Jagtem

I recently replaced my engine with a freshly rebuild long block (the new engine appears to have already failed, but that's for another thread).

I replaced my existing engine because I thought it was suffering from bore scoring. I had the classic ticking noise. Upon removing the engine, I decided to scope the cylinders just to see what they looked like. See attached images below.

I don't see a ton of obvious scoring, but maybe I'm missing it? I do see what looks almost like cracks in the cylinder walls as well as areas where the oil is kind of smudged in a vertical line on the cylinder.

What do you guys think? Signs of scoring? What are those crack - looking things? Does the oil residue look weird? I don't really know what I'm looking at here. Advice appreciated.

dporto

There is no “bore scoring” in your photos. There are plenty of threads here and other photos on the web or at FSI or LNE, or….

yelcab

Wished mine was like that ...

golock911

Yes, normal. Can't explain the squiggly lines, but it's not scoring. Change your oil every 5K mil or 6 months whichever comes first.

Chris(MA)

You don't say if you scoped from the bottom or top? Bottom is preferable as the skirt scores first.

I'm guessing you're from the bottom due to the amount oil. Like others said no scoring.
The lines, i think ive seen those before in some other posted images here, as far as i recall they aren't anything bad but maybe someone else can chime in.

Did you find the source of the ticking?

GC996

Jagtem, out of curiosity, what m96 engine is it and whats the story on the long block failing? You peaked our curiosity. 👍

hardtailer

Just throwing it out there but could the squiggly line be the two flow fronts of molten alloy have come together and chilled solid inside the cast right there?
Anyhow I wouldn't worry about it being a crack.

yelcab

Here are the two

Jagtem

Thanks for the info, everyone. The cylinders were scoped from the top with each piston at BDC.

It's an early M96 from a 1999 car (M96.01?) I recently had a freshly rebuilt one shipped after waiting almost 9 months for it to be built/ delivered. Swapped out my tired engine (the one from the photos) and began break-in on the new motor. All seemed fine. Oil pressures and coolant temps were monitored constantly. At around 100 miles, I lost power when accelerating up a hill. Felt like a bad multiple misfire. Engine died. I re-started and struggled to get up the hill. Engine started sounding REALLY bad, and then I noticed an absolute plume of white smoke. Shut it down and flat-bedded home. Have not tried to restart since as I've been out of town since the failure.

Engine still has full oil and coolant. The only thing I can think is a bad head gasket failure? Any ideas? I'm beyond disappointed and will be contacting the company regarding their one year warranty. Hopefully they will help make this right. I will withhold the company name until I get a resolution.

yelcab

Oh that is bad. At this point, you should contact the rebuilder and ask them what they want you to do for troubleshooting if anything. It does not matter what the cause of the problem is, it is their problem. Loss of power, white smoke, likely intermix, I assume they want to see the engine sent back to them. Let's hope they make it right.

996C438

Internet lore says head gaskets do not fail on these engines .

GC996

Jag, sorry about your engine problems. what does your engine builder have to say?

Charles Navarro

Correct, unless someone forgets to do the final torque angle on the head bolts. :-) Seen this more than once.

Jagtem

Thanks for the input, all. I just reached out to the engine builder today as I was out of town for about a week immediately after the failure. Hoping to get a response tomorrow. They do explicitly warranty their engines for 1 year, but I'm sure this is still going to be a giant PITA.

When I received the engine, it was missing a water pump and thermostat housing, which were supposed to be included and pre-installed. They quickly arranged the parts to be shipped to me, but I'm wondering it this oversight may have been indicative of a general lack of attention-to-detail. Based on Charles' comment, maybe they got complacent about the final bolt torques. We shall see.

Charles Navarro

It didn't occur to me before, but if the head gasket did blow, maybe they reused the head studs. If you pay close attention to what some of these rebuilders are actually changing out vs replacing during the rebuild, it's easy to see why they are charging less. It's important to read the fine print.