Montychristo128

My only consolation is all the now "bullet proof" air cooled engines had issues too. We will fix them and one day in say 10 years, our cars will be so rare in "fixed original condition" that they will have actual value.

9a1 is out of my price range I think. Better bet would be used Turbo Engine? They seem to be around $25k on ebay?

Triple Black

I was very torn at first, but after talking with my indie he offered a reasonable solution. I really wanted to keep the car so I bought a slightly used Porsche long block crate engine with the larger diameter IMSB from him. Engine had about 10K kilometers on it. Cost was about $17.5 with the installation. A very strong engine and am very pleased with it.

Ahsai

Sorry to see your loss. Something is shedding metal inside the engine so running the engine can only create more damages.

As is, there may still be parts that are salvageable such as cams, crank, oil pump, scavenge pumps, etc.

Montychristo128

Yeah, its staying in the garage looking sad until rebuild time now. New oil made no difference, no miracle cure for me.

Just waiting on the journey of discovery that opening it up takes me on. It will be interesting to see what's actually failed.

Triple Black

Good luck. Keep us posted.

Porschetech3

Just a couple of points to make. The video I listened to definitely has a lifter tick on bank 1, it's possible it could be something else as others have stated but my money is on the stuck lifter.Also no one mentioned the horrible grating sound I heard !! Sounds like a Skill saw cutting through a nail !! It's sounded like coming from the center of the engine like where the oil pump is located. Which corresponds to your observation that no metal in sump, but metal in oil filter. IF that's the case it can only come from the oil pump!! The oil pump is easy to get to after removing exhaust and engine bracket. Pull the gears out of the oil pump and have a look. If the gears are chewed up and that's what's making the Skill saw sound, I would replace the pump, put new lifters on bank 1 and see what you got. Of course there has been some metal went through your engine (that's how it got into the lifter), but you could get a lot of miles out of it for a few hundred bucks ,and can save up money for a UPGRADE top of the line rebuild in the future. What have you got to lose?

Montychristo128

Triple Black, thanks.

Porschetech3, that noise is the SAI, car was cold when I started it. Will get round to rebuilding it fortunately that one goes away once the SAI has stopped.

The metal is as everyone points out bad news. I wish it was lifter, but why would a stuck lifter be shedding metal into the engine, unless its eating the cam I suppose.

We will all find out in due course.

Flat6 Innovations

So, this debris.... Is it ferromagnetic?

I would perform a used oil analysis first, then go from there. Why? Because the exact wear metals in the oil, along with how well the additive package has held up will help determine where to look for problems.

It is possible to have two failures occurring simultaneously. I've seen that quite a few times, and as recently as last month.

The last thing I suspect when I hear a "lifter noise" with an M96, is a lifter. If a lifter fails it typically will lead to excess lash, which will beat the cam lobe to death fairly quickly, so the noise gets much louder, much quicker.

Montychristo128

Jake,

Based on a not very scientific test of the debris from the filter, strained through a cloth and tested with a fridge magnet (I know, I know but best I could come up with at the time), it seems to be at least 50% magnetic debris, all looks like white metal once the oil is cleaned off.

I'm heading down the rebuild route I think, so we will find out in due course. For now its staying in the garage until then.

I could get the oil analysed I kept the contents of the filter housing and filter itself, but not sure I need to spend any more money as teardown prior to the rebuild should reveal all?

Porschetech3

Glad to hear the noise is just the Air Pump. I had thought of the air pump first but then dismissed it after listening to it several times and convincing myself it was something much more sinister ,even seemed to change sounds with RPM's. I have never heard one that LOUD. I still think I would look for the source of metal before removing the engine to dissemble. The oil pumps (3 of them) are a common source of aluminum and steel shavings, especially the scavenge pumps in the heads. They commonly wear and create shavings and seize up causing timing chains to break or IMS shaft to break. All 3 pumps are external and easy to remove and check. I always like to find the source of the problem as soon as possible.

Slakker

$38 seems like a small investment to get some valuable diagnostics data.

