Hi guys,

I got a internal coolant leak on my duramax lmm 09. I just changed all 8 injectors due to water in fuel, and right after that, I have experienced hydro lock (truck was not Cranking at all) and there was a loud knocking sound at low RPM's. I have a big white smoke cloud when I cold
Start it and white smoke disappear after engine is getting warm. I have noticed a coolant leak (lost about 3 inches for 1600 miles trip). Oil level looks fine. Now my question is: is there anyway to break something in the coolant patherns during the injectors replacement? I had no problems before I brang the truck to the shop. I have red that possible causes are head gasket, engine block or cylinder crack or egr system. I have done the deletes and I have a efi live tuner. Truck runs good, does not everheat has a good fuel economy.

Can you help me?


GMC SIERRA 3500 2009 SLE DURAMAX SINGLE 4x4 DPF-EGR deleted 230000 miles

 

leaking cylinder head gasket, cracked cylinder bore or cylinder.
Possable to break something during the injector replacement, yes it is possable.

 

I know you had stated that the oil level is fine, IF we can double check it may be possible the water pump is allowing coolant to get into the oil. Just a thought.

 

usually bad head gasket makes a lot of white smoke. it also solves my internal coolant leak. overheating engine really deteriorate a lot of parts in the engine. good thing my cylinders and water pump are still working but i guess it will be the next part to wear out. damn.

 

My first guess would be the head gasket. The later years have better gaskets but on the earlier years it was uncommon for it to leak anywhere else