240 D 1983 Mileage complaint
 

What should be the mileage for my 83 240D manual and A/C ? I get 23 mph which disappoints me. The engine runs great doesnt lose a drop of oil. Is my fuel gauge off?

My '83 with a manual gets about 28 generally. Your fuel gauge doesn't have anything to do with your mileage, but your odometer/trip meter might. Are they both working and both working properly? Have you tested them for a reasonable distance say at least 20 miles against the highway mileage markers? If your tires are not the standard 175R14's, that could cause an error in your odometer too.

Len

My '82 auto 240D gets 28-29.
Do check your odometer. They have a nasty habit of slipping. It affects both the trip and overall odometer, but not the speedo. There are many threads that address this issue, but simply put, the metal gear slips on the shaft. It was originally a press fit, but over time they looesen up. Repair involves removing the speedometer from the car and deforming the shaft a little so that the gear no longer slips.

Do you have 240k Since you rebuilt it ?

I get 28 out on the road...

I would start in this order.....

set the valves

check the chain stretch ( using the dial indicator method because this is what the FSM says when there is a performance complaint.)

check your compression

Run Diesel Purge through it using the correct procedure

change all your fuel filters , check your air filter

pull your precombustion chambers and clean them

take your injectors to a good shop and check for correct pressure and spray pattern.

If at some point your mileage goes up 4 miles per gallon.. stop messing with it and just drive it....

my 77 240D (manual) gets 28-30.

Assuming the engine adjustments are OK--valves and injection pump--and the odometer is correct, there are a number of things to check.

Is it blowing black smoke? If so your injectors might be bad.

The prechambers could be clogged. Running at higher RPMs will help keep them clean.

As an asside, I bought this 240D six months ago; it was burning a quart of oil every 400 miles and getting 23-25 miles per gallon. I starting driving it like I drive cars and running at 80 mph on the freeway. The car now gets 28-32 and uses a quart of oil every 2000 miles. I think the rings were gumed up and the prechamber was clogged from low rpm driving. I also change the oil every 2000 miles. For oil I have been using Shell Rotella, but I am switching to Standard Oil Delo at my next oil change. You must use a diesel rated oil!!!':('

Also, when I got this car the thermostat was stuck open and the motor would not heat up. I put in the PROPER thermostat and that helped a lot. I should run at 180 degree F, or change the t-stat and don't buy a Stant. Buy a Wahler, or someother German brand as this is a reverse poppit thermostat, I don't think the Stant book lists the right one; replace the O-Ring at the same time. All diesels should run reverse poppit thermostats!!!!!!!!!


M.

My 240 stick gets 23mpg around town and 44mpg on flat non trafficky highway driving. The odometer must be working beacause i couldn't be getting any better milage than that on the highway, so 23 around town is should be pretty reasonable, especially in dense areas driving "fast" for a 240D.

My '82 240D auto gets 22city/27hwy. It was a bit of a shock after driving diesel Rabbits and Jettas, but then again this is a 67HP vehicle pushing 3250 lbs! I love my 'ol 240.

31 mpg average

Are you driving it hard?
 

I noticed no one asked about your driving habits. If this were a gas discussion that would be the first question.
Of course you are driving it hard, probably WOT most of the time; its a diesel with about 70HP in a car that weighs over a ton and a half. You HAVE to dive it hard; its underpowered!
Sort of makes you wonder what these engines could do is they were installed in an 1800 lbd econobox, and geared for maximum economy.

Your mileage is largely determined by your route. If you are doing a lot of stoplight to stoplight driving, then 23 is not too far off the mark. If you're doing all highway driving then that's scary mileage.

Good luck,

I get 30 mpg, leadfoot or no, but I sure would like to know how Maxwell gets 44 on the highway. Any hints we could use, Maxwell? 80 240D.

Maxwell is in LA... he just doesn't realize that half the time someone is pushing on his rear bumper....called " super drafting"....

No idea how i managed 44 on the higway. Drove 110 miles to hemet at 60 to 65 on 2.5 gallons. topped off to the same level before and after. filled up again after coming back, also topping it off and used 2.5 gallons again. I wasn't even drafting behind any semis.

PS. the other reason i probably get 23 around town is going up and over the hill between me and my girlfriends house every day.

I remember a long time ago that there were two things that every American male lied about, their gas mileage and their taxes.:D

Have a great day,

Larry ,I think you missed two and one is length of fish that got away.......
William Rogers.......