Air valves, throttle bodies and a high idle

The wardrobe's at it again..... x(

Question 1.
She seems to idle very high on startup (3k ish) and occasionally just sits at traffic lights at around 1000 / 1500 rpm.

Any technical guru's know what I have to clean, replace or generally butcher and how would be nice ? I've searched the posts and found nothing very detailed on this :(

Question 2.
When my turbo recirc's through the K&N cone filter I can hear it (normal I know) but latley it sounds "flappy" like the wastegate is flapping, not just opening. Any guesses how I can check it ?

Jim,
'96 855-R (The FLAPPING Wardrobe) :+

[Simon Linton]

The problem is Jim that you've now tinkered sufficiently to make all "standard"-based posts about idle speed irrelevant.

While I know that this is anathema to the dedicated tweaker, I would suggest a visit to them as has the OBD kit and a thorough fettle and adjust.

Once you've regained normality, you can start changing it all over again....

Simon,

I beg to differ.... the car has been spot on for a year now in its disgracefully modded state, however the start up idle has gone donkey in the last 10 days....suggesting to me that something in the idle "valve??" region is a bit sick...... hence my original question

When last visiting Volvo (3 months ago) they checked the car out thouroughly, because I asked them if it was likley to upset things having the K&N a bleed and a heavy right foot.

They said no need as the car would tell us if it was unhappy, I insisted and volunteered to pay so they plugged in, switched on, tinkered and produced a bit of paper stating that all relevant figures were within tolerance of the ECU's limits.

So the question remains.......... WHAT has got mucky or died to produce a high startup idle? And WHY does my wastegate sound like a very powerful whoopee cushion ???

Jim,
'96 855-R (The Local Dealer Tested and approved Flying Wardrobe)

Hi Jim

I had same trouble}


Try looking at the small air vacume pipe that pluggs into the end of the manifold cambelt side under your water thermostat. You will probably need a torch to see it but it is a common problem the elbow rots away. This will cause your car to idle between 800-1500 and give u idle problems at traffic lights,

If that is not the problem try cleaning your Air idle valve out with WD40 untill you can hear it moving inside.

I did these operations to my 96 850 T5 and have no problems my car has also been modded and with a K/N filter my car sounds like wastegate is loose but it is not as i have taken it apart before.

Hope this helps you Jim

thanks Leigh (bigbird)

Ahhhh something constructive !

Thanks Leigh, I'll go hunting by lamplight for this little pipe.... wish me luck (although the cam belts being done soon for a ridiculously small amount of money - maybe it'll be more visible whilst its being done?)

Where precisley is the Air Idle Valve ?? I've heard of it but never had the guts to try it ! :) Somewhere around the throttle body I guess ???


As for the wastegate..... I've had some more info from someone who does a lot of turbo'd car work, and I quote:

************************************************** ***************
I then went onto driving the car 'hard' and could clearly hear the BOV opening as boost levels reached the 11 psi mark upwards. It was not a full opening type of sound, more a sort of 'leak off' sound. I can only summise that the BOV does not like the extra boost, ie the closing spring is too weak.
I would be interested to know if any one else has experienced this, or would be willing to try it for themselves. It would also be interesting to see what a manual car does in the same scenario.
************************************************** ***************

This chap has since dismantled his turbo to check it out and found that the spring operating the gate - whilst within correct tolerance - is not strong enough to hold itself shut during heavy boost. I guess I should turn my bleed down a little bit !! The other option is a hybrid turbo & proper wastegate..... megga money !!!!!!!


Jim,
'96 855-R (The Flying Wardrobe)