V50 Engine 2.0D : Increased fuel consumption

[Teddy1975]

The DPF was replaced summer last year, about 45k km ago now.

I have a set of DPF hoses for the 1.6D that I bought from Autodoc last year but never got to install.

I do realise replacing the DPF isn't going to fix the underlying problem, but I'd almost rather pay an annually £230 to replace it rather than keep changing other parts that won't solve the issue or pay for having mechanics hook up their code reader to my car and state their amazement over the age and mileage of my car and that "there isn't anything wrong with it" and to return when the fault is present all the time. One indy and two Volvo certified garages so far have done that.

Anyway, I'll change the DPF hoses and the thermostate housing and see what happens after that. I think (hope) that it is because the engine doesn't get up to operating temps that is the cause of the extra soot.

[hal9000f]

Originally Posted by Teddy1975

Anyway, I'll change the DPF hoses and the thermostate housing and see what happens after that. I think (hope) that it is because the engine doesn't get up to operating temps that is the cause of the extra soot.

I can't find that you've posted coolant temperature readings before?

It would be interesting to know them before you change the thermostate...

Yes, that could be a problem...

[Teddy1975]

I haven't checked them, to be honest. Will go for a short trip and see what the temp gets up to now that it is just around freezing outside.

EDIT: I went out and drove around for about 45 minutes and I'm a bit pleased to see that it wasn't a complete waste of my money buying a new thermostate housing (The thermostate is welded inside the plastic) from Skandix. (Remember, it isn't installed yet!)

Picture 1 is after 20 minutes warm up driving, parked with the engine idling, picture 2 is while driving in third gear, which I did for a few minutes prior to taking the snapshot,
Picture 3 is when I arrived at home.

The temp is only where it's at because of the diesel burner, which at least makes for the cabin warming up but doesn't stand a chance against the radiator of course, so the engine never gets warm enough.

The DPF finished regen'ing just 2 km prior to me setting off today, so I figure the pressure values are much too high. Sometimes climbing above 120 when I put my foot down.

I've booked an appointment with my old garage Monday afternoon so they will swap the thermostate housing. I can't be bothered with draining and filling the coolant outside in this lousy rainy/freezing weather, and I'll have them replace the DPF pressure hoses and blow through them with air so at least that is okay.

I have a spare DPF pressure sensor from Delphi that I will try to install after the hoses and pipes are done and see what the pressure readings are like after that. VIDA had an amber error about the DPF pressure sensor reading being too low and voltage too low also, so that might have some influence as well.

[hal9000f]

Originally Posted by Teddy1975

Picture 1 is after 20 minutes warm up driving, parked with the engine idling, picture 2 is while driving in third gear, which I did for a few minutes prior to taking the snapshot,
Picture 3 is when I arrived at home.

We don't have the same engine, but I'd say that coolant temprature is definitely too low.
So, fingers crossed for a new thermostat!

Originally Posted by Teddy1975

The DPF finished regen'ing just 2 km prior to me setting off today, so I figure the pressure values are much too high. Sometimes climbing above 120 when I put my foot down.

Again, we don't have the same engine, but those pressure readings don't seem much too high.

I have experienced short spikes up to 290 hPa when I had problems and DPF was at 24 grams just before regen. So, 120 hPa seems not soooo much, if it was a occasional spike when flooring it, but then again if it was immediate after regen who knows

[Teddy1975]

Had the thermostate housing replaced today. Took 40 minutes and was a rather messy job. Then another 40 minutes to replace the hoses from the DPF to the two pipes running up to the DPF diff pressure sensor. One of them tore in half when the mechanic tugged on it, only using moderate force, and it was somewhat charred on the inside so it probably was about time they were changed.

On the way home I tried to floor it and the DPF diff pressure topped out at 375+ hpa (not sure exactly how much more than that as I could only risk a quick glance at the laptop screen), resulting in a temporary Engine System Service Required amber warning on the dash, which disabled the cruise control. Had to restart the engine to get the cruise control back.

Tomorrow, I'll try to install the Delphi DPF diff sensor I bought a while ago and see if that does any good. I'm getting rather annoyed with this issue.

DPF diff pressure at idle is 13.5 - 15 hpa, which isn't so bad, but the mechanic said it should never go so far up as it does when I floor it. Regen works well, however, Catalyst temp sensor 1 got up to 640C when it went through a regen cycle on the way home from the garage.

The coolant went from 75C at idle/79C at full throttle onto the motorway (30 to 140 kph) to 82C at idle/89C full throttle onto motorway (30 to 140 kph) in 7C weather. So the new thermostate is working, it just takes a lot to keep this diesel engine at operating temp.

