Billman250

Have a customer here, been coming to me for at least 7 years. 2003 s2k with 160k or so on the odometer.

He was doing a mild race with some other car on the highway. APPEARS the rear main seal let go, lost oil (only lost one quart...still 5 left in the engine, and didnt even get lower than the bottom X) and he also developed a knock in the engine. After pulling the rod caps (all spec out perfect), it appears he lost a main crank bearing.

There is also an oil journal plug back there behind the flywheel...this could be the leak also but I doubt it.

Usually the rod bearing is the first to go with low oil, but this was a pressure loss.

This is the first s2k I have even seen, or read about, that lost an engine for this reason.

Question is, has anyone heard of this before?

If not, it should be addressed. Because this can happen to any s2k.

I can see the crank area when I had the pan off...the seal did not push out against the flywheel. It is still in its original position.

SpitfireS

Did the car have Krank vents, or any mod to the original crank vent system to create vacuum in the crank case?

You say there were 5 quarts of oil left, that's pretty close to a normal fill, right?
If there was a serious oil leak in pressurized gallery's, depending on the size, one would think the oil pump would empty the sump in.. seconds?
The pump puts out 58 liter a minute @6k rpm, according to the specs.

Did the engine hold back, almost like hitting rev limiter or fuel shortage, at any time?
If so, after this it was running rough and showed oil warning light at idle?

Any shavings in the pan?

How did the oil that was still in the engine look?
Pretty fresh, as in: recently topped up?
No offence.

Billman250

to start:

race: definition: just a one gear pull with another car. 40-70 mph or so.

No crank vents. All stock engine, comptech intake is all he has.

Yes 5 quarts puts you on the first X. 6 makes it full to the top X.

You would think all the oil would come out under pressure. but he was able to drive here, and lost only 3/4 quart in 40 miles via the leak. When he arrived, it had 5 quarts remaining in the engine. He didnt notice the leak until he arrived at my place. So its POSSIBLE the shavings caused the leak. Hard to say. big issue here is the chicken or the egg...which happened first.

Engine all of a sudden sounded funny AFTER the race with the car was over. No power loss or symptom during the race. The oil level was good during and after. The dipstick showed only 1/4 quart shy of the full mark after the incident occured. He then drove 40 miles to my place. So he had no reason to top it off before coming, as he did not know of the leak, nor was he low on oil.

Running perfectly smooth. No symptoms at all at idle. No oil light at idle. Once reved slightly, you can hear the knock.

Yes on shavings in the pan...they are either main bearing shavings, or cylinder liner shavings. Rods were ok.

Engine oil looked dark. It has 2000 miles or so on the oil, I think he uses castrol syntec.

He did notice a few weeks prior, and up until this, a little smoke out the tailpipe starting off from a stop.

So this is where I am at. Thanks for joining the thread, I'm glad it was you that jumped on board. So no offence taken

jimi

This is the story: The car has 166k.all machanicals By Billman. Moble 1 Extended performance with 3000k on the oil. I stored the car nov -May with 163k We had a mild winter so I don't think this oil is old. However, since taking it out of storage in May, I noticed from time to time Smoke from the exhuast from a full stop as stated. 'Race' was from 0-102 (1st to 4th gear) touched red line in second gear, chirped the tires into 3rd to about 85 etc..No loss of power, pulled over to listen to things and it sounded like my exhuast had a hole in it. Shut it down, checked the oil level, good looked under the car, no leaks yet. Never any oil light. Called Billman and drove 70mi, never over 4k rpm except the last 2 blocks to Bill's house I hit V-tec a couple of times. When I shut the car off Bill noticed Smoke from the rear and about a pt. of oil on the ground. This was the first time it leaked. Car Has never been tracked and I don't beat it much Trying to find the cause. I figured I'd post this to help save someone else a headache. The car is at Bill's so I'm sure once the issue is resolved it will be better than new. Thanks Bill

Froth.

Once you get a look inside I'd like to see the rear main seal condition, if it became fully un-seated and is leaking because of this then I would suspect thrust washer wear allowing the crank to move in/out and thus pushing the seal out from the back. This is all theoretical speak until the car is apart though, post some pics and description I'd love to know what truly went wrong.

street_ruler

i was unaware that you could "chirp the tires" dropping into third while at ~60mph. You either have an aftermarket clutch or just beat the living shit out of the car.

if its an aftermarket clutch then id really lean towards a little crank walk caused by the stiff clutch (see it in DSM's all the time) causing the rear main to move in and out slightly

starchland

I wonder was the knock sound there all along

s2000maniac

I'm still puzzled by chirping tires in 3rd gear

dwight

The tires could be old and hard, there could be something with the pavement which resulted in reduced traction, etc.

Inspired

Oh boy, this has me paranoid now. I have high miles as well.