996 value with a blown engine

I was wondering if anyone here can suggest where to look up car values with a blown engine. I know that this is a difficult question to answer, but I just wanted to get a sense of how much such 996 generally go for. In my case specifically a 2002 C4S, 93k miles, no accidents, body in pretty good condition with a few minor dings but no rust (I'd give it a 7-8 out of 10, but I know that is subjective), silver exterior with black interior (interior I'd give an 8-9 out of 10) and an auto transmission. Curious if anyone can point to any examples of 996 sales with blown engine. In terms of engine damage, dropped a valve seat on cylinder #2, severe bore scoring as a result in that cylinder, so a full rebuilt required.

8 to 12

Quotes source post: 18873267

Well, can't answer your question about previous sold blown motor cars. But, When you say "full rebuilt required" most shops consider that to mean all engine parts are in good core rebuildable condition, that might not be the case with a 'dropped valve seat blown motor' . Wondering if you know more about the damage done.... jmo

In terms of damage assessment, I looked into the cylinder with a boroscope and I see a few small pieces of steel in the cylinder with a heavily scored bore. I also looked through the throttle body into the intake manifold and there is metal debris in there as well. I can't tell the condition of the head because there is no good way to image it. However, the spark plug is fine and not damaged. When I mean a "full rebuilt required" I was thinking something like LN Engineering Nickies, where they machine out the cylinder completely and use new pistons for either 3.8 or 4.0Liter displacement, so the severity of the scoring and any damage to the piston is not important. I also looked at the oil filter and there is no debris of anykind there, so I suspect that the interior of the motor (crank, intermediate shaft, etc.) are all fine.

I paid $4K for my 02 with 124K miles I'd rate it a 7/10 condition wise. Some cracks in the drivers seat a dime size dent on the fender and some fading on the rear carpet area.

Quotes source post: 18873728

If there is debris in the intake manifold, the engine had a significant failure. I would recommend dropping the sump if you haven't done that yet. That should give you a much more complete picture of the condition of the engine and whether or not it is a suitable candidate for rebuild.

BRS-LN. I did drop the sump. Before even dropping the sump first observation is that the oil is clean, no metal particles. There was also no metal in the oil filter. Everything looks very clean from the sump side. I am pretty sure what happened is that the valve seal dropped and caused a lot of damage to the bore and piston top, probably to the head as well, but I can't see that well. The intake valve likely couldn't close completely as it was being held partially open by the debris and therefore some of that debris was pushed into the intake manifold on the compression stroke. However, it doesn't appear that any of the debris made it past the piston into the main center of the engine because it was stopped shortly after the failure occurred. I was initially thinking about selling the car, but realizing that it isn't worth much in current condition I am just thinking of doing a rebuild this winter using LN Engineering Nickies and obviously new pistons and potentially a few other upgrade. Would be cool to make it a 4.0 engine. May have to replace the head on that cylinder bank depending on how bad the damage is. It will take me a while to do this job, but could be a good winter project.

Quotes source post: 18878735

Sounds like you got lucky and turned it off before the piston could come apart which usually then takes out the block, rod, carrier, and crank. Depending on how bad the head is, you might choose to just purchase a single used cylinder head and rebuild that rather than trying to reconstruct your existing head if indeed a valve seat fell out, which is a common failure for 3 chain heads.

Quotes source post: 18879144

Just curious,,, Does a piston have to come apart to damage reciprocating parts..? I assume the m96 engine is an interference motor. That said, hows the m96 crank hold up to a broken valve/seat jamming the works up enough that broken parts are bouncing back up landing in the intake.? Does it just beat the rod bearing flat or can it bend the rod, throw the crank out of true, etc..? Do the m96 cranks ever show up when magnafluxed with cracks..?

Allcool, good question. I don't care about main or connecting rod bearings because I would be replacing those, but I wasn't thinking about crankshaft and connecting rod damage. BRS-LN, in your experience does the crank and connecting rod get damaged in such situations Should I plan to magnaflux the cranks and rods.

Quotes source post: 18879686

We would recommend replacing the connecting rod for sure. Even if you hadn't had a failure, we would still advise replacing them as the stock rods are a known weak point. The crankshaft can be re-used if magnafluxed.

Quotes source post: 18879283

Yes, the engine is indeed interference. The rod is probably compromised but the crank can be inspected and reused if it passes all checks for cracks and straightness.