Hi Guys,

I was wondering if you wouldn

 

Just a guess, but sounds like piston ring failure to me. If that's the case... best case scenario would be that you didn't score the cylinders and you just need to put in new rings. Second best would be that you only slightly scored the cylinders and can bore the cylinders and put in a new piston & rings. Either way, labor won't be cheap since it's being done at the dealer.

BTW... I can't believe the dealer advised you to drive from San Antonio all the way back to Dallas, even though the engine was making horrific noises.

 

Just a WAG here as well - but perhaps its a broken valve retainer that dropped into the cylinder?

Is cylinder #1 the one that had the spark plug come out? Perhaps there's some residual damage that finally showed itself.

The dealer should be able to run a scope into the combustion chamber via the spark plug hole and do a visual check of the piston and cylinders for any obvious damage.

More brainstorming... Perhaps there's an electrical issue as well, and the noises are the result of knock. However given the computerized nature of the ECU and timing, I cannot see how the car would continue running at all in that case.

 

Hey, no fair.. you have additional info! Nobody said anything about a spark plug backing out!

BTW... if he dropped a valve, wouldn't he have zero compression on that cylinder?

 

I know you don't want to think about it, but should you need a new engine that is too much, even from a dealer. I recently got quoted just under $7000 for parts and labor at Vandergriff in south Arlington. That one eventaully wound up under warranty, but for a while it was going to be out of my pocket, so I trust the quote.

Good luck.

 

Yeah, Paul's car, during a trip in California I think, became one of the very first cars to have the spark plug problem that eventually led to the safety recall that many of us had done.

 

My thoughts...

A valve retainer would cause the whole valve to drop which would destroy the valve and piston and yield zero compression or 100% leakage in that cylinder.

I doubt knocking or something electrical would result in noise that bad.

Per my earlier email to Paul:

My first question is- how do you know what the engine feels like when it doesn't have enough oil pressure for VTEC? On most Hondas (not sure on the S2k specifically) that pressure is around 40psi ifI recall correctly. High enough that there should not be engine damage, but certainly if there is not that much oil pressure, something is wrong. Once up
beyond 3000 RPMs, most Hondas will develop in excess of 50psi. That pressure will approach the 70's mark nearing redline. Any less than that indicates something is wrong; too thin of an oil, too little oil or oil starvation, such as from hard/extended cornering (sump is picking up air), a leak on the pressure side of the pump, or some mechanical issue (damaged pump, poor bearing clearances, missing oil control orifice).

There is no reason that you should have ever expereinced this. Don't confuse this with the "cold" limit, i.e. the ECU will not allow VTEC to engage until the engine has warmed up. This is also accompanied by a lowered rev limit RPM.

They advised you to drive a vehicle with "a lot of valve noise and bottom end noise"??? That was not very wise on their part. Also, "grinding" indicates something horrendously wrong if that description is correct. If it sound like metal-on-metal, it probably is.

What about cyls #2 and #3? Did they check valve clearance? If the clearance is off, that might be the source of the problem or indicate damaged (such as bent or burnt) valves. That would not likely account for the bottom end noise, though.

It would be odd for cyl #1 to have damage but not the others. I have rebuilt at least one S2k motor, though (at least the #4 cylinder) that was run out of oil with NO damage other than the #4 piston and cylinder wall. It blew perfectly normal compression across all 4 cylinders. The only symptom was what sounded like rod knock (turned out to be piston slap).

My guess is that the VTEC malfunction code is correct, as is your feeling that VTEC wasn't engaging (probably the source of the code). Chances are you were either low on oil or starving the motor (somehow) and VTEC did not engage. You might not have seen an oil light as the pressure may have been there, but just too low. The light comes on at only about 5 psi at which point you will already be suffering engine damage if a pressure that low is sustained. Especially at high speeds. The pistons must have adequate oiling (as you probably know from
all the piston sprayer discussions) to prevent massive wear. Low pressure will prevent adequate/effective spraying.

