For anyone running the 3.1/3.4 L GM engines I highly recommend getting an
oil analysis done of your used motor oil from time to time. I started doing
so about nine months ago, and the most recent analysis came back with clear
signs of coolant getting into the oil.
Luckily our '02 Olds Silhouette had the included GM extended warranty which
covers to 5 years, 60,000 miles. Our van was at 2.5 years of age and 41,000
The oil analysis caught coolant traces well before there was any visible
sign of water mixed with the oil. This is good as very little bearing
damage had a chance to happen.
The dealership was excellent about checking out the problem and fixing it at
If you have one of these vehicles I strongly recommend periodic oil analysis
to find the problem early before major engine damage happens.
I get mine done by Blackstone Labs, www.blackstone-labs.com . Cost is $20
and they will mail you sample containers free of charge.
Other than my customer relationship I have no ties to Blackstone or any
other oil analysis place.