Carrera 3.2 rattles when warm, sounds fine when cold but rattles quite loud when warmed up

tonydgray@btinternet · May 12, 2009

Hi guys, new to this forum and I'm after a little help regarding a tappy kind of rattling noise coming from the engine.

I have a Carrera 3.2 Targa(65000 miles) and have owned it for nearly a year now. Apart from a few starting problems in the beginning due to a dodgy DME relay and engine earth strap it has run well and started fine. Within a the first 6 weeks of owning it I had the oil lines changed along with a general overall service.

Over the last few months I have noticed that the engine, when warm, has seemed noisier. This is most noticeable when driving in an indoor carpark or next to walls as the noise bounces straight back at me. The noise characteristics are:

- hardly noticeable when warn if at all
- more frequent as revs rise
- it is a sort of tapping/rattling noise

This is the first Porsche I have owned so I don't really have anything to gauge the noise against, only what it sounds like when it is warm which is fine. I recently put the car into a reputable independent Porsche garage to get the tappets adjusted. Upon picking the car up I was told that the tappets did need adjusting so figured that was the noise that I had heard. It was started and it sounded fine but in hindsight what I should have done is take it down the road for a few miles to get it nice and warm and then listen to it. After driving it for the last six weeks I am sure that the same noise is still there and it is not my mind playing tricks on me, paranoia and all that!!

One of my biggest concerns now is that I have read about the valve guides wearing at around 60K on the 3.2 motors so if anyone could shed some light on that that would be great. Would worn valve guides get noisier when warm?

Any help is much appreciated.

Cheers

Tony

Big_nige · May 12, 2009

If it was worn valve guides you be noticing oil burning off from the exhaust when back off the throttle and a puff of smoke when initially accelerating off afterwards. If it isn't doing this or using any oil then I doubt its valve guide wear, also don't allow the car to warm up at idle, this will induce valve guide wear, just start up and drive off taking it easy until its up to temp.

The fuel injectors can be noisy also, could also be the exhaust, or we're back around to those valve clearances. What spec oil is in it? Who's the specialist.

It could all just be paranoia too, they do emit alot more mechanical noise than a 'regular' car due to the attributes of it being air cooled.

tonydgray@btinternet · May 13, 2009

Thanks for the reply, thats a good bit of information and an initial thing for me to check. It does not use much oil at all really so hopefully that in itself is a good indication for valve guide. Also thanks for the tip of just driving it straight away. I think I will get someone to follow in another car to see if it does smoke after backing off and accelerating etc etc just a simple check.

I had a good listen to it yesterday when it was cold, actually recorded a bit of video to try and capture the sounds difference between hot and cold. I can hear a slight tappet noise when it is cold(very light sort of noise) but then after its warmed up it does not seem to be the same sort of noise, there seems to be an element of "donk" in there if that makes any sense and I think it is this that makes me slightly worried or paranoid as you said. It just seems to be like a noise that should not be there although I do appreciate that the aircooled engines are bound to be noisier.

The guys that I took it to are Tognola Engineering in Datchet who were really really good and have years of knowledge, very helpful as well. I would just pop it back to those guys down but its a fair journey for me and thus requires a bit of planning and time off work but it looks like that is the way to go maybe. The oil in it at present is swepco for both engine and gearbox, 201 gearbox and 306 engine.

Just one other thought regarding the injectors, do you think that they would alter with the engine temperature?

Big_nige · May 13, 2009

Only heard positive stuff about Tognola so I wouldn't worry there.

If you're really worried I'd be tempted to get it on a dyno, if its putting out the numbers I wouldn't worry, bear in mind alot of 3.2's give abit less than factory figure. If its using little oil and you know the valve clearances are spot on I'd say you've got a dose of paranoia. We've all had it and still do from time to time.

Never used swepco or heard reports of used in the engine, supposed to be very good for gearboxes though.

tonydgray@btinternet · May 13, 2009

Fair point about getting it on the Dyno, any chance you know of one around the Bath area at all or is just a case of google for one that is the closest?
By the way thanks for the quick responses, much appreciated!