W123 280E Fuel Usage and Trans shifts. - PeachParts Mercedes-Benz Forum

Tony 12 · #1 10-30-2007, 04:48 PM

Hi all.
I bought this car just a couple of weeks ago.
It had a rough idle on start up which I fixed by cleaning out the warm up regulator. I've checked the valve clearances and spark plugs. But it still uses a lot of fuel. btw the plugs came out quite grey in colour and certainly no evidence of over fueling there.....

The trans also takes it's time to shift up as well. You have to lift you foot slightly off the gas pedal to get it to do it. The shifts are nice and firm, just delayed.
Any chance these two sypmtoms are related?
Otherwise, any suggestions on where to start with this?
Thanks............

t walgamuth · #2 10-30-2007, 06:25 PM

What do you call a lot of fuel?

The 280es are not real fuel economy cars.

Tom W

Tony 12 · #3 10-30-2007, 06:41 PM

Yeah, sorry Tom. I should have said.
It uses about 20 litres per 100 kilometres or 14 miles per gallon with 50% highway, 50% town use.
It gets a little better on highway only at about 16 miles per gallon.
I hope that's not normal...........

t walgamuth · #4 10-30-2007, 08:04 PM

That may be about right.

They are not economy cars. My car with a five speed od would just barely get 22 on the highway.

Tom W

Wodnek · #5 10-30-2007, 08:23 PM

They eat like a V8!

Tony 12 · #6 10-30-2007, 08:28 PM

Hmmmm........ that's no good.

I had bought it to use as a daily driver and was expecting to get low to mid 20's out of it. But at 16 mpg, it's expensive motoring.
I'll do some more exact tests before I jump any conclusions.
Might just have to put it in the shed as a restoration project and buy a 230 as well..................

Tony 12 · #7 10-30-2007, 08:29 PM

Quote:

Originally Posted by Wodnek

They eat like a V8!

You're right Wodnek! My 450 isn't much worse...........

Wodnek · #8 10-30-2007, 08:31 PM

Quote:

Originally Posted by Tony 12

Hmmmm........ that's no good.

I had bought it to use as a daily driver and was expecting to get low to mid 20's out of it. But at 16 mpg, it's expensive motoring.
I'll do some more exact tests before I jump any conclusions.
Might just have to put it in the shed as a restoration project and buy a 230 as well..................

You could put a taller gear in it to get the rpms down, that may get you to the low 20s. (or put a brick between the gas pedal and the floor

)

Tony 12 · #9 10-30-2007, 08:41 PM

Quote:

Originally Posted by Wodnek

(or put a brick between the gas pedal and the floor

)

That wouldn't work, my wife would just press down harder until it crushed.

Thanks for the advice gentlemen.

Q45Denver · #10 10-31-2007, 06:06 PM

Quote:

Originally Posted by Tony 12

Yeah, sorry Tom. I should have said.
It uses about 20 litres per 100 kilometres or 14 miles per gallon with 50% highway, 50% town use.
It gets a little better on highway only at about 16 miles per gallon.
I hope that's not normal...........

Still better than my inline six. Just swap it out with a turbo diesel.

JimFreeh · #11 11-01-2007, 06:56 AM

Quote:

Originally Posted by Tony 12

Hmmmm........ that's no good.

I had bought it to use as a daily driver and was expecting to get low to mid 20's out of it. But at 16 mpg, it's expensive motoring.
I'll do some more exact tests before I jump any conclusions.
Might just have to put it in the shed as a restoration project and buy a 230 as well..................

I was able to nurse my 81 euro 280E up to the high teens, if I could keep my foot out of it. Same with my euro 280SL.
I'd imagine a USA spec engine thats down 40-50 hp would suck even more fuel.

Mid 20's, that's 300D turbo mileage.
Gas MBs are not economy cars......

Jim

JimFreeh · #12 11-01-2007, 06:58 AM

Quote:

Originally Posted by Tony 12

Hi all.
I bought this car just a couple of weeks ago.
It had a rough idle on start up which I fixed by cleaning out the warm up regulator. I've checked the valve clearances and spark plugs. But it still uses a lot of fuel. btw the plugs came out quite grey in colour and certainly no evidence of over fueling there.....

The trans also takes it's time to shift up as well. You have to lift you foot slightly off the gas pedal to get it to do it. The shifts are nice and firm, just delayed.
Any chance these two sypmtoms are related?
Otherwise, any suggestions on where to start with this?
Thanks............

Unrelated symptoms.

Also unrelated is firm and delayed..... Lifting your foot to get the trans to shift points to a worn out tranny. Careful use can prolong it, but it's still an old worn out trans....

Jim

vipercrazy · #13 11-01-2007, 05:00 PM

Quote:

Originally Posted by Tony 12

Yeah, sorry Tom. I should have said.
It uses about 20 litres per 100 kilometres or 14 miles per gallon with 50% highway, 50% town use.
It gets a little better on highway only at about 16 miles per gallon.
I hope that's not normal...........

yes i have gotten 13 mpg 50% highway some times, i have also gotten 26 mpg on highway trips cruising at 80-85 mph. i usually get 18.5.

t walgamuth · #14 11-01-2007, 10:46 PM

Oh no, not another 26 mpg at 85 mpg claim!

Tom W

Tomguy · #15 11-01-2007, 11:12 PM

Wow, 14MPG is WORSE than my new gashog gets, and it has a 5.7L V8 that rarely sees speeds under... uh... the legal speed limit. Yeah.

Anyway, I'd say delayed shifting could cause bad mileage. And sometimes delayed shifting is caused by dragging brakes. Have you checked that as a culprit? If you can rule it out, I am unsure if the vehicle has an adjustable linkage to the valve body like on 108s but if so, lengthening the rod can make shifts occur sooner.