2006 Chevrolet Colorado moisture in oil

[geardriven74]

I am currently working on an 06 Colorado with a 2.8 4 cylinder engine. I have noticed moisture in the oil since the truck was bought last year. At first I thought there was nothing to be concerned about because I have read that these motors have a common problem with moisture in the oil. But this time when I took the oil filter off the oil looked kind of like chocolate milk.

So I started to tear the engine down. When I took the valve cover off there was a very large amount of milky oil. All of the cam lobes are pitted with surface rust.

I replaced the valve cover gasket last year and it looked good then.

I am preparing to remove the cylinder head next.

The engine has about 130,000 on the odometer.

Has anyone else had a similar problem?

 

[Ramblejam]

Have you installed the updated 190°F thermostat?

 

[geardriven74]

No Sir. I didn't know of it.

 

[geardriven74]

I'm assuming I would need to buy it from GM?

 

[SOHCman]

Wow, so these engiers can ruin themselves from what, not getting up enough temperature to cook off moisture/condensation? And the 190 tstat makes them warm enough?

 

[Ramblejam]

Originally Posted By: geardriven74
I'm assuming I would need to buy it from GM?


http://amzn.com/B004942LSM

"I bought this thermostat for my 2004 Colorado which having a low cooling temp at normal run around 170 deg F (test with scan gauge II). With this replacement my engine temp showing around 198~200 deg which should be the normal operating temp. So far this stat working good with around 8K miles since replacement."

I'm assuming you haven't noticed any coolant usage?

 

[geardriven74]

It is losing some coolant slowly.

 

[volk06]

Originally Posted By: geardriven74
It is losing some coolant slowly.


That right there my friend is the issue. Its not just moisture. Theres coolant getting into the oil to cause that pitting and the milky color.

 

[Ramblejam]

Originally Posted By: geardriven74
It is losing some coolant slowly.


Is this your vehicle, or a customers/one you're working on?

Have you inspected the cooling system to determine where the leak is occurring (external/internal engine)?

 

[geardriven74]

I'm sure it's an internal leak.

 

[SteveSRT8]

That is a sure sign of head gasket failure, or impending...

I have seen that start VERY early with just a tiny bit of condensation and the slight smell of coolant under the oil cap...

 

[foresthawk]

Seems like leaking head gasket, hopefully not also warped head.

 

[The_Eric]

Originally Posted By: foresthawk
Seems like leaking head gasket, hopefully not also warped head.


Why? They're easily fixed. A trip to the machine shop to have it crack checked/ pressure tested, surfaced and cleaned is SOP for ALL the heads I do.