[willy3oy]

On my quest to eliminate my rough idle I decided to replace my ICV. My original unit definitely works to some extent but I was curious to see if a new ICV could smooth out some of the surges. I’ve already done the entire vacuum system, idle control relay, ignition system, fuel distributor, injectors and this was an easier job than overhauling the intake manifold which is the last culprit I can think of.

I bought this beautiful shiny ICV made by LÖWE when I was in Europe which is a direct replacement for my original part A0001411425 - Idle Air Control Valve (IACV) 5351425 fits Mercedes - loeweautomobil.de

I’m fairly sure that this thing just arrived broken and to make matters worse I am now back in South Africa which makes returning it for a replacement a much more complicated procedure.

With my original ICV - Starting from cold it idles at 950 RPM then drops to 700 RPM at 40°C. If I disconnect the ICV then it hits 1450 RPM.

With the new ICV - Starting from cold it idles at 700 RPM. It then rises to 1000 RPM at 40°C and then to 1100 RPM at 80°C. If I disconnect the ICV then it hits 1450 RPM just like before.

I am waiting for a reply from the manufacturer but does anyone know if this could be fixed? I’ve only heard of soaking ICVs in carb cleaner to remove the gunk but there’s surely no gunk on this one. And I guess another question would be is it worth getting this replaced if the aim is to smooth my idle? It looks so pretty though!

 

[Heikkif]

You could try this: Leerlaufsteller, erhöhte Leerlaufdrehzahl/ Vorspannung – Wiki zur Mercedes Baureihe W126

 

[willy3oy]

Thank you for sharing that. I got very excited when I read about the wax seal that needs to be removed before use! But sadly there is no wax seal on my ICV and nothing to remove. That article details the LÖWE replacement for A0001411625 but not the A0001411425 which is what I have here. This is the correct part for my 1984 model according to the EPC.

 

[ianrandom]

How annoying. I would want a swap, but what a pain.

 

[willy3oy]

It's a heartbreaker for sure. I think I actually skipped to the garage when I read Heikkif's reply! Still not a peep from LÖWE about this. Maybe they'll have some advice.

 

[isthenew]

There is another thread a few months old discussing this. There are a few resources there, including some videos. They're for other models, but the repairs should be the same. Pretty sure they'll help.

 

[willy3oy]

Thanks for the reply and for letting me know about the other thread. I gave this a good read and the videos were very helpful in explaining how the control valve actually works. The video from Richard Horvath shows my exact model of ICV which does not appear to be adjustable.

I have finally managed to bench test the new ICV from LÖWE and even at 5V the valve does not close. The original closes at 3.8V. I guess this valve is just faulty so I will return it and consider my options. Thanks again to everyone who chimed in on this!

 

[csquared4290]

Genuine MB VDO idle valves are still available new from MB. Not cheap, but worth it from avoiding these headaches!

 

[Heikkif]

How much current is idle controller able to output on your car? How much current should it be able to output? On GEN 2 cars idle control current should be between 700-1000 mA. I do not know how it should be on earlier models.

 

[blaz.kovac79]

hi, I've replaced my ICV with a Lowe one. The old one was OK, but Lowe is OK too. But... but my mechanic told me this week that the ICV is "rattling" when bumped with a screwdriver. So It seems the Lowe ICVs are a close second, but not completely the same as Bosch units. We'll see if this is an issue, because for now the potentiometer is the main problem.

I've also bought the potentiometer (air inlet meter) from Lowe.

zz