Porsche 911UK Forum

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

996 Turbo Engine Knock Comes and Goes

rgracin said:
Yep. I've decided to drop the engine for a proper look. Had a pm conversation with Ken at 9e. Very helpful chap.

Just need to break the news to the wife as it's (was) her daily!!

I've met a few 9e customers and pm via this forum. You're in the best hands for a turbo according to them. They swear by Ken and 9e. Don't ask him about k16/39 hybrids. The bigger version - be an easier sell being the other halfs car :grin:

Going down upgrade route only really worth it if the cars a keeper as its very expensive to do the work properly to Porsche standard.Alternative is to swap it for a newer 911. Nice low miles C4S cab PDK just come up for sale at 911V

:wink:
 
The bill to strip and examine what's wrong and fix it and put it back together again is gonna be big enough without any mods. Doesn't sound good if you say you have knocking and those pieces of debris.
 
We'll be keeping it standard. I'm hoping my saving grace is that the knock is not there permantly and it's at the top of the engine not the bottom.

I'll keep you posted on the progress, but it will be a slow burner as I think I'm going to take the engine out myself.
 
rgracin said:
We'll be keeping it standard. I'm hoping my saving grace is that the knock is not there permantly and it's at the top of the engine not the bottom.

I'll keep you posted on the progress, but it will be a slow burner as I think I'm going to take the engine out myself.

Best of luck in getting it sorted. If you do the work yourself please post progress reports on here. I would be very interested to see the work involved.

MC
 
Often it's one of the hydraulic valves. Bin 0w oil if that's what's in it and go to 10 or 15w as this can clear the problem(sometimes)

With 10 or 15w you just have to be more careful with the revs until it's up to temp......so keep it under 3000 rpm.
 
Best of luck, wishing to hear good news soon
 
A quick update.

I refilled with oil, started it, no untoward noises. However, once warm the knocking returned. Had a good poke around with a stethoscope and the sound was most evident on the drivers side chain tensioner cover. You could also feel it if you put your hand on it.

A new tensioner is £285 but before I get one, I thought about swapping with the passenger side and seeing if the noise swapped sides. If it does, hey presto, if. Not, engine out!

Now, they look the same from pictures I can see, but they have a different part number. Does anyone know if they are different in anyway?

I'm more curious than anything. I know that if I drop the engine for. More serious work, then these will most likely be replaced anyway.
 
I'm told a tensioner can be done with engine in situ - i think I need a tensioner replaced (going in Feb)?
 
Drivers side one is two minutes to take out as the cover is visible on the underside of the car.

I haven't been out to the car to look at the passenger side since I had the though about swapping, but I know it's on the top side of the engine, so I don't know what's in the way.
 
Anyone have any knowledge on whether the two parts are interchangeable?
 
Honest answer .. im not sure ive never done it .

They are clearly listed as LH and RH with different parts numbers though so there is a difference and with something like this then perhaps swopping side to side would be unwise ...

Unless anyone has actually done this and can confirm its ok .
 
UPDATE

So, this was always going to be a slow burner, but thought I'd update you.

The chain tensioners are not interchangeable. I was lucky to speak to one of our clients (a race team than run Porsche cup cars) and their guy gave me a couple of tensioners they had in the draw. First thing I noticed was that the one I removed could not be compressed at all yet the spares can be compressed by hand. This indicated that the tensioner had reached the end of it's travel perhaps? The cause of this can only be broken tension pad or stretched chain!

So I bit the bullet and resigned myself to the fact that the engine needed to come out, so I set about doing this myself. I have now removed engine and gearbox. First shocker was the fact that one of the four nuts that hold the gearbox to the engine had been siliconed on!!! It had clearly sheared when presumably the clutch had been replaced at some point and rather than replace the stud which would have been easy as it was one of the bottom ones, they stuck it back in place so all looked good from the outside!

I'm now going about stripping off all the ancillaries and will then be handing it over to a well respected race engine builder who has experience in Cup engines. He's going to pull it apart and check all measurements and bearings and replace anything needed and give it a good refresh.

Some photo's below......






 
So, as said before, a slow burner!

With engine removed, I set about removing all the ancillaries so that I could pass the engine to a friend of a friend who's been building race engines all his life and does many Porsche cup engines.

He set about completely stripping the engine to see what's what. Nothing overly untoward was found, but there was a slight issue with one of the chain tensioners. Where they wear and create a lip on the edges, one of the edges had broken off which would allow the chain to move side ways slightly. There was normal wear on all other bearings etc. The engine has now been rebuilt with all new bearings, chains, rings and a better set of liners (thanks to ok51mon). The original liners were ok, but after honing, there was a little wear evident on the nikasil coating, and some slight pitting so it was decided to do it properly whilst we're at it.

I now have the engine back waiting for me to put all ancillaries back on with new water pump welded pipes etc and then back in the car. Just need to get some other projects done (Boxster clutch, bedroom decorated!!).
 
thanks for updating us, always good to see the whole chain of events.
is the car back on the road yet?
 

New Threads

Forum statistics

Threads
124,350
Messages
1,439,414
Members
48,706
Latest member
SBSEA
Back
Top