240 D Highway Running Question
 

I have owned my 83 240D for the last 4 years and love the car. It is an automatic and very slow which I have learned to drive. My question is at highway speeds it sounds like it is running hard and reving high (relative for a diesel). In GA on the interstates you need to run 75-80 without getting run over. Can this car sustain 80 mph for prolonged crusing?

Also how long do these engines last I see most dying a death before 300k miles. I was hoping to get a 500k miles. Mine by the way only has 140k.

Thanks guys in advance for your time.

1. They will run at 80 all day no problem.

2. Engine life comes from how you treat it....oil changes with a good oil every 3,000 miles, valve adjustments every 15-20,000 miles, keep it in good shape.

3. With 140k if maintained so far and from here on, it should last a looong time...probably over 300k...some make it to 500, but not that many. Usually compression is lost by then. Just think about how long it will probably take you to cover 200,000+ miles in the car ;)

Hey thanks for the prompt reply. I was concerned that the engine would blow up as I don't think the top speed is much faster.

This car was a fortunate find. I purchased it about 4 years ago from the original owner who bought it new here when he got out of the military. I have every receipt for the car since day 1. From what I can tell he had the oil changed every 3000 miles and maintenance done exceeding what the owners manual calls for. Anything that broke was fixed.

I only wish the car had a manual transmission. This auto is not real responsive.

Hmmm
 

You can not blow the engine with a load on it, the vehicle load acts as a terminal velocity brake.

It can be blown with no load, and the wrong tweaks.

The engine can run away.
Run away diesel, why does it happen?
http://www.peachparts.com/shopforum/showthread.php?p=824840


Have you set the injection pump timing?
OM616/617 Injection Pump
http://www.peachparts.com/shopforum/diesel-discussion/99944-om616-617-injection-pump.html#post678986

Diesel fact.....
 

G'mornin',

Diesel engines will run best, with the least problems at around 98% of their rated load......running any diesel when cold, or at minimal load for long periods will actually be a detriment to the reliability of the engine.....

So at 80 mph you are actually doing good things for your 240D......

I had a 240D some years back.....had never driven a 300D-T until I got my present car.......driving that ol' 240D was like driving a brick, and the experience kept me from purchasing another MB diesel for 3 or 4 years......but the cravings for a diesel auto finally got the better of me!! :D

SB

the above posts are undoubtably true, but i never felt good running a 240 over about 72. to noisy.

if you were willing to give up some acceleration yoiu could swap in a 354 rear end and reduce engine speed on the highway.

if you do this you will need to change the speedo too.

tom w

I have an 81 240D manual with 200K on a rebuilt motor. I have read often that they do just great at 80mph all day long but I really just dont see that as a likely possiblity on mine. It's screaming so loud above 75 that it just feels wrong to me. Of course just about every suspension component and such needs to be replaced as well as they are all original with 385K in them so maybe it would be nicer at 75+ after that's done but I have yet to be convinced.

- Peter.

Will he still be able to negotiate the hills of Marietta Tom;)?

There is a way you can "change" the way the automatic works in the 240D. You can turn it into a "semi" automatic whereas you have to let off on the throttle and it will shift. If you are interested in finding out more let me know. After I told the wife that it was a semi automatic she quit driving it:). Said she did not know how to shift a semi automatic - lol.

thats what gears are for. when he comes to a hill it will shift down faster.

tom w

i just got home from mobile with my 240D and it ran like a champ at 75-80 on I-10 but i usually dont go much over 70 due to the engine noise :D

instead of going up the hill quietly with the lower gearing
 

it'll be screaming up it in 3rd or 2nd:eek:.

I agree with tom. You guys that are running your 240's at 80mph, report back to us with the total amount of miles that you get on the engine running at that speed.
I know that from driving UPS trucks for thirty years that even the best diesel, (cummins 6BT in my book) that running them at next to full to full governed speed, They didn't last.
At 80 mph in a 240, I would venture to say that you are seeing well above 4,000rpm.

This topic is like the "Which oil is best" threads. Everyone has an opinion.

i think top speed is about 83. running 80 doesnt seem like a good idea to me. as you noted too close to full out.

tom w

I keep my '82 240D around 70 mph on the interstate.

Well, I'm hanging in too see who has driven their 240D at fast highway speeds for 200+K. There is definitely allot of folks that believe it's not a problem including myself, but i haven't done it.