PorscheDoc

Not sure what you found out with your motor Joel, but we pulled the motor apart to see what was going on with our P1325 code. At 90k miles, this motor is well.....disintegrating, lol.

Front cam housing grooved:


3 tappets on the passenger side shot, 1 on the drivers




Inner part of the tappet has been chewed to oblivion.


I'll take a better picture that shows the cracks, but both front cam brackets are badly cracking, looks like they are matched to the main cam housings, so both will likely have to be replaced.

Kevin

Karl is there metal in the oil filter? How does the exhaust cam/thrust/shoulder look. I have customer that is having a chronic right bank misfire/with a metalic noise.. All the usual parts have been replaced. I have a feeling that we have a few failed tappets..

Guys I can LOCK your tappets (with programming) in the closed position to reduce this failure.

MechanicalEng

Kevin, Doc
Why does this kind of failure occur in our engines?

PorscheDoc

I have cut the oil filter open and looked for metal the last couple of times (started doing it at about 70k miles every oil change since he was tracking the car hard), and can never find any! I don't understand where it has gone. Only metal I have found has been attached to the top cam actuator sensor. The oil has always been clean. Motor has never made any abnormal noises. The exhaust cam should looks ok (though it was late last night and I didn't give it a real good inspection, though the cam housing is beat up, so there has to be a thrust issue), in fact all the cams look good with the exception of one ring missing from a cam. Of course there is definitely play in the crank thrust, so I am sure the bottom end has issues as well. 90k miles and a LOT of those have been on the track, but unfortunately, without a full build, this motor has seen it's last track day. The guys at Porsche logistics said the rings on the intake cam are failing fairly often, but that they just seem to disintegrate without ever really finding particles anywhere. This would explain the front grooved cam housing (the only cheap part in the system, lol) as the a ring is missing. What is really interesting is to see the aluminum cam brackets coming apart, meaning that the cam housings I guess are going to be a fairly common replacement item.

I'll take some pictures of the various components of the engine when I am in the garage this afternoon and post them up.

jpflip

PorscheDoc. Are we talking about an engine from a completely stock car or this engine had the rpm increase or some other type of mods or flash ?

PorscheDoc

Was bone stock until about a year ago when he picked up some used modified K16's and programming. He has run with as straight out exhaust for quite some time now though. While the car has been run hard at the track, I don't feel that he "beats" on it.

Kevin

I'm going to do a little RANT>>> Porsche executives read these threads but they don't offer any solutions. Either on the forum or in private emails. I have torn apart 3 engines with faulty intake tappets >> they FALL apart when you remove the intake camshafts. I have had three customers within the last 3 years require all the lifters and camhousing on one bank replaced. One customer had to replace his head (valve guide got worn beyond spec) I actually received the head for inspection.

Right now we have Doc's engine and Joel's engine along with a customer who I think is near to having his engine removed.

Karl, the metal HAS to go thru the engine. Did this engine have a DUAL MASS flywheel? Guys>> Dual Mass flywheels and the track are NOT good! We are seeing accelerated crankshaft thrust bearing wear. This was reported years ago.

This issue is NOT just contained to the 996TT engine, the 997.1TT will see it also.

Guys change your oil more often, inspect your oil filter and replace the filter at 1/2 your oil change interval. My recommendations are at 5000 miles and more often if you track your car. Filters can be changed at 2500 miles.

Like I mentioned in my previous thread, I offer to my customers that ability to LOCK the intake tappets. There is very little performance LOSS, I can spool the turbochargers quicker and give you back the torque loss in spades. By locking the tappets we reduce the strain on the hydraulic lifters and reduce the failure rates.

puma

It is when i read threads like this that i realise i don't know anything about those cars... Man i hope i'll never have such problems. Great reading anyway, love those discussions.

jpflip

Did someone said the GT1 block was bulletproof

Kevin the coolant pipes problems still exist today on newer models, 997, GT3 etc, I am really wondering if Porsche executives really read these threads.... Do they really care

Macster

Kevin, on a related note do you know under what operating conditions the Turbo engine controller switches the on and off the engine's variable valve lift system?

I read where Porsche 'tested' this to 250,000 cycles but I do not know what this number means in real world driving, how many miles this 250K cycles represents if the car/engine is subjected to normal (whatever that is) use.

As an aside, my 02 Boxster's passenger side VarioCam solenoid and actuator were replaced (the engine generated a P1341 error code and exhibited symptoms that pointed very strongly at the solenoid/actuator) at around the 239K mile mark. I believe the solenoid/actuator are activated at idle to about 1400 rpms (or when rpms drop to below 1400) and reactivated again when rpms climb to something a bit over 5K rpms.

There may be exceptions related to engine coolant or oil temperature, load, and so on.

(As a further afield aside just the solenoid was replaced but the engine generated the same error code and symptoms shortly after I got the car back. The problem was traced to the VarioCam actuator which was then replaced. For reasons I won't go into now I was not charged for the duplicate labor (and parts) to disassemble the engine (the engine remained in the car) back to the solenoid stage, but I was charged the extra parts cost (actuator: approx. $800) and labor (approx. 5 additional hours -- the cams have to come out and of course be reinstalled with the correct timing) to R&R the actuator.)

Sincerely,

Macster.

Macster

The 996 Turbo engine block is (nearly) bulletproof but unfortunately the internals are not.

(My 02 Boxster's original engine has covered just under 240K miles and while the block is in apparently good shape still (thank goodness!) I just had to have the passenger side VarioCam solenoid and actuator replaced [a $3K job]).

Sincerely,

Macster.

PorscheDoc

We changed oil after every event in this engine, and usually before the event depending on how much street driving he had done in between. Unfortunately, it went many years on 0-40 before I switched him to 5-40. I cut the filter open this afternoon, and again, no particles. I'll post up some better pictures later this afternoon once I get a few other cars on their way.

Kevin

jp > Did you see my RANT's in the previous oil thread?? Can I say Mobil 1 5W40 TDT.. Can I say, change your oil sooner!

Macster, Yes, I know what the operating conditions are > the mapping is based off load vs RPM.

Kevin

jp, they read these threads.. However, I feel that they should offer some Goodwill to some of they folks with parts discounts to get there engine back to whole.

1) IMS problems
2) Camshaft chain breakage
3) Inlet tappet failures
4) Vario cam module failures and sealing ring failures
5) Coolant nipples "glue" failures
6) Premature radiator failures
7) 2nd gear popouts

EDIT

8) Beru FR5 spark plugs > misfires
9) Beru Coil Pack, #1 and #4 take a beating from the heat and misfire

This is a good list to grab there attention.

PorscheDoc

The coolant nipples is right up there with using plastic coolant pipes on top of a cayenne engine. What idiot thought that as a good idea?