Other XC90 Problem: Excessive smoke (inconsistently)

[NMB]

Hi everyone,

I've recently bought a 2006 Volvo XC90 D5 185bhp AWD with 180,000 miles on the clock and its a great car and ideal for our family of 7. It's a great upgrade for us and were delighted as it was an inexpensive purchase as I bought it with some smoke coming out of the exhaust.

I'm well-read on the forums of the smoke/intake sludge/turbo/rings/valve guides issues/PCV/DPF Soot blockages - however, I don't really know what is the root cause.

The cars behaviours

1) No smoke on startup
2) When warm there seems to be inconsistent smoke(alot) on throttle off but this is only sometimes.
3) There is some smoke on accelerating
4) There is no whistling noise from the engine, breather system or turbo
5) Vida reports only 3 fault codes which are cylinders 1, 3 and 5 glow plugs - these are being replaced today.
6) Vida reports no other engine-related codes.

My plan so far is:

1) I have performed a DPF regen with VIDA and it was successful after 34 minutes - the Soot filter has cleared fro the moment and the car drives normally - DONE.
2) I have replaced the oil and filter with 0 / 40 fully synthetic oil - DONE.
3) I will be replacing the PCV and checking the breather system for any blockages - part ordered and awaiting delivery.
4) I will be taking apart and be cleaning the ERG/intake assembly - awaiting carb cleaner.
5) I was concerned with too much fuel in the cylinders due to faulty injectors but my VIDA reports all injectors consistent with readings of 0.3 through to -.39 - this appears to be very good and normal. DONE
6) I may consider a compression test but as the engine runs nicely and the injectors are reporting constant numbers I don't see the benefit of this immediately - Will do if I'm flummoxed.

I was also thinking about taking out all the injectors and putting some carbon cleaner into each cylinder with a view to change the oil after running the engine for half an hour and to clean out the crap - would this release the oil control rings if they are stuck?

Ultimately, if I need to have an engine change or a turbo then I will have that done (the car was so cheap!) but I hope for an easy fix.

Most importantly I want to identify the issue - can any expert on these forums help with any additional thoughts?

I will, of course, feedback my findings in this post to help others with similar issues.

[dambat]

I would give it a bit of time. If it hasn't been driven in a long while, it can take time to burn all the crap upstream and downstream of the DPF off.

Mine didn't get driven for over 12 months, then blew smoke a bit (particularly during DPF regen) for about 500 kms then came good.

Check your swirl flap also (or at least the position, if it's broken), and keep an eye on your DPF inventory.

[Tannaton]

Welcome....

Hat's off for doing the reading and getting hold of VIDA. We occasionally get new member here with problem cars that seem determined to do a "poke and hope" diagnosis which is by far the best way to empty your bank account very quickly. Fixing faults like this is 90% diagnosis, 10% effort replacing parts so it's great to see someone putting the effort in to understand their car.

However there are two critical pieces missing from the jigsaw...

- What colour is the smoke?

- What is your oil consumption?

[NMB]

Originally Posted by Tannaton

Welcome....

Hat's off for doing the reading and getting hold of VIDA. We occasionally get new member here with problem cars that seem determined to do a "poke and hope" diagnosis which is by far the best way to empty your bank account very quickly. Fixing faults like this is 90% diagnosis, 10% effort replacing parts so it's great to see someone putting the effort in to understand their car.

However there are two critical pieces missing from the jigsaw...

- What colour is the smoke?

- What is your oil consumption?

Smoke is white/blue - not black. So It's definitely was burning oil but since I have done the regen I haven't really driven it (i Regened last night) and I'm sure its better than it was previously.

So like you say it could be clearing the DPF and thus im getting less smoke but I don't feel I've solved the original issue which caused the DPF to clog.

With the codes clear I don't want to drive it really until I have replaced the 3 faulty glow plugs and I'll do that tonight.

