knock, knock...

[castex]

Really upsetting, intermittent banging noise coming from underneath/behind the seats when accelerating in the lower gears. We should be speaking to KHPC/Scuderia/Pozzi, but their answers will surely come with a big number at the end. Anyone fancy telling us it'll be okay? Please?

[castex]

Don't you worry son; it'll be okay, and cheap.

[castex]

Can you give a fuller descrption of what the noise sounds like - dull, metallic, soft, loud etc. How loud is it? Are you accelerating hard, is it just when you change gear? Does it happen if you let the clutch up slowly with the hand-brake on? Does it sound like soemthing mechanical knocking or something hitting the chassis/bodywork? Does it feel like the engine is moving? Could it be something on the suspension or anti-roll bar (but the anti-roll bar is probably too far back)? Is the rear lid shut properly? Does it affect the gear-linkage in any way?

I'm pretty sure it's mechanical. Fairly loud, metallic, and I can feel it through the seat. Started with hard acceleration, developed within miles to appearing on half-throttle in first. Change gear (smooth as ever), however, and it seems to disappear for quite a while.
Engine seems secure, rear lid always checked.
I don't think it could be susp/anti roll bar as neither are being worked very hard on a straight.
I'll try the handbrake thing this afternoon.

One final question - what were the last two or three jobs carried out on teh car and when?

- new clutch last summer (5,000 miles ago);
- full service, new head gasket, clutch linkage freed at Christmas;
- alternator work three times in 6 months, culminating in a rebuild last month.

None of the above work seems a plausible cause for this, but - clearly - I'm no expert.

Boxer. Low gear acceleration clonk. Diff. Sit down. Cash.

Ah.

If it's intermittant, it may be as you're turning slightly or one wheel spinning slightly??? That's likely to be sun/planet gear chips.

It is possible to pull the diff out the side without major effort, and if "only" an internal differential, fault, it can be repaired, But if any real crown/pinion repairs are required it'll mean a big one I'm afraid, as the pinion can't be removed without full strip down.

Turning the wheel is not a factor. I'll have a look in the workshop manual about the diff, but I won't be pulling anything out - other than my hair - unless it's lego-style simplicity, and that sounds unlikely.

From what I've gathered, driving to whichever garage would be a mistake?

Take the opportunity to install a few testarossa internals and have more confidence in the future!

Tempting...Just that she's (!) so original.

Thanks for your thoughts Kev, Simon, 360N. Just beginning to pin things down is a real help as I get around to biting the bullet.

[castex]

Just realised who you are, Simon. Thankyou so much for all the stuff you sent me!