911Tobbe

Well hope someone can shed some light on this. I´m currently in the process of inspecting the heads on my old engine that suffered a jumped timing chain, and the damage it made on the valves on one cylinder.

I know that there are two versions of exhaust valves, 99610511359 and 99610524700, the change was made around -99 and my car is a -99. The engine seems to be the original, cast dates are from -98 on various places.

Now the strange part: When removing two exhaust valves from one cylinder I find that they are different versions, one 99610511359 and the other 99610524700... They have the same level of carbon deposits and looks identical so they seem to have been in the engine for a long while togheter.

The question now is what are the difference between them? Are they interchangeable? I need to replace them both but with what version? One of each as it was or what?

Dharn55

The part number 996.105.113.59 has been superseded by 996.105.247.00.

Look here:

https://www.sonnenporscheoemparts.co...99610511359%20

911Tobbe

Thanks! My vendor didn´t list that info, along with a couple of others I looked at. They listed both as available, one version to -98 and the other from -99 and up. I´ll just order the new one then.