Engine detonation
#1
Engine detonation
My engine is detonating at around 2300rpms under moderate acceleration. The senario is this I drive from work (45min on the hwy), stop at the store for 20mins or so, stopped at light on a hill, accelerate moderatly heading to 50mph, when I get to 2300rpm the car detonates. I let off the gas and thn accelerate again no detonation. Any ideas?
My car:
95 GLE 131K, 120k service done, new knock sensor, no check engine light, 93 octane in tank.
My car:
95 GLE 131K, 120k service done, new knock sensor, no check engine light, 93 octane in tank.
#3
Thanks for the suggestions
Some more info:
Carbon - ran a tank of BG 44K car still detonates
Spark plugs - OE Nissan platium so they are NGK
Air Filter - New at 123K
Gas - 93 Texaco (use same gas in my Z no issues)
Fuel injectors - how do I tell if they are leaking?
Coil pack - if bad wouldn't the SEL be on?
Thanks
Chris
Some more info:
Carbon - ran a tank of BG 44K car still detonates
Spark plugs - OE Nissan platium so they are NGK
Air Filter - New at 123K
Gas - 93 Texaco (use same gas in my Z no issues)
Fuel injectors - how do I tell if they are leaking?
Coil pack - if bad wouldn't the SEL be on?
Thanks
Chris
#9
i had detonation in a ford ranger that was caused by the MAF sensor....but ford used MAF for determining their fuel delivery in that vehicle.
make sure your crank position sensor isn't damaged...it mounts directly to the oil pan so can't really shift, but maybe got hit by a stone. Make sure the knock sensor tests ok. Did the dealer give you the right heat range plug, should be a 5? Maybe try a BKR6e-11 and see if that helps. if you aren't throwing any codes i would guess that O2 sensors are good.
I had another vehilce with severe detonation and the mechanic ran a carbon cleaner (Motocraft "tune up carburetor cleaner") through it....you actually let the engine suck it in through a vacuum line until it stalled. let it sit for 1/2 hour then fire it up again and feed in a little more...then drive the pants off it...smoking like crazy the whole time. made a huge difference in that case. i think some service centers do something similar called a "motor-vac", which is different than a fuel injector cleaning....either might help
good luck.
make sure your crank position sensor isn't damaged...it mounts directly to the oil pan so can't really shift, but maybe got hit by a stone. Make sure the knock sensor tests ok. Did the dealer give you the right heat range plug, should be a 5? Maybe try a BKR6e-11 and see if that helps. if you aren't throwing any codes i would guess that O2 sensors are good.
I had another vehilce with severe detonation and the mechanic ran a carbon cleaner (Motocraft "tune up carburetor cleaner") through it....you actually let the engine suck it in through a vacuum line until it stalled. let it sit for 1/2 hour then fire it up again and feed in a little more...then drive the pants off it...smoking like crazy the whole time. made a huge difference in that case. i think some service centers do something similar called a "motor-vac", which is different than a fuel injector cleaning....either might help
good luck.
#10
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Originally posted by jbreit
I had another vehilce with severe detonation and the mechanic ran a carbon cleaner (Motocraft "tune up carburetor cleaner") through it....you actually let the engine suck it in through a vacuum line until it stalled.
I had another vehilce with severe detonation and the mechanic ran a carbon cleaner (Motocraft "tune up carburetor cleaner") through it....you actually let the engine suck it in through a vacuum line until it stalled.
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