General difference between 2,5D & D5 engines

[nskeates]

Hello,

i am looking to buy a v70 diesel and want around the 2000/2001 my. i was wondering are there many differences engine wise between the older 2,5D and the D5 ? ie :-

fuel consumption
power
reliability issues
smoothness etc

any help appreciated

thanks
neil

[Clan]

yes to all the above for the better .. ! The Volvo designed and built D5 is far superior and much lighter than the cast iron older VW based diesel .

[phasesonix]

d5 is faster and smoother,little bit better on fuel-but if something goes wrong your going to be paying for it(£76 for a thermostat). The old VW engine is not as refined but is a very reliable engine it's common to see them with 300,000+ which is not true with the D5. I have the d5 and the 2.5d and I'm keeping the 2.5D because I can run it on pure veg oil without any problems. If your not going to use vege oil it might be worth getting the D5 but I have heard a lot of horror stories about the injectors going on them especially the first generation of D5's.I even heard problems with the 06 d5's having injector problems.

hope this helps.

[oilburner]

Originally Posted by phasesonix

The old VW engine is not as refined but is a very reliable engine it's common to see them with 300,000+ which is not true with the D5.

Could that just be because the D5 engines haven't been on the road long enough to reach those mileages yet? An early 2001 D5 is only 7 years old, even at 20k miles a year that is "only" 140k miles. Lots of them around with that many miles still going strong.

Originally Posted by phasesonix

I have heard a lot of horror stories about the injectors going on them especially the first generation of D5's.I even heard problems with the 06 d5's having injector problems.

Only up to 2003, most have been fixed with the improved injector design by now. Please point to cases of later injector failure, I've not seen them in any numbers.

As for veg oil, agreed, I wouldn't run a D5 with veg oil, common rail engines do need standard diesel fuel.

[phasesonix]

[QUOTE=oilburner;393393]Could that just be because the D5 engines haven't been on the road long enough to reach those mileages yet? An early 2001 D5 is only 7 years old, even at 20k miles a year that is "only" 140k miles. Lots of them around with that many miles still going strong.

Thats true, But The D5's that are over 200,000 do seem to be on there last legs though.



Only up to 2003, most have been fixed with the improved injector design by now. Please point to cases of later injector failure, I've not seen them in any numbers.

I know they did use magnets instead of springs after 2003 but I have still heard of lot's of problems. Which is true with a lot of common rail engines.


Don't get me wrong-the D5 is a very nice engine-Even the police round here are using them in panda cars.

[BillB]

I have one of the last classic Tdi's (2.5D badged) although the engine was used until 2002 when the D5 came out. Just done 153k and I've had the cambelt, fuel pump belt, tensioners and water pump changed (thought of doing it myself but that crankshaft bolt is very tight and I don't have good facilities). However, it is currently averaging 47mpg - and I've checked this with actual fill-ups and mileages, not just the computer. I can get 50 mpg out of it driven carefully. I challenge the D5 to better this. That old Audi lump is some engine IMO. The worst problem is that there isn't a generic code reader for the later ECU (MSA15.8) - Volvo only. Regards,

[shimon340]

the injectors in the D5 are sourced from Bosch and injector failure is something common will all common rail and new higher pressure unit injectors (HGVs and trucks). The higher pressures and common rail systems are very sensitive with tight tolerances meaning these systems are not as reliable as the diesel systems they replaced. Parts are also expensive. Higher water content in supermarket and other "spot market" fuels is also responsible for a lot of failures but manufacturers find this hard to prove based on fuel sampling vehicles at dealerships. Testing does generally show high water content is a problem for high pressure pumps and injectors.

injector issues with the D5 (I havent heard any major problems affecting a large number of vehicles) are down to Bosch. Bosch are one of the higher quality manufacturers so issues are not as common place as say with Delphi or Denso diesel systems.

diesel vehicle reliability has taken a downturn across all manufacturers with the introduction of higher pressure systems. Problem stems from legislation requiring lower particulates and HC emissions and the need to make atomisation of diesel fuel more and more efficient.

this highlights a further benefit of the DME tests being conducted by volvo trucks. The DME evaporates much easier making atomisation easier as it does a lot of the work itself!