drola

i am about to pull the motor on my 90 c2 to address the base seals. sucks because it doesn't leak from anywhere else. question is: when i pull the heads off should i have them machined for gaskets or just put them back on. they do not leak at all now but i'm afraid that if i break the seal then maybe it won't seal up the same next time.
also, the motor runs just fine. oil consumption very minimal. should i bother doing a rebuild? or just change the seals and put it back together?
i am changing the p/s belt and seals, valve adjust/seals, cam chains seals, plugs/wires, caps, rotors, filters, cv boots, etc. should be good to go once it's done.
aside from this i figured i'll put a light weight flywheel and clutch while i'm there. PO said clutch/flywheel was done at 48k miles, now at 90k miles. i hear a clunking (not knocking) coming from under the car. i tested the flywheel as per the manual and i'm pretty sure it's going bad.
any comments appreciated

KirkF

I would drop the motor and dissassemble it first.

You may find things that make the decision for you.
When I did mine, I found a used set of low mileage P&Cs for a very reasonable cost.

But if you were doing the job right, you probably need to do valve guides. You cam is probably pitted, etc etc etc.

And one of the nicer upgrades is to replace the stock rod bolts with ARP rod bolts. (One of the weak links in the motor)

Kirk

drola

do i have to split the case to change the rod bolts?
so far the teardown is going smoothly. no major surprises. although someone had mentioned to use a 2 arm puller to remove the crank pulley - bad idea!!! mine got all screwed up and now need to replace it.
once i get the heads off i will see what i find. still not sure on splitting the case or not. 89k miles. maybe could wait till next top end. do not know if it has the head gasket update. could be because there is no sign of any leakage there.
i have no records but the car seems to have been updated. i found it has a lwf/rs clutch. most usual leak spots are dry. the only oil leaking is a liitle from the p/s seal, the vent hose clamp on top of the case was loose and leaking, and the dreaded cylinder base o-rings. other than that it looks good. engine ran really good but the burning oil on the heat exchangers drives me nuts!
i suppose i'll make the desicion as to how deep i'm going to get as i take it apart.

FRporscheman

My dad just got a 964 a couple days ago, and it too is leaking. I'll take my first look at it this weekend. It has 103k miles, and leaks more when cold/off.

I will be watching this thread closely, as I have a feeling I'll be doing much of the same work. Good luck.

drola

well, here's where i'm at. go the motor stripped and cleaned up. i ordered a yoke adapter for my engine stand so i have to wait til i get it to turn the motor over and undo the exhaust. meanwhile i'll work on the cv joints and general cleaning of all those loose parts.

drola

here's what it looked like before i cleaned it up

ilko

You've done a great job cleaning it

drola

here i am !!

parsecnc4

I am curious in how you were able to lift your car up so high.

drola

i used 2 pretty big floor jacks and put them up as high as they would go. my jack stands would not go as high as the jacks so i found a semi-good place to put them under the trailing arms just in case one of the jacks decided to give out. and i did have to remove the rear bumper. that was a no brainer. i've seen a lot of discussion on these forums about this but i really don't see why it's such an issue. it comes off in 5 minutes and makes the whole extraction much easier.
seems like that $69 atv jack from sears was sent down from the heavens. can not even imagine what a pain it would have been to do this without it. plus it rolls around like a dolly. $ well spent !!!

drola

i've made some progress. i got the engine stripped down and am ready to take some action. first of all i need to get the heads to a shop to have them refreshed. any suggestion in the tampa, fl area? also, i was really bummed that my car didn't have the cylinder head gasket issue updated. it did not leak any oil at that junction but now that i broke the seal i think i should address it. i really, really don't want to spend a couple thousand on new p/c's. does anyone know if i can get my cylinders machined to accept a sealing ring? the bores look almost new. the crosshatching is very visible and the walls look great.
suggestions are always appreciated.
so far i see no reason to split the case. does anyone know if the rod bolts can be changed with the case intact? this is the only reason i would see to split it up.

MassGuy

Cool thread...keep the pictures and updates coming. I love this stuff!

Gregg-K

Main reason I would want to split the cases would be to reseal the flanges and to replace the O-rings on the through bolts ... just to be sure you've stopped those pesky leaks!

... Gregg

drola

can the through bolt o-rings be changed without splitting the case?
gregg, what flanges are you referring to?

drola

i'm going to send the jugs out to rennsport to have them machined to accept a sealing ring. should i re-ring the pistons? is there a way to check them? like gap clearance or something? i did not have a leakdown test done before teardown so i don't have a starting reference point.