Pinging under part-throttle load

[3.0L V6]

To begin, my car, a 1998 Saturn SC1 with 151,000kms (93,800mi) has begun pinging under part throttle conditions. I can't tell if it does it at full throttle due to the engine drowning it out.

I've bumped up my gas to mid-grade (89 octane) which helps, but at am a loss to explain why it doesn't seem to like 87.

Any ideas? EGR valve?

[Cookie Monster]

The EGR valve may be stuck closed, but I don't see how running a different grade gasoline will make it ping less.

[VTEC_Inside]

The EGR valve may be stuck closed, but I don't see how running a different grade gasoline will make it ping less.

Higher octane gas is less prone to self-detonation.

[VTEC_Inside]

My Accord has started to do this a bit recently as well...

I've just backed off the gas, its helping my mileage numbers, lol...

I've been far to lazy to start poking around under there to see whats up. I'm going to have to though, I'm convinced its running a bit hot, fan is coming on a bit more than usual.

[Cookie Monster]

Higher octane gas is less prone to self-detonation.

But if his car is designed to run on 87 octane, would 89 really help at all?

[Eye of the Tiger]

If higher octane is helping, then your problem is detonation. I'd start with cleaning the EGR valve and vacuum lines.

[Eye of the Tiger]

But if his car is designed to run on 87 octane, would 89 really help at all?

The only purpose octane has is to resist ignition without a spark, so if an engine malfunctions and begins detonation, then increasing the octane is one way to deal with the problem.

[Cookie Monster]

The only purpose octane has is to resist ignition without a spark, so if an engine malfunctions and begins detonation, then increasing the octane is one way to deal with the problem.

Oh, I see.

[Rupert]

I bet I have a gunky EGR, too...

[S204STi]

A stuck open EGR valve would cause a rich condition, but a stuck closed EGR valve could certainly cause this sort of thing (under part throttle only.  Anything more than part throttle closes the EGR valve anyway).

One other suggestion would be to run a can of Chemtool B12 or Chevron Techron, or if you can find it, BG 44k through your fuel tank for a couple of tanks.  Carbon deposits can sometimes cause this sort of thing.  Either that or a nice spirited drive on the interstate for an hour or so.

[Eye of the Tiger]

A stuck open EGR valve would cause a rich condition, but a stuck closed EGR valve could certainly cause this sort of thing under part throttle.

One other suggestion would be to run a can of Chemtool B12 or Chevron Techron, or if you can find it, BG 44k through your fuel tank for a couple of tanks.  Carbon deposits can sometimes cause this sort of thing.  Either that or a nice spirited drive on the interstate for an hour or so.

The ol' Italian tuneup... should be done at least once a week.

[S204STi]

The ol' Italian tuneup... should be done at least once a week.

They call it the Mexican Tuneup out here.

[Secret Chimp]

Be Ye Aware - Run Thy Solvents Befost Thou Oil Change, Lest Ye Have Thine Particulates And Thy Whatnot About Thine Shinee Surfaces Where Be Bearings.

[VTEC_Inside]

A stuck open EGR valve would cause a rich condition, but a stuck closed EGR valve could certainly cause this sort of thing (under part throttle only.  Anything more than part throttle closes the EGR valve anyway).

One other suggestion would be to run a can of Chemtool B12 or Chevron Techron, or if you can find it, BG 44k through your fuel tank for a couple of tanks.  Carbon deposits can sometimes cause this sort of thing.  Either that or a nice spirited drive on the interstate for an hour or so.

That could explain why I've been having it lately. Historically I've always wrung the crap out of my Accord... Haven't had it over 4000rpms in a long time now.

Then again it could be more vacuum related fun too. sigh...

[r0tor]

I'm running a full can of BG44K this tank 

[sparkplug]

Time for a tune up. Might need a new warp core.

[AutobahnSHO]

Time for a tune up. Might need a new warp core.

1.21 Jigawatts!!!!!

[Rupert]

There are no warp cores in Back to the Future, and no jigawatts in Star Trek. Duh.

[3.0L V6]

The Saturn struggles to make 88mph, so time travel's out.

Also, cleaning EGR has no effect.

Spark plugs have semi-white buildup on them.

[GoCougs]

An engine running too hot will ping.

[sparkplug]

The Saturn struggles to make 88mph, so time travel's out.

Also, cleaning EGR has no effect.

Spark plugs have semi-white buildup on them.

white buildup. GoCougs might have a point.

[Eye of the Tiger]

white buildup. GoCougs might have a point.

you would know