[Lakes]

Hi all this was a hot subject few years back.
A Guy who lives near me put a camera inside his air intake to check how sooty it was, from some of the exhaust getting redirected back into motor. it was filthy . so removed it to clean it out & clean other hardware mounted to air intake.
i told him i could not see it making a huge difference, but wondering what the pistons & combustion chamber & valves look like ( but he was not going to pull head off)
i'm wondering what the high K i30 CRDi's look like inside air intake & heads after all that diesel exhaust being redirected back through the motor?

[Asterix]

Agree, it would be interesting to have a look inside. Mine have now done 248000 km and I use one of those cleaning agents once or twice a year to clean the internals, but who knows what it looks like..

I don't own a camera that can get inside the intake and I'm too much of a tight arse to pay someone to do it..... at least as long as the engine runs great... 

[sundiz]

Was the intake manifold removed? I cleaned the egr and the egr gas cooler but not the intake manifold. The cooler was so dirty I assume that the manifold would be in same condition. I'll have to see if I have time and motivation to clean the manifold next summer. What I have seen pictures of pistons in other cars there have been some carbon over the piston but not like in the egr. I assume that the burning of the fuel cleans the cylinders a bit compared to egr and intake manifold. Hard to say about the valves. Seen some dirty ones and some fairly clean ones. I used borescope with my petrol merc and there were some carbon on the piston and it did not even have egr. You can see pictures of my i30 egr: 1.6crdi (2008) DIY servicing: Coolant, EGR, cleaning, brake & clutch fluid etc.