible the turbos have sat around for some time.

Just disable fuel by pulling the EGI fuse and crank the car until you have oil pressure (takes 10-20 seconds). After that, fire it up. Real simple.

Also, if you swap out turbos, this is an easy way to double-check for oil leaks before you actually start the car.

Dale

BigJim 05-18-10 04:52 PM

i unfortunately dont have a set of turbo's just lyin around, and finding a set that i would be confident doesnt already burn oil is hard.

I do have a full 13b exhaust from an 84,if it would line up i guess i could just plug all the oil and coolant lines i unhooked to remove the turbo's and fire her up...gonna be loud

grimple1 05-18-10 05:04 PM


Originally Posted by DaleClark (Post 10003834)
To pitch in, I had a talk with Bryan at BNR Supercars a while back about what to do to prolong turbo life.

He said one of the biggest problems he sees are cars that sit for a long time (like over a long winter) and then they're started up in the good weather. Sitting for so long, the turbo bearings dry up, and then you start the car and load the turbos with little to no lubrication. This is even worse on cars that still have the 3000 RPM startup. This also holds true for installing a used set of turbos - it's quite possible the turbos have sat around for some time.

Just disable fuel by pulling the EGI fuse and crank the car until you have oil pressure (takes 10-20 seconds). After that, fire it up. Real simple.

Also, if you swap out turbos, this is an easy way to double-check for oil leaks before you actually start the car.

Dale

How long does it take for a turbo to get oil in it? I can't imagine that it's more than a couple of seconds. I know you'll say that that's ~100 rotations but I wouldn't think that that had such an ill effect on.

I tried to fry a turbo once by running it without any oil (it was an ebay oil-only cooling turbo) and I ran that thing for at least 5 minutes until I decided to give up.


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