Steve 90TTZ

I have noticed that my 2001 E55 under light throttle between 2000-3000rpm has some slight detonation. I was wondering if anyone else has noticed this and what could be causing it? It is bone stock and I have tried different kinds of premium fuel to see if it makes any difference.

Thanks in advance,
Steve

amgdriven

Funny you mention that.I just noticed a tapping/knocking noise at low speeds on acceleration....you can't hear it outside the car, just the passengers. I'm changing the plugs to IK16 and Magnacore wires....I will keep you posted if there is any changes.

amgdriven

It's gone man. IK16 plugs, magnecore wires took care of it. Did I mention it is faster also?

Steve 90TTZ

Replaced plugs with OEM Bosch plugs and noise still persists. Any ideas? The wires seemed to be fine.

Steve

aintME

I'd try the wires next. If that doesn't solve it, it might be the coil packs. The wires are a cheap(er) fix, the coil packs...not cheap.

Grumpy666

You might be getting some carbon build-up. When was the last time you did some WOT blasts?

Steve 90TTZ

It is hard to not do wot. I was on the highway last night and gave it a good run a couple times. I am a bit nervous of breaking something though.

Steve

Grumpy666

Detonation primarily occurs at lower RPMs when the engine is under a load (eg, cruising at 40 mph in fifth gear and then accelerating w/o the transmission kicking down). Try driving the car in manual mode in a lower gear where you can keep the RPMs above 3000 for a sustained period of time. If there's carbon building up in the combustion chamber, this will help blow it out.

Howellja

I was wondering if you replaced the wires on your car after the plugs didnt cure the detonation? I Just looked up the price of the coil packs just for fun, and realized that they really arent very fun on the ole' wallet! My car is idleing funny and seems to have a lot of hesitation from a stop now that it is getting warm in NY.

Steve 90TTZ

Thanks for all your responses. I had my car in for a service and they discovered a collapsed motor mount. The noise in gone now.

Thanks again,
Steve