Oil Return Pipe - partially crushed
 

85 3.2 Carrera - my oil return tube that runs along the running boards is partially crushed from a previous owner/mechanic improperly jacking up the car.

My question: Appears to run and cool fine, however I am sure the flow back to the tank is restricted. I am looking into replacing it with a new replacement tube but am curious if anyone knows or experienced the long term effect of this restricted pipe. Any symptoms that pop up?

Thank you.

Mine is bent some from improper jack/lift placement. When I showed
It to my Porsche mechanic, he said he’s seen worse and would not do anything.
So I have not.

My trombone cooler gets warm so I know there is oil flow.
If you temperatures are fine, why worry.

Repairing the line is definitely possible - it's been done before:

http://forums.pelicanparts.com/porsche-911-technical-forum/403622-fixed-my-crushed-oil-line-5-beer.html

Mine is flattened in a few areas but it has no effect on my temps....they are excellent, so it depends upon your def of 'crushed'.… thro a pic in.

If I didn't know better, I'd think they came that way from the factory. Lollypop + large floor jack + inattentive operator = two dents, one on each side of the jacking point.

It would have to be pretty bad to significantly affect temps.

Thanks all for the feed back - and good points on the temperature but I am more concerned about oil flow. Would this not restrict the oil flow timely back to the tank which would then go to the sump and pumped up through the engine? I bring this up because I know a top end rebuild is in my future and I would not want this to prematurely wear my new build. I would replace the valve seals, valves needing to be replaced, send out the injectors to be cleaned and tested, check cylinders and pistons for wear (hopefully they only need new rings) etc.

Dave - Porsche anticipated your worry, and if the flow resistance to the front cooler or back from it gets too high, a spring loaded valve in the external oil thermostat unit opens and oil, or some of it, bypasses the cooler and goes right back to the oil tank.

I cannot recommend too highly the "Fixed my crushed oil line" discussion. No special need to fix the crushed lines when the engine is out, but that's still a good time to do it as you will have drained the oil. Oil change time about equally good.

I don't recall hearing of anyone who actually quantified the flow restriction from this or that percentage reduction in cross section at one or two short sections. It may be less than one might think. Nor that anyone quantified the difference in cooling from a fully round pair of lines versus ones with some flat spots. All sound like fine engineering student laboratory projects - figure things theoretically, then see how measurements compare with theory. But most of us just fix the flat spots and move on. Though I drove and raced for several years before my conscience got the better of me, the referenced discussion emboldened me, and I took part of a day and just got it done. It helped that I had had the four thermostat connectors off before, and had used anti seize when reassembling. Those are the critical part of all this.

Take them off, plug the ends, apply air to one end, heat the outside of the tube while SLOWLY adding air pressure. As the tube heats, the air expands it back to "round"... My lines were pretty well crushed from what appeared to be a curb hop. When I did mine there was slit in the tube where it had rubbed the curb. I expanded but the slit opened up and I had to silver solder the slit shut.

Try saying that five times really fast !!! LOL !!!!

LOL!! I laughed as I was typing it. I was thinking, maybe I should call it a crease?