I have a 08 Tahoe Hybrid, Early this year I start to hear ticking noises came from the engine, I thought it's time to remove the cylinder deactivation system, so I brought to a shop to do this job, then we found that there's coolant in oil, the head cracking issue should only applies to 01-06 engines, should not happen on mine, so could anyone help me figure out what's the possible issue?

 

coolant in the oil is usually a sign of head gasket failure.

 

Need to do a compression test with all plugs out and at least do a coolant flush and oil change, asap, if you are going to drive it at all. How was it determined that coolant was in the oil? You can also have an intake problem.

 

I will clean the undercarriage first. Wish I could hire someone to do it for me. Such a nasty job. Is it OK to use a degreaser? And what about that dye stuff? 🤔 I was told I could add something to the oil that would help identify where I'm leaking. I just dont like putting anything other then oil in it ya know. It's going to take some time to clean up the mess under there. I'll do that and change the oil and filter. Check back with my findings. Im new to all this so I'm slow.