is it the idle control valve?????

[Myros]

85 500 SL. Starts like a dream from cold, burbles at about 600, then creeps up as the engine warms and ends up at 1500 in P or N, and at about 800 in D or R with the brake on hard. I've seen all the threads about the idle control valve, and have taken it off, given it a clean in white spirit(small grains of carbon)soaked overnight in brake fluid(bigger lumps of carbon) then washed it in petrol( both small and large grains) I put it back on and the same happens, a creep up to 1500 as the engine warms. I've turned the idle down so it at least is controllable when hot, but it is now a pig to drive until it warms up.
Do I need to change the valve? Has anyone got a good one they could lend me for testing purposes? I can't find one at a breakers for trying, and am not keen to punt nearly £400 quid on a new one to find it not necessary. It's a 117 962 engine if anyone is feeling generous and helpful.

Cheers

Myros

 

[Mikesmerc]

Try Parts@mercman.net

Mercman Ltd.
Units 1/2 Manor Industrial Estate
Manor House Avenue
Millbrook
Southampton
SO15 0LF

Great Britain

Tel : (+44) 023-8078 4444
Fax : (+44) 023-8078 2444

Website: www.mercman.net

Replaced my one on my 560SEC and solved the high idle. Not good for an auto box to be engaging at these high revs.I paid about 60 quid from a breaker over here.
Regards
Mike

 

[Myros]

Great minds

Mike,

Mercman called me back yesterday afternoon, having found a valve. I'm just awaiting delivery so I can swap it. Having said that, the idle-turn down experiment has,'t been that bad. As long as I'm prepared to warm the car before driving off, it behaves perfectly. It just stalls a lot when cold, as you would expect.

Thanks for the tip though.

Myros

 

[Myros]

swapped it

Put the new one on to my warmed engine yesterday. Straightaway, I had to turn the idle speed back up, so there must have been something going on. I'll keep a close eye on it and try it a few times from cold before I come off the fence and say it was an unashamed success. Full marks to Mercman though, exactly as they say on the tin.

 

[Myros]

definitely maybe

tried it agin today on my cold engine. Just as it should be, nice rich start easing off and warming up and settling at about 750 rpm after 5mins or so of running.
Thanks to Talbir and Mike for all the info.

 

[pascal]

Myros

Glad to hear it's sorted. How much for the valve?

Hope the weather is good the weekend, and you can let the roof down8)

Although knowing you, you'll be in the garage with it trying to improve on some other part

Pascal

 

[Myros]

not a lot really

80 plus vat and p&p. Very efficient they were too. Had the roof off last sunday, just to see what it must be like to be rich and famous. Sadly, my malaise is keeping me from anything other than a trip to the doctor's. The missus does the honours if I think we dare go out for an hour or two. I've just the pesky high beam warning light to fix now, and then I can have my garagiste put it through an MOT. It looks like I'll have Luc spot-weld a sump plug onto the steering wheel centre nut/bolt to get it off, so I can gain access to the instruments. Good job my mechanic is the obliging chap he is.