Diesel or Petrol

NormanC

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When browsing the forums it seems to me that there are many more threads related to problems with diesel engines as opposed to petrol engines and I wonder why. Perhaps the easy answer is that there are many more diesel engined Mercedes on the road or, alternatively, that current diesels are inherently less reliable. I don't know!

I do wonder if there is a problem related to diesels where the level of sophistication needed (turbos, particulate filters, etc.) to overcome the inherent problems of diesel engines (low power, excessive pollution, excessive noise, etc.) are leading to reliability problems.

What do the rest of you think?
 
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rapide

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diesel or not!

well, all these levels of sophistication exist in other areas , especially marine engines of 100,000 hp. 2 stroke diesel , and they are very reliable when they are maintained to a very high level , I have worked on them, generators as well working hard, hours /days on end , so perhaps some of it is operator error, either by the owner ( lack of servicing), high usage can be confused with high mileage! cars that stop and start all day need extra care than ones slogging away on the motorway 24-7, petrol and diesel share many of the same features , turbos / cats or part/filters, engine management e/g/r, etc etc, so it can be a can of worms , with the dealers not helping giving the wrong info about servicing to the owner just to sell the car ie; no it only needs a service every two years! . After all that you then have inherent faults that the technical guys on here pick up on so well as they see the cars all the time , but not to forget you only hear of the bad ones! there are an awful lot of goods ones running around for many a mile with no trouble, so something to think about! all the best Rap.
 

jberks

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As you say, there are a lot more diesels around these days. They also tend to have stellar mileages. The majority of issues are around sensors and most of the rest are related to old tired turbos. The only diesel specific issue seems to be injector leakage and the 'black death' which considering the pressures involved shouldn't be a great surprise. On the newer ones, yes emmissions and other demands seem to be pushing designs to the limits and injector design seems to be struggling to keep up, but the overall engine appears to be pretty bullet proof. Speaking for myself, I'm very impressed with the longevity and reliability of the MB diesel engine. At 101k I'd expect the odd tick from a petrol lump, the diesel is better than ever.
 

kth286

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When browsing the forums it seems to me that there are many more threads related to problems with diesel engines as opposed to petrol engines and I wonder why. Perhaps the easy answer is that there are many more diesel engined Mercedes on the road or, alternatively, that current diesels are inherently less reliable. I don't know!

I do wonder if there is a problem related to diesels where the level of sophistication needed (turbos, particulate filters, etc.) to overcome the inherent problems of diesel engines (low power, excessive pollution, excessive noise, etc.) are leading to reliability problems.

What do the rest of you think?



Absolutely agree - give me my 173,000 mile petrol straight six every day - powerful, smooth, and refined; not a turbo, not a balancer shaft, no EGR valves, or soot particle traps anywhere in sight.

And 6 spark plugs easily changed at approx £2 each.
 

television

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Absolutely agree - give me my 173,000 mile petrol straight six every day - powerful, smooth, and refined; not a turbo, not a balancer shaft, no EGR valves, or soot particle traps anywhere in sight.

And 6 spark plugs easily changed at approx £2 each.

Later petrols do have an EGR valve, but not as many going down as on the diesels
 

wireman

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If you are not doing lots of miles petrol makes more sense, the price premium on diesels will take a lot of miles to recover.
 

television

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If you are not doing lots of miles petrol makes more sense, the price premium on diesels will take a lot of miles to recover.

Very true if you are changing cars,,it is only the difference that you save, and that can takes years to recover the cost
 

hairyg

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A third option

Don't forget LPG can give diesel operating costs with a petrol engine. A good conversion isn't cheap but Autogas at 64p/litre gives my R129 SL320 a similar fuel cost per mile as my wife's Audi A3 1.9Tdi without compromising the fun.
 

kth286

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Don't forget LPG can give diesel operating costs with a petrol engine. A good conversion isn't cheap but Autogas at 64p/litre gives my R129 SL320 a similar fuel cost per mile as my wife's Audi A3 1.9Tdi without compromising the fun.

I have always been impressed with your LPG system, on a same engine as mine I believe -
straight six ?

I am thinking of doing this.

Please remind me again which system you have.

Any chance of pictures of inlet manifold area, and injector set up.

To my e-mail if you wish/easier:

Thanks
 
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OP
N

NormanC

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CLK 320 Cabrio, Celica GT4 WRC, Mk 1 Mexico
  • Thread Starter
  • Thread starter
  • #10
Later petrols do have an EGR valve, but not as many going down as on the diesels

Am I right to assume that this is because the untreated exhaust from a petrol engine is not full of carbon particulates?
 

hairyg

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www.vegetarian-and-low-calorie-recipes.com
Your Mercedes
R129 (1994) SL320
I have always been impressed with your LPG system, on a same engine as mine I believe -
straight six ?

I am thinking of doing this.

Please remind me again which system you have.

Any chance of pictures of inlet manifold area, and injector set up.

To my e-mail if you wish/easier:

Thanks

Photos sent by e-mail, I suggest you remove your e-mail address from public view.
 


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