At wit's end 70T ( sorta long )

[blackbird225]

Ok, long history shortened:
Bought a 70T from a jerk in Canada
Supposed rebuild proves likely with 150 +/- 1 psi in all cyl
Zeniths shafts leaked like a sieve - Bought rebushed zeniths
bought 70E Bosch distro to replace Marelli
Rebuilt 70E distro with new advance slipper gasket ( 6800 rpm lim)
new points, cap, rotor, plugs, magenecor wires all from PP
stock CDI and Coil.
Dwell dead on 38
Timing is somewhere around 30btdc @ what I think is 6000 RPM
Did recent valve job using the two feeler guage ( .004, .005 ) techique. The valves were indeed off a little. Now they are , without question, .004 and no greater because the .005 will not slip through.
No oil in exhaust gasses. No oil consumption.
Opened sump plate to examine screen. One (1) teensy tiny speck of metal there. Size of a grain of sand perhaps.
But I still get a very annoying clatter out of the what appears to be the rear left bank ( 123 ). I think it might be an exhaust leak. Many here have said that an ex leak decreases with heat. My noise is non existant at cold idle and loud when hot. It still idles alittle rough when cold, with a little popping and what not, but that dissapears after a minute or two. I do get some popping and backfire occasionally when hot, but usually right off idle. When I start it up cold, I hear what sounds like a "pinck-pinck-pinck" from the left side where the later load tick\clatter appears. One more thing, the power does not appear to be affected by this, but I can feel the clatter through the pedal. And under power, you can faintly make out what sounds like a deisel benz motor. A very talented local mechanic suggested that all he heard was valve lash. So I adjusted them slowly and methodically. I swear the valves are right now. I even tried to tighten the rocker arms thinking they might be clacking, but they were all tight.
My questions to the group is this: could an exhaust leak make this kind of noise? How much of a nightmare is it to remove those heat exchangers on my 70T?

Sorry it was so long. This is actually a very depressing problem that has eluded me for over a year now.
michael

[RPMClassic]

No sense in pulling your hair out.....take a drive to Tampa and go see Dave White. He'll be able to figure it out in a couple of minutes I am sure.

[Cornpanzer]

Could possibly be a loose head. Look at the bottom of the jugs and see if you see any oil leakage. The old stethescope trick works well for finding compression/exhaust leaks.
If you have been fighting this for a year, you are probably money and sanity ahead to just go ahead and have a pro look at it for you. 911's are made for enjoying!

[mb911]

Worn rocker shafts?????

Ben

[Grady Clay]

Chain trnsioner?

Best,
Grady

[JP911]

Did you check the torque on the head studs when you adjusted the valves?

[blackbird225]

Here's the funny thing about checking for oil leaks at the head\jug union. During the first valve adjustment job I did last year I put the covers on with less than perfect results. Cover bolts leaked oil like crazy all over my garage floor. It was so embarrasing, because in the morning after 3 minutes into my commute, the rear end would start to smolder burning oil, making the car look like there was a small fire behind the tire. I had people yelling across to me almost daily that my car might be on fire! Well, I bought the silicone ($40) gaskets from PP and now not a single drop for anywhere...except today, I niticed that somehwere possibly under my heat exchanger, there is a tiny oil leak of some kind. I can see it puffing out of the heat exchanger somewhere.
How can I ( quickly ) confirm that I have a loose head stud?

If I can't figure it out tonight, I take it to a $hop in the AM.



michael

[RPMClassic]

I repeat.......GO see Dave White in Tampa. It will be a fun drive and you'll get the problem fixed immediately. No guesiing, no worries and back to having fun with the porsche as Ferry intended!! Good luck.

[blackbird225]

Took it in to the shop this morning.... I'll post back the solution to my problem if he can find one...
Michael