Diesel Engines

[David Weaver]

1-3% depending based on that. Sounds like the guys driving the trucks are not telling the mechanics the right amount for how much DEF they're actually using. Or maybe they're just not doing a very good job of keeping track of it.

if it improves mileage 5% like they claim, it's the same or less than diesel per gallon and it's only used 1-3% as fast as diesel fuel, it wouldn't seem like such a bad idea as the EGR valve. Actually, maybe the EGR valve isn't the worst thing in the world, either, except for the way it's functionally applied (where a truck goes into limp mode when the EGR valve isn't functioning properly). Probably wouldn't be allowed to make an engine that functioned fine with the EGR valve not working, or people would just keep driving it that way.

[Keith Outten]

Just had my Sprinter Van serviced yesterday. I used 2.5 gallons of DEF in 5,000 miles.
.

[Chris Padilla]

I haven't a clue how much DEF my potential future 535d holds. I'll have to find that out. I'm reading around that it should last a year before needing refilled. Maybe the cars (smaller) don't use as much as trucks or Keith's van?

[David Weaver]

Just had my Sprinter Van serviced yesterday. I used 2.5 gallons of DEF in 5,000 miles.
.

That's pretty good!! Maybe there's something wrong with the heavy trucks. I won't say the company the shop foreman works for because I don't want him to be lined out. Despite what he commented about the DEF, he doesn't mind it so much like he does the EGRs, which in his words "they can't fix in the shop and nobody at the company seems to have a clue how to fix problems with them, either". Imagine it stinks being a lifetime diesel mechanic and then spending a large part of your day with "tech support" on warranty problems when the company has time quotas for how long you can spend on each truck.

[Brian Elfert]

Just had my Sprinter Van serviced yesterday. I used 2.5 gallons of DEF in 5,000 miles.
.

That seems pretty good to me. If you got 20 MPG you used 1 gallon of DEF per 100 gallons of fuel.

[Max Speedwell]

I did a search on the word "diesel" here in OT and read some interesting discussions.

I have two questions regarding diesel fuel and diesel engines.

(1) Is diesel fuel prevalent? I think it may not be as ubiquitous as gasoline but is it pretty much everywhere? I need to start paying attention to it at the gas stations I frequent.

(2) Are diesel engines any more maintenance than a gasoline engine? I mean this in terms of time and cost.

I can handle most of the mechanical work on my own vehicles (all gasoline) including most troubleshooting and repairs. Are diesels any different to deal with?

I'm seriously considering a diesel engine for our next car. I like the MPG gain plus it just sounds kinda cool to have something a bit different. I hear the torque is pretty amazing with a diesel engine. I have ZERO experience with diesel cars or engines. I'm not even sure I've ever ridden in a vehicle with a diesel engine.

Well Chris, here are a few answers:

First off, let me qualify my answers...

I've had a handful of Diesels (Big Volvo truck, VW pickup with a 1.6 turbo Jetta engine, and a long list of Mercedes 240D sedans, Kubota tractor, Iseki tractor, Kubota generator, Changfa generator, blah, blah, blah...) and can say:

*Most used diesels have been abused, and most of those through ignorance. Very few know how to own a diesel. These are not just gas engines that take fuel from the green handled pump. This makes finding a good diesel even that much more difficult.

*Chris displayed great wisdom when he said; Shop the owner, not the car." How wise... how wise....

*The fuel is very prevalent. I once had the family out on a drive and we stopped at a gas station in a small cutsie, Bavarian themed tourist town. There was a line at the gas pumps. I drove around to the back. The diesel pump was clean (less customer traffic), and right near the restrooms. A woman walked around to the back of the building to look for the restrooms and when she saw me pumping fuel AND not having to wait in line, she was more than a little indignant. Add to that and my fuel was about 20% low priced than her gasoline, and my tall geared differential gave me 33 mpg in a big, heavy sedan (ahhh... those were the good old days).

*Diesels are, and then are not more work to maintain than a gas engined vehicle, BUT they must be maintained by the book. Change the oil by the book. Do a service check by the book. Change the filters by the book. They will tolerate abuse but suddenly tell your wallet that the abuse must now stop. Treat them right and they will treat you right. Also, you just can't go out and buy a diesel. You MUST know what you're looking at. About 33 years ago Car & Driver magazine had an excellent article with something like 108 check points, on how to buy a car. A reprint of that article, and a Mercedes diesel buyers guide (un-named publisher since naming them may violate the terms of the forum agreement) in your arsenal is a must. You will only need a few tools when inspecting an older Mercedes diesel.

*Every vehicle we own (yes, even the tractor!) is a diesel. Diesel, as an anonymous person once pointed out, isn't a fuel... it's a lifestyle. Truer words about diesels may have never been spoken. Be prepared to change mental gears about vehicle ownership.

