My car made that sound and I did not beat on it. I ran synthetics and then a little MotorKote. It went away with Motorkote but mpg came down. Check the Honda website and they sell the moly additive and a fuel injection cleaner that mixed with premium is 20 times more concentrated. Honda | 純正パーツ＆アクセサリー | トリートメント（添加剤） Need to translate though.

 

I was off today and spent time on my project car, 2006 S2000 w/ a Paxton 1500 and e85. Joey Butel Uses NOVI Boosted Power To Become The Highest Horsepower Supercharged Honda S2000 Around… ｫ Paxton Auto's Blog

Anyhow, tuesday after noon I did pull the pan and used plastigauge to run the crank and rod bearing clearances. Every clearance was right at .025mm which is in spec according to the manual. The bearings were absolutely spotless and the bottom of the cylinder bores were clean and actually still had the cross hatch marking intact. The noise almost oscillates, meaning it doesnt happen all of the time. It will come and go, most noticeable at idle. Basically it wont knock with every revolution, but 75-80% of the time it will. The noise is absolutely not there when the car is cold, but develops as it warms up. Being as the clearances checked out, Im almost wanting to bet it is in the wrist pin. Im going to call techline tomorrow and see what they have to say for the next step. Realistically, the only option I imagine there is, short block. Id love to throw a new set of pistons and wrist pins in the car and see if it alleviates the problem, but I can only imagine the fit our DPSM is going to throw when he sees this warranty ticket.

This car is my daily, only mods on it are a ram air intake with a k&n filter and coilovers. I have kept it stock as it is my daily, and dont care for adding anything else. Im going for reliability and good fuel mileage. I think its ridiculous that out of the 3 92-99 Civics Ive owned with 200k+ miles, they were all quieter that the L15 in this car.

As for bottom end noise, generally cylinder cancellation should show that. Although, my ears are telling me it has to be something in cyl 3 or 4 causing this.

Ill report back as I know more...

 

Car has been on dyno oil, with service every 3k

 

Well if the problem is determined to be slap or rod knock either would need repairing.

Both can be done with the engine in the car.

If it is just the big end rod bearings you can just drop the oil pan, pop the rod caps off, slap new bearings in, gauge them and then torque the caps back down.

Piston slap requires you to not only pull the rod caps, but the crank needs to come out so you can pull the pistons out for replacing and re-hone/sleeve the block.

That is a really good point actually. But usually you get slapping on more than one cylinder when it is from PTW wear... And this sounds pretty distinctly like just one cylinder... Good observation though that had slipped my mind.

 

What do you think of the Maintenance Minder with dyno oil?

 

Doesn't Honda motor have a thrust bearing? Thats where all the torque hits and probably the noise. The OP said the bearings are with in spec. and like new.

 

That S2K is the poster child for "Fast with Class" and really makes me wish we had more convenient E85 around here.

I have about a dozen questions about that car but won't clutter this thread with them

Now this is something I feel like I should look up.. but is this a floating wrist pin?

Is there any galling on any of the bores that you could see from below? Were you able to get any appreciable free play side to side on the rods while they were installed?

 

You mean like thrust bearings on the mains? I would imagine at least the center main does.

Do you think this is from crank end play?

 

This motor does have two thrust washers, on either side of main bearing 3 if I remember correctly. The cylinder walls were perfect, absolutely no marking of any kind, except that of the cross hatch marks. I did try to test for play in the rods, like you say side to side. Couldnt get anything noticeable. I have to agree with you though, crank walk cant be ruled out, although I cant say I have ever heard that before. Some of the guys on the S2000 forums have issues with this from using too heavy of a clutch. Anything is possible.

Oh and thank you for the compliment on my S2000. I always shoot to keep things clean when possible. Im shooting for 600whp this spring. PM me if you have any questions on it, I have no secrets haha.

 

Honda engineers believe in it, but I dont feel good about how high of mileage some of the cars are going on this minder system on dyno oil. Ive seen some pass the 9K mile mark...

