ki15686

Hello,

I have a 1998 Lexus LS400 with 140,000 miles.

The car runs beautifully with one exception: The car pings when I accelerate very lightly from a standstill (more than what I would consider normal) and also when I am travelling at 60 mph with the cruise control on. When I am heavy footed all the pinging goes away and the car runs like its brand new.

I replaced the air mass flow sensor earlier this week – and have noticed a lot more power!

I have also recently replaced the coolant temperature sensor, spark plugs, air filter, fuel filter and all four oxygen sensors.

Any guidance / suggestions would be most gratefully received.

Thanks,
Ken

etex

Fuel octane first comes to mind.

deanshark

I was thinking the same at first but usually with low octane it would ping more with a load or giving it gas hard. His goes away with hard gas. But, you can always just try a bottle of octane boost to see if it goes away.

sethjon

Are you buying gas from a amjor station or the cheap crap? Also, what octane? Lastly, check the timing.

SkulCracka

sticky lifter or low octane.... but im no tech by any means.

RA40

iTrader: (6)

Did you reset the fuel injection ECU?
The other thought is if it has been so-so prior, there may be some buildup deposits. Running a few tanks through will usually clear it up. Plenty of gas threads already...

deanshark

You don't have to tell us twice. Hah, just kiddin' We're not all techs, most everything is from first, and second, hand experiences. Every idea is welcome, keep 'em coming.

skperformance

iTrader: (6)

Have/had a similar issue with mine for a year or so , since a ran tank of seafoam i haven't noticed again.
It was always at partial throttle in 3rd or 4th gear at about 3000 rpm .
Noticed it the most under highway on-ramp acceleration .
I tried to agitate it and used low octane fuel and made it so bad i wanted to stop the car .
Run a car of seafoam and have a good highway drive for atleast an hour to clean it up.

j three

I also would use seafoam then Lucas in every fill up. They are both very effective. One at cleaning the other at maintaining.