Which used "old tech/new tech" Derv

aston

The Torque Meister
Points
302
Location
South Dorset
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VOLVO and VW
There seem to be two schools of thought on buying a used derv with a few miles on the clock. From what i can make out by some rants and raves on the honestjohn forum it is not wist to buy a used common rail derv instead go for a modern petrol or an old tech derv.
So bearing that in mind, for a hassle free life which should be the most reliable and reasonably economical old tech derv and common rail tech derv engine? (and which dual mass flywheel jobbies are best avoided)? Thanks
 

HDi fun

TC ModFather
Points
637
Location
Buckinghamshire UK
Car
Passat 2.0 TDi
DMFs are a weak point, especially on modern diesels of FWD and 4 cylinder design.

Two reasons:

1. Massive flywheel torque;

2. All fours exhibit torque reversal every 180 degrees of crank rotation. Especially problematical with high preformance derv engines.

A six cylinder motor removes the torque reversal problem (whether inline or in V formation) and as such should be far kinder to the DMF and transmission in general.

Some say that fitting a solid flywheel in place of the DMF (in a 4 cylinder car) is a solution. I say not, because now the entire drivetrain is subjected to uneven torque delivery. This includes the engine and crankshaft itself.

What about a 530d ? These can be had for hald sensible money these days - the model goes back to 1998 and with a good history they're not known for creating problems.
 

aston

The Torque Meister
Points
302
Location
South Dorset
Car
VOLVO and VW
I have heard nothing good on the old tech BMW diesel, it is guarenteed that at some time the pump will pack up and the pumps are unique to thier ECU making the car a scrapper, BMW's old diesel engine is called the TDS stands for TeDiouS.
Are all dmf's a nightmare or is it just the VAG ones that are a pain?
 

HDi fun

TC ModFather
Points
637
Location
Buckinghamshire UK
Car
Passat 2.0 TDi
I have heard nothing good on the old tech BMW diesel, it is guarenteed that at some time the pump will pack up and the pumps are unique to thier ECU making the car a scrapper, BMW's old diesel engine is called the TDS stands for TeDiouS.
Are all dmf's a nightmare or is it just the VAG ones that are a pain?

I had the DMF replaced in my 406 at 115,000 miles. Thankfully under warranty because otherwise the bill would have been approaching four figures. Modern four cylinder diesels are rough on DMFs.

The 325tds which Geraint13 drives is a powered by a lovely engine. Probably the first dev engine which I acknowledged as half pleasant to use. I was the original derv hater! It's not the fastest of dervs and it'll never keep up with a common rail 320d.

But - it wil probably go forever. It is a straight six, the torque isn't outrageous and they can still be remapped, although not as impressively as a common rail unit.
 

jarrus

Pro Tuner
Points
337
Location
West Midlands, UK
Car
Suzuki Swift Sport
I'm an advocate of old skools diesel engines, but I have to admit that a lot of the old diesels now will have done about a million miles and probably won't have been looked after very well. (and all the ones that have been looked after will have been sold quickly or will be kept by the owners untill they die, I'm one such owner :) ) I know good condition 306 1.9 Dturbo's are becoming very hard to find now. They have all been tweaked up (although it's not always a bad thing) but it's usually been done a bloke who has no idea what he's doing and has probably turned the turbo all the way up.

A second hand CR engine should make a good use buy now that most of the problem have been ironed out as such. Pegueot 2.0 8v hdi's are probably best avoided as they will need the bottom pulley replacing every 60,000 miles as they do break. If it's between that and a 1.9 XUD then I'd have a 1.9 but if they did put the 2.2 16v HDi in the 306 (they never did at the factory) then I would have had one of those over the 1.9.

Fiat 1.9 JTD's are supprisingly reliable and refined. My dad's van has one and it's never missed a beat, and he raggs the nut's off it every day.

I suppose the best advise we can give you is that you need to find one that's been owned by an enthusiast. They will have cared for it and lavished lots of love on it to keep it mint but in turn they might be a little more harder to get hold of as the owners will be asking a little more for them but in my opinion it's worth the spend.
 

jarrus

Pro Tuner
Points
337
Location
West Midlands, UK
Car
Suzuki Swift Sport
I don't doubt that at all mate, mine need a new radiator, they are notoriously bad on the 306 and the cause of head gasket failure on the XUDT's

83,000 miles is nothing, I was talking more a long the lines of 283,000 miles of 383,000 miles.
 

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