R129 idling problem

[Rupertino]

Hi,

I've been looking for a good (but not too expensive!) R129 500 SL for some time now and I recently purchased a 1991 500SL in astral silver with navy interior. This is my first SL and I'm really pleased with it - it's got full service history and only done 57k miles.

It has however just developed an idling problem - it is over 1000rpm in drive and when I shift to N or P it surges to around 2500rpm. It is so bad that it has really become undriveable (when I shift from P to D because of the revving I get wheelspin!). The gearchanges have become snatchy and I don't want to damage the transmission.

I've Google'd the problem and it seems the issue could be with the Idle Control Valve? Have any of you experienced similar issues & from where could I obtain this part at what sort of price?

Any help would be gratefully received as it is stopping me enjoying my new toy!

 

[Lxb3]

Hi Rupertino,

I'm more familiar with the v8's in the S-class, but they used to have idling problems as well - check the linkages (may be something as daft as an overtightened cable / rod), then have a look for the idle control valve and clean it out with a penetrant / lubricant spray. It may have stuck!
Whereabouts are you, just out of interest?

 

[Rupertino]

Hi Lxb3!

I've been scouring eBay myself but it would appear that these items are freely available in the US but nothing coming up this side of the Atlantic!

I have had the air cleaner assembly off today and checked all connections - seemed fine.

It would also appear that the ICV for the SL 500 is specific to that model for 1989 to 1992 (typical!). The MB part number on the unit is 000 141 24 25.

I'm dreading having to go to the local MB dealer for this part (the list price in the US I think was $390).

I'm in South Wales.

As regards your SL280... once a petrolhead... I should know... I've lost count how many cars and how much I've spent over the years!

 

[grober]

i reckon your best bet is second hand unit on ebay.de Mercedes Benz R129 500 SL A0001412425 Schieber Leerlaufsteller M119 0001412425 | eBay

 

[millo777]

It would also be worth trying the usual MB breakers as well. It makes sense that the part was only used from 89-92 as 93 cars would have had electronic throttle actuators and coil packs, but the same m119 engines would have been used in the w140 and w124 500E so there must be plenty around in breakers. Carl at w140 dot co dot uk might be worth a try as he breaks a lot of 140s and 129s and is very reliable at testing parts before posting them.

 

[Rupertino]

Thanks both.

millo777 - I have e-mailed Carl with an enquiry & waiting for his reply.

 

[Rupertino]

Got quote from Carl - £95 plus vat (compared to £341 plus vat from MB South Wales!).

I have ordered some STP carb cleaner from eBay, going to give the ICV a good clean first (the car has only done 57k miles and hopefully the actuator has just stuck).

If "no go" then will get the part from Carl.

 

[Rupertino]

I've removed the ICV and given it a good clean out with carb cleaner - it didn't appear to make any difference initially but then hey presto it seems to have freed itself up. So I've given it another dowsing in cleaner and fingers crossed, since then it has been fine!