How do these bores look?

Hi All, I'm in the process of resurrecting a neglected '99 Carrera 2, intro story here: https://rennlist.com/forums/new-memb...new-996-a.html Long story short, she's been sitting for two years with a bad water pump and I got her really cheap, and since the IMS bearing has already had the LN retrofit, I figured it was worth the gamble that it's repairable. I picked up a borescope and checked the cylinders; here's what I found: Cylinder 1 Cylinder 1 Cylinder 1 Cylinder 2 Cylinder 2 Cylinder 2 Cylinder 3 Cylinder 3 Cylinder 3 Cylinder 4 Cylinder 4 Cylinder 4 Cylinder 5 Cylinder 5 Cylinder 5 Cylinder 6 Cylinder 6 Cylinder 6 The fluid is fogging oil I sprayed into the cylinders before turning the engine as a safeguard. But I can't tell if any of this is bad scoring or if it looks like normal wear. I'm also concerned about the carbon on the tops of the pistons; does that look normal to the group? The plugs all looked like normal usage to me - beige and dry. Thanks for any opinions on the photos! Nick

Not being an expert, I would say that is very minor and I wouldn't loose sleep over it. Get it up and running and give her an Italian tune up!

I would even say that those bores look really good. You would not be able to feel any of those running your finger tips over them. Quite a bit of oil in there, though. Check the crank case vacuum by removing oil filler cap when engine is at operating temp and running. If it's hard to do, vacuum is probably greater than 5" water column below ambient air pressure. This indicates that the crankcase pressure regulating valve on the AOS has failed. The high vacuum pulls oil into the (intakes of) cil 1 and 4 mainly.

Looks like cylinder #5 may have it starting but to be honest, I would drive it for a bit and recheck. Those lines could be marks from the gunk in there and your turning it over by hand. Either way, enjoy for now�

Yeah, these engines are now pushing 25 years of age. Every engine known to man will need a rebuild someday. I wouldnt loose any sleep over it. Its good to scope it and see what it looks like to develop a baseline. But here is what I would do to monitor your engines health and prolong engine life. 1. Start an oil testing program to develop a baseline and long term trend analysis. 2. Run DI50 (or equivalent) for higher viscosity and moly and lubrication. Change it 2x a year to keep it fresh. Dont skimp on using the best oil you can. 3. When you drive the car, drive it long enough to get the oil good and hot to burn off the fuel and moisture. Dont be afraid to enjoy the rev range when the oil is good and hot. Your engine will thank you. 4. Make sure your fuel injectors, oxy sensors and Maf are fresh. No need to dump extra fuel in your cylinders because these parts arent functioning properly. 5. Use Techron a couple of times a year to clean off the fuel injectors and piston heads. Hope it helps.

Quotes source post: 20409205

Moved this from your thread in the 'Welcome forum'... thought the 996 forum is the best place to discuss this. IMHO, this WP is your biggest concern now, from what you've posted so far. I say this because as you know the 996.1 are very prone to head cracks after water pump failure. I'd take out the WP and see if any impeller blades/pieces are missing in action. If so, maybe see if you can engine back flush impeller pieces out of the heads. Flushing them out could prevent hot spots from blocked coolant passage-ways that commonly cause head cracks in 996.1 heads a little down the road after WP impeller failure... To me, the WP failure and its related problems is the immediate concern. Your mild start of bore score can be slowed down somewhat for many thousands of miles with the look of your cylinders. And the right oil/care. Web Pics can be deceiving, but from what i see you're better off than most 100k mile 996. Many M96 are being driven around successfully with piston slap/high oil usage/and ticking from severe bore score. How do the tail pipes look, any excess soot/oil..? Carbon on piston tops probably looks more/worse than it is with your douche of fogging oil in the cylinders (which was a great idea for the old not run engine) Anyhow, carbon on piston tops is 100% normal on every 100,000 mile engine, so don't worry about it. Might increase your compression ratio 1/10 point, lol.. Piston tops look like carbon is getting dislodged/dissolved from fogging oil. A lot of it will probably blow right out when run for a while... Just make sure fuel trims are spot on once you get running. Good luck, show pics of the WP blades once you get it out. Hopefully no blades are busted off and engines not been run with blade pieces in the heads from prior owner. How does the coolant in the reservoir look, how does the oil on dipstick look... any intermix milkshake..? jmo

Quotes source post: 20409656

^^^This Didn't see the post. While I wouldn't loose any sleep over the bore conditions, i would loose sleep over the water pump. Find an experience M96 indy that can take care of this asap.

Likewise moved this post from welcome thread� OP - I probably would�ve done it for the price you did. Nice exterior. How many miles? Do you plan to drive the snot out of it? Those piston crowns look problematic. I don�t think an Italian tune up or detergent gas would fix them. Our engine brain trust will likely have commentary about the pistons. The scoring doesn�t look fatal any time in the foreseeable future, hence, the question of miles. Check AOS health with manometer test. If I�m walking in your shoes, I�d need to know why my piston crowns look like cr�me br�l�e crust and how to mitigate soonest. -Put a low temp thermostat on when the water pump�s replaced. -Install a UAOS. -Install Coopduc oil temp gauge. -New plugs, coils (maybe) and injectors. Some may scoff the need for new injectors, but my engine parameters didn�t get squared away until I replaced my old injectors and installed an UAOS. -New coolant -New oil -Possibly a clutch job If the car runs well enough after the new baseline, reassess how deep down the rabbit hole you need to slide for the right now. If the engine isn�t a write-off, you�re still well on the right side of the value spectrum.

Thanks for the input and info to everyone who's weighed in so far... The plan is to pull that water pump, possibly this weekend, and see the condition of the impellers. I'll post those pics once I have them. Very relieved to hear the opinions on the bores, although I realize that eventually the engine will need to be redone as they all do. But good to know it's not an immediate issue and I'll follow the oil maintenance suggestions to minimize further damage. Oil didn't have any coolant in it from what I could see, but when I drained the coolant it did look pretty dirty - not from oil intrusion, just dark and sludgy. I think, regardless of the water pump condition, I'll do a flush of the system while I'm in there. Tailpipes were rusty on the inside from sitting so long, but I didn't see a lot of soot and no oil. But then again, it's been sitting non running for a long time, so weather may have erased anything that was in there. Next up is a compression test, then I'm going to pull the pump. I'll keep you all posted; thanks for the help so far! Nick

^^^^Which impeller are you getting with the water pump?

Quotes source post: 20409817

Doing the LN kit that has a Pierburg pump with composite impeller. I read the posts about the metal impeller grenading the engine and would rather change the pump out on a regular schedule.

Quotes source post: 20409832

I see you are in the Chicago area. Feel free to reach out an pm me if you need anything. I see you have had a 944 and 928 as well. Our paths have probably crossed in the region.

Quotes source post: 20409832

You got this.

Quotes source post: 20409861

I will, thanks - I haven't been active in the community before now; the 944 and 928 were both project cars that I moved on from fairly quickly. But the 911 has been a long-time dream car of mine, so I hope to drive and enjoy this one for a long time.

Quotes source post: 20409884

God, I hope so... Thanks!

Quotes source post: 20409596

Which TECHRON do you guys recommend for the 996 - the Fuel Injector Cleaner or the Complete Fuel System Cleaner? Thanks, Jeff

Complete Fuel System

You have to scope from the bottom side to see the real area the bore scoring starts. You need a very flexible scope with as small of a camera end as possible to make it easier Just the way I was told to do it.. YMMV.