Symptoms:

Increased oil use , changed turbo for new one , since then : thick white smoke from exhaust , took back to garage and they said new turbo is faulty so they fitted another new one. Picked car up and it’s still throwing out white smoke especially once warmed up and under load. Also now get a warning for low coolant level and p0030.

Any ideas anyone please.

2017 superb 1.6 diesel.

Thanks

Is the engine actually losing coolant? If so, how much?

Could be faulty head gasket or cracked head - has the engine been overheated?

Have the remaining coolant tested for combustion products and have the cooling system pressure tested.

I haven’t noticed any coolant loss externally but I’d say it’s losing around half a litre every couple of weeks. Not overheated so far

If I recall correctly, white smoke from a diesel indicates burnt coolant - although I'd expect more than 0.5 litres being used if the smoke is as heavy as you indicate.

Have the coolant tested for combustion products and locate source of loss.

Was the engine losing coolant before the turbo was replaced? If not, possible that your garage has created a leak in its cooling circuit and then repeated mistake.

Did the turbo replacement fix the oil use issue?

Edited 16 May16 May by Warrior193
question

New turbo did not fix the oil leak , garage now suspects the seals between the rocker cover and the injectors. Wasn’t having any coolant loss before the new turbo .

According to Rosstech Wiki, P0030 indicates a problem with the Lambda sensor - Open circuit Bank 1, Sensor 1. This will certainly cause fuelling issues - but I'd expect the ECU would overfuel, which would cause black smoke!

The cause of that DTC could be something as simple as a broken wire at the sensor connection.

I'd stick with your white smoke being coolant getting burnt.

Stinks of oil though

Fix the Lambda issue first, then investigate further for the coolant loss.