All of a sudden my 380 decided one day to shake badly while idling and shaking more heavily when gear is in D and sitting at a light lets say. I have recently replaced the cold start valve with another used one and has improved the starting but not the engine shaking. It shakes all the time...cold or hot and the economy guage has showed an increase also while idling. When cold and you want to proceed the acceleration doesnt react immediately.....you press the gas, the economy rises to near red and 3 secs later the car will accelerate and go. It will do this until its warmed up a bit.......sortive like its surging. I was thinking it could be a vacuum leak but not sure. How did this happen overnight? I really dont know where to look and help would be greatly appreciated as soon as possible. Thanks.

__________________
99 C43
98 S420
99 C230K
01 C240

Did you just fill up? we get a lot of water in our gas here in the North West a good dose of water might restrict you fuel filter at idle.........

William Rogers.........

I filled up just after it happened.

__________________
99 C43
98 S420
99 C230K
01 C240

Your problem started suddenly and you had just filled up, well wait till that tank runs out, then see if it was bad gas. I had a similar problem which I tried to self diagnose on my 83 380sel, changed the ICV, ignition wires etc etc until I took it to an MB Doctor, who said it had a million t hings wrong with it, including timing being off, wrong ignition wires, and few others which were all adjusted. The source of the shaking and rough idle was an air leak under the intake manifold, I am going to get that done nxt week. I don't think that is your problem though, see what happens when you fill up again. Some injector cleaner should also help. ( don't dilute it that much though.)

__________________
**A few Hondas etc... etc... Not Worth Mentioning**
83 Euro W126 380 sel Money Pit (Sold)
91 W124 300e 2.6. (Sold) 3.0 Motor is Much better!!
93 BMW E34 Touring Wagon (Sold) Sweet Car!!
91 300e (Just 200k with Ease.)Best car ever ???(Sold)
90 420sel (Black with Tan Interior) Best car ever!!!!!!!

I dont think its the gas because it didnt happen AFTER I filled the tank. It started to shake and then a day later I filled up the tank as it was only at half.

__________________
99 C43
98 S420
99 C230K
01 C240

Benzonline,

Sounds like you've developed a "miss". Could be one of quite a few things. First check the simple things, make sure all the ingnition wires are in place and in good condition as well as the dist. cap and rotor are in good shape. Second you may need new spark plugs. If you decide to change them make sure you use Bosch DC 9's and not the platinums. Let us know what you come up with.

__________________
Brandon



2008 S550
1957 Dodge D100
1967 VW Microbus 21 Window
2001 Suburban
2004 Beach cruiser bicycle
-----------------GO DUKE!-----------------

"It cannot be emphasized too strongly or too often that this great nation was founded not by religionists, but by Christians; not on religion, but on the Gospel of Jesus Christ. For that reason alone, people of other faiths have been afforded freedom of worship here." Patrick Henry 1776

I narrowed it down to being the thermal regulator.


What do u all think.....?

__________________
99 C43
98 S420
99 C230K
01 C240

i have just had the heads reco-ed on a 380sel which was purchased for $4000 with a bad smoke problem,valve guides offcourse. I have also tuned and serviced the car for the customer and i also have a miss at idle in this car.i have narrowed it down to a bad injector in this case as it has spark and compression in the cyl but no difference when the cyl is shorted out; i have run an injector cleaner through it and advised the customer to run a few tanks of shell optimax through the car and let me know how it turns out

it was the thermal regulator............car is running like butter

__________________
99 C43
98 S420
99 C230K
01 C240

Is that the vacuum switch toward the front (at least on my 560) of the intake manifold? I got the shakes really bad, and a bum shoulder, so a minimal repair would be a blessing!!

__________________
Earl McLain
'02 C230 Kompressor
'89 560 SEL "Frau BlueCar" (retired April 2004)

Stefan, Could you tell us more about Shell Optimax?

William Rogers.......

certainly.shell optimax is a new unleaed fuel in australia produced by shell.it has certain cleaning agents in it which help clean injectors and cylinders from carbon build up.alot of peopole have tried this new fuel and the reports are all good with mosy sayiny an improvement in power and economy.i am not sure how long untill it is available in other countrys or if it even will be as it was manufactured for australia.it is about 10 cents per litre more than normal unleaded,but the savings in fuel economy and performance make up for it. we are paying between 90cents upto $1 per litre for optimax at the moment and 85--95 cents per litre for normal unleaded.i will try to get some more tech info for you over the next few days

The shell optimax overhere in Canada is a mere 91 octane....maybe it is different in Austrailia but here I condider that as regualar compared to the Ultra 94 I always put in from Sunoco.


Its award winning gas and has done miracles for my 380.

__________________
99 C43
98 S420
99 C230K
01 C240