[extrabigjon]

I have a suspicion I might have a castech cylinder head leak. Bought the truck in November 2012 with 57,210 miles and now has almost 66,700. The water pump was leaking and it was replaced shortly after purchase. Even after replacing the water pump the coolant reservoir slowly drops. I've add just over four gallons of dexcool mixed 50/50 with distilled water over time since owning it. I change the oil every 3,000 miles or slightly less. I think it may have been leaking coolant before I purchased it.

My question is how much damage, if any, may have been done to the engine by now.

 

[barrrf]

You MAY have scarring on the walls from the freeze keeping the oil from lubing the cylinder walls.

I have a suggestion for you - go get the GM Coolant Tabs from the dealer and put them in your coolant - see if the disappearing act stops.

A guy I work with did that - his truck would knock and belch a huge cloud of blue smoke. Put those tabs in 3 years ago and has not had a problem one since.

These fkn things - [ame]http://www.amazon.com/Genuine-3634621-Cooling-System-Tablet/dp/B000QIH3C4/ref=sr_1_1?ie=UTF8&qid=1416000933&sr=8-1&keywords=gm+coolant+tablets[/ame]

 

[Graystone]

Pin hole in the radiator is possible too

 

[Mathew Hulsey]

You MAY have scarring on the walls from the freeze keeping the oil from lubing the cylinder walls.

I have a suggestion for you - go get the GM Coolant Tabs from the dealer and put them in your coolant - see if the disappearing act stops.

A guy I work with did that - his truck would knock and belch a huge cloud of blue smoke. Put those tabs in 3 years ago and has not had a problem one since.

These fkn things - http://www.amazon.com/Genuine-36346...1416000933&sr=8-1&keywords=gm+coolant+tablets

New to me. Never heard of these before.

 

[jerd]

If you've got a head leaking coolant into the combustion chamber, you can typically tell. Performance will degrade, the exhaust will smell sweet and be more visible, as well. Also, when you loosen the oil drain plug, if there is coolant in the oil, it should start to come out before you get the plug out.

 

[extrabigjon]

No noticeable drop in performance. The mechanic I have do the oil changes and lube never says there is anything unusual about the oil. Should I do anything to "flush" out the oil? Read a few places that say to change the oil at 1000 mile interval three times to get the coolant out.

 

[jusdragit]

Send your oil for an oil analysis, it's cheap and then you will know 100% if there is coolant in the oil.

 

[Mathew Hulsey]

Im also throwing codes p0171 p0174 any way thats related

 

[extrabigjon]

I have a kit and will try and get it done this weekend with the "warmer" temps.