Idle Speed 2.8

[rmoconnor41]

On start up this evening the car initially idled at just under 1000rpm.

I noticed that as I was changing down gears whilst slowing the Rev counter was dropping to 500 rpm.

pulled over and the car was idling at 650 rpm

Is this a normal range, is the engine misbehaving or is it the Rev counter?

Thanks?

 

[NZ00Z3]

The M52/M54 engine normal hot idle is 700 rpm.

If you're worried, have a look at the four fuel trims with a scanner.

• There are a short term and long term fuel trim for each bank. Bank 1 is Cylinders 1-3 and bank 2 is cylinder 4-6.
• Find the total fuel trim for each bank = Short term + long term. They should be in the +/-4% range. If they are in the +/-8% range, then you have problems to find.
• A positive total fuel trim means a lean condition
• A negative total fuel trim means a rich condition

 

[rmoconnor41]

Thanks. Hot idle seemed around 650/700 cold nearer 1000

 

[NZ00Z3]

That sounds normal