C240 Poor Running

[pace]

Hi all, thanks for the advice about my whistling car, the general opinion seems to be that it shouldn't whistle!
Anyway I now have another (possibly related) problem. yesterday I noticed the battery seemed to be getting weak as the car was turning over slowly and by the evening it refused to start. I only use the car at weekends and it has low milage and I presume the original battery so at 7 years I can accept that the battery may need replacing (the battery in my C180 lasted 9 years).
I checked the levels in the battery diconnected it and then gave it a fast charge for a few minutes, I then managed to start the car. However the car then ran very poorly, it idled o.k. but when I rev'd the engine it misfired badly. I thought maybe if the battery has had it, it may affect the running of the car? So I left the battery on charge over night and have just re connected it. The car started fine but is still running like a bag of s**t so my question is could the battery be affecting the way the car is running or is it something else possibly related to the whistle? The car was serviced 2 weeks ago and has been running fine since (I have done about 400 miles) the garage changed the plugs, fitted a K&N air filter (not at my request), replaced the auto filter, replace the transmision fluid and added an 'oil additive to the engine at £25 plus other service related work. I assume original parts have been used. So do you think I should try a new battery or call the garage on Monday and tell them to come and sort it out? I don't want to drive the car in case I damage the cat's with the missfire. Help Please!
Paul.

 

[Stevie A]

I would change to new battery and try that then see. I hope you haven't fried anything when charging battery.

Maybe faulty alternator has drained battery. Would this cause poor running though?

If whistle is an air leak then maybe it is getting worse / blocked causing poor running?

 

[pace]

Thanks for that Stevie, the battery was disconnected while being charged, so hopefuly we can rule out any damage to the electrical system. I wonder how much current is being drawn from the battery while the car is standing? there is no alarm fitted so it can only be radio memory, clock etc. Does anyone have that information so I can check with a meter?

 

[jberks]

I'd start with a new battery. Mercs are very touchy about power levels - far more so than any other make I've come across. Weak batteries can cause no end of wierd problems so if its 7 years old and has failed once, pop a new one in.

Also - why have the fitted a non MB filter? - K&N filters are not necessary and could cause the MAS to fail prematurely (IMO). They are fine on carb based fords etc (I had one) but I wouldn't tolerate anything non MB spec on the Merc, especially if she's not running right in the first place.

If she's idling fine then the ignition system should be ok and I'd be looking at things like the MAS.

 

[pace]

Thanks for that, today I fitted a new battery, the car started fine but is still running bad. I phoned the garage who serviced it and they were not very helpful, they just said "bring it in and we'll look at it". I don't want to drive the car in case I damage the cats and I have lost confidence in the garage so I think I will get the garage I normaly use to pick the car up on their transporter and take it in. I guess a diagnostic check will find the problem?

 

[w124_E280]

Sounds like an Air Flow Meter to me mate. Get one brought or try and clean the old one first is a common problem on 112 engines

 

[jberks]

You could just try disconnecting the MAS and see if it runs any better. If it's way off, then removing it will actually improve things. Should prove the diagnosis anyway.
On the same vein, check the air inlet pipes. If they are disconnected after the MAS or just leaking, this will give a similar effect.

 

[Nidge]

I had exactly the same symptoms when I replaced the battery on my E240. The advice here was to give it a run it for 20 minutes and it sorted itself out. Be aware though that it is almost impossible to drive for the first 5 mins so take it on the quietest road you can

 

[pace]

Thanks for the info, I have taken the car to another garage today. They carried out a fault code test while I was there which showed no faults. Their first guess was the air mass sensor. I think I will try the idea in the last post and give the car a run, I was worried about damaging the cats if the car is not running right, do you think it will be O.K. to drive it?

 

[jberks]

dodgy - you could kill the cats if it's throwing unburnt fuel down there. I also can't see why it would be hard to drive for a few mins after a battery change?
People seem to think that it takes ages to reset computers. It's normally a few seconds if that. Their ranges are minimal too so even if they are way out, it should be hardly noticable.
Poor running combined with a whilstle - just get it to a workshop and get them to find the whistle first - if its a leak - that will put all the sensors out of kilter.
I fixed a ford once that would start, idle but wouldn't run. It was a simple leak between the MAS and the intake. small but enough to stop it running.

