300TE 4matic cutting out

[Robin Thorn]

Hi there, just arrived to this site after buying a very nice 1991 300TE 4MATIC for my wife. Collected the car and all was fine.

After a few days she complained that it had died on her, but started with no problems after leaving it for about 20 mins. This has now got progressively worse to where it will now cut out several times a day usually when showing just over 80 degrees engine temp.

Sometimes it will restart with no problems but generally is very lumpy at idle and dies when you engage drive. It will start with the minimum of cranking. It will rev itself sill under no load but will die as soon as you put on any load. Often the only wat to get away is to rev up to 2000 rpm, foot on the brake and drop it into dive with a prayer. It is then ok until the next occurence, sometimes days later.

Local BOSCH man is convinced it is over fuelling, Have replaced theKE control unit with no improvement, the next step is to replace the metering head as it is believed that the 'electro hydraulic pressure actuator' that controls the over-enrichment may be faulty.

Any other ideas or positive resonse?

The OVP relay is brand new and the coil and the HT leads.

Help please, Robin Thorn :cry:

 

[paulcallender]

Two things you could check:

1. Fuel pump relay. Mostly they either work or not, but sometimes they will show this intermittent behaviour in the dying stages of its life. Approx £50 to replace.

2. Spark plugs loose or worn out?

 

[Robin Thorn]

The problem with our 300TE 4MATIC has progreesively got worse and would cut out after a couple of miles and be increasingly more difficult to start. We left it in the drive for a few days and it would refuse to start. Checking the 'KING' HT lead produced a 1" spark to earth but we could not find a spark at the plug leads. On removing the distributor cap shold moisture inside, strange as the car had been stood for several days, but more to the point the centre contact in the cap and the centre of the rotor arm had both serously burnt away!

£90.00 later and a new cap & rotor she started on the first crank and so far there is no evidence of the cutting out we peviously detailed.

So after a fule metering head anad a KE control box as recommended by the Bosch specialist I did it myself.

But why should there be moisture in the distributor head when it has not been run for a few days? Is this moisture related to the original problem of the car cutting out when reaching 80 degrees from cold and then possibly drying out?

Regards

 

[LNM]

is there still moisture in the dizzy cap?

seals? or rather ex-seals as in now in-the-bin-knacked-seals-from-old-dizzy seals?

Mine's still a bit rough, £30 fro gfs car parts for new dizzy for 300 next step. Dirty throttle bodies are not the be all and end all......

bah !!

 

[bcinnz]

Cutting out as temp rises to 80 degrees

Hi , I have an S500 1994 which has been behaving the same as your car.
Mercedes changed all the leads and coil etc. and it still behaved the same.
Symptoms: Starts perfectly after being in a garage or outside for more than 12 hours. After engine starts to warm up, and temp gauge gets to 80, then the spluttering starts. If you are in stop start traffic, and running low revs, engine cuts out. Battles to re-start, even backfires!
If you can get it started, and manage to keep revs above 3000 for 10 mins, then problem goes away and doesn't return until next cold start.
I found if you park the car as it reaches 80 degrees, she will not start at all. I had to get mine towed last time I tried that.
So one morning I opened up both distributor caps and both had tiny drops of water on the inside surfaces. So I cleaned one cap out, and sprayed inside with moisture dispersant, but left one as was found, and replaced both caps. Started a usual and went for a drive. As she got to 80 then engine became very rough, but did not die as usual. I now know that it is moisture in the distributor cap that is creating the problem. It seems that the mositure starts to heat up it creates havoc inside the cap. After the cap has heated up sufficiently, then the moisture has evaporated, and any new mositure can't settle down as the engine and cap are too hot for that to happen.What I don't understand is where it is coming from? I tried sealing both caps with silicone rubber, same problem. So moisture must be coming from the engine side through the seal to the rotor. What is the point of new distributor caps if the mositure getting in will cause another problem later on, especially after some HT arcing takes place?
I look forward to any comments and suggestions.

 

[sebastianforbes]

hi there robin

i had exactly the same problem just before christmas and i called the aa out. they fixed the rotor arm and only charged me £20 for the part from mercedes. there is no charge for labour. i even left them to sort the car out while i went off in my matiz. when i got back the next day, it was sitting in my driveway all sorted.

cheers

sebastian.

 

[pde2000]

4matic wont start

thank god for this forum. ive been baffled by my car not working for nearly a year now and thought it was something fatal. i had considered taking off the dizzy cap before i read this posting and now i have, found the water and now it works yippee i have totally given up on the whole mb agent route for service/repairs as they are not only expensive but also dishonest and incompetent. my local european parts supplier is about 1/3rd the price of merc, admitedly not all parts available, but £60 for ht leads compares very favourably with £200 from merc.

theres nothing quite so dreadful as a 2 tonne lump loosing power in the middle of traffic with no servo or power steering. my wife has insisted that i sell the car now it works and replace it with a zafira, shes so sick of the thing letting her down. we only got it because of the 7 seats.

list of faults sorted so far:
split in front cv gaitor
complete silencer set replaced
smoking exhaust (only use the best oil - not magnatec)
overheating (installed aftermarket electric fan but needs new viscous)
frightening judder on motorway (steering damper, common fault and cheap)
cutting out - water in the dizzy

list of faults i cant afford to sort:
4matic does nothing
self leveling does nothing
rear diff noisy (seals leaking)
oil leaking from all over the place
valve seals need replacing
coolant leaks and doesnt maintain pressure
apparently all the bushes and suspension mounts, bearings etc need replacing but it passes an mot.

would be cheaper to replace the engine/transmission/drive/suspension with a new set (ie new car) bodywork, electrics, leather seats are all fantastic but 170,000 on clock probably spells end of the road for this one.

 

[pde2000]

4matic cutting out

having done a bit of research found there is a seal one can buy from mb for about £10 to keep out any moisture.

 

[thebeard]

Stalling when hot problem was ICV

My 4Matic had a stalling problem when reaching 80deg + no water in the dis cap but a very very dirty Idle Control Valve which I cleaned with carb cleaner spray it seems to have cured the problem which is strange as there is no reason I can think of as to why the ICV would cause the stalling other than it may have been sticking when the temp under the bonnet rose. Very strange but now supper idle and starting.