GMCtrk

iTrader: (27)

When I got the 6.0 in, I didn't have any coolant, so we just put straight tap water in. It's been like this for about 2.5 months. How bad is this? I know I need to flush it before it gets cold anyways.

krambo

iTrader: (4)

Tap water has alot of minerals in it that will scale along with rust the coolant passages not to mention there is no "lubrication" for the water pump. If you used a few bottles of Water Wetter, you would be somewhat O.K. however still run the potential for scale and corroding the passages. Personally, I would dump the Tap water ASAP to avoid further corrosion. If you were only using Tap water temporarily (such as to drive to the auto parts store to pick up some glycol) you might be O.K.

trever1t

iTrader: (14)

+1
Flush it and add coolant.

quicksilverado

iTrader: (8)

I use tap water every summer. Never had any issues. I do have an aluminum block though.

trever1t

iTrader: (14)

even worse. The oxides that will form and corrode passages will cause you troubles later. Aluminum oxides are no better.

GMCtrk

iTrader: (27)

so my engine is screwed?

What problems will present in the future?

trever1t

iTrader: (14)

no not scewed, just drain and add the proper coolant. Tap water has minerals in it which will solidify and eventually corrode and clog the passages not to mention it has no corrosion preventive chemicals to rust also forms and solidifies. If you have no access to coolant add distilled water but never tap water.

TXsilverado

iTrader: (19)

your saying to fill with 100% coolant?

trever1t

iTrader: (14)

if it comes pre-mixed. otherwise follow the instructions on the label

budhayes3

iTrader: (19)

A 50/50 mix of engine coolant and distilled water is a good rule of thumb...I usually get the pre-mixed stuff myself...