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Mercedes-Benz 300-Class, Engine, Fuel System, Diesel, Coupe, Sedan
#442 of 2332 Re: Cost of R12 [burdawg]
by MrShift@Edmunds HOST
May 26, 2005 (7:43 am)
Well I don't like amateurs messing around with R12, both for their safety and everyone else's. I don't know why everyone makes a big deal out of this. You just go to an authorized shop and they have plenty of R12 to sell you. I just got an R12 recharge on my Porsche, including of course leak testing and the whole bill was $100. Screwing around with cans on eBay or going to Mexico instead of sipping coffee and watching a pro do it for $100---well I don't get it. Sure, if you need actual mechanical WORK on your AC, that's expensive, but that's expensive no matter where you go. Any pro AC shop is going to charge you, and parts prices are parts prices. I have used a used compressor on one 300D, to good result, so that saved money.
1992 300D Purchase: Well, look, if the car was in good mechanical and cosmetic condition it might be worth $6,500. So you have $4,500 worth of room here, which is pretty good.
I'm not a big fan of "Mickey-Mousing" these cars to get them to work. The climate control issue can be diagnosed and you can get an estimate....always think "worst case scenario"...be a complete and utter PESSIMIST when the buyer. The seller can afford to be an optimist, you can't.
As for the "starting problem", you weren't clear what that was about but if the mileage is very high on this car you may very well want to have a compression test or cylinder leakdown test done. Most Benz diesels don't start because of minor things like bad fuel or bad glow plugs (they do need replacement every few years) but sometimes they are just tired in the cylinder head region. Diesels rely purely on compression to ignite the fuel so if it's low the car isnt' going to start easily no matter what you do.
AC and diesel operation have no connection that I can recall, unless you mean that if you have a leak in the vacuum lines that control some AC systems, then yes, this vacuum leak can affect engine operation. But if your vacuum lines are tight, you can just throw away your rather fussy and marginally cold 300D AC system if you wish. Climate control problems are especially bad on the W123 models, gas or diesel. A common issue is that dirty coolant (a maintenance boo-boo) jams the valve on the servo that controls coolant flow. Another common problem is the loss of vacuum to the ducting (air flaps), and of course, the electronic issues associated with a bad control head in the dash. These systems really aren't very good and you will have to deal with them time and time again, so suck it up W123 owners and be of good cheer about it.
EMISSIONS -- yes, starting in 1985 Mercedes fitted diesels with a "trap oxidizer", which is upstream of the turbo and was meant to trap particulate matter in a ceramic shield---this particulate matter was theoretically burned off during hard acceleration. Unfortunately, the oxidizer on these cars usually either clogs and causes power loss and overheating, or worse, the mesh inside broke up and sent metal into the blades of your turbo (ouch!). The oxidizer got better for 1986 and 87 and then quit using it for obvious reasons.
So the problem cars with the oxidizer are:
US models: 1985 300D, 300CD, 300TD 300SD (California models, sold in western states of the USA); 1986 300SDL (again, California version) and the 1987 300D turbo, 300TD turbo and 300SDL (California AND federal versions).
You'd be advised to avoid these models or if you are having problems with one, this is no doubt why.
#443 of 2332 Re: Cost of R12 [Mr_Shiftright]
May 26, 2005 (9:48 am)
Thanks for everyone's insight, it has been an education! Wish I had known of this site and had the luxury of time before I bought a replace 1980's Mercedes. Well I'm stuck with it now. Turns out it HAS been converted to the 134 freon, and my "shade tree" mechanic whom I adore found the leak in 2 minutes. It's really small, is in some little valve thing that is up front close to the grill work. He put almost 2 pounds of freon in it, and it might last weeks, or maybe months. When it gets low again, then he'll replace the valve thing and "drain" the system and put in new freon? Hey, I'm a woman, this is the best I understand. He fixed the AC (for the time being) and did an oil change, all for $75. REgarding the oxidizer problem and California models, is there anything I can do to prevent this, or tell if it is happening, etc? Is this another difficult and expensive item to replace? I do have the 1985 300SD, as you might recall. Thanks so much, this site is really interesting, even to a female!!!!!!!
#444 of 2332 Re: Cost of R12 [sandrastevens]
by MrShift@Edmunds HOST
May 26, 2005 (10:49 am)
Symptoms of a bad oxidizer are bad fuel mileage, a drop in performance, and overheating at times.
No there is no cure, you just keep replacing the defective part when it dies. I don't recall the replacement cost but I'd presume it is substantial given the labor involved.
As for climate control issues, you might be sure to flush your radiator coolant.
Other good things to do is always add a fuel additive when you fill up. Redline diesel fuel conditioner is a good product. Read the label and follow the instructions.
Let's see....if you have a Becker radio you can throw that over a fence, it won't last long.
But don't worry, the oxidizer could last quite a while. If you are in California that's a plus as you have fuel with a lower sulphur content.
May 26, 2005 (12:22 pm)
Could read through all 444 of these postings and still go out and buy one of these cars is beyond me!
Still, for some perverse reason, I like these cars. Not enough to go out and buy one but I do like them.
#446 of 2332 oh not that bad really...
by MrShift@Edmunds HOST
May 26, 2005 (2:13 pm)
I think you could say the same about the 300D as Mark Twain said about the music of Wagner: "It's better than it sounds".
Some cars get this kind of "mythology" built around them, so when you actually bring out the true facts behind the myth, it makes it sound worse than it is. It's all relative. If a hyped-up Hollywood celebrity ends up selling shoes it's a tragedy, but if a drunk sobers up and sells shoes, it's a great thing.