 

[pace]

The car was running fine before I disconnected the battery even with the whistle. Is there any way that disconnecting the battery may cause any related sensors to re configure and then have a problem with a possible air leak? The garage say they have cleaned the throttle body, the wistling noise seems to come from the top of the engine between the blocks. I dont want to start pulling things apart I know nothing about. What do you think they could have done or not put back right to cause this whistle? I will have to drive the car about 8 miles to take it back to the garage, if I go steady and dont make her splutter too much will I be o.k. to drive?

 

[television]

Air leaks or an incorrectly fitted vacuam pipe. MB's have more vacuam pipes than any other car, and MB's do not whisle, As Jberks says the car will run very poorly the way it is, and I will endorse that. tell the garage that if they do not put it right, you will go elswhere and charge them


Malcolm

 

[pace]

UPDATE! I have taken the car for a steady drive this evening and after about 10 miles it started to get better so I gradually pushed it a bit harder and now it seems to be back to its old self (but still whistling). I would still like to get it checked out properly by another (impartial) garage. Can anyone recommend a garage in the Reading or Oxford area? Greenoaks Reading charge £103 (+vat) an hour so I won't take it there unless I have to!

 

[mstar]

out of intreset does a K&N filter make much difference its bizare a MB specialist put that on

 

[pace]

I agree and so does everyone else I have spoken to (inckuding other mechanics). I have looked at the filter and it is disigned to fit the car. when it came back from the service it had a sticker on top of the air box telling me not to replace the filter as it can be cleaned and re fitted. I would rather have had an original filter fitted though. Its difficult to tell if it has made the car run better as I think the possible air leak may be affecting things. I just want someone who knows what they are doing to look at it.

 

[Uncle Benz]

I have only just read this thread in its entirety, and have seen this before. If you can avoid disconnecting the battery on late c class it will help no end. I use a memory saver that plugs in the ciggy lighter to hold ecu memories when changing a battery. Obviously this is no good if the battery is already dead!!. Jump starts can also cause running faults, but should all be cleared with a long enough drive. I have occasionally found these probs with W210 E class too. All manner of lights show when initially restarted, ABS, ESP, BAS etc but a good drive usually sorts them out. When you try to clear the codes with a diagnostic machine it says "some codes require a test drive to clear" and its always worth a go before calling at the dealers door!!

 

[Uncle Benz]

Oh, and I would put the K&N filter in the bin as these are an oiled filter, which is a well documented reason for contamination of the MAF sensor.

 

[mstar]

Oh, and I would put the K&N filter in the bin as these are an oiled filter, which is a well documented reason for contamination of the MAF sensor.

i knew there is a reason why to keep things to the original spec

 

[pace]

Thanks for that information Uncle Benz. I am going to take the car to another local garage to see if there is an air leakand if so put it right. I will get the filter changed and get them to check the other work done by the so called MB specialist.

 

[Shala]

Battery disconnected???? and other faults

i had my battery disconnected on my 1999 C180 esprite auto to fit my sound system. shortly after that the front windows & mirrors were randomly stopping to work & then they both stopped working permanently. After this i went on the motorway & they car suddenly stopped going over 60mph (unless going downhill) & over 3000 rev. Oh and the car shaks when you come to a stop afterwards.

A garage told me yesterday that i'll hav to pay £1.5k for new gearbox which i thought was silly as my car covered only 55k miles so far.

Mercedes CROYDON quoted me £120.00 + vat to plug my car to a computer to check faults

I then found another garage in wimbledon that i'll be visiting on friday who'll plug the car onto computer for £60.00 + vat

So searching through the forums I've found that it could be the following things:

* ECU (may need replacing)
* MAF (may need replacing)
* Gearbox (may need replacing)
* Computer (faults may need clearing)
* other electric faults may cause car to go into LIMP HOME MODE (even light bulb)
* Electric components draiing too much power

all the discussions are about the problem but has anyone actually resolved the problem??

PLEASE HELP!!!!!