Mercedes-Benz Forum banner

21 - 26 of 26 Posts

·
Registered
1984 300D, 1985 380 SL, 2009 E350
Joined
·
291 Posts
Hanson. Had the similar rough idle and hesitation at lights on warmed engine- 1985 380sl. Changed filter/accumulator and also ran full can of Seafoam and Italian tune-up. Car runs perfectly for last 6 months. It was somewhat underused since it was a car my son used daily until 2 years ago when his job moved him out of state. As a do it yourself-er, my philosophy with older cars is to use simple fixes before going in big. Good luck.
 

·
Registered
Joined
·
3 Posts
Hanson. Had the similar rough idle and hesitation at lights on warmed engine- 1985 380sl. Changed filter/accumulator and also ran full can of Seafoam and Italian tune-up. Car runs perfectly for last 6 months. It was somewhat underused since it was a car my son used daily until 2 years ago when his job moved him out of state. As a do it yourself-er, my philosophy with older cars is to use simple fixes before going in big. Good luck.
Hi
Looking to solve the same rough idle on my 1986MB-560
Everything is Ok when i start, when driving.. problem only on warm idle !
3 monthes turning around no solution, seem to become more important..near to stall when stopped at a traffic light.
New cap and rotor, new air valve idle control ..
I expect to look after vacuum leak , but i Don’t know where to plug a smoke tool (?)
i’ll try to wash the inside of cold start injector,
Someone have a (genial) idee?
Rgds
Pascal.fr
 

·
Registered
1984 300D, 1985 380 SL, 2009 E350
Joined
·
291 Posts
Pascal- your list of fixes are throrough except the one "hail mary" approach of seafoam (or some aggressive fuel system Additive cleaner) with high revving drives we call 'Italian Tune-ip' in America. Bon chance!
 

·
Registered
Joined
·
3 Posts
Thanks Joe for your quick answer,
i remember i cleaned 2 years ago my injectors (ultrason cleaning)
I’ll use an additive cleaner (i bought one but i thought i could have running problems if there is injector problem, no?) but car did not ran for years.
you mean fuel filter,? In this case, do you think it could be necessary to change also the 2 fuel pumps?
Tk
 

·
Registered
1984 380SL
Joined
·
2,284 Posts
Thanks Joe for your quick answer,
i remember i cleaned 2 years ago my injectors (ultrason cleaning)
I’ll use an additive cleaner (i bought one but i thought i could have running problems if there is injector problem, no?) but car did not ran for years.
you mean fuel filter,? In this case, do you think it could be necessary to change also the 2 fuel pumps?
Tk
No, start with the easy stuff first especially if you only drive your car sparingly. Remember, these are analog machines and they get very cranky if they're not run regularly.

Get a can of Chevron Techron - https://fr.texacolubricants.com/fr_fr/home/products/by_brand/techron.html
It looks like it can be purchased en France.

Run the tank of fuel down as low as possible, pour in a can of this stuff, and fill it up to the top.

Then, put the car into 3rd gear and monter comme la sale pute qu'elle est!

Do that for a good bit. Really don't be afraid of hurting the car. She'll love it!
Then maybe change the oil if you haven't done so (optional).

The next steps after this would be to inspect your engine ground strap underneath the car. I would remove the bolt, degrease, sand, and reattach the strap to the chassis.

If your car is still rough running come back here and we can go onto the harder steps.
 

·
Registered
Joined
·
3 Posts
No, start with the easy stuff first especially if you only drive your car sparingly. Remember, these are analog machines and they get very cranky if they're not run regularly.

Get a can of Chevron Techron - https://fr.texacolubricants.com/fr_fr/home/products/by_brand/techron.html
It looks like it can be purchased en France.

Run the tank of fuel down as low as possible, pour in a can of this stuff, and fill it up to the top.

Then, put the car into 3rd gear and monter comme la sale pute qu'elle est!

Do that for a good bit. Really don't be afraid of hurting the car. She'll love it!
Then maybe change the oil if you haven't done so (optional).

The next steps after this would be to inspect your engine ground strap underneath the car. I would remove the bolt, degrease, sand, and reattach the strap to the chassis.

If your car is still rough running come back here and we can go onto the harder steps.
Thanks, i’ll tell you
 
21 - 26 of 26 Posts
Top