Apparently 5 991 GT3s of the 785 produced have succumbed to fire.
Reports that the probable cause are faulty oil cooler bolts, causing oil pipes to fracture thereby pouring oil onto the exhaust system. The factory has recalled the rest of the herd for preventive catastrophe. Click to view attachment

time to sell bruce jenner back his 914

The problem is where the rocket scientists located the heat exchanger! Its only this way on the GT3 and not the Turbo, or standard 991. They even mounted the PWM oil pump externally! Its in the sump of the other engines, because the GT3 is the only engine with an oil tank.
Click to view attachment

Just canceled my order !

Pulse width modulated oil pump..... is that the main oil pump?

Its the ONLY oil pump. It handles all scavenge, primary and secondary functions.

Here's the standard 9a1 pump, its much the same as the GT3 pump, but fits inside the sump. This pic is from one of our 4.2s


Here it is from the GT3 intro book for the 14' car.
Click to view attachment

Interesting, does it shut the engine down automatically if the PWM fails? Not sure how much that would help but it would definitely react faster than the driver, those MOSFETs/IGBTs blow on occasion.

What's the benefit or just couldn't drive it from the engine?

Working toward CAFE in 2016 where everything needs to go on demand for maximum fuel efficiency. Its also PWM to adjust for lateral and longitudinal G forces. Oil viscosity really wigs it out, don't even thing about running heavier oil, doing so will create low OP as the pump believes its moving more oil, so it pulls the volume back and you get a low OP warning.

These engines have really taught us a lot over the 4 years that we've been tearing into them, and killing warrantees on purpose :-)

Does it just go to default on start up until the oil is warm or do they take temperature into account?

At start up it goes full on! Oil pressure will hit 175+ for a split second and then the pump pulls back.. We've had it crush oil filters with a single start.

Sounds like another ' bone head idea ' similar to the 'lets' just glue the coolant lines on the 996 engines vs actually welding them as in the race cars. Ps..look up coolant line investigation on the NTSB website. Reminds me of the bone head floor mat mistake that Toyota made which cause a lost of life.

Not to mention the early Cayennes with the under the intake manifold PLASTIC radiator lines...finally superceded to aluminum.

Jake, good info on GT3, I have a neighbor that has one on order, he actually sent me the link with photo. He might have some retrofit news for us soon
Marty

When the accountants are in charge and a computer designs everything, and nothing is practically tested, this is the result. See that plastic coolant tube in the pic? What dumbass does that?

I knew about this 3 weeks back and I am awaiting some of the parts that are being replaced to head my way in a couple of weeks :-)

The engines have another issue that I don't believe they have addressed yet, Blake and I designed a fix for that one yesterday and just need a prototype to start testing. Its a simple retrofit that the factory should have employed when they created a single pump that incorporates scavenge and primary oil systems into a single, segmented pump.

A chain-driven oil pump sounds like a bone headed idea.

The Cayenne has had one since the beginning and they don't fail. The system is very similar, and even the way the chain is tensioned is similarly. Its kind of weak, but hasn't led to any failures that I know of. The 9a1 engines have had instances of the drive on the oil pump shaft slipping/ bolt backing out. Its not nearly as robust as the Cayenne method.

Here's a Raby 5.1 948 engine for comparison :-)

One of my favorite Porsche design goofs is the first two years of the 964 not having any head gaskets ! brilliant.

Over on the Rennlist in the 991gt3 forum, the members are getting short on patience waiting for the Factory fix. So one member (Ringmeister27) did a hilarious youtube on the topic...check it out.

Post a link....could not find it

http://www.youtube.com/watch?feature=playe...p;v=2x0IwfxEF0A

Is this it?

That was funny

Looks like you hit the nail on the head Jake. Good job.

News today from Matthias Mueller at Porsche that the remainder of the 785 Gt3 cars will be recalled and fit with new engines. While the cars are getting the engine transplants, the respective owners will get 991 turbos as loaners. I wonder how the engine "Fix" will look...stay tuned

Actually, the problem is bad rod bolts - or if not bad, poorly torqued/installed. My assumption is they let go, punch a 9000 rpm hole in the case, dump oil all over the hot stuff below...and poof

If you're REALLY interested in the saga, go to Rennlist and under 991GT3 forum, the Stop Sale thread...now up to 190 pages and nearly 2900 posts!!

Yes, I am completely aware of the cause and have been for a little while now. The GT3s have used titanium con rods since the 996s and they spec a fancy anti seize for the bolts. I don't know why they were failing only that they were "loosening."

Rod bolts loosen when they stretch.

Rod bolt "loosening"... Like we haven't seen that from a modern Porsche engine before.. Nothing new around here.