Got A New To Me 240d - couple of questons for 240d owners

[1981_300sd]

Hey all. I took some advice from some of the users here, I had a 300SD that had some problems, and live in a HOA where I can not work on my car. So I ended up selling the 300SD, and got myself a 240d (pictures attached). Got this car because it has been maintained great, has a rebuilt engine (30,000 miles ago), brakes are great, and had new clutch and all at 30,000 miles. I chose this car too because of the better fuel economy and because it is much more simple than the 300SD to work on when I need to. Anyway, its a great car but had a couple of questions about some of the minor issues I have with it, as follows:

1. The oil pressure stays at "3" all the time. When I go to a stop light or anything, even after being warmed up and sitting idle, it stays pegged at "3". Does this sound like a possible bad ground or faulty sensor, or should it really stay at "3" all the time?

2. What is up with the climate control lol? On my 300sd you can select economy, or AC, and change heat and ac pretty easy. This one makes no sense to me. The center dial obviously changes fan speed, but the two on either side show what looks like hot to cool dials. Why are there two of them? And how do I set "economy" mode? Im just really lost with these dials. Im sure its simple, just need to be pointed in the right direction.

3. The stereo does not power on. Im sure it is a fuse problem, but when I checked for the fuses under the hood, I saw none. Is there another area the fuses are located on these cars?

4. What coolant temperature should this car read? Im wondering what is acceptable for it - is 90-100 degrees C ok?

5. Last question, it is obviously slower than my 300sd, but what speed should I keep it under - like on the freeway? Will running it at 80 mph do damage? It seems to go that fast, but just running at pretty high RPM's. Is there a suggested speed to keep it under? I do understand that around 55-65 will get the best fuel economy, but I am asking more about the engine condition.

Thanks for your help as usual!

[kerry]

Nice looking car. Oil pressure gauge on this is mechanical, not electric so you should be reading pressure directly.
Temperature seems a little high to me. Check the coolant level. Flush and refill if necessary.
Lots of these 616's have been running wide open day after day in many applications so I wouldn't worry too much about slowing down to save the engine.

[hitwtom]

My Becker radio has a fuse right behind the radio.

[62bhp]

The fuse box is located directly behind the brake booster {giant round thing that connects to the master cylinder} and you have to unscrew both nobs inorder to open it. It is alittle tricky to get back into place but after some fiddling with it you should be able to get it. The tempature dials are for the left and right passengers with the middle being the fan control. Adjust them to your likeing.
Mike

[pj67coll]

That's one nice looking 240D. Congratulations.

The oil pressure could well be high if it's just been rebuilt but it should not stay pegged at 3 permanently I dont think. Is your idle adjust knob at max? (all the way anti-clockwise). If so, adjust it clockwise some and see if it comes off 3 at idle after a while. Mine will drop to just below 2 after it's warmed up and had a good run but it typically stays just above 2 most of the time at idle. That's with 220K on a rebuilt motor. I keep my idle adjustment about 3/4 of the way to max because of an annoying sideways shake if the adjustment is lower.

The center switch is indeed fan speed. The two on either side are the heater controls for the left and right side of the car. No heat to max heat independently.

Temperature should be around 85C. Mine runs at exactly that after I replaced the thermostat and radiator caps. The needle never quite leaves the top of the 8 in 85 on the temperature gauge. I belive that 90 - 100 is too high.

I'm not really sure what excessive speed is for these but I've been keeping mine below 70 as I just dont believe it's good to rev any engine excessively. Especially a rebuild with 220K on it. No idea what quality of work was done on it after all. But I will say that since I had my motor mounts, tranny mount and flex disc replaced a couple of weeks ago my car has smoothed out remarkably at speed such that it now seems to be quite happy being pushed above 70. I'm fairly sure though that I'll seldom reach 80 with it.

If you dont mind. I'd appreciate you letting me know if your car is equipped with engine mount shock absorbers. I'm trying to determine if mine is supposed to have them and it's also an 81.

- Peter.

[centroid1]

hey congrats ! that's an awesome color. is it a manual or auto tranny ? any rust ?

i'm brand new to the 240d owership too. i bought an '82 240d manual 4 speed about a week ago and drove it back from CA to MN, 2000 miles. this car is slow to take off but maintains speed at cruising well. we tested out different cruising speeds from 70-85 range. i broke my alternator belt at 85 cruising so it could have been a bad belt (brand new, just installed it before the trip, could have been too tight.) i would say 65-70 is ideal for me personally. it has nothing to do with mechanical preference, just the right amount of engine noise and still hight enough rpm's to go up a gentle hill. i think you get better milleage if you decrease speed.

the PO walked me through the vents, its a little different. the two sliders are for defrost and footwell, look at the little white arrows, they point up or down. if you have them both together, then both is off, and if both are completely apart, then its max. the slider next to the ac is for fresh air which blows heat but not ac or vice versa, can't remember. i just know it doesn't do both. avoid having everything close and turning on the fan, it will blow the cover off the vents (i've heard.)

my temp gauge reads around 85 at cruising speed. it went up to 120 went the belt broke. oil pressure gauge pegged at 3 at cruise but drops down when i stop.

enjoy !

