dallasdriver

When I start my car, it makes a very high rpm sounding engine noise is this normal or should I take it in? The noise is some what a grinding chhhh after the engine has turned over and then a big rev. I just got the car used, the owner was my dad's friend he changed the oil every 5k with Mobil 1, and the car only has 14k on it right now.

jago1244

i dont think i've ever noticed that with my car, but i have no idea what it could be. good luck.

DSMIT

could be vaccuum pump.runs for about 2 minutes,then stops,sounds like a vaccuum cleaner.
or even the air pump for emissions purposes

Dema

I believe it's normal. Every car I knew had higher RPM just after start of engine which goes to normal after few seconds.

dallasdriver

thanks yall

Juke-box

i think its normal too. all the mb's that i've driven do rev higher for a minute or two before settling into a lower rpm when first starting the engine..

6.3

I also agree that after you start the engine revs faster, my 98 e430 does that as well as my 71 280sel 4.5
I don't know about the noise. I find the e430 really quiet even on start up. The 4.5 is another story.

Chad Oliver

Only on a cold start should it rev higher. That is the Choke adjusting so your car doesn't stall out when you put it in drive. I would only run oil that the manufacturer recommends, mobil 1 is great if he's used it since day 1, but not all oils are compatible with the gaskets on various vehichles. This is especially true if you change brands of oil on a higher milage car that has been become conditioned to a non synthetic. You shouldn't have any grinding noises though.

ChrisVoong

Hello, same thing for my car i have an e430 140k miles,Today after work i start my car and started making a very High RPM sounding engine noise i waiting for the RPM go down but doesn't after i step on the brake the RPM went down to zero but when i let go the RPM went back up above 1 now. Anyone got an answer? 9-2-13....