e220 w124 coupe. A few questions

[d215yq]

I posted this in the general section by mistake so thought i should post it here as well....

Hi all,

Just bought my first Mercedes - a w124 1996 e220 coupe auto (125k miles) and as my previous car was very different (a 1.4 Rover) I have a few (probably stupid) questions regarding the car.

1) I've not had an auto before but at low speeds in 4th gear the torque converter seems quite "loose" and engine revs increase from 1200 to 1600 without barely any change in speed of the car. Also on the motorway I still can't get more than 33mpg - Is this likely to mean the gearbox fluid needs changing or something more serious? (it was last changed 4 years ago at 100k miles).

2) once warm the temperature gauge fluctuates between 80 and 90 degrees depending on speed. The radiator looks OK but on previous cars the temperature gauge has always remained constant so is this normal?

(Also when the temperature gauge rises to 90 and the car is stopped the oil pressure gauge can dip to 2 instead of 3).

3) brake pedal sometimes feels spongy and if it is pumped quickly it becomes firmer. The car always stops very quickly and passed the MOT and the hydraulic system was checked - could this be solved by a brake fluid change or is somethign else likely to be wrong

4) the front windows sometimes judder a bit as they go up and down. As the coupe is pillarless which bits should i silicon grease to ease their operation?


If you have any DIY suggestions as to what to do regarding any of these I'd be grateful. I've just had it serviced and MOT'd and none of this was picked up so please tell me if I am just worrying about nothing!

Thanks,

Ben

 

[wireman]

Auto boxes or at least their torque convertors do exhibit aparently sloppy speed behavior although 1600 RPM does sound a little high (my diesels speed firms up at about 1400 RPM). Change the fluid and filter every 30k, do not over tighten the transmission sump bolts.

The thermostat could be tired and starting to stick. Change it and check the water pump for drips at the pulley seal while you have it in bits, replace the coolant with new every two or three years.

There is some lost motion in the brakes at the wheel cylinders ( unlikely with disk brakes unless there is a lot of wheeel bearing slop) or there is a small amount air in the hydraulics. Renew the brake fluid (push back the caliper pistons to get fresh stuff in them) every year (in spring according to MB) and bleed it from the back first, then the NS front and then OS front. If this does not get it sorted a pressure bleeder might help.

The window regs are often sticky and jerky, take off the door card and lubricate any bits that move with the glass as well as the two vertical channels the glass runs in.

Your oil pressure is OK this happens with them all when they have been used for a while.

 

[Bolide]

Just bought my first Mercedes - a w124 1996 e220 coupe auto (125k miles) and as my previous car was very different (a 1.4 Rover) I have a few (probably stupid) questions regarding the car.

1) I've not had an auto before but at low speeds in 4th gear the torque converter seems quite "loose" and engine revs increase from 1200 to 1600 without barely any change in speed of the car. Also on the motorway I still can't get more than 33mpg - Is this likely to mean the gearbox fluid needs changing or something more serious? (it was last changed 4 years ago at 100k miles).

I wouldn't expect to get more than 33 mpg. I would expect the torque convertor to lock up but at higher revs than 1600 rpm. If the gearbox oil's not been replaced very recently I'd replace the filter & gasket using MB parts & Dextron II

2) once warm the temperature gauge fluctuates between 80 and 90 degrees depending on speed. The radiator looks OK but on previous cars the temperature gauge has always remained constant so is this normal?

Do you have aircon? If so the a/c dumps heat into the cooling system & raises temperatures. If the gauge drops as you speed up you might have a bad header tank cap, partially-blocked rad or a bad viscous fan coupling. I'd replace the rad cap & test again. I would expect readings to rise a little in traffic but readings between 90 and 100 would have me checking things. If it doesn't go above 90 I'd leave it alone

(Also when the temperature gauge rises to 90 and the car is stopped the oil pressure gauge can dip to 2 instead of 3).

Normal. Make sure it has the right grade of oil at the next oil change

3) brake pedal sometimes feels spongy and if it is pumped quickly it becomes firmer. The car always stops very quickly and passed the MOT and the hydraulic system was checked - could this be solved by a brake fluid change or is somethign else likely to be wrong

I'd replace the front pads with MB parts, replace the fluid & bleed the system through. If problems persist I'd suspect the master cylinder

4) the front windows sometimes judder a bit as they go up and down. As the coupe is pillarless which bits should i silicon grease to ease their operation?

This is a typical Coupe problem, I believe. I don't know the cure yet

Nick Froome
www.w124.co.uk