I have a 2005 Chevy 3500 4x4 with the duramax and the allison. It has 97,000 miles on it. Over the past couple months I have been noticing my coolant level to be going down to the point where the low coolant light comes on. I refilled it a few times, also in that time ive noticed that the oil pressure seems to be low. I called the dealer and they said it was within operational range and not to worry about it. Well my days of not worrying about it came to an end last week. The low coolant light came on again so i filled it up. It was time for an oil change so I did that also. When i pulled the plug all that came out for the first 3 seconds or so was milky brown/grey crap then after that pure oil. I instantly called the dealer and explained to him what the problem is. He told me to bring it in, when i took it in they said it could be a head gasket issue and that for the most part is covered under warranty. I then asked him about the noticeable drop in oil pressure. Sometimes at 70 mph it only shows 35 lbs of pressure. He said it could be many things, I have been around engines for long enough to know that oil pumps and proper bearing tolerance is where you get your oil pressure. He told me that even though the coolant was in the oil (i'm not sure as to how long because i change oil when the computer tells me to which is around 10,000 miles) that they cannot under the warranty look into the lower end of my engine. I think that is totally bogus, I did not do anything to make the coolant go into the engine so why should I have to drive around with something that has had coolant wearing the bearing surfaces out when the head gasket issue is the only reason for it to even be a possible issue? How should I approach this, I honestly think its a no brainer to look into the lower end to see if the coolant caused any problems but for some reason they along with a few other dealers dont seem to think so. Am i in the wrong here? Any input would be great.