All cars have faults and it's best to know them and with this knowledge you can anticipate them and work them out. If someone tells me "I just bought a 300D and the seller says all it needs is a recharge" well I know that if probably not true, because we are dealing with a chronic problem here.
May 26, 2005 (2:29 pm)
These forums are like hospitals. They attract people with problems and we don't hear the success stories very often.
I've learned that when a car's A/C isn't working, it's never "just a charge" that's needed. That freon had to go somewhere and that applies to ALL cars!
#449 of 2332 Re: Oh, I know... [isellhondas]
May 26, 2005 (5:28 pm)
“..These forums are like hospitals..”
Well here is a success story that didn’t have anything to do with a “hospital” :0).
5 years ago I was Sunday driving in Gastonia NC and I happened across a 1984 Mercedes Benz 190D forsale so I stopped, checked it out and drove it, the guy was a car dealer selling the vehicle off a private lot. He seemed honest enough and had a whole list of things that he thought was wrong with the car. I went back the next morning unannounced because I wanted to verify that the vehicle started up ok and didn’t smoke, it did and it didn’t, I bought it for $2100. I drove it almost 80,000 miles (pur. OD reading was 194,000 and 270,000 +/- when I got rid of it.) and I probably could have gotten another 20,000 out of it. The week before I got rid of it I took it to an inexperienced non-diesel mechanic, he over filled the vehicle with oil, instead of blowing out any number of gaskets, it blew a huge spooge of oil straight into one, many or all of the cylinders…that day will be forever known to me as “the day I shutdown the road”, Interstate 85 Concord exit looked like a white cloud…all 6 lanes. I had the vehicle towed to back to my house outside of Charlotte. I called my buddy in Charleston SC and asked him if he wanted it for scrap (thinking I blew it up)…he came up, tinkered with it a little and drove it home, 180 + miles. To this day he still runs it around town…
When I was younger buying a vehicle with 100k on the motor was foolhardy at best and with very few exceptions…Mercedes Benz Diesels being one of them. Now, not only is the reliability and dependability well known, but the environmentally freindy aspects are being highlighted and with biodiesel and B100 on the front pages, those old vehicles are drying up. People are buying the hell out of ‘em in the Northwest as can be testified to by the $3600 purchase price we had seen a few posts ago…from where is it I come from, we call them treehuggers under our breath but watch fad after fad, turn trend into trend, turn commonplace into commonplace…the old diesels are drying up here in NC as well…diesel mechanics better be honing their skills...
But cheer up little Honda dood, there is hope for you yet…if you are still not buying a MB, from the looks of things, one day you will be able to “get in the game”
“..Honda’s new Accord 2.2 i-CTDi Sport has this week set no fewer than 19 world speed records and achieved 3.07 litres / 100 km (92 mpg) fuel economy to boot. British racing driver Robin Liddell and freelance journalist Iain Robertson were part of the European record-setting team…”
Honda diesel set record
for the rest of us that don't want to wait around for a *concept* car, wondering if Honda "got it right"...the MB is the answer :0)
May 27, 2005 (6:29 am)
I guess only time will tell if you are correct.
The big problem I have is the outrageous price of diesel. If it were priced where it should be...much less than gasoline, it would make a lot more sense!
#451 of 2332 Re: Oh, I know... [bio0rb100]
by MrShift@Edmunds HOST
May 27, 2005 (6:51 am)
But this is all anecdotal, not evidence as we know it. That car you bought might have had a new engine installed, you have no idea, right?
Most old 300Ds I see are worn out pieces of junk and buyer beware is definitely the rule.
But if you find a well cared-for 300D or SD or TD, they can be great cars and quite reliable (mine was, after I fixed all the botched up things done by previous cheapskate owners). I'm sure mine is still running happily.
My point was this: Just because it's a 300D doesn't mean it's any good. It could be the biggest money pit you ever walked into if you aren't careful. People "bought the hell" out of tech stocks, too, some years ago, but it wasn't being smart, because they didn't know what they were buying, they were just following a mini-trend.
B100 is great, but it's expensive, so it's really a "feel-good" thing and in some ways quite noble----but it's not economical and therefore will not be any wave of any future until it makes sense in dollars AND cents. That's how new tech succeeds, in the realm of the user's checkbook. (see SOLAR energy as an example of this).
Right now, where I live, driving a 300D on biodiesel is the financial equivalent of driving a gas car getting 17 mpg. If it were a totally modern 2005 gas car, the emissions differences between it and a diesel running on B100 would be negligible, and perhaps the gas engine actually better. The area where the B100 car does best is that it is using a renewable energy source.
California doesn't even allow new diesel cars at the moment, but they should be back in a couple of years. I"m not sure how manufacturers are going to meet the Calif. standards. Low sulphur fuels will help, and possibly they will use urea injection to eliminate nox. Whether owners will refill their urea supply to keep the engines clean enough is a problem for the EPA.
You wanna jump on the B100 bandwagon? GREAT! GOOD FOR YOU! But have that old 300D checked out top to bottom and keep shopping, shopping, shopping.
4 out of 5 300Ds you see for sale will be beaters and not worth fixing. This is why when you shop for used parts in the wrecking yard, you will see LOTS of them.
The reason 300D prices are going up is because of supply and demand. The old ones are getting junked out, the beaters are on the road limping along, and finding a nice clean one is getting harder and harder.