rdhayward

I believe my car's oil pickup tube broke yesterday: noisy valvetrain at low rpm, loss of oil pressure. I'm curious to know what could suddenly cause this, as I try to determine what to fix IF it's going to get fixed. Fact is, I've been hanging on to this car a bit too dearly, as it was originally owned by my late mother, and also because it's potentially evidence in a lawsuit against a shop that painted it in early 2008.

Raj suggested that a balance shaft could be misaligned. I replaced the belts in April 2008, 48k miles ago, so I know the car is due for new belts. But in recent times up to and including the event yesterday, there wasn't a persistent vibration at higher rpms as I would expect with a misaligned balance shaft.

Rather, there was a bad buzzing at idle that reminded me of a car with a Fidanza flywheel. It was otherwise smooth up to redline.

Is there another culprit here? I'm thinking a bad dual-mass flywheel, or even bad motormounts.

PorscheDude1

All 3 could be the culprit:
Bad DMF
Balance shafts out of phase
Bad Motor Mounts.

rdhayward

Thanks for the response. Could you elaborate on each of these three possibilities, by describing the symptoms of each? E.g., what else would I experience with bad motor mounts?

Damian in NJ

Ralph, I can assume you're going to have this welded on?

http://www.crank-scrapers.com/ebay%2...ckup_ebay.html

PorscheDude1

Bad motor mounts:
viberations at idle (feels kinda of lumpy and jittery)

DMF:
higher frequency that can be felt thru all rev ranges and can be felt in the steering wheel.
Your hands will go numb.

Balance shafts:
lower frequency thud felt around 3k rpm.

rdhayward

Thanks, PorscheDude1, that helps immensely. I'll ponder replacing the belts and motor mounts, and save the DMF for another day.

Damian, yes, I've seen that and another modification technique to strengthen the pickup tube. Can such a crack in the tube itself be welded, or is the entire part a loss?

Also begs the question about how difficult are the crank bearings to do while I'm in there? Is it just a matter of removing the endcaps from the connecting rods, turning the crankshaft out of the way, and snapping in new bearings; or does the crankshaft have to be taken out completely?

Also, crank scrapers & windage trays? I put one in a Jeep straight-6 engine I built (made by this very company, Damian), and loved the difference it made. Almost suprises me that Porsche didn't include one the 968 engine, considering all the other esoteric goodies in there.

ramius665

Ralph, sorry to hear about the troubles. The hardest part of fixing the oil pickup tube and replacing the rod bearings is getting to the bottom end of the motor. You'll also need a new oil pan gasket (haven't replaced one while in the car, could potentially be a real b!tch) but otherwise is fairly straight forward.

Replacing the rod bearings is as simple as removing the con-rod nuts and moving the crank out of the way. Should take 30 minutes or less from start to finish. Just remember that you will have to replace the con-rod nuts with new ones, they're one-use only.

PorscheDude1

A new oil pick up is less than $100.
Rod bearings are also under $100.

The R&R is not hard just time consuming. You'll have to pull the cross member
(great time to do them motor mounts) and more than likely need an alignment afterwards.
The crankscraper can be a little finiky to hold in place during installation.

rdhayward

I've seen photos of a special tool to suspend the engine for jobs like this. Are there other means of lifting the engine just enough to be able to remove the oil pan and/or motor mounts?

ramius665

I actually believe you can find the proper engine mount at Harbor Freight. It's secured on each fender, and chained to the stock hoist points on the engine. I don't know how comfortable I would be working under the engine while it's up on jackstands with that method though. If you have access to a lift, it shouldn't be a safety issue.

FRporscheman

When I did this service, I used a 4x4 across the strut towers, and about 5 or 6 loops of rope around both motor mount brackets. I got sidetracked and the service took me a few months, and the 4x4 and rope held for all that time. The torque tube was also supporting the motor.

Even in good tune, these big 4 cylinder engines do vibrate a lot more than others, so it could just be a matter of time until a pickup tube cracks. I'd just buy a new one and be good for another decade or two. But definitely change the motor mounts if you don't know when they were changed last, since you will have them out anyway while you change the oil pickup.

mikey_audiogeek

That's a lot of trips out to Smitty's in Lockhart...

rdhayward

It's going to be one of those "while I'm in there" jobs, for sure. I also need to replace the power steering pump, and bring the timing and balance shaft belts up to date.

Can the engine be held up by an ordinary cherry-picker hoist?

ramius665

Absolutely! A regular shop hoist or cherry picker will work. Just remember, if you don't utilize a cross-bar to distribute the weight between the two engine hoist points, you will bend the hoist rings (happened the first time I moved the engine). Shouldn't cause any permanent damage, but just a bit ugly.

PorscheDude1

Check with autozone or pepboys, you might be able to rent
the engine support.
Autozone has free rental with a deposit.