My guess is that there was some oiling issue and there is probably massive cylinder damage to the #1 cylinder. If you have them pull the head, that money is lost if you need a new engine. There is a tool used in the automotive and gun world known as a borescope that can be used without removing the head. The dealership should have one. If not, I would highly recommend they get one. Their local Snap-On dealer should be willing to loan them one in the interest of getting them to buy one. This will allow them to look in the cylinder through the spark plug hole and check for cylinder wall damage.

I would encourage them to do this and then look at the walls for scoring. 30% leakage is not too bad, but if the COMPRESSION is 30% (i.e. 70% leakage) then that's bad. 30% leakage might not have very deep scoring, 70% will. Either way it should be visible with a borescope.

Deep scoring will mean the piston is a loss and the cylinder wall will have to be bored/honed for an oversized piston. Unless compression is excellent in the other cylinders, they may be damaged as well and need to be repaired. Boring/honing will require complete removal and disassembly of the engine. A complete rebuild may not be necessary (new bearings, seals, etc.) but I would recommend it. If you have not installed the updated piston sprayers, I would recommend that as well.

The "grinding" noise bothers me. That sounds like more serious damage. I can tell you from experience that the engine may not be salvageable. Certainly, at a dealer's pricing, it is likely not a wise financial decision if it requires a complete rebuild. Most dealers outsource all the machining work, anyhow, so you will be somewhat at the mercy of the shop they use for that work.

Certainly it is not worth ditching the car. If you decide to unload it, call me!

I would:
1) Ask the dealer to pursue using a borescope to identify the condition of the cylinder liners.
2) Ask the dealer to remove the valve cover and look for damage to the
cams/rockers (severe oil loss/damage will show up and indicate that the engine is probably a total loss).
3) If the above checks out OK, ask the dealer to pull the oil pan and inspect the rod and main bearings for oiling damage.

If you find valvetrain damage, it would likely require a complete rebuild of the bottom end and head (possibly require a new head). I would recommend a brand new engine at that point. If the problem is limited to one or more cylinder walls, and possibly some bearings- the bottom end can be rebuilt. You will have to compare pricing, it might be cheaper to buy a new short block.

If the problem is just one cylinder wall (bearings OK), it will probably be
cheapest to have the dealer pull the motor and have the piston replaced and the cylinder wall sleeved.

Another alternative is here:

http://www.hmotorsonline.com/shop/sc2000se...page&item=30013

though the dealer might not approve. hmotorsonline.com has a good reputation (I have used them in the past) and you would have a transmission you could then sell. I suspect that you can find a buyer for your old motor, too, at a price that might surprise you. There is a large market for used (even damaged) S2000 engines.

Finally, I would be very concerned about how this happened. If you kept it full of oil (I know you are meticulous with the car) there is absolutely and utterly no excuse for this happening, aside from possibly a high-G sustained turn at such a degree and force to make the oil pickup in the pan go dry. Even then, it would take an inordinate amount of time for that to happen.

I would challenge the dealer to explain what happened. How much oil was in the vehicle when it arrived at the dealer? I would have them drain and measure it. I would ask them to take apart the filter and take a look inside of it. I would not challenge them directly, but to be honest- there is no reason aside from some mechanical failure for this to have happened.

Good luck!

 

This is what lack of oiling looks like in the #4 cylinder:



The engine suffered a complete loss or nearly a complete loss of oiling when an external oil cooler sprung a leak under relatively easy driving. The only symptom was a sound like rod knock. The piston skirt looked as bad as the cylinder wall does. Rings were in decent shape (some damage, but compression was OK). Bored and clearanced to an OS piston and the problem was solved.

 

Guys -

Thanks very much for your thoughts. Todd has also been conversing with me by e-mail directly...

Elistan, it was not the same cylinder as the spark plug backed out of (that was #2).

I also mentioned to Todd that about two months ago, I had an oil loss incident. The dealer (same one) failed to properly tighten a new oil filter, it worked loose on the road, and I ended up driving back from DFW to Plano by dumping a few quarts in. But it was leaking heavily all the way.

The dealer's position today is that any failure that this might have caused would have appeared right away, not two months later. To paraphrase Todd, maybe, but maybe not.

Todd also agreed with the writer above that the dealers giving me advice that it was ok to drive from San Antonio to Dallas were probably wrong.

Thanks again,

Paul

 

And, Shrike, thanks for the tip...