A few weeks ago I received a call from a 996TT owner who had issues with his engine. In the process he decided that it was better for him to purchase a new crate engine and have it installed vs rebuilding it.

I loaded up the family and dog in my motorhome and drove south..

The Porsche dealer did a quick examination of the engine and verified that the engine was siezed.

Here is a few pictures of the late model X50 engine.



The engine was secured and strapped in for the drive back to the shop.



I mounted the engine on the engine stand and began to remove all the components. These engines suck up alot of labor. It takes alot of time to remove all the components and hardware to get to the longblock. As you can see in the next photo, this engine had a catastrophic failure. The FINAL straw that broke this engine was bank 4,5,6 timing chain breaking one of the links.





As I mentioned, the chain broke. For future owners, you will get a instant CEL, and the engine will lose power. While this is happening, the broken chain starts to wrap it's way around the intermediate shaft drive sprocket. At the same time you will have all the exhaust valves and on this engine one intake valve meeting each piston. From talking to ALL the owners from these failures>> one thing stands out. The owners will either push the clutch in and grab a lower gear to restart the engine OR turn the ignition over to start restart the engine. Please realize that the ECU has shut down the engine. We have camshaft deviations between each bank and crankshaft. These restart methods will either break the crankshaft OR wrap the timing chain against the engine case. In this situation the chain was wrapped 3 times around the sprocket wedging itself between the crankshaft and engine case>> this caused the engine case to give/expand resulting in a cracked engine case.

 

At the present time I have not removed the rods from the crankshaft or split the engine case. However, what I have found was alot of metal in this engine. The very first thing that I did when I looked at the engine was examine the oil filter. It was packed with metal.. Aluminum, steel and bearing material.

Now, while one might come to the conclusion that this damage was a freak failure in a bullet proof engine. I highly doubt that the chain just gave out. Each exhaust camshaft on both banks of the engine drive a scavange pump that removed oil from each head/cam housing. There is alot of oil volume being pumped into the Variocam module and multilift cam tappets. There is no physical drain tube like earlier 911 designs. So pumps must evacuate both banks.

Please note that the right bank 4,5,6 had metal sucked into the scavange pump. The drag on the pump most likely stretched the chain and causing it to fail. It took me a good 45 minutes to rock the engine back and forth to pry out the timing chain. The pictures look deceiving because it shows the chain untangled. Imagine all of that chain wrapped around the intermediate sprocket.

For a little background on this engine, as mentioned it is a late model X50 engine that was running a K24 hybrid, 5bar, exhaust, and tuning. Please note: I did not tune this engine nor did I build the 18G hybrids.

This engine was detonating, datalogs were run in real time. I seen the values and tuning. This engine was killing itself in 2500 miles since the upgrade. Running a 5bar on 18G's and boost greater than 1.0 bar will cause a lean condition. Your injector duty cycle is off over 100%. The timing in the maps was too much for the requested power and boost. The engine was fighting itself. The Tuner set the Rev limit to 7500 RPM's. This is similar to another failure posted from a forum member who lived in Oklahoma. His engine failed within 4 or 5 pulls after his initial install.

 

wow! is the engine a total loss, or will you be able to rebuild it?

 

It's pretty much a total loss. Engine case is cracked and heavily scored internally from the chain whip, the crankshaft took a hit, along with the intermediate shaft. The GT3,GT2,X50 oil pump is packed with metal. One head and three pistons should make it. The oil looked like aluminum/bronze anti-seize.

 

That story makes me sick to my stomach and it's not even my car!

 

Ouch.

 

i hope you did not pay too much for it! such a shame.

 

I was sad to see the crack in the engine case.

 

Every time you post these horror stories, I get a pit in the bottom of my stomach...

Mike

 

This story makes me glad to have an extended warranty...

 

QUOTE:
This engine was detonating, datalogs were run in real time. I seen the values and tuning. This engine was killing itself in 2500 miles since the upgrade. Running a 5bar on 18G's and boost greater than 1.0 bar will cause a lean condition. Your injector duty cycle is off over 100%. The timing in the maps was too much for the requested power and boost. The engine was fighting itself. The Tuner set the Rev limit to 7500 RPM's. This is similar to another failure posted from a forum member who lived in Oklahoma. His engine failed within 4 or 5 pulls after his initial install.

WHAT ARE YOU REALLY SAYING KEVIN ?

 

Datalog, Datalog and Datalog. Your fuel pump can be failing and pissing all the fuel back into the fuel cell and you won't even have a clue. Now this was NOT the case in this situation. But when you install LARGE hybrid turbochargers and jack the boost with high timing you will quickly exceed your injector duty cycle. There is no more reserve.. The engine detonates and you get a blown head gasket (welcome a blown head gasket>>it's the engine fuse) or worse. Guys, there are some tuning kits that are being run on the ragged edge. If you are ringing out the maximum Power thru boost on pump gas you really need to datalog. It is amazing to see kits being purchased and dialed up to the max without any datalogs produced.

In the next few week I will be introducing a new RAM cell datalogger that will allow all of us to see what each cylinder is doing.. All of us know what tools are available right now. I will be bringing a tool that has sample rates that will allow more indepth review of what our engine are doing.

I am letting the cat out of the bag, because I am tired of seeing this happen over and over all over the country. My little list is growing monthly with all the engine failures. The logging system will be able to clear engine codes, and operate at speeds only wished with values approaching 20 units. My customers will know that I like to log 12 values.. On top of those values we will be able to see the knock retard for each cylinder.. This will show us that our timing map is either to high or we are running to much boost for the octane of fuel that is being run.

I have a plea for anyone that is interested in purchasing the logging cable please email me Kevin@Ultimatemotorwerks.com Right now we are in production with the circuit boards. The more that can be ordered in the first run will bring the cost down. I am NOT asking for monies, but a kind hearted yes or no.. I didn't plan on this post to this thread. I spent 2 hours on the phone this afternoon speaking with another individual with a similar engine issue. Cheers..

 

My take on this as a guy with K16's....

Cheap big horsepower is not necessarily cheap.

 

Just to be sure I understand this - is it only an issue if you've installed larger turbos? Lots of people seem to remap on the original turbos (at least in the UK) and raise boost to about 1 bar - and the general opinion is that this is pretty much a risk free change.

 

Programming that is poorly done will knock out these engine. What are your AFR's and injector duty cycle. While it is going to be hard to use all the fuel up, it will be easy to run a LEAN AFR. Setting a 7500 RPM rev limit will also shorten the life of a stock engine. We have the tools available to teach yourself what your tune is doing. If you don't care about doing the data logging ask your tuner for logs that HE has done and ask your fellow forum members. In the end it is better than a dyno sheet.