[coadman]

Originally Posted by 1981_300sd

Hey all. I took some advice from some of the users here, I had a 300SD that had some problems, and live in a HOA where I can not work on my car. So I ended up selling the 300SD, and got myself a 240d (pictures attached). Got this car because it has been maintained great, has a rebuilt engine (30,000 miles ago), brakes are great, and had new clutch and all at 30,000 miles. I chose this car too because of the better fuel economy and because it is much more simple than the 300SD to work on when I need to. Anyway, its a great car but had a couple of questions about some of the minor issues I have with it, as follows:

1. The oil pressure stays at "3" all the time. When I go to a stop light or anything, even after being warmed up and sitting idle, it stays pegged at "3". Does this sound like a possible bad ground or faulty sensor, or should it really stay at "3" all the time?

2. What is up with the climate control lol? On my 300sd you can select economy, or AC, and change heat and ac pretty easy. This one makes no sense to me. The center dial obviously changes fan speed, but the two on either side show what looks like hot to cool dials. Why are there two of them? And how do I set "economy" mode? Im just really lost with these dials. Im sure its simple, just need to be pointed in the right direction.

3. The stereo does not power on. Im sure it is a fuse problem, but when I checked for the fuses under the hood, I saw none. Is there another area the fuses are located on these cars?

4. What coolant temperature should this car read? Im wondering what is acceptable for it - is 90-100 degrees C ok?

5. Last question, it is obviously slower than my 300sd, but what speed should I keep it under - like on the freeway? Will running it at 80 mph do damage? It seems to go that fast, but just running at pretty high RPM's. Is there a suggested speed to keep it under? I do understand that around 55-65 will get the best fuel economy, but I am asking more about the engine condition.

Thanks for your help as usual!

Hey, did you buy this from the guy in Arizona? Looks like the same pictures I had sent to me. Really nice car, I needed to buy it before he did the paint job, and could have saved quite a bit of money!. The left dial controls the heat to the drivers side, the right dial controls heat to the passenger side(dual controls, if you can believe it?) Of course you have found the fan speed in the middle. The dial on top of the fan speed is your ac temp. Just turn it too colder, and you should have AC. Hope the car works out, as I was considering it myself, but the location and price were a little out my area!
Jim

[barry123400]

I would tend to suspect the high oil pressure at hot idle just tends to confirm a good rebuild of the engine 30k ago. How much noise you can comforatably tolerate might determine your cruise speed more than any other factor. For a diesel these 240ds seem to rev up pretty well at high cruise. The only cure that I am aware of is to install a five speed manual transmission. I would love to get my hands on a couple of them.

[WINGAS]

NOT a 240D owner, so proceed at ur own risk...

Re oil pressure, have you changed the oil/filter lately? I wouldn't worry about too high a pressure, my 220K mile 95 pegs the guage at anything off idle. Its a good thing! Assume your bearing clearances are tighter. If you have no oil leaks, you might want to convert to synthetic motor oil if you havent already. I'd stick to the "fleet" or "diesel" oils since we have cams and non-roller followers of one type or another in all our engines. In fact, I use a few ozs of GM's EOS in my solid cam motor. Likley dont need it in my hydraulic follwer motor ( MBz 95 606.910), but still do, since its older.
EOS is akin to STP oil treatment I should think. Getting pricey at $12 a can, so I use it sparingly.

If you start the car in outdoors cold, synthetic is much better at that task. Everything else, imho, is a "push" between dino and synth oil. YMMV!

The only drive I've given my 95 so far, is the run home from Philly, 450 miles through a Nor'easter, to boot. Once we got out of the storm we all went 80 mph min., as all the troopers were behind us dealing with more disabled vehicles than I;ve ever seen, except maybe Beirut after a missle attack.

Noticed the tach above 3000 rpms at 80-85 or so. Thought it was revving somewhat high, defintely not an OD trans! Must ahve 3.07-3.20 gears int eh back on small 15" rubber. BUUUUUUTTTT, with one bad injector Lil' Blackie gave up 34.7 mpg ripping at 80mph.

