sh944s

Kevin's got it right. I know that if I add back the balance shafts my problem goes away; can't argue with Joe on that one. If there is a proven method of re-inforcement then I am willing to give it a try. If not the fall back plan is to add the shafts back to the motor.

Chris Prack

Yeah, I am not holding my breath on finding one. I have literally hundreds of pics to go through.......sigh.

RajDatta

How about some food for thought. A 968 turbo S also uses a vibration dampner. Porsche felt the need with bigger displacement and no DMF to add a vibration dampner to the setup.
Something for guys with large displacement turbo's to think about.
Raj

pete95zhn

Take an old ( like 20 yrs ) pick-up tube and try to bend it. Most likely it'll crack. Now do the same with a new one, it'll bend. ( Then of course it's u/s and not to be installed. ) The message is that old ones get brittle with the time.
Vibration accelerates the failure, but it can happen to cars with ( correctly balanced ) balance shafts.

Lemming

FYI, I am in the process of rebuilding my #1 968 engine that was used for the 2006 season and replaced in 2007 with my #2 engine. I dropped the oil pan this weekend and sure enough the pick up tube has a large crack at the top. Glad I pulled that engine at the end of the year At that point I was running an S2 flywheel with no harmonic damper (balance shafts in place). At the beginning of 2007, when I installed #2 engine, I also went with the harmonic damper from the S2, hopefully this will help (especially since I'm running solid motor mounts).

Pics of the pickup tube reinforcement would be great

Oddjob

Track cars run w/o balance shafts or w/ balance shaft belts incorrectly timed are known to have oil pickup tube failures, fuel rail failures, crossover pipe failures, etc due to the extra/excess vibration.

But there are pickup tube failures on cars that are running B/S's, although its less common. So lot of track guys have their pickup tubes reinforced just as a precaution.

Main reason for cracking at the tube/base mount, is because the bolt on the tie-bracket (between the pickup and return tube) vibrates loose, or that small/thin bracket cracks, allowing the two tubes to shake/vibrate independent of each other - which allows enough movement that it can/will eventually crack the tubes at the base (pickup tube will typically crack first, since it has the heavier cup/screen on the end, amplifying the vibration/motion).

A common reinforcement method is to do a full seal/seam tig weld around the base of the tubes to the mounts, and to reinforce the small bracket that ties the pickup to the return tube with additional/thicker metal tabs.

Lemming

That bracket is broken on mine.

mjensen

I race a 86 951 in PCA and NASA. In May @ mid-Ohio I had spun rod bearing #2. When I removed the pan I found the oil tube broken, bounced around and broke out the oil baffle. Balance shaft belts were ok and timed correctly. Will rebuild the engine over the winter(pulled the engine and trans already)...

sh944s

Well, I am glad to see I am in good company with this failure. My engine ran the balance shafts for the first 5 years after my rebuild. I only ran it a little more than a season without the balance shafts. My tube failed at the start of the first bend after the base. I would bet it was brittle as Oddjob suggested. I wonder if it makes sense to purchase a new one rather than run a 20yr old used part.

I plan on reinforcing it in any event.

Chris Prack

I have seen new ones break in the same fashion FWIW.

993944S2

I posted this to the racing forum just 3 days ago...

At Mosport this year I thought I blew the motor in my 944S2. (three laps from the end of the enduro. I pulled the oil pan and found the oil pickup broken and lying in the bottom of the pan. We pulled the No. 2 bearing and there is some scoring. Also some very small metal flakes at the corner of the bearing, next to the crank. My plan was to pull the crank and have it professionally checked. I can see some slight coloring on the journal surface from heat.

I was very quick to kill the motor when the idiot light went off. I was in the T3 right hander, at the bottom of the hill.

My question is... do we think I need to replace the oil cooler as there may be some debris lodged in the cooler? I will be pulling the engine and replacing it with a spare race motor I have. I was planning to use the same oil cooler.

Chris Prack

Get it ultrasonicly cleaned or replace it. Do not run the new motor with out doing this and cleaning the oil lines etc.

Oddjob

I think it was Pete95zhn that made reference to the metal "aging".

Cracked tubes will be a fatigue failure from vibration loads, but I think use has much more impact on failures than mileage/age. I have not heard of many/any broken oil pickup tubes on street only cars, even very high mileage ones.

special tool

You guys realize (especially you guys with 2 race engines) that there is a good solution for this.
One that solves about 30 other 944 problems at the same time.

PorscheDoc

This is the one out of my old motor. It had near 2bar pressure at hot idle, but I yanked it due to compression numbers (150k hard miles on it) and rebuilt a different motor that I had laying around which is now in the car. This motor sat on the stand for the last year, and I just pulled it apart about 3 weeks go to go through it. I can be a brute when taking things apart, but I dont think I was that hard pulling the pan off, lol. You can't really see it, but other parts are broken as well, lol.