Idle Purr???

[DMDRIFTING]

Hi all,

hope you can help?

The RX7 has begun to make a 1 second purr (only way i can describe it) as it returns to idle. Car is completely standard apart from cat back exhaust!

It seems to happen also only when the throttle is held open very slightly say 1% -  2%?

I\'ve just recently changed the oil and filter to Castrol Mineral, after i topped it up with Mobil 1 15w 50 Fully Synthetic :Nono!

Also going to be doing a full service within the next week or so!

Can anyone tell me why it is doing this at idle?

[gillard28]

could be the air pump. get ya head under the bonnet the air pump is on the top left

[RedRummy]

sounds like air pump moo

[DMDRIFTING]

The intake system is making more intake noise, on boost, than normal?

What is the purpose of the air pump and what am I listening for to know it is ok or faulty!

[grinder]

the air pump blows air thru the exhaust from 0001 rpm thru to 2500 rpm ( i think ) and it keeps the emmisions down

if you remove it - you wont get thru a MOT ( unless you know them )

to be honest - i dont know much about the FD air pump - but thats the basics i think

[DMDRIFTING]

Ok, not to much of a drama then. I\'m off to the Nurburgring in a week or so!

[DMDRIFTING]

I\'ve just found a rather large crack on one of the rubber coupling\'s from around the main intercooler pipe that runs from the turbo\'s and under the  strut brace

Will replace the part and let you know if it sorts the idle purr out :Thumbs-up

[DMDRIFTING]

Pipe now on and \'idle purr\' is no more, car has completely changed, strong progressive power and solid boost, thank\'s again to Lee for sending me the new rubber coupling :Thumbs-up

Thank you everyone for your quick reply\'s and help