Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
2000 E430 Sport
Joined
·
343 Posts
Discussion Starter · #1 ·
Hi All!

I'm noticing less mpg than when I first purchased my car. I'm not even in the 20's anymore...at all. Will a new MAF and fuel filter impact my MPG for certain? I'm not getting any codes but I read somewhere (dont know if its true) that the MAF doesnt necessarily give a code until its gone all the way out. I've got over 100k on the clock and dont know if it was ever changed.
 

·
Registered
1997 E320, 1997 S320
Joined
·
2,946 Posts
have the spark plugs ever been changed, cuz they are due, and a tune up could take care of your problem.
unless you have changed it before, you are also due for a new fuel filter, replacement schedule is every 60k miles. i would wait til your next oil change for the fuel filter though. add 1 can of bg44k or seafoam to a 1/3-1/2 full gas tank, drive the car close to an empty tank, and then change the oil and the fuel filter.
for the maf, you could try cleaning it first and see if it works and also throw in a new air filter. you could buy the insert, it's only $135 and unfortunately eventually you will need it.
 

·
Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
Joined
·
17,193 Posts
I think I have also read that about the MAF and possibly the O2 sensors. I think tirona has given you some good advice and I am unable to add anything to that.
 

·
Registered
2000 E430 Sport
Joined
·
343 Posts
Discussion Starter · #4 ·
have the spark plugs ever been changed, cuz they are due, and a tune up could take care of your problem.
unless you have changed it before, you are also due for a new fuel filter, replacement schedule is every 60k miles. i would wait til your next oil change for the fuel filter though. add 1 can of bg44k or seafoam to a 1/3-1/2 full gas tank, drive the car close to an empty tank, and then change the oil and the fuel filter.
for the maf, you could try cleaning it first and see if it works and also throw in a new air filter. you could buy the insert, it's only $135 and unfortunately eventually you will need it.
Ok good deal -

I have the spark plugs already (havent gotten around to changing them though) and did the air filter with the Service A (still have a ways to go for service B). I'll order the fuel filter and new MAF before I try cleaning the one I have just in case something goes wrong...I read these are wear items and cleaning might only be a temp fix anyway. Just wondering if anyone experienced better MPG with just these two changes.
 

·
Registered
1994 E320 Wagon,1999 E320 Wagon,2000 E 320 Wagon, MGB Track/Rally, ,1988 300E ,more....
Joined
·
6,019 Posts
Maf

would throw a code if failing or out of range.Over 100 k time for plugs,NGK 7090
not multi tip:eek: just 16 7090's and you have the special 17mm boot tool I sell for $28 delivered,a must for the job and saving your wires from damage.
New air filter autohausaz.com oem filter no k/n:eek:
over 100 k o2 sensors start to go and lazy slow to heat sensors can affect mpg and they are 100k replacement items.
ohlord:bowdown:
 

·
Registered
2002 e320 4 Matic Wagon
Joined
·
364 Posts
Ok good deal -

I have the spark plugs already (havent gotten around to changing them though) and did the air filter with the Service A (still have a ways to go for service B). I'll order the fuel filter and new MAF before I try cleaning the one I have just in case something goes wrong...I read these are wear items and cleaning might only be a temp fix anyway. Just wondering if anyone experienced better MPG with just these two changes.
I have changed my spark plugs and I gained 4-5 MPG highway( I was doing 12.9 Litres per 100 km highway now I do about 10.1 per 100 Km my best was 9.1 Highway per 100 KM.). It is my second time cleaning my MAF . Also if you have a CEL light coming on and it is the MAF me it usually takes a week or 2 after I clean my MAF for it to go away.I also plan on changing my fuel filter soon.
 

·
Registered
2000 E430 Sport
Joined
·
343 Posts
Discussion Starter · #7 ·
I have changed my spark plugs and I gained 4-5 MPG highway( I was doing 12.9 Litres per 100 km highway now I do about 10.1 per 100 Km my best was 9.1 Highway per 100 KM.). It is my second time cleaning my MAF . Also if you have a CEL light coming on and it is the MAF me it usually takes a week or 2 after I clean my MAF for it to go away.I also plan on changing my fuel filter soon.
Great!

I'm going to give the DIY a go tomorrow. Also - Do I need to worry about wires or are they an "if it aint broke dont fix it" deal?
 

·
Registered
'01-E320 & 02-ST2
Joined
·
31,631 Posts
If you follow the cleaning DIY closely you cannot hurt the MAF. If you do the plugs wrong you'll damage the wires, which are stunningly expensive, so be very careful with them. Absent a code I would not replace the MAF and instead use the money to buy O2 sensors..not from ebay.:)

Take care and enjoy the ride,
Greg
 

·
Registered
2000 E430 Sport
Joined
·
343 Posts
Discussion Starter · #9 ·
If you follow the cleaning DIY closely you cannot hurt the MAF. If you do the plugs wrong you'll damage the wires, which are stunningly expensive, so be very careful with them. Absent a code I would not replace the MAF and instead use the money to buy O2 sensors..not from ebay.:)

Take care and enjoy the ride,
Greg
I was just about to order both the MAF and O2 sensors - Man I didnt know they were so expensive but for 100,000 miles I cant complain. I'll hold off on the MAF (no codes) and get the O2 sensors. Thanks Greg! I cant find my book right now - I'll do a search for what else needs to be done at 100k.

Bosch Oxygen Sensor; Front Left; OE Version; Four Wire; Heated $99.99

Bosch Oxygen Sensor; Rear; OE Version; Four Wire; Heated $85.70 x2

Bosch Oxygen Sensor; Right Front; OE Version; Four Wire; Heated $96.65
 

·
Registered
1994 E320 Wagon,1999 E320 Wagon,2000 E 320 Wagon, MGB Track/Rally, ,1988 300E ,more....
Joined
·
6,019 Posts
You

can get away with just doing the pre cat sensors since the post cats are along for the ride and only serve to function as testers of cat function.
Spark wires will last for a lot longer if you remove them from the plug end only and leave them attached to the coil,by using the 17mm spark plug boot removal tool.It makes the job easier,safer,faster,and you wont harm the wires.
also bump up your tire pressure to 32 front and 38 rear.worth about 3mpg.
ohlord:bowdown:
 

·
Registered
2000 E430 Sport
Joined
·
343 Posts
Discussion Starter · #11 · (Edited)
can get away with just doing the pre cat sensors since the post cats are along for the ride and only serve to function as testers of cat function.
Spark wires will last for a lot longer if you remove them from the plug end only and leave them attached to the coil,by using the 17mm spark plug boot removal tool.It makes the job easier,safer,faster,and you wont harm the wires.
also bump up your tire pressure to 32 front and 38 rear.worth about 3mpg.
ohlord:bowdown:
Yep - I got the tool off ebay a while back. Says JTC 1308 on it. I'm going to put it to use tomorrow. So far for the 100k I'm going to to the tranny fluid, a/c leak fix with hose and drier, o2 sensors, & fluids. Also dealer stated I have loose lower ball joints and ("serpentine") belt tensioner binding up so I'm going to order new belts & tensioner, lower ball joints, front stabilzers, front meyle "heavy duty" control arms. Figured I might as well try and get it all out of the way as I dont know if these are wear items or not. Looks pretty straight forward if I get the ball joint removal tool.
 

·
Registered
2004 CLK 320 Elegance Cabriolet
Joined
·
673 Posts
Fuel efficiency

I'm getting about 10 litres per 100 kilometres. Is that good? This is on Caltex high octane 98.
 
1 - 13 of 13 Posts
Top