Hey guys,

I've got a Paxton/Nelson SN-89 supercharged 87 6-port. Two days ago on the way home from work, after a downshift to 3rd during deceleration on an interchange, I got a large sudden cloud of blue or grey smoke from the exhaust.

Engine temp was fine, and it still boosted just fine afterward. There was no discernible loss of power. Upon inspection at home, all fluid levels were okay except the lubricant for the supercharger (which is automatic transmission fluid, for what it's worth,) which was below the low mark on the dipstick. I filled it to a bit over the high mark on the dipstick, and let the car sit 'til today. I tried driving it for about 40 miles, and hit boost a few times. About the second time I hit boost, I got the smoke from the exhaust again. Checked the supercharger lubricant again, and it's back down to about 1/3 of the way above the low mark.


So, what's happened? My gut reaction is that I blew a lubrication seal of some sort inside the supercharger, and I'm seeing that come out the exhaust, but I'd like to hear ideas from anyone who may happen to have input.

Thanks,

Collin

 

Given your description, a seal in the blower is the obvious logical culprit.

Or, it could be the TPS, because that seems to cause no end of weird problems for folks.

But really, it's a seal in the blower.

 

I lol'd at that one

 

Since I posted this thread originally, I had the blower rebuilt by Paradise Wheels (the company that services the blower and owns the rights to it, etc.) and had an intercooler added and the car re-tuned. I had the smoking issue again, and sent the blower back to Paradise Wheels - they found no moisture in the blower, and no cracks in the casing. If that's accurate, it means I'm getting oil (or something that's causing smoke) sucked into the engine another way.... unless smoke could be caused by running too rich. Is that possible? For what it's worth, it seems to be a greyish smoke, though I could be mistaken.

 

If possible maybe there might be some vacuum lines sucking the oil out of the super charger and into the intake ports or something?

 

Is the chargers atf low again after the rebuild with the excess exhaust smoke?

 

Not really - the only path between the AFT going to the supercharger and the air intake or engine in general is through the supercharger itself.

It is, however the guy that builds the supercharger said thatthe dipstick wasn't seating properly and that it needs a new o-ring, and spring to hold it in place.... so it seems like it may be something other than ATF getting into the engine.


If it was running too rich on deceleration, could that cause this problem?

It's only when the car is run up to 6k rpm or so, and only on deceleration.

 

if it's not the SC oil then it is likely a hint that the internal engine oil seals are going.

 

Oil control ring on your motor are not sealing. Your engine needs a rebuild. Your decel, followed by a puff of blue smoke confirms its the control rings. Classic test.

 

What are you running for engine management? Are you running a VAF and a blowoff/diverter valve?

 

Thanks for the input. I was starting to consider this as a possibility, tho it's a 30k mile engine... Is it possible it has blown that fast?
Makes sense... Hoping it's not the case though.
It's a Haltech Sprint RE, and there is a blowoff valve installed. Not familiar with the term VAF.

 

mileage generally has zero association with oil seal failure, age and lubricants used is usually the determining factor.

 

Is it possible the car is just running way too rich on deceleration?

 

VAF = vane aif flow(meter). Aka the factory trap door air meter on fc's. Since you have a haltech thats a none issue. VAF and MAF cars that run a vent to atmosphere valve can get real rich after the initial dump of pressure and leave a quick puff of black smoke since the ecu has already metered air that was ditched. Your haltech is a map based system so that is a non issue. I would say everyone else is probably right oil control rings.

 

if you are mechcanically inclined check this,,

check for oil in the charge pipe thats one

check the plugs if you see oil on it and if there alot of carbon thats two

check the vaccums on the omp lines thats three

all this could conclued where the oil burning is coming from .

Im guessing that you dont have any emission stuff correct ??