Viewing: What is a PD engine

**xavier** · 10-10-2009, 12:10 PM

I was wondering what a PD engine is and how this differs from the older diesel engines?

Can all PD engines be remapped? Is it just VAG that do PD or is there another name for the same thing from other makers?

***HDi fun*** · 10-10-2009, 02:45 PM

PD stands for Pumpe Duse, which translates into unit injector.

VAG has replaced PD with common rail now.

***HDi fun*** · 10-10-2009, 02:45 PM

PD stands for Pumpe Duse, which translates into unit injector.

VAG has replaced PD with common rail now.

**oilman** · 10-10-2009, 06:24 PM

These special engines, the VW pd engines, are very severe on the oil, the mechanical fuel pump delivers fuel at approximately 25,000 psi!! to enable a very precise injector spray pattern which, in turn, gives excellent driving characteristics.

The very high loads on the fuel pump will lead to VI improver shear down and oil viscosity loss if the engine is operated on lesser oils that ones approved for use in PD engines.

Cheers
Guy

***HDi fun*** · 10-10-2009, 06:28 PM

Quote:

Originally Posted by oilman

These special engines, the VW pd engines, are very severe on the oil, the mechanical fuel pump delivers fuel at approximately 25,000 psi!! to enable a very precise injector spray pattern which, in turn, gives excellent driving characteristics.

The very high loads on the fuel pump will lead to VI improver shear down and oil viscosity loss if the engine is operated on lesser oils that ones approved for use in PD engines.

Cheers
Guy

I'd gathered the same ide as well. The 16v HDi engine I had ran about 18000psi fuel pressure but that was a common rail so driven by belt driven pump. 25,000psi is an enormous amount of pressure to deliver by cam driven injectors - it's surprising that the engines last 5 minutes.

The 4 cylinder PDs are exceptionally economical and respond well to remap tuning but they're a bit coarse compared to common rail system offerings. I believe VW has now adopted a common rail diesel system.

**pgarner** · 10-10-2009, 08:36 PM

VAG have no switched to common rail diesels but they are only now starting to see similer economy compared to when they used PD.
as oilman said it used and pump on the actual injector - this meant in reality 5 fuel pumps on a 4 cylinder engine, 1 main from the tank and the 4 on the 4 injectors - to generate the very high pressure. the benefit of high power, 150 bhp form a 1.9, with great economy as its not unusual to see close to 60mpg.
unfortunatly VAG had to dump these engines to meet the euro emmissions

**oilman** · 10-10-2009, 09:00 PM

I have a pd enigne, I can confirm they respond very well to a remap and the torque figures go through the roof for a 1.9 diesel.

However, boot it and the mpg is not better then a petrol.

Cheers

Guy

**pgarner** · 10-10-2009, 09:02 PM

what have you got ? i was loking at the 130 and 150 engines but couldnt get over the £3k difference between a 130 diesel with high milage over a 180 petrol with under 18k on the clock

**oilman** · 10-10-2009, 09:12 PM

Ive got the Seat Cupra TDI 150, its now at 198bhp with 358ft of torque according to a dyno but I always take them with a pinch of salt.

If my memory servs me correct the 130 has a smaller turbo, essentially the 115 with a factory remap so not much more room to play. The 150 with the bigger turbo means you can remap away for some decent gains.

It goes well, the only thing I miss about a petrol is the rev limiter when giving it some, the diesel even with a remap is all out of ideas at 5,500rpm.

Cheers

Guy

**pgarner** · 10-10-2009, 09:19 PM

yeah trying to find the 150s were a pain an most if not all were supidly overpriced.
turbo, map, intercooler are all different off the top of my head. theres notreally that much difference as im getting out of puff by 6000prm and limiters somewhere around 7400 - redline is 6900

***HDi fun*** · 10-10-2009, 10:03 PM

I saw 192 bhp from my 2.2 HDi and 320+ lbft with a custom remap. But the economy was middling 35-36 MPG on average. I did drive it quite purposefully though. I suspect a PD 150 tuned to the same level would do better on fuel, even if it was to be a little bit more vocal.

**WLBjork** · 11-10-2009, 06:38 AM

For fuel economy, if both our computer readings are as accurate, my 2.0CR (170PS) just beat my fathers 1.9PD (105PS) on a similar run - Forest Town to Scotland and back. I averaged 52.2mpg and father averaged 52mpg. He has an estate compared to my liftback, but on the other hand he went up for the day whereas when I went up it was for 3 days so had luggage as well (and did a little touring).

I know my computer was about 6% inaccurate as I checked the economy to the actuality (miles driven/fuel into tank), however when I wanted to compare with my father's he hadn't (sob!).

On the otherhand, they do seem to have fixed the oil problems (reminds me, must remember to check that today) that the PDs reputedly suffered.

**oilman** · 12-10-2009, 04:00 PM

Mine runs on around mid 30's mpg, but then I am not gentle with it.

If really pushed I can get it into the 20's and on a real long motorway run early 40's but thats it.

Cheers

Guy

**pgarner** · 12-10-2009, 04:07 PM

that makes me alot happier seeling those figures

***HDi fun*** · 12-10-2009, 05:15 PM

Diesel is not the super economy choice it once was but it's now possible to drive a 2 litre or thereabouts 4 cylinder diesel with the same clout as a 3 litre V6 petrol but still get will over 30mpg even when making swift progress.