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Traffic 1.6 dci 2015 Coolant Pressuring not circulating

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38K views 51 replies 20 participants last post by  bradwright9797  
Interesting thread.

@steve inv.eng I'm puzzled why, if it was exhaust gasses pressurising the system due to fail(ING) head gasket, why wasn't this picked up through detecting exhaust gasses in coolant?

I'm assuming your failing turbo was leaking oil into inlet gasses and causing the carbon build up your referring to? I guess oil vapour from crankcase venting would do the same i.e. be a source of carbon build up.

Surely if EGR cooling tube is blocked by carbon, that reduces gas recirc back to engine. As I understand it, the gas recirc is used to reduce combustion temperatures in the cylinder by reducing the oxygen in the cylinder and thus reduces NO2 generation.

So if EGR cooler blocked, no exhaust feedback to combustion process leading to higher cylinder temps and probable cause for HG failing. I guess similar effect as fitting EGR blanking plate.

I don't understand why a blocked EGR coolant tube would cause "loss of heat transfer to coolant." Perhaps you could explain? Sure, blocked coolant pipes to the EGR coolant tube would.

My interest here with respect to improving my understanding in this area better to ensure my replacement Espace engine (3.0dci) doesn't suffer from overheating (which is common) and displays many similar symptoms as on here.

I'm thinking it may be best to replace crankcase venting into the inlet circuit with an oil catch can and blocking the crankcase vent to the air inlet circuit.

I know a number of people have issues with EGRs coking up. Perhaps oil vapour in crankcase vent is root cause and which can lead to localised cylinder overheating ultimately leading to HG failure.