I know that the valve clearances is an every-15,000-miles job, but is there any way to tell if they need doing? (The problem is I don't know when they were last done)

I can hear a regular 'tapping' kind of noise from my engine. I tried to time the clicks last night, and my best guess was, on tickover, about 300 per minute.

The car is going back to the dealer next week for them to look at some of my niggles, and they say that "they would have set the valve clearances when they serviced the car" (as opposed to saying that they DID).

Of course the tapping may be something else entirely, or even completely normal!

Apologies for this not being a light-hearted Friday post!

PS to Roly - I know you're going to tell me I can do them myself, and I will next time - just makes sense for the dealer to do it for me FOC!

 

You can't easily tell. If the clearance is too big, you will get a tapping sound.

If it's too small (and if it's really small, this is when pistons can get to know valves very well indeed at high revs) then it won't make any noise at all - at least, not until the pistons actually hit the valves........

 

Rob,

Dave is right, it's quite hard to tell from engine noise unless your getting really loud tappet sounds, so don't assume anything.

Is the dealer an OPC? and are they doing the work themselves?

Also check this out...

http://www.pelicanparts.com/techarti...lve_adjust.htm

Ade

 

Rob,

Just have them done regardless, but as this is possibly the most annoying (ie: time consuming) service task on the 964 don't expect the dealer to do it without first putting up a fight (or if they seem very eastgoing about it then perhaps they are just saying its gonna get done).

How many miles on your car? The ticking noise is quite normal (and how on earth did you count 300 ticks in a minute!!) and it comes mainly from the exhaust valve guides. These wear with time (overheating, especially if the car is sat in traffic often) and thus the ticking increases. Only way to 'shut them up' is a top end rebuild.

I thought mine were bad, untill I heard a friend drive away in his 964! Wow, those were loud (and he had had a bottom end rebuild only 12k miles ago!).

The thing I find annoying is driving through enclosed spaces at slow speeds and hearing the ticking noise quite clearly.

 

Riccardo - thanks for your input;

Counting up to 300 was quite tricky! (actually, I counted 10 seconds only)

85000 miles, no rebuilds, no oil drips (but I removed the undertray last night to make sure no leaks). Dealer's not OPC.

I'll wait to hear some others - Wales on 17th August should do the trick!

 

FYI

When I was adjusting my valves for the first time since I owned the car I was asking myself the question how long has it been since they were adjusted - I had no records from the previous owners as to when it was done. The corrosion on the exhaust bolts maybe an indication as to how long its been since they were removed in order to perform the adjustment. When I was into the adjustment I found a couple tight and a couple loose by about a thou and after the adjustment the ticking sound was slightly diminished - very subjective. One thing I did notice is that a half a tank of gas now gets me 400+ kms whereas before the adjust I was getting slightly over 300kms per half tank.
Oh yeah - I almost forgot - I also replaced the plugs, wires and distributor caps/rotors - which will have a definite affest on mileage.

Hope this helps
Bill

 

Bill, does that mean you get about 800kms with a full tank? That is a lot of kms! Have you got the larger (optional) 92 liter tank?

I only get max 500kms (300mi) on one tank!

 

Nope - I'm still reeling from your and JohnFM's outrageously provocative comments about LHD cars.

Seriously though, I was pretty careful with this job and although the clearly tappety noise I had previously has dimished considerably, there is still what I would call chatter from the engine, which irritates, as Riccardo says, in enclosed spaces. I think with cars of this mileage there is bound to be wear that can't be 'adjusted out'. I think the reason you're hearing 300 clicks per minute is that one valve might be particularly badly adjusted. For every two revolutions of the engine each valve opens once so this would equate to about 400 clicks per minute - not far from your estimate. Or am I talking bollocks?

 

Roly - I think you're right with the numbers...the engine rotates twice to fire all cylinders. (and the accuracy of my 300 is questionable - I just wanted a ball park figure).

Who are you calling provocative? Me? I have a LHD car (my M3), so it wouldn't be me - although I did make a comment about a certain £12.5k LHD car...

 

Nothing wrong with £12.5k LHD cars matey...

 

What other skeletons have you got hidden in your closet? Don't tell us you've got.....an Impreza

Mind you I just picked up my SVX from the garage. They very kindly billed me £1760 for a gearbox rebuild. Cheap as chips, Jap cars are...

 

Roly

all LHD comments are not only tongue in cheek, but all back reference to the 12.5k LHD thread of a few weeks ago. Being on the 964 board, this sort of humour is permissible!!

 

Hey I'm cool.


Just don't think I haven't forgotten about your paint bubble comment.

 

You gotta admit it was a bit funny, especially the 'option code' bit...

...I'll get my coat..

 

But you made a fundamental error: I have checked with Porsche and they confirm that option code 'M293 - Anti-Rostluftblase, Unterere Tür' was NEVER available on the Friday afternoon shift.