romaniac85

Hello all,

It's been years since I last posted anything here considering how for the last 11 years of owning this car, this has been the first time something has gone wrong.

Background -
Recently had the 200,000KM service:
Oil, oil filter, valve clearance, fuel filter, NGK Platinum plugs, diff oil, coolant flush and brake oils all replaced/flushed. I also had it plugged in to check for any error codes; none found.
Before that service I had a problem with one coil pack so I replaced them with Denso's.
Also, I had a ultrasonic injector cleaning thingy done about 8-10,000km ago.

Problem -

In the mornings, the car has started rough for 2-3 seconds and then jumps straight up to normal 1900rpm warning up ritual.
For the rest of the day, it drives great. Under heavy acceleration, the car detonates/pings.
Lastly, my fuel consumption was around 560-580km a full tank down to around 470km a tank.

I'm asking -

WHAT THE HECK IS GOING ON? I've read that an O2 sensor maybe the cause, to reset the ECU may help, whack the MAP sensor (I'd rather just replace it), check spark plugs (they're less than 200KM old). Does any one have any suggestions on how to bring my S2000 back to its former glory?? I'm genuinely at my wit's end with this problem.

Thank you in advance,

Dan.

windhund116

Pinging and knocking are not good. What octane gas are you running? Is the ignition a stock setup? Any aftermarket mods? Did the car always have pinging issues? What RPM range is your usual shifting point?

Could you pull the spark plugs and post a photo?


Thanks!

zeroptzero

At that mileage it would be a good idea to install a new primary o2 sensor regardless, that could solve your issue.

Make sure the spark plugs are tight, if they come loose due to improper torque the cylinders will go dangerously lean and you will get all sorts of damage, worth a quick check to make sure they are tight.

romaniac85

Gentlemen, thank you very much fr your replies.

@windhunt116

- I have always run octane 98 (Australia has this)
- The ignition is completely stock.
- Absolutely zero aftermarket mods are on this vehicle except for a stereo system including a subwoofer
- The car has not had pinging issues since late. It was circa around the time I swapped over the coil pack/Bosch spark plugs replacment OR the ultrasonic injector cleaner thingy.
- My RPM shift point is generally around the 3200-3700
- I installed brand new NGK platinum plugs two days ago.
- However, When I replaced the plugs, the rear Bosch plug had oil on it. I've now ordered new spark plug valve seals x4.

@zeroptzero

- I'm off today to pick up said parts as mentioned above and will get a quote for a primary o2 sensor. Could I ask, does it really matter if I get Denso ($80 delivered) over NGK ($110) or even over OEM (>$150)??

Thank you again for the replies.

Dan.

zeroptzero

All of those o2 sensors will work well, get the one that fits best/easiest (direct fit) and is in your price range. OEM Honda is always more money.

windhund116

What year is your S2000? The front O2 sensors maybe different from early AP1 versus later AP2. However, it's model specific and I don't know what engine is in your Australian S2K.

Good luck!

romaniac85

Gentlemen, again, thank you for your reply.
On another post here I so a moderator do a write up on a O2 sensor he bought from RockAuto both front and rear Denso's. The stealership wanted $709AUD for OEM so I opted for the aftermarket.
I'm gonna replace that part and see if it brings it back to its former glory. The scary bit is I don't have error codes hence why I was stumped.

Anyway, thanks for the help. If this doesn't fix it, I'm trading it for a 370Z :-)

Regards,

Dan.

Car Analogy

Well, you had a bunch of service done, and soon after there were new problems. So one has to wonder if something was done wrong and this caused the problems.

Wrong plugs. Plugs not torqued properly. Valve adjustment done wrong. New (non oem) coil packs no good, etc.

Do you still have the old coil packs? Try swapping them back.

Im confused about the plugs. They were done at same time as that other service, or more recently?

You could check valve clearances again too.

Sent from my SM-G920P using IB AutoGroup

romaniac85

@Car Analogy

Thanks for your reply. The issue was happening BEFORE the major service. I ended up having pretty much bang on 200,000 thinking that an issue with fuel not getting into system thru the filter may be the probelm.
You're right tho, maybe the service wasn't exactly on point but like I said, it was happening before. I spoke to a mechanic today and he said, like many others, I may need to source out a cooler running spark plug. However your advice re the old coil packs isn't a bad idea. I ordered a front and rear O2 Denso sensor from RockAuto and having that put in the day it arrives.
If my tank still doesn't last till 550km, then I'll swap the coil packs and try that. Even the mechanic was sympathetic to my case.

Thanks again for the reply. When I get it sorted, I'll post it up. Hopefully it may help others in the future.

s2000Junky

4 things come to mind as most likely possibilities to rule out.

-bad valve adjustment
-oil consumption, moderate to severe oil in combustion cycle will cause detonation
-bad injector/s causing lean condition
-broken/check knock sensor.

Any of these things above (certainly if pinging is audible) I would expect a chronic misfire or other fault code.

The ECU on this car is designed to pull timing and deal with a range of parameters that might otherwise cause detonation/pinging. If in deed you are pinging, I suspect something mechanical/external from this is exceeding the ECU ability to cope. Such as oil contamination for an example. You mentioned oil on the plugs, I would try and determine if this is simply a tube seals issue or an engine one. Either way its not helping your cause so you need to address it.