996 Turbo rattle

Ive just purchased a 996 turbo with low mileage a couple of weeks ago and i think it has devolped a small rattle from the engine, on tickover it has a rattle but when you rev it the rattle goes, it sound more like a ticking noise more than anything, can anyone advise what it could be? or is it me just being picky.... Thanks Craig

Hi Craig, The 911 engines through time have never sounded silky smooth like a V8 or V12 etc. Earlier 911's in fact even sound a little ropey...until you rev them!! The 996 TT engine is no exception. Mine is also the same, there will be a tiny "ticking" from 2 sets of complex valve gear but it depends on how loud yours is as to whether to be concerned or investigate further. Id get a second opinion but be careful that you dont take it to someone who gets you to spend a vast amount of money when there is fact nothing wrong with it!! Maybe run round to a OPC and get a technicial to come out and have a listen! But be careful where you go!! When was the last oil change done?

Turbo wastegates can rattle on tickover, but it is a proper rattle noise rather than a ticking.

The last oil change was done about 4000 miles ago, ive just had another look and the oil filler cap has a yellow residue round the top is that normal? Also does the fan on the top of the boot bit run all the time? ive had a good listen and the noise maybe coming from one of the pulley wheels more than the engine, as soon as you rev it the engine sounds sweet. Sorry to be thick but the last 996 i owned was 10 year ago.

normal to get a rattle at idle, that's what my OPC said,

Well the service interval says 12 months or 12,000miles miles so 4000 miles is well within tolerance. Although i was put off by one of the 12 996TT's I looked at having a slight mustard in the oil filler cap, I would not be particularly alarmed by this now. In fact my own car had a slight residue in the cap when I topped my own oil yesterday...and I am not worried. The breather system has a vent outlet that can lead to moisture in the filler neck and in the underside of the cap, and this can be more evident if the car is used to make shorter frequent journeys. Plus we are just coming out of winter and the recent exceptional cold weather. I really would not be concerned about it. But keep an eye on the oil and coolant levels, but again seriously I wouldnt be losing any sleep over it! My engine boot lid fan was also running yesterday when i was checking the oil but the last time i heard it running previously was on hot summer days last year. I think it is ecu/temperature controlled and its speed is determined by these factors. See if this noise changes when you engage/disengage the air-conditioning as mine also has a noise emminating from the pulleys. Im sure its nothing. The 996TT engine is pretty bomb proof and much less prone to failure than the other 996 variant engines. Hope this helps. ps. You are not sounding thick, these are perfectly valid questions and the exact queries i had myself when i was looking/first acquired my car!

Ian, thankyou very much, that has answered a lot of my questions i really appreiciate it,hopefully i can sleep better now thanks Craig