Oil for 1981 Benz 240D?

[JHZR2]

Originally Posted By: KlooksKleek
Thank you to all. I've read and appreciated all responses.

The dirty deed (literally!) is done. Rotella T6 is now in the engine and let's hope it will help at least a bit in terms of a cold start. We got it running today in 24F degree temps but the machine was not happy to do so. Seemed to crank decently but took several tries to get it to catch. Fuel is fresh and from a local place, so I'm sure it is blended for winter and not a problem. Regardless, we threw in some Power Service anti-gel and filled the tank. Gave the car a 8-mile run before the oil/filter change and an 8-mile run after.

It's a dirty burner, for sure, and honestly I'm not much of a fan having now experienced the car up close. It looks and seems pretty worn, although it's got a really great, classic appearance. Having owned a 2000 TDI of 1.9 liters, this 1981 2.4-liter 240D is an entirely different animal and not a very admirable one in its present state. It's got hard-core diesel exhaust odor, probably doesn't have a single item of pollution control, and the owner says he's got to add oil more than just infrequently (no leaks, he says). With the T6, I guess he'll probably need to start adding even more, and to prepare for leaks, too. We'll see. But what can you do, it's flippin' winter time in Chicago.


Yes they are a different animal than newer diesels. That said, what was the condition of the battery? What were the starting parameters? How does the owner run the glow plugs (they stay on longer than the light and you can hear the relay click off, you can also glow multiple times)? The 81 model may have loop type plugs which run in series and can be upgraded. What is the throttle position for starting cold? Idle adjustment?

When were the valves done last?

Oil consumption concerns me. Neither of my current w123s burn a drop of oil. It amazed me when driving me 82 300cd cross country!

 

[KlooksKleek]

[/quote] Yes they are a different animal than newer diesels. That said, what was the condition of the battery? What were the starting parameters? How does the owner run the glow plugs (they stay on longer than the light and you can hear the relay click off, you can also glow multiple times)? The 81 model may have loop type plugs which run in series and can be upgraded. What is the throttle position for starting cold? Idle adjustment?

When were the valves done last?

Oil consumption concerns me. Neither of my current w123s burn a drop of oil. It amazed me when driving me 82 300cd cross country!
[/quote]

Here are my observations: After a couple no-go starts this morning, I put my charger on his battery. It initially drew 9-10 amps of charge but fairly quickly settled down much lower and by the time we came back from coffee, the needle on my charger was barely above zero. The battery is supposedly 4.5 years old.

I advised him to run the glow plugs twice. With the hood up and the engine cranking, I could see the throttle cable move rapidly as he pumped the accelerator. I don't know enough about these cars to know whether that's the proper procedure for a cold start with this engine.

I don't know the idle adjustment, nor the condition of the glow plugs, nor the condition of the valves.

Despite the car's rather frayed overall condition, he seems pretty devoted to it and he seems willing to do what's necessary to step up into this new winter reality that he's living, but he doesn't know what needs to be done. IMO, he's got to rise to the challenge because this is a very serious climate compared to where he and his car came from (San Jose).

He sought out an independent Benz mechanic right away upon arrival to Chicago but has been put off because of the guy's impatience and apparent negativity. I'm sure that's not the only independent mechanic out there, but knowledgeable MB guys surely aren't a dime a dozen and traveling across the city to a better shop seems highly impractical.

He claims a very high rate of oil consumption (1 quart every 300 miles). There are reportedly no leaks and I followed him to and from the filling station, seeing no blue smoke upon start-up nor upon acceleration.

He really needs a knowledgeable mechanic to assess things and give him the low-down.

 

[B320i]

I recall on families '92 Toyota LandCruiser 80-series, the recommended cold-start procedure for diesel was foot halfway or all the way, can't quite recall. It was actually *both*, but one was for cold-weather starts and the other for a warm engine. The 1HZ is an equally "agricultural" (but big at 4L) inline-6 diesel.

That rate of oil consumption is definitely not good and probably suggests the vehicle has got internal issues. Does it smoke badly?

Also thought I'd chime in on the old oil chart posted. You will notice the "5w30 CCMC-G5" rating. That right there is your predecessor to ACEA A3/B3 oils. My '93 Bimmer calls for an API SG/CCMC-G5 rated oil. So rest assured a good diesel oil today should be more than adequate to meet this 1980's pre-ACEA spec

I assume the guy isn't really much of a car buff, otherwise I'd recommend looking on YouTube for "MercedesSource" for the DIY videos he's got up there.

