Technical modern diesels too complicated?

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Technical modern diesels too complicated?

blotch

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Hi All,

Am very interested in the Doblo. However, I came across a couple of threads at www.honestjohn.co.uk about how the complexity of modern diesels is such that owners should be prepared for very big bills if something goes badly wrong. A couple of guys wrote in to say that they were switching back to petrol engines.

The moden diesel electronic controls seemed to be the main trouble. Now I like diesels, or have done up to now, but I would like to know how the JTD engine fares on this issue. Any comments, anyone?

It's a pity that the Doblo isn't offered with a good petrol engine that gave us a choice.

Best wishes,
 
I wouldn't worry too much, no specific evidence to disprove that. JTDs are good diesel engines, you are unlikely to have a problem.
 
I took delivery of my JTD last week.

My main reason for picking the Doblo over the Kangoo & Berlingo/Partner was that the JTD appears to a good all rounder. If anything at 105bhp standard tune it appears to quite de-tuned/unstressed?
That and the fact that thousands of Taxi/Private hire guys wouldn't have bought them or continued to buy them if there was expensive problems. If you follow the servicing schedule (either at dealerships or DIY) then you're going a long way to prevent expensive damage in the first place. I know that certain markets get a 1.6 petrol model but it would be interesting if anyone knew the sales figures 1.6 petrol to 1.9jtd...

Alex
 
The electronics are nothing to worry about when comparing against a petrol. Both have systems controlling fuel delivery and timing (obviously diesel timing is controlled through injection rather than ignition timing). The big bills relate to failures on the fuel system.

The common rail system was developed between FIAT and Bosch to achieve the Euro 3 emmissions a few years back. One of the key improvements over previous fuel systems was the increased injection pressure. A high pressure pump and common rail feeding all the injectors was introduced. The previous systems used mechanical injectors - once a certain pressure was sent from the pump it would open and spray in the fuel. The common rail system injectors are always holding back the full fuel pressure from the pump and are now actuated electronically (a bit like a multi point petrol system however the fuel pressure is hugely greater on the diesel).

On the older fuel system, if an injector was stuck open due to internal failure or debris, the engine would smoke terribly however a new injector would fix the problem.

On the common rail system, the full fuel pressure continually 'hoses' from the injector, washing the cylinder bores from oil and erodes away the piston very quickly (within minutes), destroying that cylinder. At this point, unless your dealer accepts a warranty claim (which they should) you're faced with a bill for a new engine. This is fairly rare but you need to be aware of it so that you take particular care when changing any fuel system components or the filter to keep debris out of the system.

Modern diesel fuels also have less lubricity meaning that every fuel system now wears away quicker than it would have say 6 years ago (they use the diesel as a lubricant, not engine oil). This leads to the next failure you'll see with premature wear of the high pressure pump.

All said, the common rail diesel engine is extremely reliable and far superior over it's petrol counter part.
 
Hi All,

Well, thanks for your replies. I've been cruising the web for info on this topic and it does seem that modern diesels are very reliable. Unfortunately, when something major does, rarely, go wrong, as RSPilot has pointed out, it can be horribly expensive.

Now I'm unlucky with cars and think that I'm going to switch back to petrol. Sadly, this rules out the Doblo, a well designed and useful vehicle. Funny how Fiat released it with a puny 1.2l engine that had it condemned by every reviewed who had to drive it. Got it off to a really bad start.

Cheers,
 
Hope you enjoy your new car....whatever it is...personally I'd take doblo no question,great for the kids etc & keep until 3 years old,you cant let repair bills worry you as this applies to all cars no matter type/make! There are many reconditioned/specialist repairers of pumps etc these days if the worse did happen;)
 
Here. here!

We have 3 diesels in the fleet including Marea JTD!

Get the Doblo it's the best one out there :)
 
Hi Fellas,

I'm still tempted by the sheer practicality of the Doblo, despite my earlier comments.

Is the new 1.3 diesel engine a JTD and does it run under the similar high pressures of the 1.9? In other words, would it be reliable and durable?

Thanks for you inputs.
 
hey blotch,
didn't you already ask that same question 3 weeks ago in a seperate thread???
so just go for the car or leave it....you're boring me with your behaviour of not being able to take a decision,,,
_s
 
When your buying a new car theres no point in rushing in with both feet & then regretting it, look at the opposition, Kangoo, Berlingo, Partner etc etc. I do think though that a 1.3 is on the small side.
 
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