W124 E220 Economy mode switch and heated rear window failure

[AJN]

Dear All

Just had this site recommended to me. I have a 1994 E220 W124. It's been very good to me - it's covered about 85k miles.

Recently heated rear window has stopped working - I took the multi-relay out (the one that does the hazzards and wipers). I replaced it without the cover. The solenoid switch operates when the dashboard switch is operated. Could it still be the relay, is this common?

I'm pretty sure the actual window is ok as I put a multi-meter across it.


Also while I'm here my economy mode switch does not operate. In either E or S the car still max's out at about 6200rpm before changing gear. Any ideas.

Finally my oil pressure tends to drop a bit when the engine is about 80 deg celcius. It happens when it is in gear and at a halt. As soon as i pull away it pushes up to 3. I haveeen told this is just due to age and mileage. Is this right, can i minimise this?

Any advice would be greatly appreciated

Many Thanks

AJN

 

[Andy]

Hi

You don't say what the oil pressure goes down to. But I don't think you have a problem if it goes straight up.

The HRW. You need to check if current is getting to the rear screen. The relay sounds more likely to be the problem.

The ES switch only works when the switch is showing E. If it does work its just reverts to S. I don't think there much good any way. It only stops the g\box from droping down a gear when climbing hills etc. People think it makes a differnce on the motorway or normal driving. The switch makes no difference to any gearbox ratio. Most people drive a little more sedately when they know they flicked the switch & that I believe where the better fuel comsumption comes from. IE better driving.

From memory there is a soleniod by one of the shocker struts with vacuum pipes going to it. The switch merely stops vacuum to the box or supplies it depending on the switch position.


Regards

Andy @ www.mercedesservicing.com

 

[mail2neil]

Re: W124 E220 Economy mode switch and heated rear window fai

Dear All

Just had this site recommended to me. I have a 1994 E220 W124. It's been very good to me - it's covered about 85k miles.

Recently heated rear window has stopped working - I took the multi-relay out (the one that does the hazzards and wipers). I replaced it without the cover. The solenoid switch operates when the dashboard switch is operated. Could it still be the relay, is this common?

I'm pretty sure the actual window is ok as I put a multi-meter across it.


Also while I'm here my economy mode switch does not operate. In either E or S the car still max's out at about 6200rpm before changing gear. Any ideas.

Finally my oil pressure tends to drop a bit when the engine is about 80 deg celcius. It happens when it is in gear and at a halt. As soon as i pull away it pushes up to 3. I haveeen told this is just due to age and mileage. Is this right, can i minimise this?

Any advice would be greatly appreciated

Many Thanks

AJN

Hmmm :roll: If I am not going anywhere on my W124.., the oil pressure slowly goes down below 3.. - probably 2 on the dial.. , then as you build up revs/speed again, the pressue goes back up to 3.
Is this what you see? I thought that was perfectly expected really.
The real problem is if you don't have any pressure..

 

[Geoff_Slade]

Hi

I'm a fairly new W124 owner (300D just been serviced by Andy ). My oil pressure sits at 3 all of the time except if I'm stopped when it will sometimes drop a bit (lowest is about 2) but goes back up as soon as I touch the accelerator. I thought this was normal as well although as this is the first car that I've had with an oil pressure guage I'm not speaking from experience but I'm sure Andy and his guys would have mentioned something they are very thorough.

 

[AJN]

Thankyou all for your responses, I can now rest assured about the oil pressure.

Mail2 and geoff, that is exactly what happens. I will take that as normal.

Andy, WRT the HRW - there is no current running to the back window when the switch is activated - as you say points to relay. Worth seeing if the live feed to the relay is there? Also i agree with you about the use of the eco switch - however it's nice to have all the bits working isn't it?

I'll have a look at this solenoid - many thanks, wouldn't have thought of that.

Thanks again - i'm off under the bonnet.

 

[Jim Gallagher]

Heated Rear Window

I had a similar problem on my E220. It was cured by changing the relay. About £70 +VAT from dealers or £30 from a second hand parts shop.