Rumbling sound when car is started???

[supersnake83]

Hi everyone,

Almost everytime I start my car for from being cold (cold as in not warmed up or have been driven for a few hours) I start to hear this low rumbling sound from my engine. Then my idle starts to jump a little, but then it settles down. The idle only jumps for about 4 or 5 seconds and then it settles to normal.

Could this be one of my belts, or could it me the MAF sensor, or could it be the Idle Air Control Valve or what?

Could it be the timing belt or timing?

I changed my spark plugs and fuel filter about six months ago. I just changed my alternator last week and I changed my oil two days ago.

If anyone cold help, it would be greatly appreciated. I am going to have my Idle Air Control Valve cleaned ($100.00 by the way, is this a good price for a cleaning?) in a couple of weeks, but I need to know if this sounds like a power problem or an air problem or timing problem or what kind of problem?

Thanks everyone,

Geoff.

[driverdriver]

The J is known to start up like a 50's Buick from cold (even when new). It eventually settles down. My needle has always jumped on start-up from since when it was new. The jump my first winter was dramatic, the dealer adjusted the base idle which helped, since then there is a jump but it isn't anything dramatic. I kind of like it, as my neighbour says "you bring the beast back to life".

[supersnake83]

Hi,

thanks for the reply. I was wondering if it is also normal for my idle to be as low as 3000 rpm when I am in drive/stopped at a light/or when in reverse.

I am not sure if my car is running too rich or what, but that low rumbling sound is what I hear at the same time that my car is having an unstable idle. It only lasts for a few seconds at a time and thats it.

It also seems like my car is working too hard when I am stopped at a stop light. Sometimes it seems like not enough air is passing through my system, but this could all be to my exhaust leak.

Thanks,

Geoff.