What did you do to your NBS GMT800 Tahoe/Yukon Today?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

BG1988

Full Access Member
Joined
Nov 14, 2018
Posts
2,967
Reaction score
1,350
Still stressing about the used oil analysis tests showing coolant in my oil. I have also noticed signs of coolant or moisture on the bottom of my oil fill cap, but NOWHERE else. But two tests two YEARS apart showing coolant in my oil? WTF is going on? Could it be such a small amount of coolant that it doesn't quite get a chance to do any harm because I change my oil regularly? Because of that, plus the fact that it's my daily, I'm still driving it. I just hope nothing bad happens before I get the chance to investigate it further. I'm off half a day on Saturday, so I'm planning on taking the valve covers off to see if I see any signs of milkshake oil. Truck still runs perfectly fine, doesn't run hot at all, and the oil "appears" to have absolutely no coolant in it on the dipstick and when I drained it from the oil pan. I guess I need to double check and make sure I don't have the dreaded Castech heads. I could have sworn I checked for that a few years ago when I last replaced the valve cover gaskets. That was around 2012 I believe.
just don't use any sealant with sodium silicate aka water glass
 

ScottyBoy

Full Access Member
Joined
Jun 27, 2010
Posts
2,609
Reaction score
1,822
Location
Shreveport, La
just don't use any sealant with sodium silicate aka water glass

If never add any shit like that to my coolant. Lol
But a small update, I did take the valve covers off to inspect the heads. ZERO signs of coolant on either of the heads. No milkshake, no peanut butter, and no areas that were abnormallly clean or shiny. The ONLY sign of coolant or moisture was on the bottom of the oil fill cap. I'm starting to wonder if my oil got contaminated a while back when the plastic "T" at the heater core broke and sprayed coolant EVERYWHERE in my engine compartment. I've only changed my oil twice since then, and although it's far less,it's still showing trace amounts of coolant. I'm going to inspect the cylinders next as soon as the borescope camera comes in that I ordered off eBay. And I'm going to send in another oil sample after that, regardless of how many miles. I only have about 800 miles on this oil so far.
My lower intake gasket (the plate with the knock sensors) is leaking, so it's QUITE possible that coolant seeped in through that gasket when the T fitting exploded. But I still won't feel comfortable until I inspect each cylinder, and get a few more oil analysis tests done.
 

Forum statistics

Threads
132,717
Posts
1,873,140
Members
97,543
Latest member
Gates_21_Tahoe
Top