Dead Engine Autopsy (picture intensive)
 

So I finally got around to taking the head and oil pan/MBSC off the engine that died. I was hoping for a definitive cause of death....but, I'll let the pictures do the explaining. Also, on the head where I suspected the fatal compression loss to have occurred, I turned the cams and watched the valves seat across the board just fine. No signs of any valves sitting even 1mm out of place...nothing. Couldn't find any cracks in any piston, headgasket was fine.... I guess when everyhting comes apart (valves, springs, cams, rods, pistons) there may be something more obvious.

I did find a few interesting things though...but none of which I believe was a specific cause...I'll let you guys find them in the pictures.

Remember I am running a coolant re-route on the stock 01+ headgasket.

Discuss-


Valves Cylinder 1

http://farm5.static.flickr.com/4097/...2dceaf70_b.jpg

Valves Cylinder 1

http://farm5.static.flickr.com/4098/...d85bce95_b.jpg

Valves Cylinder 2

http://farm5.static.flickr.com/4141/...5322fe03_b.jpg

Valves Cylinder 2

http://farm5.static.flickr.com/4081/...c851b5e4_b.jpg

Valves Cylinder 4

http://farm5.static.flickr.com/4120/...797b75ab_b.jpg

Valves Cylinder 3

http://farm5.static.flickr.com/4140/...6d516765_b.jpg

Valves Cylinder 2

http://farm5.static.flickr.com/4122/...9cfd5d0a_b.jpg

Valves Cylinder 1

http://farm5.static.flickr.com/4082/...71e61497_b.jpg

Engine Bottom

http://farm5.static.flickr.com/4094/...e572551e_b.jpg

Cylinder 4 Rod

http://farm5.static.flickr.com/4074/...ca910673_b.jpg

Cylinder 3 Rod

http://farm5.static.flickr.com/4115/...98f45ab9_b.jpg

Cylinder 2 Rod

http://farm5.static.flickr.com/4123/...02116936_b.jpg

Cylinder 1 rod

http://farm5.static.flickr.com/4140/...0e6ccf7f_b.jpg

Piston 4 w/flash

http://farm5.static.flickr.com/4077/...387f89fa_b.jpg

Piston 3 w/flash

http://farm5.static.flickr.com/4119/...eaaea008_b.jpg

Piston 2 w/flash

http://farm5.static.flickr.com/4102/...537a8091_b.jpg

Piston 1 w/flash

http://farm5.static.flickr.com/4080/...805cdb85_b.jpg

Piston 1 closeup

http://farm5.static.flickr.com/4121/...75b98991_b.jpg

Piston 2 closeup

http://farm5.static.flickr.com/4122/...3a1d51ed_b.jpg

Piston 3 closeup

http://farm5.static.flickr.com/4093/...5d8b9386_b.jpg

Piston 4 closeup

http://farm5.static.flickr.com/4075/...58298ee5_b.jpg

Top of engine

http://farm5.static.flickr.com/4136/...f157603d_b.jpg

I see bunch of detonation.

it looks like rod #1 is slightly bent.....but its probly due to the angles in the picture.

i'll second detonation. You can see it really bad on the closeup for 1 and 2.

Holy carbon build up Batman! It does look like #1 is bent, it's even pushing against one side of the piston, where as the other three look centered.

Things I'm thinking-

1) Detonation- I have a strong feeling the spots on valves 1 & 2 are a direct issue with the coolant reroute and the lack of flow to 1 & 2 because of the headgasket design. A track day the week before brought on some ignition-like problems. I have a feeling the cylinder head was getting VERY hot on 1 & 2. Odd how there is detonation on PISTON 4, but not on VALVE 4, PISTON 1 looks decent/no metallic dust from detonation like #4.

Carbon buildup-
I had been on the track for a few sessions a week before and had some ignition issues that produced a metric TON of unburnt fuel. I didn't drive the car much after that track day and didn't "blow it out". Also, I tried a TON of times to fire the engine back up and there were several MINUTES where it ran stupid rich because the engine was barely turning over...massive amounts of unburned fuel fumes filled my garage...plugs fouled. Oh and when the engine died (while moving and in gear) I opened the throttle multiple times to see if it would return to normal...lots of flames came out the exhaust doing so...more unburned fuel.

Bent rod- Dunno. Considering the detonation on the top of #4, I'd think that would be the logical one to be bent. Only thing that makes sense to me is excessive heat and detonation from the coolant reroute.



What do you guys think of what I think?

i think you should pull the pistons out.


i bet there is a chunk of missing ringlands.

Detonation.

Also, that looks like a perfect candidate for methanol/water injection.

Did you already post pictures of the spark plugs? If not, do so.

i was bout the say the same thing,

+1 on water/meth..

what was the mileage on the motor?

How far are you retarded from MBT or detonation? I'm 6* back from MBT for this reason.

Is it the pictures of the valves that is giving away the detonation? I have been staring at the pictures of the pistons for five minutes and can not see a noticeable difference between them..

If you look closely you can see small pits in the tops of the pistons

I agree, #1 and #2 valves look like detonation.

Like everyone has already said, I agree with detonation in 1 and 2. And #1 rod does look bent in the pic.
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This.

1 & 2 will be ugly, and were probably a week from losing material on the crown by the time you started losing compression.


#1 rod definitely bent, and I imagine another one is bent on the other axis. Mine were split dead even like that...one on each axis, and one on both axes, last one fine.


I've seen worse carbon on valves, but the head and pistons have a LOT. Detonation probably worked the surface a little giving it more of a foothold, although the build-up may have been there long before, contributing to the det. I forget how many of your miles were boosted...

Carbon build up can also create hot spots that will aggravate your tendency to detonate.

Would you mind posting your spark map when you get a chance?

Very curious about your timing map. Your detonation doesn't look nearly as bad as mine did though.

Attachment 195789
Attachment 195790