As per above, oil consumption is not clear yet as we have just bought the car but there is an oil smell at the back of the car. When buying it and driving home I had to top up the oil but I didn't notice how full the car was of oil on collection.

Long story short, it was smoking on hard acceleration and puffing smoke on throttle off.

Because of how the engine runs and drives I'm suspecting just a worn engine with no major component failing as the car came with a full-service history from new from 4 different garages so it looks genuine and with this service history I don't suspect anything "blowing up" immediately.

I guess my biggest worry is whether it is the turbo?

[SwissXC90]

Glow plugs are only used to start the engine, they have no role whatsoever in the running of the engine, so completely unrelated to your oil problem.

You may have worn oil seals in the turbo, sucking oil into the intake manifold.

Have a look under the engine and see if any oil seepage around the charged air pipe is occurring.
A small amount is normal.
But drips of oil would be abnormal.

Keep track of any report your oil consumption....

And why is a turbo more of a worry than a worn engine?

[NMB]

Originally Posted by SwissXC90

And why is a turbo more of a worry than a worn engine?

I had a turbo go on a Ford Galaxy and when it let go it destroyed the engine!!! So I'd rather know its the turbo and replace that or the engine and replace that - not both if I can avoid it!

I understand about Glow Plugs - I'm just trying to work out what the issue is by removing all posibilities.

[JohnL]

You can do a compression test with Vida, without taking the injectors out. Close to where you check the injector volumes same page.
What is the turbo pressure? You can check this with Vida, and drive and record with some load up a hill.
Oil level on this model is critical, make sure its a bit lower than max level, but monitor it, regeneration can increase the level with excess diesel.
You could close off the vacuum feed tubes to front and rear engine mounts and see what happens.

[NMB]

Hi All,

Firstly, thank you for taking the reply to reply to my messages it's greatly appreciated.

So the update:

1) Glow plugs done and she now starts when cold beautifully and is very smooth on idle.
2) I have driven the car today for about 40 miles and the DPF Soot Filter Full warning message came up at the end of the journey... The car was consistently smoking once the car has been stationary and idling for 5+ seconds - when you rev and pull away there is a cloud of smoke.

Oil is clearly being burnt but on throttle off or acceleration there appears to minimal smoke (if any) it is just after the engine settles on idle and then revs.

Any comments on this behaviour?

My feeling is that it suggests the breathing system(?) as with the rocker cap off there is a loud popping (I have checked the vacuum to the engine mounts and this is not the problem as they hold vacuum).

I have a 600-mile journey planned in a couple of weeks so I need to get to the bottom of the cause - help is of course greatly appreciated.

Nigel.

[NMB]

Originally Posted by JohnL

You can do a compression test with Vida, without taking the injectors out. Close to where you check the injector volumes same page.
What is the turbo pressure? You can check this with Vida, and drive and record with some load up a hill.
Oil level on this model is critical, make sure its a bit lower than max level, but monitor it, regeneration can increase the level with excess diesel.
You could close off the vacuum feed tubes to front and rear engine mounts and see what happens.

I have done the compression test through VIDA and the following values:

Engine Speed Cylinder 1 - 695
Engine Speed Cylinder 2 - 693
Engine Speed Cylinder 3 - 698
Engine Speed Cylinder 4 - 700
Engine Speed Cylinder 5 - 705

With the values all well within tolerance of 675 - 725 (in fact bang in the middle) I'm thinking that the cylinders as are the rings with the fault trace heading to:

1) Breather system
2) Turbo
3) Valve stem seals

Any comments?

[JohnL]

What's the colour of the smoke when idling?
Does it smell of oil or brunt diesel.
I don't know how the regeneration system works unfortunately, but I wonder if the diesel feed to the regen at idle is still letting in diesel, hence knowing the smell may help.
You should be able to read up in Vida how the regen system works, I cannot do that on my Vida as my car doesn't have it, I think it uses the serial number to list the info from the manual, somebody else may be able to confirm I'm wrong.
Are there not any other codes listed?
John