Carbon clean?

Solus · 19 Oct 2017 at 20:11

So I had a blown turbo pipe in my Renault grand scenic 1.6 dci. I replaced the pipe but the same symptoms were there, an air leak elsewhere I thought.

Garage took a look today and said the turbo vanes are stuck on max causing the car to enter limp mode. Makes sense. He's going to dismantle and clean the turbo of carbon.

Main thing I want to know is, is there anything I can do to help this in future? I don't go on massively long journeys but I do give it a good boot once a week at least on the dual carriageway / motorway.

Will the diesel fuel additives help? I do normally only buy from supermarket fuel stations, is there any actual evidence that the other stuff is better for my car?

My thoughts are based on the dpf, if I've got issues with the turbo now (5 years old, 60k mileage) then what will the dpf be like.

andy_mk3 · 19 Oct 2017 at 20:15

Solus said:
I don't go on massively long journeys

Buy a petrol.

Nasher · 19 Oct 2017 at 20:16

Carbon buildup is the big problem with some direct injection engines, especially diesel ones. I had a turbo explode in an Audi A3 around 80k miles because of what I suspect was buildup. It slowly chokes the engine to death and expensive things start to go wrong.

I think additives help, but it won't clean behind the injectors (as the fuel can't reach there). So they won't clear an already clogged up engine.

Solus · 19 Oct 2017 at 20:34

andy_mk3 said:
Buy a petrol.

Find me a decent petrol 7 seater mpv (new, not an old zafira) with 3 isofix points and I have my replacement car in a year's time

Nasher · 19 Oct 2017 at 20:40

Ford Galaxy 1.5 or 2.0 petrol?

andy_mk3 · 19 Oct 2017 at 20:45

Solus said:
Find me a decent petrol 7 seater mpv (new, not an old zafira) with 3 isofix points and I have my replacement car in a year's time

Galaxy or S-Max come to mind, 2.0 Ecoboost.

Solus · 19 Oct 2017 at 20:54

I shall take a look in to them. Test drive perhaps as I need to check if they would lack power. Thanks!

I've noticed there are mobile carbon cleaning companies, is this all a load of bull?

andy_mk3 · 19 Oct 2017 at 21:13

Solus said:
I shall take a look in to them. Test drive perhaps as I need to check if they would lack power. Thanks!

I've noticed there are mobile carbon cleaning companies, is this all a load of bull?

They do a 240PS version, they are by no means slow

Personally I've never believed in this carbon cleaning. I have seen the inside of an engine after this treatment was carried out and didn't cure a fault, didn't look like any of the build up of carbon had been touched.

Solus · 19 Oct 2017 at 22:49

What about petrol turbos? Still better to steer clear?

andy_mk3 · 20 Oct 2017 at 16:10

Nothing really wrong with a petrol turbo, they don't really clog up like a diesel.

Ryan-3 · 20 Oct 2017 at 17:54

Solus said:
I've noticed there are mobile carbon cleaning companies, is this all a load of bull?

If you want the problem dealt with, you need the carbon deposits walnut blasted. I had my head done on an R56 Cooper S, as they're notoriously bad for build-up on the intake side as that's where the deposits aren't burnt off. It ain't cheap, but sure is effective.

Nasher · 20 Oct 2017 at 23:02

It can happen on any engine with direct injection, not just diesel. Some are just cleaner than others though.

Some engines have port injection as well which should prevent it. But from what I can see it's mainly the Audi and Ford V8/V6s, as well as Subaru's flat 4 and Toyota engines.