Compress Loss!

[superfans]

Guys, I have been encountering some small backfiring issue with my 996tt (2002 tip) and the chief mechanic of the authorised dealer said it was the sticky hydraulic tappets which caused the backfiring. Accordingly, I have taken my car to them to have the tappets changed. My car has been with them for almost 2 weeks and yesterday I was told that my car is now encountering some engine compression loss (probably something is leaking after the change of the tappets). I mean how could this happen? Is this poor workmanship or what?

Actually I would like to ask (i) is it reasonable to take 2 weeks to change the tappets? (ii) what can cause the engine compression leak in this situation? Thanks in advance.

[1999Porsche911]

2 weeks is a long time, but you have to remember that the average Porsche mechanic has little experience working on the internals of the engine and they probably had to look in the book to see what a lifter was I assume this is warranty work?. They probably had to order parts too. Sounds like a valve is not sealing. Did they say that the leak was 1 cylinder or all?

Edited August 25, 2005 by 1999Porsche911

[superfans]

1999Porsche911, thanks for your quick response. Actually I wait until the parts have arrived before taking the car to the dealer. I reckon that they did not work on the car immediately when I took it in. They haven't said what causes the problem. All I know is that the chief mechanic will take a look at it. I am afraid that the tappets were changed by a junior mechanic and he may have forgotten to following the proper instructions in replacing the tappets (e.g. to pre-load the tappets first, etc.) Do you think the compression loss can be a serious problem?

[1999Porsche911]

1999Porsche911, thanks for your quick response. Actually I wait until the parts have arrived before taking the car to the dealer. I reckon that they did not work on the car immediately when I took it in. They haven't said what causes the problem. All I know is that the chief mechanic will take a look at it. I am afraid that the tappets were changed by a junior mechanic and he may have forgotten to following the proper instructions in replacing the tappets (e.g. to pre-load the tappets first, etc.) Do you think the compression loss can be a serious problem?

<{POST_SNAPBACK}>

It is unlikely that it is a major problem. They'll have to take it apart again check the lifters. Keep the pressure on them. By the way. Do you live in a hotter climate and been using 0w40 oil? If so try going to at least a 5w50 in warm climates and this will help keep the lifters from cocking and jambing. Assuming that is what caused the lifter problem to begin with.

Edited August 25, 2005 by 1999Porsche911