Noticed today with the hood open and the engine at idle it kinda sounds like a air compressor running towards the top of the engine, lots of engine noise. What would all this noise be the fuel injection pump? Sounds almost like a air compressor running, a lot of mechanical noise. It gets fairly well muted when the hood is closed and almost not noticeable from inside the car. Just curious what causes all this engine noise for anyone in the know? I think it's normal because it's made all this noise ever since I got the car. I don't think it's valve train noise, not really that kind of sound. Plus I do remember seeing a you tube review and the reviewer said there was lot's of engine noise and it could be heard in the video.

All I'm asking is does this M157 motor make more engine noise than your average car? I think I read somewhere else or saw a review on youtube a while back that says it does? With your hood open and listening to the car idle do you all hear a lot of mechanical type noises? I don't think by nature it's as quiet as say like a Lexus or something? Is this correct?

Yes. With hood open you would not think its an amg.

I guess I should probably have the dealer take a listen to it just to be safe, there is quite a bit of mechanical noise that comes from the engine, more so than any other car I've owned before.

yup....alot of ticking......normal as far as i know.....i purchased an extd warrenty just in case.....but i plan to be a long term owner....

Ok, now I know it's normal, here is a review of the car and the motor from up front sounds like mine, sounds like a old rotary lawn mower or something, lots of mechanical noise. Check it out, go to around 4 minutes.

love saabkyles reviews ...........

Ya, he is great, I love the "and now without further a due" part, lol. It was a good review of this car, but wow, these engines make a racket, I'd still like to know where all that mechanical noise is coming from, it does not sound like all valve train noise, I think it might have something to do with the fuel injection or something. It's fine with me if it keeps making all that engine noise as long as I get 200K out of this motor, I guess it's possible right, this motor is a older design I've read and there must be a lot of people with many miles on this motor I'd think.

This is the sound of fuel injection pump your right its annoying if keep paying attention lol

vdubpower I thought you going to trade it for a M5

yeah right....im a mercs guy....my best bud has a blue one like pertplus, so we trade off sometimes but i still think mine is better
have you done full weistec upgrades yet

Nice to see you staying

Not yet getting things slowly. You should attend Shift-S3ctor to stretch the beast

yes i need to do that....whens the next one

Not sure when the next event but I think beginning of 2014

The video mentions Direct Injection which incorporates a high pressure fuel system. Fairly certain that is what people are hearing as my Lexus LS460 also has it.

direct injection injectors made a very noticeable ticking sound. That said, I've found many mercedes engines to be a bit noisier than counterparts at lexus, acura, etc.