bg996

Hi everyone!

About two years ago my engine suffered from 2 badly scored cylinders / pistons and was shipped to Germany for a rebuild. Over the past couple of weeks it seems that the problem has returned. High oil consumption, lots of smoking when starting from cold and ticking noises from the right side of the engine.

I know lots of people have opted out for a rebuild or a new / used engine, but has anyone continued driving their car without fixing it?!

I was wondering what else could get damaged in the process and are there any other risks to the engine if you put the ticking and oil consumption to the side.

Any help would greatly appreciated.

Thank you!

Flat6 Innovations

Recent cold temps have really skyrocketed these reports of scored cylinders. Nine calls last week alone came into the failure hotline all with the same symptoms and most with a misdiagnosis of a "lifter issue".

You need to stop driving the car.. No noise is a good noise and continued use will lead to a cracked cylinder and a resultant D chunk failure. If this occurs (and it will if you keep driving it) the results will lead to a core engine thats a complete loss.

The noise you are hearing comes from excess piston/ cylinder clearance. When that clearance increases the noise gets louder until the skirt of the piston simply breaks off. At least thats one way you can experience a failure.

When the chunk of cylinder illustrated below breaks away the coolant pressure forces the "chunk" into the cylinder where it contacts the piston and wipes out everything.



Right now this is what you have, see the rest of the pics here of this 27K mile replacement engine.
https://www.facebook.com/media/set/?...4914693&type=3




Mechanical noises are the engine SCREAMING that it has a problem. They will not get better and they will not go away until corrective action is taken. Failure to listen to the engine will find you in a position that much more complicated, expensive, time consuming and you won't like what happens, when it happens. It will happen.

jumper5836

From a positive side. I done 30k km after it started ticking. Countless track days. Yes oil is being burnt and I expect even my 200 cell cats will get plugged eventually. I expect it to burn lots of oil and keep an eye on it. It would tick and smoke on cold start until warmed up. Now if ticks all the time though somedays it burns no oil which surprises me. I don't drive it much now as I bought a 996tt and don't use it as a DD or track it anymore. Plan is to rebuild it before it breaks but if it happens it happens, I'll just get anther engine.

Here is the sound of an unhealthy engine starting up cold in cold temps. Once is warms up, it doesn't smoke. Which means the cats are doing it's job. Going on 31k like this. Scares the mechanics when I take it in for an oil change. Also dyno'd same as 2 other 3.6l engine on the same dyno day.

2013


2014

Flat6 Innovations

I'd question if your issue is a cylinder and not something else. Generally these things aren't that forgiving.

Rebuilding it before its broken is whats wise. I can't stress that enough, because some core parts are near impossible to find. Hell, we can't find any used crankshafts or IMS shafts and we had to have them made. Please don't scatter your core, its a real bitch to deal with if that happens.

jumper5836

One cylinder is scuffed had it borescoped when I had my plugs changed. I've changed cats every two years and its always burnt oil since new. It was so gradual it took too long to notice it, thats until I was bringing 1L then 3 until it was 5L every time I went to the track.

Flat6 Innovations

Never ever heard of one of these instances holding up so long. Play the Lottery!

Soaringman

What's the corolaction between scored cyclinders and cold temperatures? And how do we avoid it ?

Flat6 Innovations

In Canada the only way to avoid it is not to drive the car at all in winter. Note where the guys are that have these issues and you'll see the same common denominator over and over.

The factory did not allow for adequate running clearance in cold temperatures with these engines, especially those that have forged pistons. After being just started the piston expands faster than the cylinder and the clearance becomes too tight, which makes it impossible to gain boundary layer lubrication from the engine oil. To make it worse, the oil is still cold and thick when this occurs as its only seconds after cold start up.

Cayenne engines have the same issue and its so bad that a couple of Canadian dealerships send us their engines rather than installing a crate engine that will just do the same thing all over again. One Cayenne owner has had this occur 4 times!

We have done much more of our testing in super cold, than in super hot. Next month we'll have a test car start a 20,000 mile loop of N America. I wish he was on the road now, taking advantage of all these awesome opportunities to see single digits and below zero values. Then we'll take it apart and see how it looks. The record on one of our test engines is 5,200 cold start cycles.

If you have to drive in the cold try to keep the car stored in a warm environment and when driving down stay parked so long that the engine completely cools down!

GermanCarSpecialists

Interesting to hear Cayennes!

Flat6 Innovations

Because there's a ton of them in cold climates used for primary transportation..

But it does not happen to the Cayenne Turbo, as they have Nikisil cylinders.. Just like it doesn't happen to the 906/997TT as they have the same.

This issue is all we have found wrong with the Cayenne.. They are my favorite modern Porsche engine.

Macster

In the UK the solution is to fit a lower temperature T-Stat. And sign up with at least one company offering some kind of service/warranty for this condition and other conditions.

mikeborden

How cold is too cold?

Doesn't it get really cold in Europe where these cars are engineered? I can see maybe Canada being more cold there than Europe but the US contiguous 49 states?

Mike

alpine003

??? I think he means outside cold ambient temps, I'm assuming below freezing.

Very interesting on Jakes Hypothesis. You wouldn't happen to know the magic point where this becomes the biggest risk? Are we talking 32deg F or more extreme.

Macster

Yes, I know what Jake means. I was just pointing out there are at least two different opinions on what is going on. Jake's view is that cold temperatures bring about scoring.

OTOH, in a region where temperatures are mild and can be cold, the opinion is the problem is brought about by the engine running too hot.

Like I've said I think this borescoring is going to be the new IMSB.

alpine003

So your thought is that increased running temps can bring on the scoring as well?