 

[BrocLuno]

I don't know if these diesels have adjustable injection timing? But if they do, look for a few degrees advance. Just like all engines that get worn as the miles add up, these start to slowly retard and parts wear. Get them back to sharp timing, or even a few degrees advanced and they perk right up and clean up the exhaust some.

We do it with tractors and trucks all the time. Run them at max factory timing. But with the CATs, I run 3* more than factory and they are a LOT happier

 

[bullwinkle]

If it uses a lot of standard HDEO, it will DRINK T6 5W40! I only used 5W40 for a short time in my '82-it helped with the neglected stuck rings & low compression it had when I bought it-but it consumed it by the gallon. The best way to start it cold is to listen for the "clunk" of the glow plug relay, turn the key off & back on, then when it clunks again, hold the throttle to the floor & crank it over. Might make sure your glow plugs are good & getting power, pretty sure you have the pencil glow plugs like mine did, might have an open one or two.

 

[CrAlt]

I quick test for the condition of the engine is to loosen the oil cap and just let it rest. If the blow-by pushes it off the cover then its worn out.
Example of bad
https://www.youtube.com/watch?v=aEwqpc0GYn4

Example of good
https://www.youtube.com/watch?v=x8k6Be5BG7s

I drove a '82 240D 4speed manual to 320K miles. The PO took it to quicklube places and judging by the recites i got it looks like used mostly bulk 10w40. I ran it on Rotella Triple T 15w40.

These are interference engines so at 150K miles they recommend the timing chain be replaced.

My 240D wouldn't start in the real cold unless it was plugged in. At those temps are you plugging the block heater in??
Also it would guzzle oil if i drove to fast. It was happy at 55-65mph. 70+ and it would use oil like crazy.

I gave the car to my brother. He get rear ended turning on to a busy road. Lady behind him in a big SUV saw him start to take off. She had her head turned watching traffic. And since the 240d was so slow he was only a few feed ahead of her and BANG. Totaled.

 

[bullwinkle]

Originally Posted By: CrAlt
I quick test for the condition of the engine is to loosen the oil cap and just let it rest. If the blow-by pushes it off the cover then its worn out.
Example of bad
https://www.youtube.com/watch?v=aEwqpc0GYn4

Example of good
https://www.youtube.com/watch?v=x8k6Be5BG7s

I drove a '82 240D 4speed manual to 320K miles. The PO took it to quicklube places and judging by the recites i got it looks like used mostly bulk 10w40. I ran it on Rotella Triple T 15w40.

These are interference engines so at 150K miles they recommend the timing chain be replaced.

My 240D wouldn't start in the real cold unless it was plugged in. At those temps are you plugging the block heater in??
Also it would guzzle oil if i drove to fast. It was happy at 55-65mph. 70+ and it would use oil like crazy.

I gave the car to my brother. He get rear ended turning on to a busy road. Lady behind him in a big SUV saw him start to take off. She had her head turned watching traffic. And since the 240d was so slow he was only a few feed ahead of her and BANG. Totaled.


You want bad, price out what it costs to resleeve a Benz diesel-I could have dropped $5-6,000 in the engine in my 300D turbo-I could have bought 3 or 4 beaters for what it would've cost to fix that 300D right!

 

[Silk]

Diagnosis of older diesel engines is done by smoke - white smoke is called cold smoke, and you'll get it on a cold start, on an indirect injected engine it means one or more glow plugs out. Also can indicate retared timing, and if all else is good just a tad of advance on the pump will cure it. Black smoke is excess fuel or lack of air, dripping injectors etc, can be caused by advanced timing too. Engine oil burning won't usually show up, if it does it will be grey smoke. No smoke is a problem, an old indirect diesel should smoke to some extent. No smoke is lack of fuel, blocked filters, or max fuel screw wound out...people do this to fix smoke problems.

 

[bullwinkle]

Originally Posted By: Silk
Diagnosis of older diesel engines is done by smoke - white smoke is called cold smoke, and you'll get it on a cold start, on an indirect injected engine it means one or more glow plugs out. Also can indicate retared timing, and if all else is good just a tad of advance on the pump will cure it. Black smoke is excess fuel or lack of air, dripping injectors etc, can be caused by advanced timing too. Engine oil burning won't usually show up, if it does it will be grey smoke. No smoke is a problem, an old indirect diesel should smoke to some extent. No smoke is lack of fuel, blocked filters, or max fuel screw wound out...people do this to fix smoke problems.
My 300D had smoke cold, smoke hot, smoke blowing off the oil cap when loose-only time it had no smoke was when it wasn't running! Actually, my (ex-ODOT fleet maintained) 6.2 IDI GMC in my sig only smokes when started really cold, or under full acceleration, normally there's almost none.