All common rail diesels are inherently flawed?

[davidstone28]

Was speaking to bloke who used to be a senior engineer for about 20 years with two large car manufacturers (one Swedish and one German) and he reckoned that the injectors on practically all common rail diesel engines will run into problems.

He gave me a long technical explanation (which was over my head TBH) but the gist of what he seemed to be saying is that the diesel injectors across many manufacturers (with the exception of Honda who use their own design as in the most recent Accord) come from limited sources such as Bosch, Siemens, Lucas etc and that because of the extremely high pressure which diesel is forced through them (something like 1200 bar, or psi?), a spring mechanism within those injectors will fail sooner than those found in petrol engines or non common rail diesels engines.

He says failure rates are reflected in the types and number of warranty claims made against the manufacturers he used to work for with far higher than average incidences of injector failure on common rail diesel engines etc. He reckons that manufacturers are still strugglying with high mileage tolerances with the injectors on common rail diesel engines.

I did some scanning of various user websites as I've been considering a Volvo S60 and Mondeo recently and true enough, there do seem to be problems with the injectors used in the 2002 D5 engined Volvos and a higher than average number of injector faults with high mileage Ford TdCI engines with numerous owners stories about such failures.

Anyone have any views, technical or otherwise?

[5lab]

i've heard there are some problems with some diesel injectors.. i think its noticed more than petrol engines cos it costs about 4 times as much.. one of the reasons i opted for an engine without hdi technology (had the choice given the age/type of car i wanted) was because whilst you loose a bit of power/economy, they're alot easier to maintain and a lot less expensive when they go wrong

[Zak33]

I've been told the same thing...good find mate.

Honda really are (again) late into the market, and now perfecting it (again)

They really do rock

[Stapleballs]

(something like 1200 bar, or psi?)

PSI, if it was bar, it'd be something like 15000 PSI. which is kinda a lot of pressure

[Fox]

Honda have FAR from perfected the diesel engine. In their quest to make it as petrol like as possible they have ended up with an engine that has a huge number of complains about substandard fuel economy, many people with Accord i-CTDi's are struggling to beat 36mpg which for most people defeats the point of a diesel.

[Flibb]

Did a bit of reading about common rail diesels, as I wasnt aware of the problem. Anyway 3rd generation 2003-> did away with springs on the injectors in favour of piezo electric valves, wonder if that did away with the problem.

[454Casull]

PSI, if it was bar, it'd be something like 15000 PSI. which is kinda a lot of pressure

That is correct. Some common rail injection systems run up to 3000 bar.

[kalniel]

Looking at failures for volvo and mondeo cars would surely just indicate that Ford have a reliabilty problem - something I don't find too hard to believe

A lot of early generation products have problems that come to light later - as mentioned piezo electrics are now used in bosch injectors. Delphi, Siemens and Stanadyne are other manufacturers of diesel injectors.

Though I can't say I've experienced much benefit in going common rail - my diesel's the izusu 1.7 dti lump (in a vauxhall astra) and I was blown away by the performance and mpg. Yet I drive a common rail vectra for work and the mpg was worse and the performance was more sluggish (but the cars a lot heavier too I guess).

[5lab]

Looking at failures for volvo and mondeo cars would surely just indicate that Ford have a reliabilty problem - something I don't find too hard to believe

A lot of early generation products have problems that come to light later - as mentioned piezo electrics are now used in bosch injectors. Delphi, Siemens and Stanadyne are other manufacturers of diesel injectors.

Though I can't say I've experienced much benefit in going common rail - my diesel's the izusu 1.7 dti lump (in a vauxhall astra) and I was blown away by the performance and mpg. Yet I drive a common rail vectra for work and the mpg was worse and the performance was more sluggish (but the cars a lot heavier too I guess).

the volvo lump in question is pre-ford, however the injectors are all from the same company..

the vauxhall lumps are available in different power ratios (you can get a vectra with ~70bhp common rail diesel i think) so maybe you've the better one in the astra and the worse in the vectra?? increasingly modern cars are loosing the mpgower ratio battle as more stringent regulations kick in and cars get heavier in general..

[Hobart Paving]

In their quest to make it as petrol like as possible they have ended up with an engine that has a huge number of complains about substandard fuel economy, many people with Accord i-CTDi's are struggling to beat 36mpg which for most people defeats the point of a diesel.

Source? Weblink? Otherwise it's conjecture....

Personally, I'd rather take the lower mpg (assuming that it is the case rather than just speculation) than go around in a car that sounds like a tractor and which has plumes of smoke coming out of the back of it.

[Fox]

Personally, I'd rather take the lower mpg (assuming that it is the case rather than just speculation) than go around in a car that sounds like a tractor and which has plumes of smoke coming out of the back of it.

a) So buy a petrol car then
b) Most new commonrail diesels neither sound like tractors nor emit plumes of black some. Go and drive a 330d or something.

[texteditor]

I have a nissan primera 2000 turbo diesel it's a 2000 as in year model is this a common rail diesel? (it's done 135,000 miles, I've had it since 95,000)
texteditor

[Tumble]

Fiat are also playing about with Diesel injectors - look at the new Multijet motors - they are ridiculously efficient. Chap at work gets 800 odd miles out of a 50 litre tank of juice in his 1.3 Multijet Dobló van.

[Barakka]

Fiat are also playing about with Diesel injectors - look at the new Multijet motors - they are ridiculously efficient. Chap at work gets 800 odd miles out of a 50 litre tank of juice in his 1.3 Multijet Dobló van.

Fiat created the Common Rail diesel engine (as used in passenger cars) and the first car to have a common rail diesel engine was the Alfa 156 - in fact they pioneered the direct injection diesel engine 10 years before that.

More recently they created the 2nd Gen common rail - MultiJet technology, and as you mentioned they can get insane economy (and power) using this. The 1.3 you mentioned is being used in the Panda, Punto, Corsa, and Suzuki Swift and won engine of the year 2005 beating VW, Honda, Pug etc.
The 1.9 version is being used in various Fiats, Vauxhalls, Suzukis, and Saabs as apparently it is that damn good.

I don't know a lot about the MultiJet technology but it electronically divides the injection into smaller "Jets" to reduce noise and emissions, and increase economy and power. So maybe they have also addressed the issues with Common Rail injector springs too.

[jon bda]

Fiat are also playing about with Diesel injectors - look at the new Multijet motors - they are ridiculously efficient. Chap at work gets 800 odd miles out of a 50 litre tank of juice in his 1.3 Multijet Dobló van.

Problem is, of the Doblo's i've seen i doubt if it will do all 800 miles in one go!.

[Tumble]

You may be right, although the new gen ones seem to be actually welded together, rather than held up with spit and baling wire...