E420 revs low rpm
04-17-2017, 07:16 PM
#1
E420 revs low rpm
Me again with yet another problem!!!! When the car is warm and is in drive or reverse it will rev on its own, it will drop down from 600rpm to 400rpm. I have 0 leaks I have checked all the vaccum hoses I have cleaned the maf replaced the filter and I have no idea what it could be. I have researched online and I cannot find a straight answer to the issue. Please could someone help?? I like this car and at this rate it will be launched of a cliff!!!!!
04-18-2017, 10:40 AM
#2
Out Of Control!!
Have you googled your engine and it's idle speed control circuit to learn the components that control\effect the idle?
Do you have any diagnostic tools to work with? Are you waiting to be told you have a faulty throttle body actuator that is not a DIY test without he documentation.
Do you have any diagnostic tools to work with? Are you waiting to be told you have a faulty throttle body actuator that is not a DIY test without he documentation.
04-18-2017, 08:48 PM
#3
MBWorld Fanatic!
If you would - please be a bit more descriptive of the exact RPM issue you are having:
1. What do you mean - "it will rev on it's own" - do you mean coming to a braked stop it drops "too low" almost like it going to choke/stall, then catches itself and goes up over normal idle - drops down again - something like that ? Common issues for these symptoms cans be failed MAF (part# 0280217807) or Fuel Pressure Regulator diaphragm has broken/failed (part# 0 280 160 587)
2. Genuine Bosch MAF is pricey $200-$230 for genuine Bosch ONLY from a trusted source - China knockoff's are generally sh*t and internet offers on MAF no-brand/quasi-brand-or actuall counterfeits abound. Check the shape of the MAF connector so you get correct replacement MAF if you go that route.
3. Genuine Bosch Fuel Pressure Regulator is cheap at $35.. and replacement "on top" of engine is very straightforward.. in later W210 this Pressure Regulator feature was built into the 4-hose fuel filter - on your 2-hose fuel filter - this pop-off fuel regulator in on top of the engine
4. Heck - make sure you have fresh Fuel Filter - very straightforward - NOT retail store fuel filter - Mahle/Hengst is about $20 - Bosch genuine is about $30
5. Throw 1/2 bottle $9 Stabil Marine Formula (Blue) in the tank after you solve your issue to do cheapie fuel system cleanup
1. What do you mean - "it will rev on it's own" - do you mean coming to a braked stop it drops "too low" almost like it going to choke/stall, then catches itself and goes up over normal idle - drops down again - something like that ? Common issues for these symptoms cans be failed MAF (part# 0280217807) or Fuel Pressure Regulator diaphragm has broken/failed (part# 0 280 160 587)
2. Genuine Bosch MAF is pricey $200-$230 for genuine Bosch ONLY from a trusted source - China knockoff's are generally sh*t and internet offers on MAF no-brand/quasi-brand-or actuall counterfeits abound. Check the shape of the MAF connector so you get correct replacement MAF if you go that route.
3. Genuine Bosch Fuel Pressure Regulator is cheap at $35.. and replacement "on top" of engine is very straightforward.. in later W210 this Pressure Regulator feature was built into the 4-hose fuel filter - on your 2-hose fuel filter - this pop-off fuel regulator in on top of the engine
4. Heck - make sure you have fresh Fuel Filter - very straightforward - NOT retail store fuel filter - Mahle/Hengst is about $20 - Bosch genuine is about $30
5. Throw 1/2 bottle $9 Stabil Marine Formula (Blue) in the tank after you solve your issue to do cheapie fuel system cleanup
