bigmackloud

Just got home from VIR. This event did not go well for me. 6 laps into the very first session, I see smoke behind me on the back straight. Bring it into the pits, and there's oil and coolant all over the passenger side of the engine bay.

Coolant appeared to have come out of the reservoir. Oil dip stick was pushed out so I assume that's where the oil came from. Nothing appeared busted.

Oil temps were around 225, coolant was under 200. (Cool weather, and only 6 laps in).

2 problems. Within 2 mins of idling, the coolant would go from the full mark to the top of the reservoir. And there is "smoke" puffing out of the oil filler. You can put your hand over it and feel puff puff puff to the rhythm of the engine.

My first thought was head gasket. But after dropping both the oil and the coolant, there was no cross contamination.

I drove it around the paddock this afternoon after changing the oil and the coolant, and noticed the coolant level fluxuates. Even once fully warmed up, it will go from a half inch below the full mark to a half inch above. And the oil filler still smokes like a chimney.

Saturday afternoon while trying to diagnose things, I got a low oil light. Now obviously some sprayed around the engine bay, but it didn't seem like multiple quarts. (They didn't have to clean the track after me). So I'm not sure where all the oil went.

Car was running great, no indication of being down on power or any problems until I saw the smoke. Motor seems to run fine even now.

I run a catch can. Only a small amount of oil in the can. I disconnected the pcv line before the can, and there's smoke puffing out. I disconnected the line after the can at the TB and smoke puffs out there too. So the pcv lines aren't clogged.

I did a coolant change while prepping the car for the track. Drove it several times after and saw no indication of an air pocket or over heating. But I suppose there could be an air pocket??

Any thoughts? I'm totally bummed. Missed a great event. Perfect weather, and I missed running grand course.

Thanks in advance

Dirk Miller

So the mustang wanted to spend time back at the barn?

zrtman1

The pulse coming from oil filler points to broken piston or ate a ring possibly. Do compression test. Coolant still could be head gasket.

Grand course is fun. They should run that more often. Did you see the c6z burn?

bigmackloud

I did see the c6z burn. Or at least the aftermath. I keep telling myself he had a worse day than I did haha.

I'm going to do a compression test (hopefully today) and see how that comes back. I thought about the broken ring idea, which would explain pulsing crankcase pressure.

One other data point I'll add, there's no smoke from the exhaust. (At idle at least).

zrtman1

If compression is ok do a leak down test. Look at the plugs as you take them out. A very clean plug could mean head gasket. Obviously a dirty or oil soaked is other problem.

​​​​​​​The smoke from it was pretty bad. Heard it was a new engine that blew on back stretch. Hopefully he had insurance but at least he didn't get hurt. But yeah your day could have been worse.

jlutherva

Bigmackloud, you made out better than me! I blew my engine Friday morning in the second black session. I think I spun a rod bearing. Part of a connecting rod was laying on the floor of the trailer by the time I got it to the shop. I also had a burst of flames come out the hood vents but I quickly got the fire out with the AFFF extinguisher system. I got a grand total of 1-1/2 days on that LS3.
Good Luck with yours,
Jim

fatbillybob

It takes more time and energy to do a leak compression and you want to know as much data as you can right now. So put a pressure tester on the cooling system and that can tell you alot right there.

bigmackloud

Well it sounds like this was a tough event for corvettes. You have my condolences.

Thanks for the suggestions. I post back as I get more data.

bigmackloud

This poor c6z definitely got the worst of it. As they were making sure the fire was out, I watched them fold over his wing like it was melted cheese. Glad to see the driver got out ok tho.

froggy47

Quick, simple, easy.

Mark@AMT Motorsport

Wait what!? Brand new LS3 blew to bits? Any more info you can share?

bigmackloud

Ugh, I finished the compression test. All cylinders at 200-210... Except cylinder 7 at 90.

I'm beyond disappointed. The motor only has 65k miles. And I've only done 6 days on track with it. I can't believe it already has motor problems.

aaronc7

Sorry to hear....welcome to the club. Mine was #7 as well. Block was cracked too along the coolant passage.

Poor-sha

Just for clarification, this is a C7 Z06, right? 65K seems like a lot of miles even if it's a 2015 but it still shouldn't have blown. What color car and run group were you in? I was really surprised to see so many C7Zs at the track. Lots of Vipers too.

I'm likely going to pack it up mid-day tomorrow myself. I think my wheel bearings are shot and I have a service air bag system light on.

bigmackloud

No mine is a 2001 ls1 c5.

jlutherva

Nothing yet. I just loaded it up and took it back to the shop for the forensics work. I'll let the shop figure it out with the engine builder.

Jim

bigmackloud

So I've been doing some reading tonight, and apparently the 7 cylinder failure is a major issue. But what's the long term solution? I certainly don't want to go down this path twice.

FASTFATBOY

If it popped a ring land it will pass a leakdown test.

Possibly a bad thermostat also.

Bill Dearborn

Jim,
It seems like the only luck you have with that car is bad luck.

Bill

StreetSpeed

I'm just curious if it was a crazy race motor making 700hp strung out to within an inch of its life or a stockish LS3? One of my competitors went through three brand new motors this year all put together by the same household-name shop. Some people just don't get it right.