amirpc

I finally got my pistons out and got a good look at everything. I've never seen any of this before except for in pictures, so I figured I'd get some opinions.

All bearings except for #2 are mirror finish, and so is the crankshaft.

The #2 rod bearing has some black markings on it, and the crankshaft has black markings all over it. Besides the odd markings, there doesn't appear to be damage to the bearing.

Also there were metal pieces in my oil pickup screen. I've attached pics of the metal in the oil pickup screen, as well as the crankshaft at #2 and the bearings.

Thoughts?

jacksonrw

I have seen this before
I am sorry
expensive and painful

amirpc

What exactly is it?

ShApE

that sucks man, I have spun the #2 bearing....twice....in one year.

any pics of the undamaged bearing?

amirpc

So its definitely a spun bearing? What is the fix here?

I mean I'm doing a full rebuild of the motor already, if I just measure everything and do the standard rebuild stuff (which would include getting the crank polished and replacing all bearings)... should that take care of it?

You mean the other bearings? I didn't photograph them, they are perfect looking I think.

ShApE

you need to take the crank to a good machine shop, have the #2 journal welded and ground down then buy a new set of rods and bearings. The bearing size will depend on what the machinist brings the journals down to.

amirpc

Seems like it might just be cheaper to buy a new crankshaft...will the standard 944 cranks fit a 951?

Here's a cheap one on ebay:

http://cgi.ebay.com/ebaymotors/_Car-...ht_1822wt_1202

DanG

Amir, be careful buying a used crank. That auction does say its in excellent condition and the journals are standard size, but you want to be sure you're not getting an anchor. Have the seller take better close up shots, especially of the #2 rod journal. Ask him to take a picture with a pair of digital calipers on that journal to prove its size.

If your crank doesn't have a lot of damage you still might be able to get away with having it clean up to standard journal size, no welding/grinding process necessary. Take it to TWPS and see what they think.

jlturpin

I've got a great 2.5L T Crank, and A good rod if you need one. I can get you photos next week if needed.

Van

Looks like a spun bearing (see the metal smeared onto the crank journal?). Not enough lubrication caused an excess of friction, which caused the bearing to start smearing on the crank (another way to say it would be the crank was machining the bearing from the inside), this caused excessive clearance, this clearance caused rod knock, and, perhaps, low oil pressure...

The good news is you tore it down before having a catastrophic failure - like the rod breaking, punching a hole in the block, and tearing the piston up.

Is the metal at the pickup screen magnetic?

Kool

Most definitely a spun rod bearing.

It might clean up. Were you on the track when this failed?

On the bright side you will learn a lot about your car rebuilding it yourself.

Rob

You'll also want to get the rod big end re-sized or a replacement rod.

95ONE

I too am curious when you first noticed the rod knock.

Kool

They way I see it is he was on the track and spun it or ran it out of oil. If it ran out of oil there may be other surprises in that motor. I know when I spun the rodbearing on my K20A2 acura there was starvation damage on the cam races. It wasn't huge but definite evidence or the cam "touching down" on the race.

amirpc

I wasn't on the track per se, but some days the world is my track if you know what I mean.

What happened exactly is outlined in my other thread but essentially:

Going 110 and I start to hear a loud ticking sound
Start pulling off, by the time I'm off the road it is really loud.

I had diagnosed it myself as rod knock by watching videos on youtube and listening with a steth, but TPWS told me it was lifter tick. I rebuilt the top end and it obviously didn't go away.

Basically the car leaked oil, a lot - I knew that. I topped it off like every other week. I got into a minor accident (spun out hopped a curb) and it hit the oil pan, I think it started leaking oil much worse at that point. I think I hadn't checked the oil in a few days, a lot leaked out...then I drove it like a madman - and poof.

I'm planning on measuring everything before I start buying parts. I think I've got all the tools I need to make sure everything is within spec, but we'll see.

This morning before leaving for work I think I noticed some light cylinder scoring, I'll get pics up tonight.