Pete54

I bought a 1999 Boxster with 17,000 miles on it several years back. The engine sounded perfect until the first oil change. After that I started getting a tappet noise which DOVE ME CRAZY! The local Porsche dealer did the oil change. I brought it to another garage that specializes in Porsches and they ran lifter cleaner through it which did not help. The problem was this: when the engine was cold it was quiet but after I drive it for a while I could hear tappet noise with the top up, or when I was at an idle with the top down. When I revved the car the noise would go away for a short while. Finally, after this problem drove me crazy for three years I added Lucas synthetic oil stabilizer. If you are old enough to remember STP additive it appears similar to that, basically a really thick additive. I started the car after the oil change when Lucas was added and the lifter noise was gone. I stored the car last year and when I picked it up this year and since then, no lifter noise. Okay, maybe a couple of tappets are noisy for a second after starting but then quiet. I use 0-40 Mobile One synthetic. My guess it an increase in viscosity is allowing the lifters to operate like they are supposed to. I would guess that you can use any additive that increases viscosity as long as it is a synthetic additive. Looking back it makes sense. The old owner probably put an additive in the oil to quiet the lifters. When I had the oil changed it had stock oil and the lifters were noisy. When the car was warm the oil wasn't thick enough to make the lifters operate properly so they were noisy.. Also when I revved the engine the oil pressure would increase quieting the lifters. I would guess that a thicker oil may make it harder to keep oil in the IMS bearing? So use any oil additive at your own risk.