desmotesta

that percentage is a lot higher than the percentages for IMS bearing, no?

Unless I am reading it wrong and its 5%-10% of cars that come into the shop with issues, and not cars on road

Charles Navarro

Correct, that is 5-10% of blocks being sent to us for repair are MA1/9A1, and then only the 3.4, 3.6, and 3.8 liter models. We get calls with Macan and Panamera models with scoring, but to date not a single person has actually chosen to rebuild one of those engines. I'm guessing most of those cars end up getting off-loaded or crate engines put in while they are still somewhat affordable. We do see Cayenne V8s too, but they are far and few between, and most come from colder states and Canada.

We no longer service cars at our location. The service shop was spun off as a stand alone business and sold to one of my techs back at the beginning of 2020 and is now run as Speed and Suspension:

https://speedandsuspension.com/

Last I checked, they fail about half of the cars that come in for IMS Solution installs for bore scoring, but granted we do see our fare share of cold weather, so that is to be expected.

Wayne Smith

For full perspective on the % it might be interesting to know the number of 997.1 motors that have not been updated vs the same number for the 9A1 motors.

The turbos received a different annealing process. Is that a factor?

Are we dealing with straight bore scoring or an end effect of cold seizure?

Ed99

It's sad but we are seeing more and more 997.2 now with bore scoring as well and everyone was saying they were bullet proof at one point.

Wayne Smith

Baz reported on these motors some years back, discussing the importance of proper warm-up as well as cold climate challenges.

Also ... Cold seizure, which Baz figured was the primary culprit.

In the first case, we have limited control.

In the second case, it may be luck of the draw. But from what Baz said at the time, if you don't have a problem after X miles, you're probably fine.

Having a 997.2 that burns no oil with 162K miles, I'm hoping for only the second case. So far, I haven't seen data to support 1, 2, or both. Of course, I'll continue a prescribed warm-up procedure regardless.

Additionally, as Jake and LN point out, DFI fuel injector failures could cause problems in a hurry.

Charles Navarro

We actually offer and recommend cryogenic treatment on the MA1/9A1 blocks. It's best to do this before any work is done to the block.

I will say that I don't think we've ever had a turbo block come in with scoring/seizing, so certainly the different processes carried out by the factory may indeed have helped.

Most are seizing rather than traditional bore scoring, but we do indeed see blocks with scoring that do not have seizing.

Wayne Smith

Thank you, thank you, thank you for your response.

From what I have heard (not seen), I would guess the scoring goes along with bad injectors. I know you advise using a good cleaner with PEA. Do you have any other advice on caring for the injectors? Or testing the injectors? Or recommendations on refresh intervals? I speak as a 2010 C4S PDK owner with 162K miles running on all original drive train. I'm still burning no oil. I'm planning to do a borescope the next time I change my plugs.

Thanks in advance for any words of wisdom you can share.

Charles Navarro

I'll tell you what I do with my own modern cars. I don't have access to Top Tier fuels, so I run Injector Defender every other tank. If you run a Top Tier, I'd say run an additive with PEA every 2-3k miles.

The direct injectors are notorious for not coming out without breaking, so I'd just leave them alone. Not like port injectors that are easy enough to swap out. If you do have wonky fuel trim values, then I would for sure dig into why this is occurring.

Wayne Smith

Excellent information. Thank you again.

Jim986

FWIW my Indie uses Liquid Moly 5-40 for Porsche Oil changes. I trust these guys!

Wayne Smith

Add a can or a can and a half of Ceratec or MoS2 to the LiquiMoly per long standing oil threads and UOAs on the 997 Forum.