Blocked Particle filter and turbo C5

[horsedentist]

Just out of interest I have been told that driving a C5 with a blocked particle filter can blow the turbo is this correct?

[Peter.N.]

Its going to increase the internal pressure on the turbine side but whether it would be sufficient to cause any damage I don't know, I would be interested to know the reason for this assumption. The pressure would still be lower than the oil pressure so what damage is it going to do. I would ask your source for the theory behind this assumption.

Peter

[horsedentist]

I was talking to someone who has a heavy smoke problem with a 2003 C5, and he said the particle filter blocked light had been on for about 2 months when it suddenly started smoking whilst on motorway and went into limp mode. He had it recovered and fitted a new filter and he said quote " i bought new particulate filter £165 there was a warning with it saying fit new turbo as blocked filter damages turbo the after fitting car ran ok but still smokes badly" He now has what he believes is very bad diesel smoke so thinks he needs to buy a new turbo?
Eric

[Peter.N.]

Well the only way the turbo itself can fail is if the bearings/seals go, unless its damaged by a foriegn object in the air intake. If the seals had gone he would be getting blue smoke and if the turbo had failed completely it certainly wouldn't run OK, it would be very down on power. Black smoke could be indicative of low boost pressure but normally under those circumstances the ECU would throttle back the fuel which would would give poor performance.

A note with the DPF says that the turbo would be damaged is very arbitary, there are many people who have replaced clogged DPFs without replacing the turbo and the cars are running quite happily. I would be interested to know exactly what it supposed to do to the turbo.

Peter

[horsedentist]

Apparently the smoke is very very heavy black smoke, it starts ok and runs but he says he hasn't actually driven it since fitting the new filter as he is worried that the seals have gone in the turbo and it is going to suck oil into the exhaust.

[Peter.N.]

Black smoke is either due to over fueling or lack of air, if the seals had gone he would be having blue smoke. Tell him to try disconnecting the air intake from the manifold and trying it, in case there is an obstruction in the system, you should also be able to feel air coming from the pipe if the engine is revved.

Another possibility is a clogged/inoperative EGR valve, this will restrict air to the engine, its possible to clean it but its a messy job.

Peter

[Hell Razor5543]

The colour of the smoke can indicate what the problem might be. Blueish smoke indicates oil being burned, but black smoke could be due to poor air quality or too much fuel. It might be worth checking the air filter.

[horsedentist]

So you don't think it is turbo related then? I think he has more or less given up on it now if it's not the turbo I might have a crack at it myself seems a shame to write it off if it's not too expensive to fix trouble is it is a bit far away to go and put the lexia on it. He seems convinced it needs a new turbo because that's what it said in the particle filter leaflet and I can't get him onto any other track he is convinced it is going to cost over a £1000 to put right.

[Hell Razor5543]

I don't know enough about turbos to give a good answer on this. However, if the DPF had become blocked then the particles have to go somewhere, and (at a guess) they would have got stuck on surfaces before the DPF. If the filters and the EGR are good, it could be worth taking it for a "blaster" run on the motorway to get the crud out. You might also want to use an injector cleaner (something like Wynes Diesel injector cleaner, which Halfords sell for £5.99), as if they start to clog then the fuel doesn't atomise to a fine mist, so it doesn't burn properly, which can also cause black smoke.

The biggest problem you have got is that your friend has lost his trust in the car. Getting that back is going to be the hardest job.

[Peter.N.]

Yes I would agree. The problem is not the particles, they have to pass throught the turbo any way, its the pressure build up due to an obstructed DPF but I still don't believe that this is a common cause of turbo failure, sounds like another money making scheme to me.

Peter

[horsedentist]

As you say the main problem is now no confidence in the car. I might be tempted to trailer it home and have a look ,I need a project for the winter lol.

[Hell Razor5543]

I don't think it would take long. Unless damage has occured (doubtful), you've got 2 months worth of particles to get rid of. Check/change the air filter, drop some injector cleaner into a full tank of fuel, check the EGR (whatever/wherever THAT is) and then take her up the motorway late at night to blow/burn the crud out. With any luck the soot/crud will come out and jobs' a good 'un.

The problem is that we (who don't know better) have to trust that what we are told is true. Recently I had to get the chip in my vans' windscreen repaired. The company I work for pay for the repair directly. I took it to Autoglass who quoted me £85 plus VAT, but when the "expert" looked at the chip he said that it was not repairable; in fact, he said that when they put their repair machine on it, it would cause a massive crack. I accepted their opinion, and did not get the screen repaired. Later I was calling in at a DIY store, and there was a chip repair guy in the car park. He looked at it, said it COULD be repaired, and did so for £25 plus VAT. His equipment was far simpler, but it meant that he had fine control over it. There is a slight blemish where the chip was, but, so far (touch wood) the repair is good. I won't go back to Autoglass (unless told to do so by my employers).

[horsedentist]

I don't think it would take long. Unless damage has occured (doubtful), you've got 2 months worth of particles to get rid of. Check/change the air filter, drop some injector cleaner into a full tank of fuel, check the EGR (whatever/wherever THAT is) and then take her up the motorway late at night to blow/burn the crud out. With any luck the soot/crud will come out and jobs' a good 'un.

The problem is that we (who don't know better) have to trust that what we are told is true. Recently I had to get the chip in my vans' windscreen repaired. The company I work for pay for the repair directly. I took it to Autoglass who quoted me £85 plus VAT, but when the "expert" looked at the chip he said that it was not repairable; in fact, he said that when they put their repair machine on it, it would cause a massive crack. I accepted their opinion, and did not get the screen repaired. Later I was calling in at a DIY store, and there was a chip repair guy in the car park. He looked at it, said it COULD be repaired, and did so for £25 plus VAT. His equipment was far simpler, but it meant that he had fine control over it. There is a slight blemish where the chip was, but, so far (touch wood) the repair is good. I won't go back to Autoglass (unless told to do so by my employers).

Your right there I have been there before as well did mine with a diy kit cost a tenner.

I have a lexia so I could have a good look in it before I did anything and see what it thought was wrong with it's self

[horsedentist]

took lexia over and did a stationary regen even though it had new filter, with a double dose of wynns cleaner in tank . No smoke now !

[Hell Razor5543]

I'd still do a "blaster" run up the motorway to make doubly sure, but it looks like you've cracked the simple job. Now convince your friend that his car is now working, is reliable (provided he takes note of warnings), and can be trusted.