Keep the oil good. Use some EOS ( a few ozs) for "added additives", and drive the tar out of it like it wants to be driven.

Guys, do they gear them down in teh Eurpoean configuration> or drive drive the tar out of 'em like these rides prefer.???


Nice looking ride dude, sounds very good-to-go as well!

[1981_300sd]

Thanks for all the responses so far. To provide feedback to what has been asked:

Im not outside right now, stuck inside at the good ol desk job, but from what I remember the oil peggs at 3 all the time, even when the engine is off. I will verify when I drive home today. So if its down before I drive home, than I am ok at having it at "3", and if its still at three before I start the engine, it must be a stuck or broken gauge right?

And yes, I did buy the car from an arizona owner (im here in az myself). He had 2 of them, one with broken odometer at 110,000, no paint job, but looked to be a good running car for 2500 dollars. I got mine for 3500 dollars but it had the nice paint job, and have about 4400 dollars of receipts of things that were done to the car (rebuild, brakes, clutch), and other. So I went with the 3500 dollar one - it shows 150,000 on working odometer and has 30,000 miles since rebuild. He still has the non new paint one if interested, let me know!

The car is manual, no rust - its a born and raised Arizona car - we are a rust free state! HAHA.

PJ67coll - How would I tell if my car has engine mount shock absorbers? And fyi, the 240D is a 1982 model, my old 300sd was a 1981.

This car totally lives up to my expectations. I have fun just driving around in it. Its not going to get you from point a to b quickly, but its fun getting there. Now I understand why someone way back in the day stated that it changed their lives, saying it allowed them to enjoy the scenery. One other thing im excited for - no more speeding tickets YAY!

[coadman]

Originally Posted by 1981_300sd

And yes, I did buy the car from an arizona owner (im here in az myself). He had 2 of them, one with broken odometer at 110,000, no paint job, but looked to be a good running car for 2500 dollars. I got mine for 3500 dollars but it had the nice paint job, and have about 4400 dollars of receipts of things that were done to the car (rebuild, brakes, clutch), and other. So I went with the 3500 dollar one - it shows 150,000 on working odometer and has 30,000 miles since rebuild. He still has the non new paint one if interested, let me know!
!

Yes, that's the one I considered. I corresponed with the owner several times and talked to him twice(his name is Jim if I remember correctly?), he sounded like a decent fellow. He was even going to drive it to Kansas for me as he just got through delivering one to Oregon. I just didnt have the funding he required, so I kept searching and found a 1979 240D with a 1980, in the same state I live in, which is unusual. I bought it last week. Jim had told me about the other one he and his mechanic had bought in Arizona somewhere. He questioned the mileage at the time, but said it drove nicely. Good luck with your new 240D!
Jim

[1981_300sd]

Haha thats funny, yep his name was Jim. And this weekend while we were driving to various banks to find one open to notorize a title, he was telling me about how he had just gone to Oregon to drop off a car. Ya he seems to be a nice person. I just found out that the AC is not holding a charge, and that after refill, there is some liquid that is dripping - in our contract he did say he would repair the AC because we both knew it needed charged - so we will see how good of a guy he is about keeping to his word .

[vahe]

Originally Posted by 1981_300sd

5. Last question, it is obviously slower than my 300sd, but what speed should I keep it under - like on the freeway? Will running it at 80 mph do damage? It seems to go that fast, but just running at pretty high RPM's. Is there a suggested speed to keep it under? I do understand that around 55-65 will get the best fuel economy, but I am asking more about the engine condition.

My only comment is regarding the 80 mph, yes the 240 will go 80 mph, but I would not do it, the sound of the engine at that speed will give a warning to cool it, 65 to 70 is a good average for 240D's. I have also noticed that 240D engines get awfully hot if pushed over 75 mph.

Vahe
240D 77/350K

[pawoSD]

Originally Posted by vahe

My only comment is regarding the 80 mph, yes the 240 will go 80 mph, but I would not do it, the sound of the engine at that speed will give a warning to cool it, 65 to 70 is a good average for 240D's. I have also noticed that 240D engines get awfully hot if pushed over 75 mph.

Vahe
240D 77/350K

It may also just be your particular 240 that does those things.

It should have no problem running flat out/top speed, especially with a rebuilt engine. I run my 617 flat out sometimes for a while and it enjoys it just fine. I am still waiting for the day I can get one. I want either a nice 240 manual...or a C220 auto or manual. While keeping my SD of course. I've put waaaaaaay too much $$$ into it to ever even consider selling it.

[centroid1]

yeah, on my 240d, we open her up on a flat stretch for a while. most of the time at 80-85. temperature never changes with speed, i don't think it should.