A question I've had for almost 20 years!

[kbohip72]

About 18 years ago, back when I was young and reckless, I had an '88 Toyota MR2 with the factory supercharger on it. I always ran M1 15W-50 in it. On a trip to the mountains here in Colorado I was driving through a very familiar long straight section of the highway. It's a very long stretch that goes for at least 10 miles without a single turn. Anyway I decided to see what my little MR2 could do. I gunned it up to about 130 mph and held it there for around 5 minutes. The engine was screaming at 7,000 rpm. Keep in mind the redline was 7,500 so I was really pushing it.

After around 5 minutes I noticed a huge cloud of smoke coming from the back of the car.

I figured I had broken something so I slowed down to around 70. The smoke stopped and the engine ran fine until I traded it in 2 years later. I must admit that almost 20 years later I still don't know what caused this. I've asked many car guys and mechanics and the best answer I ever got was that the cylinder walls heated up so much that the oil started blowing right past the rings.

I would love to hear any thoughts here on what you guys think this could've been. Keep in mind the engine ran perfectly for the two years I had the car after my Banzai run.

 

[brianl703]

Probably an indication that the oil cooler, if any, was inadequate.

 

[af0h]

That's what you call 'Blowing Out The Carbon'

 

[Shannow]

ring flutter would be my best guess.

First car had a 138c.i. 6, an auto tranny, and a "demon"diff (really low).

Didn't burn oil until just before valve bounce, when it smoked really badly.

 

[autoreign]

Originally Posted By: kbohip72
I've asked many car guys and mechanics and the best answer I ever got was that the cylinder walls heated up so much that the oil started blowing right past the rings.

Hmmm... I wonder what could be the caused. However, I'll give you my thought and see what you think.

Here it goes...

Have you experience hydroplaning while driving on wet road? With the thick oil that you were using I would assume that something similar was happening inside your engine. At that speed, the piston rings was floating on the thick oil film on the downward stroke and being dragged back up to burn together with the air-fuel mixture.

That also explains why the "burning" stopped when you slow down. Using thinner oil would have helped.

Just a theory, I wonder if it make sense. If so, your mechanic is half correct.

 

[cven]

Could have been oil getting pushed into the manifold thru the pcv breather.

I've seen oil pushed into the airbox on motorcycles ridden at hi rpm for a long time, especially if the oil level is high.

 

[chad8]

another possible. you ever think that with the high heat that a temporary leak from a head warp could have occurred between the head gasket , a cooling jacket, and a cylinder wall. poof. white smoke.
when it cooled down it would seal up.

 

[Familyguy]

It's an alien conspiracy.

Trust no one.

 

[chad8]

maybe a grain of rice got burned up

 

[94supraonchrome]

I'd like to have that MR2....

 

[Pablo]

Originally Posted By: af0h
That's what you call 'Blowing Out The Carbon'

AKA the top side of an "Italian Tune Up".

Just a year plus worth of [censored] in the cc and exhaust blowing out.

 

[Carbuff]

During that run you must have been at full supercharger boost.

The PCV system may have been blowing oil back into the intake?

 

[rich0001]

That was chalk that you brought up from the road..

 

[StevieC]

You were leaving everyone in the dust... Literally!

 

[hounddog]

PCV system not scavenging well enough.Thats why race cars have open type/modified systems.Done the same thing a few times extended rpm's low gears or in a way doing donuts and smoke boiling off a rear tire and then BAM smoke pouring from the engine.Go searching and found fresh oil in pvc/tubes and such.

 

[lexus114]

Originally Posted By: af0h
That's what you call 'Blowing Out The Carbon'

I agree!!

 

[wavinwayne]

This thread makes me wish I had a place where I could take my GTI for a 10 mile WOT run. Then again, something would probably break.

 

[ARCOgraphite]

Originally Posted By: cven
Could have been oil getting pushed into the manifold thru the pcv breather.

I've seen oil pushed into the airbox on motorcycles ridden at hi rpm for a long time, especially if the oil level is high.
My first thought. You fog oil at that rpm and it saturates the PCV system - IDK how PCV is setup in the blower cars. Now why the super-heavy oil, oh I guess we all ran this "racing" stuff as kids since we didnt know how much HP we were loosing - never blew a healthy motor though!

 

[ATS-V]

I'd say PCV due to high heat and blow-by from high RPM usage.

 

[lexus114]

Originally Posted By: wavinwayne
This thread makes me wish I had a place where I could take my GTI for a 10 mile WOT run. Then again, something would probably break.


It wont break.