Flat6 Innovations

Yes, the oil system is comprised of these 3 pumps. These create both the primary, and secondary oil systems. The primary system provides high pressure oil to feed the internally lubricated components and is located in the front console of the engine, at the crankcase parting line. This pump uses spur gears.

The other two pumps provide low pressure, high volume scavenge oil from the cal;under heads, back to the oil sump. Due to the engine being horizontally opposed in its layout, the oil does not naturally return to the sump with gravity alone, like a V8, or a more conventional engine.

These two scavenge pumps never fail, or wear unless they see secondary, collateral damage from some other component wearing/ failing. Why? Because they are constantly lubricated with a huge amount of oil, and they are loosely based on Gerotor design. The Gerotor is a great oil pump design consisting of an inner and outer rotor. The inner rotor has N teeth, and the outer rotor has N+1 teeth. The geometry of the two rotors partitions the volume between them into N different dynamically-changing volumes. During the assembly's rotation cycle, each of these volumes changes continuously, so any given volume first increases, and then decreases. An increase creates a vacuum. This vacuum creates suction, and hence, this part of the cycle is where the intake is located. The problem with this? The pumps have very tight tolerances, and are highly susceptible to damage by debris laden oil.

Since these are high volume pumps they have a great intake volume, and do a great job of scavenging waste oil from the chain well area of the cylinder heads. The issue with this is a high probability of inducing debris that stems from failing components in each respectful cylinder head, especially valve train. This can be bits of broken valve spring (just the end), pieces of timing chain rollers, casting flash, valve retainers, and etc. It can also be debris from deeper within the engine that has been delivered to the cylinder heads via the main timing chains, which act as huge "conveyor belts" to shuttle debris to the cylinder heads. A good example of this is the debris from a failing IMS bearing that is picked up by the bank 1 timing chain, and then delivered to the chain well of bank 1 cylinder head, where it is picked up by the bank 1 scavenge pump. This is why the failure of a bank 1 scavenge pump is always part of the collateral damage that stems from an IMS bearing failure.

When I have an engine come from another shop (typically because someone gave up on it after a mis- diagnoses) that has a new scavenge pump installed, I never question the old pump failure. I immediately question what else was failing that CAUSED that scavenge pump to fail.

In every instance the fault path associated with a scavenge pump failure is determined to be from some other issue, and the scavenge pump illustrates the symptom first. This occurs due to the tight tolerances and the fact that no filter is present to protect the scavenge pump from debris. The only scavenge pump that is protected is found on the M97 engine which has a two stage scavenge pump that provides vacuum for the power brake system. The factory protected this pump with a small mesh screen, so the chances of it failing due to foreign object debris were greatly reduced. On an M97, if the bank 2 scavenge pump fails, you no longer have power brakes!

Over the years I have developed methods to protect the scavenge pumps from debris for my engine program. The best policy is, and always will be limiting the wear metals that are generated, and if this is done, the pumps go forever with no wear, or damage. These pumps have exceptionally hard rotors, and can eat a valve keeper without seeing damage. The material is at least 72C and that's tougher than an other component in the engine (cams are 78C as an example).

So, now that you have found debris, and some is ferromagnetic, you need to determine the fault path of the failure, which is now becoming failures (plural) since the debris generated is taking out other items within the engine already.

The used oil analysis (free when buying some oils from www.rndeuroparts.com) is a key to determining the root cause. The next step is to remove cam covers, and the sump plate, and start collecting clues.

Don't automatically assume "a rebuild" because of this. If you have caught this early, and limited collateral damages, and the root cause is found somewhat externally, then the engine can easily be saved. With advancements like ur master linked main timing chains, and others, some items can be addressed easily, which previously required full engine disassembly to address.

dporto

^ Another post for "The Raby Files"^

TAGPorsche

No doubt. Thanks to Jake I know more about the M96 and I don't even own one.....yet.

docmirror

Are these methods available as a stand-alone offering for field retrofit? I have a full flow filter, a magnetic drain plug, and have put in a chip detector, but more is better to minimize damage from the oil circuit contamination these engines are notorious for. (gah - dangled the participle)