Re: Engine rumble at low speeds

From: Merullo (Merullo@ix.netcom.com)
Date: Wed Sep 02 1998 - 16:10:43 EDT


I have heard the same phenomenon in my 1993 V6, but also in other engines
totally different.

I think (and this is only a hypothesis) that it is due to the engine not
being at normal operating temperature yet. Doesnt the pcm chip 'force' any
modern engine to run very lean until it reaches
the most efficient operating temperature, to minimize emissions?

My guess is that this very lean combustion sounds different, like a roar,
when you open the throttle.

-----Original Message-----
From: ryanmc@concentric.net <ryanmc@concentric.net>
To: dakota-truck@buffnet.net <dakota-truck@buffnet.net>
Date: Tuesday, September 01, 1998 10:09 PM
Subject: DML: Engine rumble at low speeds

>I have noticed that at certain times also when I first start off and in
>lower gears, my engine has a loud roar. It sounds like a totally different
>engine. Also, in my Grand Cherokee, it does this every once in a while
>also. It isn't the fan, because that is going all of the time and it isn't
>the A/C because I can tell when that kicks on and off. I have asked other
>people what it is and they don't know. Once thing I do like is it makes
the
>engine loud, but the other thing is I can tell a big decrease in power when
>it is rumbling. I notice it on V6's only. Does anyone know what that is?
>Ryan McMillan
>ryanmc@concentric.net
>Ultra South Park
>http://ultra.simplenet.com/ultrasp/
>
>



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