weird sound and rev

Sep 5, 2005 | 09:36 PM

torquemonster

Thread Starter

Member

Joined: Aug 2005

Posts: 100

Likes: 0

weird sound and rev

i just put a second engine in my car because the block on the original cracked due to morons at the local firestone, but anyway the new/used engine has 100,000 miles and runs great but today whenever i am at a stop the engine makes a weird ssshhhh noise then the revs shoot up a tiny bit. this doesnt seem too serious now but need to know if anybody else has encountered this problem and i need to know whats going on and if it will get worse. just curious what you guys think, although ill probably take it to my mechanic. thanks for any input!!

Sep 6, 2005 | 11:30 AM

shadowgriffen

MBWorld Fanatic!

Joined: Jul 2005

Posts: 3,094

Likes: 0

From: Boston

is a German Tank

Have you checked your spark plugs? If you haven't then get them replaced with super coppers, do not use platinum plugs, they will give you an erratic idle.

Sep 6, 2005 | 11:33 AM

torquemonster

Thread Starter

Member

Joined: Aug 2005

Posts: 100

Likes: 0

K ill do that thanks

Sep 6, 2005 | 02:13 PM

cap'n jasper

Senior Member

Joined: Jan 2003

Posts: 429

Likes: 0

From: London, UK

W124

What model are you talking about?
How can you give advice on the plugs when you don't even know which engine he has?

Sep 6, 2005 | 03:11 PM

X03

Super Member

Joined: May 2003

Posts: 560

Likes: 1

From: Walnut, CA

MB 1990 300E

i had a different but somewhat similar problem. it was the spring in the throttle body.

Sep 6, 2005 | 10:10 PM

torquemonster

Thread Starter

Member

Joined: Aug 2005

Posts: 100

Likes: 0

i have a '94 e320 sedan

Sep 7, 2005 | 04:58 AM

cap'n jasper

Senior Member

Joined: Jan 2003

Posts: 429

Likes: 0

From: London, UK

W124

Quote:

i have a '94 e320 sedan

In that case the LAST thing you want to do is try different plugs.
The spark is controlled by the ECU and messing with different resistance plugs can blow it up. Stick with Bosch super F8DC4.

The idle is also ECU controlled on your car. It sounds like you have a vacuum leak on the inlet side which is altering the mixture and confusing the ECU. Make sure all the clips are tight and all the pipes are connected and not split. See if you can hear where the ssshhhh noise is coming from.