Code 53 KS circuit malfunction/oil issue

[titaniumdave]

Code 53 KS circuit malfunction. Can someone tell me what this is, please?

I was at the track today and my car started blowing oil smoke on the first hard lap. I pulled in, checked things and everything seemed in order. Went back out and the car ran fine, seemed to smoke a bit under hard acceleration down the straights, most noticable when going onto 4th gear.

I finished my session and noticed the oil was lower than when I started, I usually track the car with about 1/2 quart below max and it has never used any oil to speak of, this time I had topped the oil a week ago when I changed the oil. We all scratched our heads and figured the car burped the extra oil out the breather into the intake, made some smoke and was going to be OK. I was sharing my car with another driver and we got in 4 sessions in the morning and everything seemed fine. I checked the oil at lunch and I was below the fill mark on the dip stick but it was still showing, put 3/4 of a quart in and went to get some gas.

My buddy took the car out for the first session after lunch and on the second fast lap the car blew a ton of oil smoke, he let off the throttle and let the car coast into the pits. When he stopped there was oil dripping out of the air box drain, the throttle body had oil standing in it when we pulled back the bellows. We once again scratched our heads and figured the car was just 'burping' oil again, cleaned everything up and figured a little run would clean the oil off the plugs and get the car running again. I went out and got a code(53) with in a 1/2 mile and the car was blowing smoke like crazy, pulled back in to the pits and the car would not even idle. When the PCV is pulled there is oil smoke pumping out of the breather.

So I limped home, washed the oil off and now it looks like a leakdown test is in order. Any ideas about what happened?

 

[Eddy]

Do a leakdown and see if it's the valves or rings? There might be severe detonation during your track days. I have seen a B18C with Toda forged pistons that went from running fine at the beginning of the weekend to smoking to the engine won't start before the end of the weekend. Took the engine apart and the pistons tops are beat to the point of falling apart and the rings are deformed so you start losing compression and oil starts coming up into the cylinder and smoking. And when you start to lose compression, the engine will start to idle funny. Hope it's not that but a leakdown will be able to tell you.

Eddy

 

[Cbender]

I'm not sure that "buddy" is, any longer, the appropriate term given that the big cloud of smoke happened on my watch, but I thought I'd chime in to say that I'm keeping my fingers crossed for the results of the leak-down TitaniumDave.

CB

 

[hlweyl]

Try changing the PCV valve out first, a stuck PCV can cause oil to come out of the breather.

 

[titaniumdave]

PCV

Checked the PCV first, it is working.

Still wondering what a 'KS Circuit' is?

 

[titaniumdave]

Waaaaaaaaaaaaaaaaaaa!

Worse than any of us had imagined, 2 cylinders at 60 PSI, 2 cylinders at 120 PSI, 1 at 190 PSI, 1 at 210 PSI compression. At least the heads seem good, no leak through the top end. Leak downs from 5-80%, crap!

Looks like I lost 4 cylinders, at least rings, maybe pistons. Next step is dropping the engine and tearing it apart.

KS is the 'knock sensor'.

Can anyone help me with piston options? Maybe lower compression pistons for the supercharger?

Guess I will start saving for the project ahaed.

 

[the nsxnut]

Ouch. Bummer. Looks like a classic case of detonation meltdown... (ask me how I know). Can be caused by: not enough timing retard under boost (can't run OE ECU advance under FI); not enough fuel supplied (running lean) under boost. Oh, well. Other recent threads in FI had asked the question if CT engine management was totally reliable...

Good Luck, Dave. Regardless of whether you elect to do low-comp or stock pistons, you'll probably want to do something more with engine management, either with fuel supply or timing control.

BTW, on your worst leak down numbers, did it happen to be #2 and #5 (the center pistons, front and rear)? They run at hotter combustion temps than than the 'corner' pistons (1,3,4,6).

 

[titaniumdave]

cause?

