Pinging noise at higher RPMs

[Jiggerachi]

It seems my car is developing a pinging noise at hard acceleration in higher rpms. It sounds kinda like marbles rattling in a tin can, except pretty quiet, but notcible. At first I thought I was driving over some gravel on the road, but now im thinking valve tapping.

I described this to my dad & he is thinking preignition, or the cat going out. But the noise seems to be coming from higher up in the engine, & it still pulls strong, so I dont think its the cat.

Now this weekend im going to do the Seafoam intake & Deep Creep treatment, throw some in the crankcase & gas tank, then next weekend im going to change the fuel filter/oil/gear oil. Im sure the fuel filter is as old as the car, 120k, do you think this could be causing preignition?? Or is my timing off?

I searched the board, but didnt find anything specific enough to my problem, plus id like some more local help on this problem.

Im hoping it is either my fuel filter or the timing, & since the timing setting are probably equally as old I probably need it readjusted, but im a total n00b on this subject, & dont have access to a timing light.

Are there any tuneup/meets going on any time soon, maybee someone wouldnt mind bring a timing light with them??


Thanks guys, always a big help.

[Titus]

Put some 93 octane gas in it and see if it goes away. If so, then you need to keep using the 93, or drop the timing a little.

[Jiggerachi]

^I hope not...I cant afford that stuff. But I was planning on trying that whenever I run this tank out.

[Kags1969]

93 does wonders for pinging.... and

LORD YES CHANGE THAT FUEL FILTER!!!

[Jiggerachi]

^haha...

Yea I just bought this car 3 months ago, & the guy kept up with the normal maintenance, but all the tedious stuff I dont think he touched. There is gunk all over this car, it just needs a good all around flushing.

And the shocks..dont get me started on the shocks, theyve been progressively getting worse, I think im riding on the bumpstops now, because every bump almost hurts, then you get a nice floaty rebound & get it all over again. But that being said, the car still corners like hell & is a blast to drive...these little cars never cease to amaze me.

[channelmaniac]

Do the seafoam treatment first...

Carbon deposits build up and those create hot spots in the ignition chamber that can make the pre-ignition problems worse.

Get rid of those and see if you keep pinging.

You may be able to move up to plus rated gas to get rid of it... Try that as well.

If those don't work then you have 2 choices. Back off the timing or use Premium.

Fuel filter shouldn't be causing anything like that but you should replace it anyway on a car that old.

RJ

[Kags1969]

Fuel filter shouldn't be causing anything like that but you should replace it anyway on a car that old.
RJ

Uh.... a dirty fuel filter can cause pinging at high rpm. Dirty fuel filter = less fuel flow...

Chris

[tailchaser]

Fuel filter shouldn't be causing anything like that but you should replace it anyway on a car that old.
RJ

Uh.... a dirty fuel filter can cause pinging at high rpm. Dirty fuel filter = less fuel flow...

Chris

= lean burn = higher peak cylinder temps = increased risk of detonation = bad whether you're getting detonation or not...

yup.

[altiain]

increased risk of detonation = bad whether you're getting detonation or not...

[tailchaser]

increased risk of detonation = bad whether you're getting detonation or not...

referring to the lean burn/higher peak cylinder temps, dingus...

[Jiggerachi]

^

[Screamin'Screw]

I would put premium in immediately.

Change the fuel filter and try to run Regular.

Premium fuel is a lot cheaper than a new motor.

[MadMerv]

That noise you hear.........is the tops of the aluminum pistons burning off in little balls that bounce around like a pinball

Everyone is right....fill er up with premium and see if it goes away....NOW!

[Jiggerachi]

Premium fuel is a lot cheaper than a new motor.

Good point...

Im doing the seafoam stuff in about 3 hours, im putting premium in it as soon as this half tank of gas is gone, probably tomorrow.

Ill let you guys know if that does anything.

How bad is pinging/detonation on your engine?? It has only been doing it the last week or so, & only when I put my foot in it. After I started hearing the noise I have gone easy on her, only gassing it to figure out the noise.

I need someone with a timing light & some time to kill, who likes beer. Regardless if the seafoam/fuel filter solves my problem, im sure the timing is way out of wack.

Thanks for all your help so far guys.

[Jiggerachi]

That noise you hear.........is the tops of the aluminum pistons burning off in little balls that bounce around like a pinball

Everyone is right....fill er up with premium and see if it goes away....NOW!

DAMN!! serious??

[Billy Blaze]

I kind of have the same problem, I was only putting premium in, then the gas really started going through the roof so I went to midgrade I have a pinging now that wont go away whether I put in premium or not its there.
I should have never lowered octane, I didnt know these cars are so sensitive to octane levels.

[Screamin'Screw]

The Miata is not sensitive to knock unless the timing has been advanced. My guess is that the timing might be too far advanced for the warmer weather.

Back the timing down a couple of degrees until it is between 10 - 12 degrees.

[POS Racing]

Back the timing down a couple of degrees until it is between 10 - 12 degrees.

Can you change the timing on an NB like Billy's? I thought it was fixed?

Now you can adjust it on the NA's

[Screamin'Screw]

I think only the 99s are fixed.

[channelmaniac]

You can't adjust it on the VVT models... Now for the others, I'm not sure.

RJ