problem oil return tubes and exchangers
 

Hello everyone,

I have a couple of questions:

I examined my '78 SC underside today and noticed a couple of problems. I have a lot of oil on the underside of the motor which appears to be mainly from oil return tubes. I also observed that upon grabbing the tubes, I could turn them quite easily and end-end play was about 1/8" on all 4. The car has 62000 original miles with the original tubes. Is this play normal? and is it likely that they need replacement?

I also examined the heat exchangers and when I pushed up on one of the exchangers, it also moved up approximately 3/8 ". The whole
exchanger moved while the bolted on portion that is attached to the motor remained stationary. Is there play with this or are these also on there way out ?

Anybody's experience would be much appreciated.

Thanks Jerry S

78 SC
81 930

I FORGOT TO ASK ALSO , ARE THE TUBES AN EASY REPLACEMENT WITH THE NEW EXPANDABLE ONES?

Jerry,

I believe the 'play' you discovered on the sheet metal/tin portion of your heat exchangers is normal for a 20+ year old car.

And, the play in your oil reurn tubes is excessive, and an indication that you need to remove them with Vise-Grip pliers and replace them with the new two-piece design and new seals lubricated with Dow Corning 111 Silicone Grease or a high-quality moly grease.

Yes, the replacement is easy with the 'Crush-Twist-Tug' technique to remove the old tubes!
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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 01-29-2001).]

I guess I will be replacing them this week.

Thanks Warren

Jerry S

Another tip that worked well for me was to put a hose clamp on one end, against which you can pry without damaging the tube. Getting the old ones out is fun. I mean that. Crush the suckers and twist 'em out.

Oh, and both symptoms are quite standard. At some point soon you will begin to hope the heat exchangers get rusty and fall off. Apparently they are the single best improvement you can make over the factory stock part. That and the pressure tensioners.

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'83 SC

Jerry,

The outer shell of the heat exchangers will move if the spot welds which stabilize the shell to the headers themselves have been broken by rust and/or hitting something. If you are taking these off anyhow and they are in good condition (and you dont want to upgrade to pre-74 exhaust) you could have them re-welded at your local shop. Oxyacetalyne torch weld would be best as the shells are pretty thin.

If you're not taking them off for any other reason, I would leave them alone. The movement has no effect on their function.

Nick.

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Nick Shumaker
1982 911SC Coupe

thanks guys


Jerry S

Montana?? -- Heat is probably very desirable.. If your heat exchangers move significantly it is a good bet they are not sealed tightly around the exhaust pipes allowing heat to dump over-board. SSIs would be a great improvement, on the other hand, if you already have SSIs -- then they must come off to change your oil return tubes.

Alan

Does your car have the smog pump and related air injection tubes?
If so, I think you will find that on one of the sides (can't remember which one), you will have to remove the heat exchanger to get the new collapsable tube in.
I'd give it your best shot to get the new tubes in place without removing the exchanger, but just don't be surprised if after an hour or so you find that you have to!