Well here are the results of the different tests:

Front bank
Cylinder #1 120 PSI, 80% leakdown
Cylinder #2 120 PSI, 50% leakdown
Cylinder #3 210 PSI, 5% leakdown

Rear bank
Cylinder #4 60 PSI, 80% leakdown
Cylinder #5 60 PSI, 80% leakdown
Cylinder #6 190 PSI, 20 %leakdown

All leakdown blowby seems to be going down into engine, no air sound in exhaust or intake so our guess is the valves are still good. I am guessing we will find broken lands on the 4 pistons making it so the compression rings are not sealing. I will post when we get the engine out and apart. Interesting pattern and pairing for damaged cylinders.

My big question is what could cause this and how to make sure it doesn't happen again. Having so many cylinders go bad at once seems odd. I know I was burping oil back through the intake side/back cover breather, is it possible to draw enough oil into the cylinders to almost 'oil lock' the cylinders? The first big burp was after a long vtec straight, over 1/2 mile(lots of oil in the valve covers), with an easy left hander, soft right hander then a hard right where I toss the car followed by an increasing radius right hand turn onto the front straight where I am at WOT just past the apex. I know I was driving much faster than the last time I was out, carrying more speed into and through the corners(thanks to the instruction at NSXPO!) so there was more force on the car and oil. Has anyone seen this kind of thing?

Spoke with Shad at Comptech and I have quite a few piston options they can install on my rods. Does anyone have experience with forged pistons? Opinions on stock compression or lower compression pistons since I get to replace them, I am running a low boost SC and don't have plans on upgrading anytime soon.

 

[DanO]

Sorry to hear about your engine

Can you give us a brief description of your car's modifications?

Thanks,

DanO

 

[titaniumdave]

Car mods

I have a Comptech low boost super charger, carbon air box with Uni filter, high output oil pump, headers, test pipes(currently), Comptech exhaust, 6 speed transmission with 4.23 final drive, stage 2 clutch for engine and driveline mods.

Car has Eibach springs, Koni shocks, non-compliant bushings and toe links, Brembo front brakes, 17x8.5 & 10 Kinesis wheels to make it go faster at the track.

 

[KGP]

Re: cause?

My big question is what could cause this and how to make sure it doesn't happen again. Having so many cylinders go bad at once seems odd.

Your symptoms pretty much match what I had. However, my leakdown results showed only one bad cylinder, #4. #4 matches your results exatcly. After the engine was torn down, the ring land (or remnents of it) for #4 was found in the oil pan. Other pistons did show signs of detonation, but the lands were in tact. I suspect that the reason I only had substansial damage to one piston is because:
A) I was not non the track when the symptoms started.
B) I noticed pretty quick, shut it down, and didn't drive the car after I noticed.

I had quite a few engine experts take a look at my engine after break-down, and they all came to the same conclusion; That detonation, and the resulting excesive heat caused the rings to expand to a point where the end-gaps were closed, then expanding verticaly with enough pressure to crack and break apart the land. So tiDave, if yours ends up being the same, as in detonation, the next question becomes "what caused the detonation". A few pics from my recent tear-down:

 

[matteni]

Breaks my heart to see engine pieces and problems like this. Sorry about your FI / engine problems / hope it all goes back together well for you.

 

[titaniumdave]

Tear down

So I got the engine open on Saturday, 4 pistons had their lands in pieces, big sections falling out as we pulled the pistons out of the block. 2 cylinders had some 'odd' looking sections, like they were pounded/pitted. Less than .001" deep, you can just catch a finger nail in them. Looks like new pistons and sending the motor to get bored. The bearings are well within spec when we Plasti-gaged them so the bottom end looks good. The valves are in good shape too, except for a bit of oil residue they are even very clean so that was some good news.

KGP, how do I figure out what went wrong? What did you come up with on yours? This sure is a lot of damage and I don't really want to go through it again. How have you prevented future issues?