Idle surge e320 coupe question

[zac slack]

The last time i posted on here you guys managed to help me pick up a wonderful (96) P reg e320 coupe so hope you don't mind another post so i can keep it in perfect condition. I'm a merc lover but when it comes down to it i'm no engineer.

1. Firstly, I have noticed that the idle is surging, ticking over at 5/6 and when stationary the car is trying to surge forwards and jerking - it's the same in in reverse and sometimes cuts out at the lights. I must obviously get this checked out but before I do i wanted to get some info on what could be the possible problem and solution to this? It obviously needs some sort of tuning but wanted to ask if it could be a sensor somewhere not working or something else...

2. I'm also getting an average of only 200 miles out of a full tank and wondered if I should be getting more and if the above was related?

3. My last question is that when I start the car and drive off in the morning, the car doesn't want to get into 3rd gear. But if I put my foot down and drive fast it eventually gets there. An whirring/air noise is now evident from the engine when i'm accelerating or slowing down that wasn't there before and i'm wondering if the automatic clutch is on its way out?

Any feedback so I'm more clued up at the garage is very welcome.

Zac

 

[d215yq]

Hi,

1) Obviously the jerking is not normal but tickover when engine is warm and car is in D or R of 600rpm is normal i think

2) Out of my e220 coupe I sometimes manage 480 miles on a tank before the refill lught comes on, which is 38mpg. Although yours is a 320, even if you are thrashin it or in traffic all day it should still manage a lot more than 200 miles which if your tank is the same size as mine would equate to 16mpg.

3) This is normal - until the engine is warm the car holds 2nd a lot longer than it does when hot to heat up the catalyst. I find this results in a notchy change up from 2nd to 3rd when the car is cold, but once temp gauage hits 80 or above it should start changing up earlier and then be silky smooth.

 

[Bolide]

Some W124s have an air pump to reduce cold-start emissions. They whine like crazy for about 2 minutes then go silent. The air pump is above the alternator - it's easy to see if your car has one

As d215yq said the box holds first to about 3200 rpm when cold

Nick Froome
www.w124.co.uk

 

[kth286]

Zac

Go get the codes read by a specialist familiar with your generation of car.

Where you based.

 

[zac slack]

Kensal Green, North West London.

 

[zac slack]

So, I have just had my car in the garage again trying to fix the problem of the idle surge. It comes and goes. So far 2 garages have failed to find and fix the problem which is a real pain.

Early this week new spark plugs, fuel filter and some fuel system cleaner was added to the car from a recommendation of a garage but unfortunately it's still surging. Should i give the fuel system cleaner some time to work through or is this not a given?

After searching some forums i heard from one guy that the 'gas recirculation valve at the charcoal canister could be stuck'. Anyone have any idea of if this would relate to my e320 coupe?

Would appreciate any information of people's experiences with this and also any ideas of who could help me locally here in West London. Thanks.

 

[television]

Hunting as it is called when then rpm goes up and down is an air leak around the inlet manifold, often caused by a poor fitting or split pipe in the vacuum side.

Max vacuum is achieved at idle, so the engine sucks in more air via the leak, and speeds up, as it speeds up the vacuum drops and the engine slows down again, and so it repeats

 

[zac slack]

Thanks TV. What degree of work will this entail to fix? Are we talking major parts, large costs and hours of labour or simple stuff?

 

[television]

All simple stuff,,is the car a 124 or 210

 

[zac slack]

It's a 124 yeah.

 

[television]

Any thing connected to the engine is suspect, open after BM in the link
http://www.detali.ru/cat/oem_mb1.as...&GA=722.369503&GM=717.450&CT=F&Cat=15T&SID=80

There are some other component,,I will post back