Caveman

Hi Everyone,

My 1995 C4 has about 97,000 miles from memory. The last few times I have used it I started it up and got a cloud of smoke - literally a big puff - which then went away. The first time I put it down to not having used it for almost a month but I then had to use the car a further two days in a row and it did the same thing. Are talking "normal for a 911" to sticking exhaust valves? Has anyone had this and what happened next? My garage suggested that I take a spirited drive one day then then leave it till the next day and see what happened. Sensible?

Cheers,

David

95_993

Sounds like a leaky valve seal to me if it's happening all the time.

Caveman

Sounds expensive?

I should flag this is just a generous puff of smoke followed by nothing.

95_993

Not too pricey. Not too severe either

Gbos1

There is no cheap Porsche ... Engine out / Top End Rebuild / $10K - $15K

mpruden

Just a big puff on startup? It's probably just some oil that got sucked into the intake. Try to maintain your hot oil level around 1/3 up the twisted section on the dipstick. I bet the smoking goes away.

Caveman

So far I prefer mpruden's response the best! When you say "hot oil level around 1/3 up the twisted section on the dipstick" mine is always right at the top as I don't do mega mileage so it never really drops, I noticed this the day after a 30 C day (hot for us) when I had given the car a really good hard drive. On the hot day I found the engine fan had come back on once I put it in the garage and I ended up opening the garage and the engine lid so I wondered if it was anything to do with that?

Thanks,

David

mpruden

I think it has everything to do with oil level and nothing more. Not sure why folks think this would require a valve job and $10k+, but perhaps they know more about these cars than I do.

Many experts recommend keeping the oil (when up to operating temperature) below half way up the twisted section when checked with the dipstick. If it is near the top, it is most certainly overfilled, increasing the likelihood that some gets sucked in the intake manifold. A high ambient temperature will just make it worse as oil expands when heated.

You can get a fluid transfer pump at an auto parts store (around $10 here in the US) and pump some oil out of the oil tank until you get the proper level. I bet the smoking will get better over time as the residual oil in the intake is consumed.

LexVan

Too high. Take some out.

Caveman

Endoman

If the oil level is high and you park on a slope the oil level in the sump may be a bit high at start up until the scavange side of the pump has cleared it so I've heard.

911F1

Check hot oil level while the car is running at idle or off?

Endoman

Always at idle just be careful where you poke your dipstick. As my mother used to say.

95_993

Overfill will result in blue smoke out of one side and likely continue while driving.

Just to be clear, replacing valve seals is not a $10k, engine out or top end rebuild. It is a cheap viton seal on the valve stem that can replaced with the engine in the car.

Steve Weiner-Rennsport Systems

Best advice right here.