S80: Engine Problems won't go away. What else could there be?

[venomtail]

"scan tools reveal codes & offer guidance as to what the issue(s) may be"

The problem is no scan tool that I had, could read any of the codes. The best I could get was live diagnostics data. I haven't tried the VIDA/DICE made for volvo's so I can't comment on those.

I mainly go to one mechanic, however he said he does not have the gear to check injector functionality nor have the time back then to redo all of the wiring if need be. Went to a few different places. One place could check the injectors without me having to take everything appart and delivering the parts seperatley. Injectors are fully functional after testing, so the problem must be elsewhere. Next step is a compressions check but the new garage did not have the gear needed to do compression tests on my engine size, so they recommended I go elsewhere, otherwise they'll need to take appart the engine which will be costly, looking at the hours they ask for.

Went back to my mechanic but he also does not have the gear. He knew a guy who did however, and after a few phone calls he found out that they closed a while ago. He later found a guy who does have the stuff needed for a compressions check and is able to do it.

But in general I don't tend to go for the corner mechanic shops. I try and stick to my volvo specialist mechanic, but since he does not have everything needed, I don't have a choice but to look elsewhere.

[Kev0607]

Originally Posted by venomtail

The problem is no scan tool that I had, could read any of the codes. The best I could get was live diagnostics data. I haven't tried the VIDA/DICE made for volvo's so I can't comment on those.

I mainly go to one mechanic, however he said he does not have the gear to check injector functionality nor have the time back then to redo all of the wiring if need be. Went to a few different places. One place could check the injectors without me having to take everything appart and delivering the parts seperatley. Injectors are fully functional after testing, so the problem must be elsewhere. Next step is a compressions check but the new garage did not have the gear needed to do compression tests on my engine size, so they recommended I go elsewhere, otherwise they'll need to take appart the engine which will be costly, looking at the hours they ask for.

Went back to my mechanic but he also does not have the gear. He knew a guy who did however, and after a few phone calls he found out that they closed a while ago. He later found a guy who does have the stuff needed for a compressions check and is able to do it.

But in general I don't tend to go for the corner mechanic shops. I try and stick to my volvo specialist mechanic, but since he does not have everything needed, I don't have a choice but to look elsewhere.

I hope you find another garage that can do the work for you. Ask them if they're equipped with VIDA/DICE too.

[Laird Scooby]

Originally Posted by venomtail

Diesel.
Can really a full sensor make my car go in limp mode where it struggles to get uphill? One full DPF filter to cripple a car seems like a really extreme safety measure?

If a dpf filter is full it basically blocks the exhaust system and yes, the sensors failing and telling the ECU the DPF is full can cause limp mode, lack of power and so on.

A few questions - when was the timing belt last changed and has the injector timing been checked since? Also has the cam timing been verified as being correct?

Hang on, scrub checking the injector timing, this is the electronic engine.

Check all your hoses between the air filter and inlet manifold and also your intercooler for internal blockages.
White smoke is usually a sign of oil burning which would most likely come from the turbo, however it could also be water content in the fuel, have you drained the water from the fuel filter? There should be a tap underneath for this.

Has the fuel tank been drained and fresh diesel added instead?

If all the above checks out ok, add between 0.5-1.0L of synthetic ATF to the engine oil. This will help free off sticking valves, sticky hydraulic tappets, sticking piston rings, revive oil seals and so in generally cleaning and improving the engine internals.

It won't give instant results, the car needs to be driven but it's worth a try.

I always run both my beasts with at least 0.5L of synth ATF added when i do the oil/filter changes, my 760 gets a full litre as it takes 6L to fill the sump so it works nicely on a quantity basis that way. My other beast is 4.5L total fill so gets 0.5L of ATF then 4L of engine oil,

As yuo seem to be running out of options with electronic diagnosis, going back to basics with a few old trade tricks might be the way to sort it.

[venomtail]

Seems I have forgotten to mention this but the timing belt was changed along with the rest of the adjustments when it snapped earlier in the year. How can I forget such a vital thing? But the timing was all correct and verified. That was done before we went to the Volvo dealership and they made our car non running.

DPF filter was changed to a new one along with all the tubes and sensors. Turbo has been checked and is fully functional. Last time I checked I coudn't find any air blockages, but that was ages ago and can't remember what I checked and didn't.

I'll just find out what the compression test discovers and see where we go from there.

[RM955I]

The timing belt snapped? Can you be sure there’s not valve damage? Normally a snapped timing belt trashes the head: you’d be very lucky to escape damage.

[Laird Scooby]

If valve to piston contact has occurred and you've been lucky, the valves won't be bent. However it's possible the hydraulic lifters/tappets aren't pumping up corrrectly so the valves aren't opening properly.

If the compressions are generally low, try what i suggested further up with the synthetic ATF as this will help clean the gum/residue inside the lifters that may well be preventing them filling up. You may still have to remove all the tappets one by one and prime them in an oil bath (use synth ATF to make life easier) especially if priming them was omitted at the rebuild stage.

[venomtail]

Came into to check what's new and was told that the compression check has been done. Was completely prepeared to be told there's leak and will be expensive but I was told that the compressions are pretty much perfect, especially considering the age and milage of my engine. If I remember correctly at most there was a pount of pressure difference between all the cylinder. Even the one that does not work.

So the pressure check found nothing. Nothing at all.

What did appear was a new "DPF filter full" message, after some 6 miles of driving since the installment of the new one with all of its sensors. Which is just wrong. Impossible.

Where everyone is at, is that every part checked runs fine yet the car does not.

What was suggested to go from here, is to reset everything on the cars computer again and to check for any build up anywhere. Another cleaning specialist checked the DPF filter that the car is saying is "full" and found that it's perfectly clean, showing all of the numbers correcty. Also checked the injector, they're fine. The one thing left to check is the exhaust portion after the exhaust manifold.


But after that there's nothing really left. The engine (one cylider) still won't run. No power when the pedal's down.

Will hopefully get the car home after the next check. Might get the DICE/VIDA diagnostic scanner out of curiosity, since I doubt my £80 scanner will find something that a £8k specialised volvo scanner won't.

Will give an update if the cleaning specialists found any forms of blockades/build up anytwhere.

[Laird Scooby]

There will be a sensor somewhere on/near the DPF to tell the ECU that it's full/blocked. Chances are this sensor is TARFU so needs replacing then the codes resetting. It will deliberately limit the power available as it senses (rightly or wrongly) that the exhaust/DPF is blocked so it restricts the output to prevent further blockages or worse.

That said, given how many problems "seem" to be present it might be worth getting the ECU checked and/or repaired :

https://www.atpelectronics.co.uk/

I think it's about £40-50 for testing which is refunded against the repair if you have it done. They guarantee the repair for life as well which is handy.

[venomtail]

Nice thanks. I'll check out the site you have recommended.

However all sensors on/near the DPF filter were changed to new ones, as well as the ECU checked itself. There was no water damage, damage and all the connections themselves were fine. And the parameters or whatever gets reset when the DPF filter was changed, but I did ask one mechanic to reset everything if they have the chance.

[Tatsfield]

Originally Posted by venomtail

Nice thanks. I'll check out the site you have recommended.

However all sensors on/near the DPF filter were changed to new ones, as well as the ECU checked itself. There was no water damage, damage and all the connections themselves were fine. And the parameters or whatever gets reset when the DPF filter was changed, but I did ask one mechanic to reset everything if they have the chance.

Perhaps it's as well to be suspicious of work carried out directly relating to the area of the now evident fault. Are the sensors the correct ones, are they fitted correctly, are they functioning correctly? Worth thinking about as it is a coincidence that this fault is present now.