 

There was 4 things I was thinking of Knock from carbon, piston slap, thrust bearing, and EGR but none should be flowing at idle and that goes to knock from carbon. It sounds like it was coming from 1 spot on the high rpm and I picked piston slap or thrust bearing. My car made the exact sound so its common.

 

I figured the center main would have a couple thrust surfaces to deal with end-play. It should be rare, especially since I can think of only ever hearing about 2 hondas with that problem, and one was an S2K with the F20 and it was heavily modified.

An overpowered pressure plate is usually the culprit but a mis-adjusted or out of spec clutch with too much throw will walk the crank too.. as the 7-bolt 2G DSMs from 94.5-1997 taught so many the hard way

Weird things happen in the field, and I hope you find out before your eating into a bore or a bearing race!

Off-topic:

Those Honda cylinder heads make for some amazing numbers. 550whp at 24psi on a 2.2L is pretty nice!

That whole compressor map (V-1T) is full of nice, fat >70% efficiency islands. That is the one you typically see on the 7 liter vettes!



That Novi 1500 should be good for about 800rwhp (1200cfm) worth of air on a big enough engine.... or if you wind out your F22 to >12k rpm!

 

Thats interesting oyu have the same noise. I have compared the noise to no less than 10 Fits, as we have quite a few coming through right now for the headlight switch recall. I have yet to heat any of them, a/t or m/t make the same noise. It does make me feel a little better that there is another occurrence. Still want to figure this one out.

 

In the Fit every 6000 mile with Mobil1. I have a civic now and use the MM which is 6500.7000 miles mostly highway with the oil Honda uses. They said Honda supplies them with the oil. I check the oil once a week looking for signs of break down. The oil holds up pretty good. I have 5500 miles on this oil at 12000 miles on car. I also use premium or mid grade but thats in other posts.

 

See that makes me nervous too. It is the easiest and one of the cheapest things you can do for an engine that will make it last. Yet some people insist on going 15k/1 year just because they are on synthetic.

They call me crazy or ignorant on this forum when I disagree and list out the reasons why, of course. For the most part I trust the MM, but not more than a visual inspection which I do every 3.5k miles.

Thats pretty sound reasoning IMHO. Hopefully he'll be able to tell us soon enough!

 

My Fit is a A/T sport. 72.5K on it. I have to look into this weekend if the weather is good to see if it is the exact same sound, but listening through the hood in the dark, the sound is from the same area as yours. It is louder cold, but will not go away after driving 50+ miles.

**Off Topic** Is the recall involve the headlight switch or the harness? My light switch is not working correctly, it jumps to highbeam if I have my right turn signal on

 

Just extends one of the wires in the harness as it is too tight at some levels of the steering height adjustment

 

Thanks for the info... looks like I have to pay if I want it fix... This maintenance bill is getting bigger and bigger... ticking sound, engine vibration, broken switch, etc

 

I know that carbon buildup knocking was mentioned By Silver Bullet but it can also cause connecting rod problems.... Way back in the days of air cooled VWs it was common the block the exhaust tube that heated the intake manifold ,increasing carbon build up... I know that carbon coated piston tops on numerous motorcycles contributed to piston slap also.... With the tune I have it is a concern of mine... I remember old time shade tree mechanics pouring ATF into the carburetors while revving an engine to loosen carbon then taking the car onto the highway to "blow it out"... Others did the same except used cold water to break the carbon off of piston tops... I'm not suggesting that anyone try this but it did work... Methanol/ Water injection is said to do the same and on my list of things to get...

 

Just like the ethanol engines that are run in the "sweet spot" you would not believe how clean some of the water/meth engines are after tens of thousands of miles.

A couple of WOT and engine braking runs will usually blow some funky stuff out, but if the engine already sees a good deal of WOT use it won't do too much.

K_C can testify to this as well, if I recall correctly..

Edit: Tex, I finally got back to you in the GE8 S/C thread with some actual info on the Rotrex boost curve!