V50 Engine 2.0D : Increased fuel consumption

[SnineT]

Originally Posted by Teddy1975

I went to log several parametres in Vida the other day and before I set out, I erased all codes.

For the first 50 km, the consumption was appalling. For instance, city traffic at 50 km/h on a level road in third gear just maintaining speed: 15l/100km.

However, after those initial 50 km of driving, suddenly, like the flip of a switch, it went back to driving flawlessly. Mixed country road/town traffic came to 4.6l/100km. Now, after driving to work and back, it's at 4.9l/100km which is good. What isn't good is that there is no apparent reason for it.

I've got my fingers crossed that it will remain like this, if not, then I'll start looking if all the components involved in DPF regeneration are working as they should, although the mechanic says that failed DPF regen cannot be the cause of this. The DPF on my car is not blocked.

Rising oil levels can be from failed DPF regen AND injectors failing. In my case it was the latter.

What are the engine temps saying, from what you've told us it sounds like an engine that isn't getting warm under urban conditions, also if these tests are being done on journeys less than 15 miles you won't be getting a correct overall mpg report, mine would report on the app that I was doing 23 mpg on some journeys even with a hot engine but only on short 1 mile journeys, by the time I'd done a 20 miles trip semi urban I could then see anything from 32-43 mpg traffic dependant, all lined up with the fuel receipt ok as well overall, iirc I would get 220 miles out of a £50 squirt and the readout would line up with the mpg overall.

[Teddy1975]

I don't ever drive distances shorter than 5 miles, and I keep those to a bare minimum.

I usually travel about 25 miles as that's the distance to work from where I live presently.

The route I take is made up by country roads where I pass through villages and towns for every 5-10 km. I drive at 85 km/h, 50 mph, and at 50 km/h or 30 mph through the towns/villages.

If it was the engine not getting up to temp, how can you explain that it suddenly drives flawlessly again? And that it had been driving flawlessly for 6 months prior to this along the exact same route.... Sorry, but I'm not buying that.

I'll still strongly advice people against buying any volvo with the PSA 2.0D engine, even if mine is back to driving fine again for the moment.

[SnineT]

Originally Posted by Teddy1975

I don't ever drive distances shorter than 5 miles, and I keep those to a bare minimum.

I usually travel about 25 miles as that's the distance to work from where I live presently.

The route I take is made up by country roads where I pass through villages and towns for every 5-10 km. I drive at 85 km/h, 50 mph, and at 50 km/h or 30 mph through the towns/villages.

If it was the engine not getting up to temp, how can you explain that it suddenly drives flawlessly again? And that it had been driving flawlessly for 6 months prior to this along the exact same route.... Sorry, but I'm not buying that.

I'll still strongly advice people against buying any volvo with the PSA 2.0D engine, even if mine is back to driving fine again for the moment.

Just trying to rule out all possibilities as stuck open thermostats can do this.

D2 you won't make that mistake again will you, absolute dog of a lump people I knew who had 407's had nothing but hassle with them as well.

[Simmy]

we have a 2.0d psa engine but ours is the one without eloys . we have replaced egr all manifold sensors and the turbo control valve and dpf pressure sensor it runs well an often returns more than 60 mpg on a run .

[SnineT]

Originally Posted by Simmy

we have a 2.0d psa engine but ours is the one without eloys . we have replaced egr all manifold sensors and the turbo control valve and dpf pressure sensor it runs well an often returns more than 60 mpg on a run .

They're economic enough it's just how many times I heard "it needs another turbo" from 407 owners. Maybe Volvo was able to tweak it and improve it, I dunno but it put me off an S80 a decade ago.

[Simmy]

any car is only as good as the maintenance its had. you know the type zero servicing low or no oil bald tires ect and the crazy thing is there's hundreds of them out there .

[Teddy1975]

I know that buying a used car is taking over other people's problems. I bought this Volvo because it came with full service history mostly from Volvo, so I hoped that meant I'd be spared from the more expensive jobs. Some of which were the timing belt and the DPF that was changed 28K miles ago.

When it drives fine, it does give me about 60 mpg, and still have enough oomph to overtake that I often don't have to switch to a lower gear. I come from a 1996 4 door 850 that had the 2.0 petrol engine and while it was an extremely comfortable drive, it was like driving a battleship where you had to plan your overtakes minutes in advance so you could shift down and do a proper run up before venturing into the other lane.

Anyway, it's still behaving. The engine reaches temp within 5 miles, even in winter due to the aux diesel heater it's fitted with. I wanted to service that aux heater this summer, but with the other more severe problems I never got that done. If it begins to smoke too badly again, I can always remove the fuse for the heater which only means a few more miles for the car to reach working temps. Denmark fortunately doesn't often get any colder than -5C to -8C.

I just don't like not knowing what the issue with the sudden increase in fuel consumption is. All four injectors are swapped now (They were the ones installed from the factory), which has made for a slightly less noisy engine, so some good has come from it.

[SnineT]

The aux I believe can only be used in the right condition, they do smoke but you should avoid using it if the door cill is below the snow level, now you mention it though it could be the heater eating the fuel rather than the engine, hope you get it sorted as it's not a nice place to be when things just won't reveal what needs to be mended.

[Teddy1975]

Yes, the aux heater only kicks in when it's below 7C, I think it is, and only if there is enough fuel in the tank (If low fuel warning is lit, the heater won't activate when starting the engine). It also only starts if the coolant temp is lower than a certain number of degrees, which I must admit I can't remember here and now.

I need to resolder the power wires to the fan within the aux heater, and I have a new burn chamber and full service kit here on my table, just haven't been in the mood to fiddle with it as I know it won't be easy to remove from the car. It's fitted to the firewall just below the pressure sensor for the A/C lines and the official instructions involve loosening the engine mount and moving the engine forward an inch or two. Doesn't sound like my kind of fun, really.

Anyhow, the aux heater hasn't been running since the end of March, probably, and there are no fuel leaks, anywhere, so unfortunately it isn't that.

My dear old mother suggested it might be a loose connection somewhere, which I discussed with the mechanic when I spoke to him Friday. It could be that, but where to start hunting for it when the car reports no errors.

And the thing is, even when it did guzzle diesel like an 70s locomotive, it drove fairly well. Except for that one, very important thing, particularly now with these all-time high fuel prices: it would only go 430 miles on a full tank, instead of the usual 650 miles.

[Teddy1975]

So, on the way home from work it happened again without any prior notice while driving. Mechanic is out of ideas but has ruled out the DPF. He says it might be the EGR that's sticking in the open position because the EGR pipe was extremely hot when I arrived at the garage, and he asked me to log the two EGR parametres in Vida now while it's driving poorly, and hopefully it will go back to driving fine again some time real soon so I can log it then for comparision.

There are still no codes set apart from those three nagging about the audio system missing (I removed the original basic sound system and installed an after-market head unit and amplifier), but of course they aren't related to the fuel guzzling.