Och

iTrader: (3)

Help! I noticed very distinctive pinging when I gun it and and RPMS raise to around 4,000-4500 RPMs!! Its a 2001 GS430 with 78k on the clock. This is not a continuous ping, it only pings for fraction of a second and then then engine is smooth as RPMS continue going up, then shift, pings again for a fraction of a second and smooth again. The pings are very distinctive and loud, sounds almost like little rocks flying inside wheel wells. I added some octane booster but the pinging is still there. There's no check engine light, the car runs very smooth, no loss of power or anything. And the screwed up thing about it, is im having almost the same problem with my LS400, but the LS pings continuously after 3,000 rpm under hard acceleration, but the pinging can be barely heard.

luciano

I had the same problem a year ago on my 98 gs4, had the car lifted on a hoist and revved to pin point where the noise was coming from, turns out it was a torn gasket in the Y-pipe, replaced it and the noise was gone... I let my friend gun my car tonight while i was following in his car listening and I can hear it coming back a little... maybe another gasket.. :|

Och

iTrader: (3)

Mine doesn't do it at all in neutral - I'm pretty sure its engine pinging, not any other noise.

DaveGS4

iTrader: (2)

Did you change the gas station you use recently or did they switch their octane rating / forumula? Have you run more than one tank of gas through the car with the same issue, filling up somewhere different?

Just trying to get the obvious out of the way

Och

iTrader: (3)

I dont know I haven't been noticing it because I don't gun the car past 4,000 too often. I noticed it over the weekend, so now I added octane booster to the gas, and fueled up at a different gas station, but it still pings, although it seems to be to a lesser degree. I still had 1/2 tank of old gas when I added octane booster and different gas, so once that runs out completely im gonna try full tank of different gas and injector cleaner.

Och

iTrader: (3)

I was also thinking about just taking the car to a good diagnostics shop - are these able to detect problems without check engine light on?

Tammy

If not previously performed, try reseting the engine ECU by disconnecting the battery for half hour or removing the ECU fuse, located under the hood

Techron and BG44 are the better opinioned injector cleaners, it you feel the need. It's important to follow the directions; too concentrated may damage the injectors or fuel pump.

There are additional components with the V V T i engine, cam positioner hydraulics for example. I wouldn't rule out an intermittant coil defective. The failure may only occur with the engine under load, not relating to idle or in neutral.

I would suspect a questionable sensor in the system, which can be detected with the proper diagnostic equipment.

The diagnostic shop is the best next step, just as you posted.

Och

iTrader: (3)

So I brought the car to the shop today and they determined that a computer is not functioning properly. They are charging $400 to have the computer repaired, plus $80 diagnostics charge. I'll pick the car up tomorrow morning, so I'll know how it is. I will also ask for more details.

BA_GS400

iTrader: (1)

hope you got some kind of guarantee with that..... and the old computer in your hand afterwards. Most of them are not really "repairable".

.

Tammy

Thanks for the feedback ...

Och

iTrader: (3)

Well... They said they reprogrammed the powertrain control module (PCM). They said the program in the module wasn't working right, and it wasn't sending enough fuel, therefore I had the pinging problem. They said they do it on Lexus vehicles pretty often.

JeffTsai

iTrader: (1)

Reprogrammed it? I don't even think that is possible on our ecu's. At the very least, you gotta run a piggyback to change the air/fuel settings. I bet all they did was rest the ecu lol

See if you can get a detailed report from the shop to see exactly what work was performed for $400. I would be pretty pissed I was charged $400 for someone to disconnect my battery and then plug it back in.

Och

iTrader: (3)

Its not the ecu, its the PCM module - I don't think it's the same.

JeffTsai

iTrader: (1)

Eh, I'm just used to calling it ECU. Engine Control Unit same thing as PCM.

It's refered as PCM in American cars. Japanese cars usually refer to it as an ECU.

Well the most important part, did it fix the pinging?

Och

iTrader: (3)

It did fix the pinging. If all they did is reset the ECU by disconnecting the battery, then I'm stupid... and when you're stupid you get to pay.