Here’s the latest reader question, along with my reply!
Tom asks: I found out from my mechanic that there is a service bulletin out about my 2007 LaCrosse CX describing an oil leak at the valve seals (I’ve been using about 4 ounces of oil a week). Well, a $900 valve job buys a lot of oil, so I’ll let it ride. Would it be good, and is it possible to get copies of all the GM service bulletins issued for my car? It might give me a heads up on possible problems.
My reply: Technical Service Bulletins (TSBs) are sent out by manufacturers – the car companies – to dealers and so on, to “hip” them to potential maintenance/repair issues that crop up after the vehicle was manufactured – and possibly not covered in the original service manuals. I’ve pasted below a screen shot of some of the sources for TSBs and agree it’s sound policy to stay up-to-date this way.
The 3.8L likes to leak out of the valve covers (oil) and intake gaskets (coolant). Valve seals aren’t very expensive but – labor.
I have stopped oil usage on a few vehicles, my Z 71 included, at past 200,000 miles using Amsoil. I used Amsoil crankcase/transmission cleaner first and then used Mobil 1(cheap at Wally)with an Amsoil filter to clean the engine for 4,000+ miles and it was filthy when I drained it. I then started using Amsoil, the Real Deal I call it. It went nearly 6,000 miles and used a quart, the next change it went 6,000 miles and used very little. Since then I have put as much as 16,000 miles on it with minor oil use but never down a quart. Since then it has used NO oil. Don’t know where the LS was using oil but I’d suspect the valve seals.
Amsoil isn’t magic but it’s as close as I’ve seen in my life. It would certainly be worth trying it rather than to continue using oil that is “used” by the engine. Whattaya got to lose?