*My VW is a little more difficult for maintenance than the Mercedes(s). Not as much room, a different way to adjust the valves, and VW are hard to kill, but easy to wound. Grandma can work on the '80 - '85 240D. The '72 Volvo, and the '64 Impala I once owned (NEVER should have sold either car!!) might have been easier to maintain the the 240D, but if so, not that much easier.

*I have the factory manuals, sales brochure, videos, bulletins, service bulletins, Bentley, Haynes, and possibly even Chilton manuals. I have most every piece of literature even written about the W123 series. If you decide on a Mercedes, then you will need the same literature too.

*Not all diesels are created equal. The Mercedes Benz 300SDL was horrible, but a very beautiful car. The Isuzu NPR have had questionable engines. Some survived, some grenaded at 110,000 miles. Kubotas are the VW of industrial diesels... easy to wound, and if you're not careful, you can kill it. The small Kubotas (wanna buy mine?) are a nightmare to own. Electronic controls, remove the head to adjust the valves (yes... really), and have you thinking they are totally reliable then, WHAM, get out the wallet.

*Chances are very good that my next car will be a W123 (240D, 300TD), or a W116 (pre '80 300SD). I currently have a pair of 240D sitting outside and can't imagine owning any other vehicle.

If you want ultimate reliability, long life, cheap, and easy to service, and unquestionable quality, then buy a Camry.

-Max

[Mike Hollingsworth]

I loved my diesel rental in Europe. Until I stepped into a bit at the pump. Brought it into the carpet and smelled my whole trip. Smell is a big downside for me.

[Jerome Stanek]

Our truck drivers carry rubber gloves in the side box to use when the refill. One driver even has a pair of over size boots in there to put on so he doesn't carry the smell into his truck becuase like he said he sleeps in there.

[Jason Roehl]

I loved my diesel rental in Europe. Until I stepped into a bit at the pump. Brought it into the carpet and smelled my whole trip. Smell is a big downside for me.

One of my first real exposures to diesel was on a job site. We had been running a 4WD, 66', diesel boom lift for several days. I knew that it would be bad to run it out of fuel, so I started calling around to see if someone could come fill it. No joy. So I grabbed a 5 gallon gas can (yes, a red one--I didn't know the "protocol" and it was what I had). The job site was about 45 minutes from my house, but there was an interstate exit on the way about 5 min from the job. I pulled in, and it was a truck stop. I open the can and the vent, grab the pump nozzle, stick it in the can and pull the trigger all the way. Yeah, those pumps were for filling semi tractors...

[Jim Stewart]

Max,

What Kubota do you have? I found the Kubota diesel very reliable in an older bobcat. I have a 2009 kubota M108X 96 pto hp. I love that thing. I was considering an L38 to mow along my woods and spray with. I have a wonderful kubota dealer near me. I want to ask them about your concerns. JIm

[Chris Parks]

For all the good intentioned advice and anecdotes here one thing needs to be remembered. Any late diesel is common rail and any common rail is beyond the home handy man. They are also invariably overhead cam/four valve per cylinder and controlled by very complex electronics. The days of self maintenance are over unfortunately.

[ray hampton]

For all the good intentioned advice and anecdotes here one thing needs to be remembered. Any late diesel is common rail and any common rail is beyond the home handy man. They are also invariably overhead cam/four valve per cylinder and controlled by very complex electronics. The days of self maintenance are over unfortunately.

If each cylinder got 2 intake & exhaust valves, DO the set of valves open at the same time ?

[Chris Parks]

Yes is the short answer.

[Paul Wunder]

I have owned two diesel vehicles, both were Volkswagons. The first, a Rabbit, ran 287,000 miles before I tired of it. It averaged 50 mpg and I used it for a long commute to work. The model year was a 1984; it was slow, smelly, and the heater took forever to warm up. BUT, it was reliable.

The second diesel was a VW New Beetle, a 1999 version. it was a piece of junk. Electrical problems abounded; car repeatedly failed on the road; three a/c system failures and replacements, and serious undiagnosable problems with significant loss of engine power.. I dumped the car at 93K miles.

The biggest problem that I had with both vehicles was the lack of diesel trained mechanics (my cars were always dealer serviced) to repair my vehicle. Because of the low sales volume, not many mechanics were trained on diesels and I suspect that would be true today even at BMW. Pretty scary when quite often I knew more about my vehicle than the mechanics did.

Personally, for me, my first diesel served its purpose but never again for me.

[Jim Becker]

Paul, I think that the mechanics thing is going to resolve since more and more diesels are being offered now and going forward. It was a "chicken and egg" problem, but the tide is turning.