Spinout

I had thought I had the same issue. I heard a death rattle coming from the bottom of the motor while idling and thought I had spun a rod bearing. Flat-bedded the car 150 miles home to my tech. He heard it but wasn't exactly sure until he drilled a cat and shoved a rod into the element. The rod made the knock stop. whew. Bad cat.

ChicagoSpeed996

Hope your diagnosis is correct Van!! Good luck!

alpine003

Rennlist members have been brainwashed into always thinking of the worst case scenario. Lol

We're all pulling for ya.

Gretch

same ****, same flat bed ride, different result. Water pump....... I paid for that repaid with a HUGE smile on my face!

Flat6 Innovations

Pull the sump. Move each cylinder to TDC and then sneak a bore scope into the back of each cylinder, accessing through the sump. See what you find.

This week has been cylinder failures left and right. We are at 11 cylinder failure calls from 996/997 and Cayenne on the week. ALL of them were recently driven in cold.

But of course, I have no freaking idea what I am talking about.

ejs1

From page 1:

Jake, can you elaborate on what you mean by driving in cold temperatures? Are you referring to cold starts or even driving in cold temperatures even after a warm start? I assume your point is bore scoring and how cold temperatures impact it... What is 'cold' in your textbook and what advice would you give to people who drive their cars year round in 4-season climates?

Thanks

Van

Well... the prognosis is not good. I used the old long-screw-driver-as-a-stethoscope method and listened all over. The noise is loudest at the front-end of the passenger-side valve cover. It does seem to lessen in intensity when the revs are brought up (even a little bit, like to 1,200-1,500 RPM).

Could it be the timing chain slapping around in there due to a failed tensioner ramp?



(Touching my phone to the screwdriver helped amplify it, too!)

Schnell Gelb

BTDT
If it is the chain tensioner pads, there will be black/brown plastic debris in the sump/filter.

Flat6 Innovations

Listen under the cylinder, just where the head meets the block. If the noise is louder there, than the cam cover, you have lost a cylinder.

If it's louder at the cam cover, you have lost a cam/ lifter.

Pull the filter and drop the sump, see what debris you find and if it's ferrous or not. Report back.

Van

It was definitely louder at the cam cover, as opposed to the base of the head or the block. In fact, I was impressed how well I could pinpoint it with the screwdriver-to-the-ear!

When I get to play in the oil, I'll report my findings.

Macster

After listening to the clip and reading your posts afterwards then I would have say the noise is lifter or cam related.

This is not the end of the world.

However, I would advise you to avoid any more running of the engine.

You need to be sure the engine is worth working on. It probably is as the engine would have grenaded long before now with you continuing to run the engine with this noise present.

But it never hurts to double check as JR has stated many times. Thus checking the filter housing oil and filter for scary metal debris is a good step. In this case I would not be against dropping the oil sump plate but I have to remind you there can be stuff there that was there long before this problem appeared and which then could have no bearing on this problem.

If the cam lobes are fine you are probably looking at new lifters at least for the noisy cylinder. Porsche recommends if one finds say one bad intake lifter at a cylinder to replace all on that bank. The concern is I believe that dirt has gotten into at least one lifter and caused the problem and then all lifters are suspect. The lifter body tends to act like a little dirt/debris trap. Even if the build up isn't bad enough (yet) a possible concern is if this accumulation of dirt/debris gets disturbed it can affect another lifter. And then one is back in the engine, at least under the same cam shaft cover to replace yet another lifter. This gets expensive quick.

Flat6 Innovations

Check the sump too.. Always go straight to the sump! Remember, for debris to make it into the filter it must first pass through the oil pump. At minimum, you'll have pump damage, and that damage usually hurts the body of the pump first, as it is soft.

I bet they aren't ok.. He should be hoping to find the smoking gun there, though. Nothing else it can be is as cheap or easy to fix.

So they can charge more for the repair. That said, IF I have one bad lifter, I replace them ALL on the entire engine. Under no circumstance will I leave one side together. Why? Because lifters are miniature oil filters and the debris from the bad one will clog the good ones, then they become bad, pick up lash, and fail too.


Thats the proper mindset. It doesn't have to be a dirty lifter to fail. Porsche goofed up the lobe taper on some cams, and that effects lifter rotation surface speed.

Because oil has one way in, and no way out. Horrible design.

And have each cam lobe measured, using a cam profiler/ cam Doctor.

Debris is ALWAYS my major concern. Once the engine is back together shorten the service intervals and run break in oil. Employ a spin on filter adaptor to get rid of the factory filter bypass, and employ a filter mag, with a magnetic drain plug. Resurrecting an engine after this failure is possible, with positive results, IF you take everything to the point of overkill with cleaning, flushing and servicing the engine afterward. I do my first oil change 5 minutes after the engine fires back up again!

If I had to guess, you'll find something similar to this. I know I'd be hoping to, if it were mine.

DeWolf

Thought the spin oil filter and magnetic drain plug etc was a good idea. Went to the LN site and ordered the bundle including the filter etc. Went to shipping as I'm in Australia and US$170.00 to post!!!! WTF!!!

Flat6 Innovations

Email them. The website calculates values oddly for international shipping.

DeWolf

lol....oddly is understatement. I'll send an email. Thanks.