[hal9000f]

Thanks for the update.

Sorry to see, your agony was not resolved.

But great to see your new thermostat is working as your coolant temperatures now seem much better, if not totally correct now.

Perhaps your only remedy would be to clean everything that could be clogged by years of soot accumulation in the intake and exhaust pathways.

[Teddy1975]

On my way to work today, having to battle several long stretches of black ice, I got the Engine System Service Required message 4 or 5 times (a record) and went into limp mode requiring an engine restart twice (also a record) during the 76 km ride.

I think the DPF is clogged up now as it's like something is holding it back even when not in limp mode. It's just sluggish and kind of lurching. I haven't had the time to scan for error codes today, but simply ordered the cheapest new DPF I could find, which is from BM catalysts. At a price of £190 it's only about the equivalent of 3 hours of garage labour here.

The last DPF I had put on cost three times as much but has lasted less than a year, and if that's how much I can get from one of those with my nightmare of a car, then the cheapo BM catalyst one will serve just fine. It certainly won't have enough time to rust through at this rate.

I think, (again I can only assume since there are no codes being shown and no-one seems to be able to find the cause), that for some reason Eolys isn't being injected into the diesel when I fill it up, despite me having tried to fill the additive tank twice and it wouldn't take much if any at all.

I've seen the DPF reach up 650C degrees when it goes through the regeneration stage, which should be hot enough, but if there's no Eolys, no particles will be burnt off even at that temperature, naturally. There are two old errors showing in Vida about the ADM, additive control module, signal lost and voltage too low, if memory serves, but nothing current.

Now, of course, a new Eolys tank and control module cost an arm and a leg so I will not go that route, I simply can't justify the extra cost on top of everything else I've had replaced to this date.

I will instead, as a test when I've fitted the new DPF, manually add Eolys to the diesel tank every time before I fill it up. Around 10 ml Eolys per litre of diesel. That's the closest I could get to the proper formula, scouring the internet for information about this nasty additive. Hopefully, that will keep the car running for an exorbitant amount of years to come, so I can redeem some of the money I've poured into this sinkhole of a car.

Sorry for my rant, it's just... Argh. Frustrating.

Happy New Year everyone.

[hal9000f]

Originally Posted by Teddy1975

Now, of course, a new Eolys tank and control module cost an arm and a leg so I will not go that route, I simply can't justify the extra cost on top of everything else I've had replaced to this date.

...

Sorry for my rant, it's just... Argh. Frustrating.

Happy New Year everyone.

Happy New Year to you and may the solution arise at last.

Best luck with that Eolys stuff...

Rant is totally OK, it's full of potentially useful info.

[Teddy1975]

Alright, so new DPF and injecting Eolys into the tank at every fill up hasn't sorted the problem. A regen is started every 120 km, or so, with the inevitable squirt of diesel going into the sump every time. Oil level is definitely rising again.

I've read other threads on here about minor surging when maintaining speed, which I also experience but haven't tried to address seeing as the near constant regenerations are killing the mileage and my wallet, 6.1 L/100km is no good when I drive 150 km every workday.

Some of the posts pointed out the TCV could be bad. I believe the TCV is the orange thing sitting on the right hand side of the engine near the battery tray. One like this:


I had a look at mine and it doesn't look like it's ever been replaced. It looks identical to the Pierburg that I've linked to, but it says Volvo (or Ford, I can't recall) on the one in my car. I removed it and checked the coil for continuity, measured 16 ohms across the two pins.

I tried cleaning the filter in the TCV, which was filthy, with soapy water as per a youtube video prior to reinstalling it, but with no noticeable change. Then I test drove the car with the wiring to the TCV unplugged and the surging was much worse along with heavy turbo lag, as might be expected. Basically it was what I am experiencing with the TCV plugged in, just 10 times worse.

So, I wonder, if my TCV can still be bad, even if it seems electrically sound, and whether it must be OEM or if it can be replaced with a new Pierburg, which is almost half the price?

[IainG]

Hi
My V50 has 3 of those solenoids, they are all the same and interchangeable. 1 does the turbo and 2 do the flaps in the air intake "Y" piece

https://www.volvoforums.org.uk/showt...errerid=116256


from the thread

All the solenoids are the same and interchangeable.
They can be tested with 12 volts and you hear an audible click


When I bought the solenoid a few years ago I was told the solenoid on its own was £50 but if I bought it with all the hoses (30757740) it was £29 !!!! The number is described as "Hose" but does actually come with a solenoid as well.!!
so I bought one with all the hoses.