Alan G.

An old time PCA Racer once commented that he knew he could probably rebuild his own engine, but he payed the big bucks because too many freinds had rebuilt their own motors, two or three times. It stuck in my mind.

I rebuilt my 3.6 two years ago, and the only problem that I had was a nasty oil leak from a backwards breather gasket. That backwards gasket thing left me wondering what else did I do wrong? My confidence got better as I roled up 7,000 miles. I even commited the mortal sin of declaring the job a success with some out of region DE friends. The track was just starting to dry up so I was out running 4 tenths looking for grip.

As I was coming off the track I noticed the idiot light was on and the pressure gauge was flatlined. It had been raining a couple of days, and there was the possibility that it was electrical. I had the car towed home to play it safe.

I drained the oil and found what appeared to be a rounded piece with internal splines. I pulled it apart earlier this week, and found that the IM Shaft / Pump coupler had failed on the pump end. I found another chunk on the bottom of the case. It looks like it broke pretty cleanly, and all peices are accounted for.

The pistons, rings, cylinders, and rods all look good. I haven't split the rods yet, but the main bearings are scuffed a little, but the crank mains looks no worse for the wear. The IM shaft bearings look good. The little bearings got nicked up but all bearings were sitting nice and snugly.

My original rebuild was at 93,500 miles. I replaced all of the bearings with OEM parts, and upgraded the rods bolts to ARP. All of the original components were up to spec, so I just added new OEM Rings, chains and chain rails. New wrist pin bushings were pressed in, and the rods bottoms were resized.

The oil pump spins freely by hand, and the IM shaft looks good. Unless there was some kind of imbalance/vibration it is hard to immagine what else could cause the failure. I'm happy with what I found. My work held up well. The worst wear that I saw was on a couple of 4-6 cam lobes, and scratches on some of the same cam tower journals.

What would you do?

(Above cross posted from P/P Engine Building Forum)

I made 10K offer for a 200,000 mile 92 C4 this morning. It went in thinking parts car, but the car has good maintenance records, is clean and runs solid. I have a (company) 4WD truck, and a suby beater (mostly wife's), but I'm thinking that the 1-5 hour ski drives become an "adventure" in a 964. Understanding that "not all adventures are created equal".

If anyone has any engine suggestions or 4WD related experience with repair costs, and/or parts cost and availability, please enlighten me.

Alan

tbennett017

There aren't too many stories of C4 drivetrain related problems... They're pretty solid as far as I know... My C4 is nearly at 200K, and I have had great luck with both the engine and the extra driveline equipment.

I can recall only one major thread on here related to the front diff and driveline, and the circumstances on that one were pretty strange.

Ski adventures... all I would add is that the correct tire will greatly help your performance... ;-)

-nick

The light next to the AWD switch that blinks on when the PDAS engages itself during driving burnt out recently. Does that count as an AWD problem?

I can only give a data point, but mine has been perfect and I've buzzed around in some snow covered roads more than a few times. Only difference from C2 maintenance was rebuilding the two extra axles went I went through my CV joints, changing the front diff fluid in addition to the trans fluid, and I had a shop bleed/refresh all the hydraulic fluids.

Goughary

I use michelin alpin PA2 snow tires on mine - was climbing steep hills in 12 inches of fresh snow last winter with zero problem - was absolutely awesome. So +1 on the correct tire comment...

A 964 with 200k miles in decent shape for 10k? All-in 35k mechanically sorted and rebuilt? Potentially 20k or less if you do the work yourself? Or 10k as a fun driver? Sounds like a steal to me...

napaul

you should get the parts car and then sell me your abs ecu to help offset the cost of the parts car.

From my understanding and reading i have done these awd components appear to be bullet proof.You said you put 7000+ miles on it so surely if it was something you failed to do it would have been apparent sooner wouldn"t it?

napaul

Well i think you should get the parts car and sell me your abs controler to help offset the cost of the car !

From all the reading and experience so far with my c4 the awd components appear to be bullet proof.Plus you said you had logged 7000+ miles on it so surely if it was an error on your part it would have shown up sooner wouldn't it?

napaul

sorry for the double post thought first on hadn"t gone through my bad!

Alan G.

A freind and longtime Hudson Valley Region friend. Well he's a 944 guy, and he already told me a story about the last guy that actually bought one of those!

What happens when the abs controller gets bad? I don't suppose it's as easy as living without anti locks. I guess I have to go to school on how it all is supposed to work.

Alan G.

I've always been a Nokian Hakapalita kind guy. They get lots of practice up there. There are probably better performing tires, but those Haks keep digging. I wonder what the selection is like in 16s these days?

QUOTE=tbennett017;8838792]There aren't too many stories of C4 drivetrain related problems... They're pretty solid as far as I know... My C4 is nearly at 200K, and I have had great luck with both the engine and the extra driveline equipment.

I can recall only one major thread on here related to the front diff and driveline, and the circumstances on that one were pretty strange.

Ski adventures... all I would add is that the correct tire will greatly help your performance... ;-)[/QUOTE]

Alan G.

I could live without the light!

napaul

as i am finding out bad abs controler equals no abs or traction control as they are both linked to one another and you have the annoying light lit up on the dash!

altarchsa

I bought a 109k C4 just rebuilt by an indy (they still had the car) with an $11,000 bill owed for the work. With 8 911 rebuilds under my belt, I'd rather trust my own work than any non Porsche ONLY shop. While performing $11k worth of work, they missed the valve guides and 4 months after buying the car I dropped a valve. Lots of damage.

I did the repairs myself, again, and again. Moral of this part of the story is, if you have a catastrophic failure, take EVERYTHING apart, including the entire intake system, and clean it thoroughly. Also, have everything fly cut or planed by a machine shop. Buy aftermarket machine cut valve covers, at least lowers, if possible.

However, even after the frustration of doing the job several times until I found the source of the continuing problem, I am very proud of having a motor that I have total confidence in. it runs great, and I think our 3.6s are really good engines and all mechanicals are generally very durable.

Alan G.

You really hit the nail on the head for me. The hardest part of my failure is that I'll never know for sure if was related to my work, or was just a bad part. As I do things over, I get a better understanding and touch, a little more experience. It is a whole lot of work for slightly more confidence in my work.

Thanks
Alan