Oshin11

I always wonder about this, and it would be hard to tell when the connection is perfectly made. So I set my car to TDC for cylinder 1 and the rotor is not perfectly at the notch on the distributor, its actually like 15 or 20 degrees behind. In other words if the notch is 12 o clock, the rotor is actually like somewhere between 10 to 20 degrees counterclockwise from that point. Does this sound right? I dunno I was hoping that doing this service would lower the amount my car smokes on start up but its not getting any better. Hopefully fixing the clearance on the exhaust valves will help.

Daniel Dudley

Your mind is a dangerous place. Don't go in there alone.

The worst thing you can do to a car is to go in and change a lot of things at once. If it doesn't run right aftrewards, then you don't know what the problem is.

There is no way that smoke on startup has any relationship to timing the distributor, as far as I can see.

You need to use the buddy system, and get an experienced 911 owner to help you while you still have a car. In the process of teaching myself mechanics, I destroyed several engines, and caused myself untold extra hours of labor. And Cost. Get help.

Tippy

Timing and valve clearance have zero to do with smoke on start up.

Yes, the rotor is before top dead center of the pistons relationship.

Oshin11

thanks

Tippy

Smoke on start up is a result of oil passing the rings on the pistons. I almost said "or overfilling the cranckcase with oil", then I realized I am not in the 996 forum.

LaughaC

Is the startup smoke light or dark color?

Does the car always smoke at startup or only after sitting for days?

My understanding is that it is normal to puff some light colored smoke after a flat 6 engine sits for days. This makes sense because the cylinder bores are horizontal so some oil can sit in them when the engine is off. This sitting oil slowly seeps past the piston rings over time.

On the other hand, dark smoke is caused by a rich fuel mixture, but this is unlikely to be your problem.

Oshin11

The color is white, but sometimes it is thick, but I think the thickness just varies with outside temperature...colder nights, warm exhaust, a thicker white smoke. The smoking goes away after the car warms up and it does this even when the car hasn't been sitting for days. My car gets driven several times a week. My friend who was a wrench in germany for 15 years saw it for the first time, took a smell of the smoke, and magically decided it was valve seals....I suspect I'll rebuilt in about 20K miles even if the car doesnt need it....better than waiting 40K miles but having something break. causing catastrophic damage to my engine.

mo_gearhead

QUOTE: "Distributor Rotor Lag...normal?"
________________
I am assuming you had the distributor out?

Upon replacing it you should be certain that it goes back in EXACTLY as it was (one should mark the position of the rotor before pulling it) or... if the engine has been rotated for some reason while it (distributor) was out, you must then determine top dead center on the #1 cylinder, on the compression stroke, again.

Since the gear is helical cut, the distributor will rotate slightly upon installation and seating fully. If it is not where you want it, pull it back up, rotate the shaft slightly and re-seat till it is where you want it.

Because you rotate the housing to adjust the timing, one can install them a 'tooth off' ... but sometimes with vacuum advance or other protrusions, you may not be able to set timing correctly if it is indeed 'off a tooth'.

Oshin11

I thought that there is one and only one position that a rotor can be installed.

mo_gearhead

QUOTE: "I thought that there is one and only one position that a rotor can be installed."
_____________________

Perhaps I mis-read what you are doing/have done? The plastic rotor is indeed 'notched' and will only fit on the distributor shaft in its correct orientation.

It was my feeling that you had removed the distributor (out of the engine) for some reason? If that is the case, then one can replace it in as many wrong positions as there are teeth on the gear.

Sorry for the confusion.

Oshin11

BlackPearl

Whoa! Hang on a minute. Not to highjack this thread, but converstaions with my mechanic and numerous P-car owners/wrenchers have told me that star-up smoke is normal in 911's from early 70's on. Even some of the 60's models will smoke when first started.

There was a thread about valve-guides somewhere around here and more than one person spoke of valve guides not being a 'perfect-fit' from Porsche. All that (and more) said, I'd wait on a rebuild until a really good inspection is done. A little smoking may not indicate a "catastrophic" event forthcoming. The 3.0L and 3.2L engines are some of the toughest and longest-lasting Porsche ever built, IMHO.

My '83 smokes when first-started, especially if the oil level was previously toppped off (I always fill her way up near the top mark with oil before a track event per my mechanic's instructions). The smoke is anything from light to fairly thick-blue depending on how it's parked (slight leaning to the rear generates slightly more smoke) when first started, and will continue for 10 to 30 seconds. I've been told numerous times this is normal. If the oil level is 1/2 in the tank, the smoke is lighter, and slightly less duration.

I've had my engine tested for compression and leak-down (When purchased in 2007), and the valves/valve-guides "relationships" were "checked" ("grab-and-rattle" or something like that) by a very competent shop that said that everything was tight and good for tracking at high rpm's for somewhat long durations. The car drives and runs perfectly, without high consumption of motor oil.

With horizontally opposed cylinders, gravity-fed oil returning from the top-end, and today's high-penetrating oil compounds I'm not suprised there's a little smoking at start-up. I'd be a little worried if my SC stopped smoking at start-up.

Got oil?