well, changed the temp sensor and the maf and still no deal...pinging as bad as usual....NOW WHAT???? am running out of money and patience i have to admit

uhh.. what're you talking about?

Alan, quit throwing money at it. I have spares...

What is the timing set at, could be as simple as that.

Yup, inspect your timing or use a higher grade fuel.

 

-Brian

hmm, time to refresh everyone new plugs/plug wires/disty/rotor/cap/premium fuel by chevron/shell/texaco/timing right on at 20 degrees/carb cleaner sprayed around intake--no leaks/new temp sensor/new maf/pcv looks good/new o2 sensor

 

comparing this to when i first got the car its a very strange story..wouldnt pass emissions---too rich!! tailpipe black...o2 sensor black..warren, the smog guru tweaked this and that, still wouldnt pass...new o2 sensor, passed...few months after...going down a hill doing about 60, saw traffic was coming to a halt, pushed in clutch and took foot off of accelerator, cel came on, o2 sensor....about a couple of weeks before that, car started to ping a bit, gas mileage went to around 37 mpg...any type of load and it pings, heck, going east on 90, take the exit for north 5 and there is a little incline, pinged in first and pinged after i shifted to 2nd....

 

anyone??

when and where was the timing belts last serviced?

the when was around 25-30k ago, the where i dont know...the guy who i bought it from had bought it from someone else who had the paperwork...

Have you steam cleaned the pistons yet? Could be carbon buildup in your combustion chambers.

How much oil does it use? Could be burning some and causing carbon buildup, as Morgan indicated. Also, it wouldn't be terribly unusual or surprising if a timing belt has hopped a cog or something, as indicated by Miles, which could also contribute to some carbon buildup. Sounds like good places to start.

Starkiller has been chasing this problem, by himself and with help from the Board, for a month or two now. He has checked/replaced lots of stuff. AFAIK from what he has said, it doesn't burn a significant amount of oil; I asked him this, knowing that oil in the air/fuel stream can promote detonation. There is no real way of knowing the amount carbon buildup without an engine teardown, something that he is very unlikely to do for several reasons. The detonation seems to occur during all running regimes, and the plugs seem to indicate a lean mixture (per another Board member). Power is good, fuel economy is excellent. Timing has been checked and rechecked, so I doubt if a timing-belt skipping a tooth is the cause of this detonation... plus the power and economy are good. He is running the highest octane of gas that is available, and major brands.

As I recall, didn't Starkiller say that at one time in this ordeal he had replaced the O2 sensor and that helped for a while, but then the problem returned? If so, what's the chance that he's got some sealant that's not O2 sensor friendly somewhere in his system and it's causing premature failure?

off teh top of my head

i would think clogged fuel filter restricting proper fuel delivery

thus making it run lean and ping

 

as far as carbon inspecting go get one of those itty bitty 1 AAA cell mag lites put it on a string pull a spark plug and drop the light into the plug hole and you can at least look in the cylinder

 

or a simple white l.e.d light on long wires with a battery on the end willw ork well as well

 

 

also check for leaks in the intake system from the maf to the throttle body and all the vacum lines ect

any leaks between the maf and the motor will cause it to run lean

getting more air from a leak thats not been metered by the maf sensor so its not injecting the correct amount of fuel

 

oh and plugged injectors will restrict fuel delivery also

i have 2 ea82t intake setups here with injectors and such

 

think you can limp it down to longview?

lol

wHAT KIND OF SPARK PLUG HAS HE USED? sOME RUN ALOT HOTTER THAN OTHERS AND CAUSE PINGING

Starkiller's original problem with the EGO sensor, as stated previously in this thread, was with passing emissions; I don't think that anything was applied to the EGO sensor's threads. Forcing open-loop by disconnecting the EGO sensor did not noticeably effect the pinging. Doing a cylinder inspection with a dangling light invites the possibility of tear down to retrieve said light; not going to happen. Besides, I suspect that physical limitations caused by not being 18 anymore would limit his ability to see anything meaningful. I am almost certain that plugs are correct NGKs. Fuel filter scenario is unlikely, because pinging also occurs in situations of low fuel flow (low- to mid-RPM, part-throttle transitioning to just a little more throttle). SPFI, so only one injector; he has not yet replaced the TB. I previously asked him to check for vacuum/air leaks, and a little judicious spraying of carb cleaner showed up no obvious leak points... plus, IIRC, the idle is pretty smooth (should rule out vacuum leaks, at least).

 

He drives it all over, so "limping" is not really an issue... just the miles/gas/time inolved. Plus, he would still be in Longview! :-p

I was thinking more along the lines of someone using non-O2 sensor friendly sealant on the exhaust system or head gaskets. From what I understand, if it's used anywhere between the combustion chamber and the sensor it can cause problems. But, that's just hearsay from me. Mostly just brainstorming for something.

Have you tried running it without the maf yet?

 

Results on that would rule out a whole lot of stuff.

I fixed my pinging problem by slowly feeding BG fuel system cleaner into the throttle body via a small vacuum hose. Worked, but had to keep doing it from time to time.

just to jump in here new fuel filter also...oem subaru....ngk standard plugs, correct heat range....changed the maf...no difference...havent run w/o the maf, just know it idled the same w/o it.....

 

 

just seems strange that the car was running rich when i bought it, black tailpipe and o2 sensor...failed emissions...replaced o2 sensor...passed...going along fat dumb and happy and one day doing 60 had to dump the clutch and take foot off accelerator as traffic was coming to a stop and the cel came on with o2 sensor...pinging started soon thereafter and even was present when i disconnected the sensor...

...changed the maf...no difference...havent run w/o the maf, just know it idled the same w/o it.....

 

 

I reckon you should still take it for a drive with the maf unplugged.

 

My reasoning: If the pinging is indeed being caused by a lean mixture, one thing that could cause it is an inlet manifold leak. Without the maf connected, this leak wont effect the amount of fuel the computer puts in - it is set to run rich. If your car still pinks with the maf disconnected, you can all but rule out a leak as the cause.

ross

 

 

will try out your idea this afternoon btwn trips for our moving day

any other ideas as i need to resolve the pinging issue before trying to sell it...

faulty fuel injector?

ignition coil?

compression test?

 

whatever sensors you have (MAF and TPS in particular) - trace the wiring by hand. start at the sensor with the car idling. wiggle the connector first and see if it does anyting with the engine idling. gradually work the wires to that sensor between your fingers and gently bend them around...keep working your way back as far as you can go. if you hit a bad spot in the wires the motor will jump, stall, idle high, or even idle correctly if it's bad....it will show itself. i've found two bad wires this way, one on a TPS and one on a MAF. both were about 4 inches from the sensor. replacing the wiring helped alot. it's an easy quick check for a real PITA problem. and the TPS issue never threw an engine code ever. the car started running bad and eventually wouldn't even start and still no codes. after lots of swapping of sensors i found the TPS wires to be faulty.

 

be sure the throttle plate is opening/closing smoothly and completey. they can get stuck or sticky.

 

gotta go, good luck with this one.