Will a car with a knock sensor ping?

97 Integra GSR

Sometimes, when I increase the throttle, I hear a faint tinkling sound
from the engine. It only lasts for about a second or so. It sounds
similar to the pinging or knocking or whatever sound you get when you
run too low octane gas. It doesn't happen all the time, and tends to
happen even less when running Chevron gas. I always use 91 octane. I
had a mechanic check the timing and it was ok, but I think he was
supposed to disconnect some sensor to check a "base timing". In any
case, what should I do at this point for troubleshooting?

 

two things.
switch to premium for a tank or two and see if it goes away. 91 (US spec.)
should not be a problem but it is possible that your car has some other
problems such as excessive carbon deposit (causes the cylinder volume to
decrease leading to increased compression leading to knock and causes
trouble with heat disipation, also leading to knock) in which case run some
injector cleaner. if you run chevron, i doubt this is your problem.

check the plugs.
if it is minor (and you know it is knock) as in very brief and sporadic,
then it most likely is not the end of the world, but then again...

as for "base timing", i am well versed in octane, but not so good regarding
specific engines. so, you know, every single person in tis NG will have
some advice.

 

Whether a knock sensor eliminates pinging is going to depend on the ECU
timing profile and how much the ignition gets backed off when it detects
pinging... and of course the gasoline octane characteristic. Oxygenates
have complicated this issue.

I have a similar tinkling sound in my '99 Integra GS which of course, has
no knock sensor or VTEC. In mine it happens at a very specific
RPM=2300/2400 and I notice it most when going up a hill which prevents the
RPM from climbing quickly. This is quite a high RPM to get pinging based
on my previous experiences, especially since there's none below that RPM.

I figured it might be a rattling heatshield but both cat heatshields have
now fallen off<GRRR> and the fasteners removed, so the only things left are
the B-pipe heatshield which does not appear to be loose and the infamous
double-wall A-pipe rattle.

I've tried premium gas, manual specifies regular, and it makes no
difference to the tinkling. I keep meaning to back off the ignition timing
a touch to see if that makes a difference. I checked it a couple of years
ago and it was closer to the high mark than the center red one but I left
it alone. I'm beginning to think this is just a flaw in the Honda ECU
ignition timing profile.

BTW when I checked the timing, I found that the jumper to set the ECU to
base timing made no difference at all... confirmed by Mista Bone who said,
IIRC, that below 950rpm the ECU does not apply any "correction".

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

Yes. There's a service jack that needs to have something done to it.
It zeros the ECU's timing adjustment so the mechanical timing can be
seen. I think adjusting the mechanical timing is more for the sake of
the ignition rotor and points but I could be wrong.

Some component of your emissions system may be getting crusty with age.
The O2 sensor, EGR valve, spark plugs, and intake manifold coolant flow
are the usual suspects. An EGR valve, if you have one, plays a critical
role in combustion speed at light to moderate throttle.