Hello all. I have a difficult question regarding oil drain-back and viscosity in regards to a dohc GM 3.6L. I own my own automotive business and I run into oiling problems pretty frequently, however, this one has me stumped. I personally replaced all three timing chains, two idler gears, guides, and tensioners on an '04 CTS. The chains were obviously stretched and had already damaged the primary chain tensioner, all of the guides, and the crank shaft sprocket. I was led to this initial diagnosis due to the typical constant timing chain racket and a cam position code. After I completed the job, I test drove the car for about 65 miles. I then let it sit overnight, and fired it again the next morning. Everything was fine. However, when I started the car today to do some weekend cleaning at the shop, a rattle was evident upon start up. Knowing how dangerous this can be, I shut the car off and cranked it a while. After doing so, she fired and continued to run silently.
I pride myself to run a VERY honest business. This job cost the customer close to 2200 bucks and I won't charge him a penny until it's right. I filtered the oil today and found no traces of bearing material. It was evident upon tear down that oil changes were anything BUT frequent for this vehicle. The engine has 140k on it and I am OUT of the recommended 5w30 oil. In fact, the ONLY synthetic oil I carry is 10w-40 and VR1 20w-50 for the race cars I build. I used 10w-40 upon re-filling the crank case. Could this be a problem? Also, I used a run of the mill oil filter (canister). To my knowledge, there is no drain-back feature attached to any oil filter for this vehicle. Could I be wrong again? Thanks for the help in advance, Josef.
I pride myself to run a VERY honest business. This job cost the customer close to 2200 bucks and I won't charge him a penny until it's right. I filtered the oil today and found no traces of bearing material. It was evident upon tear down that oil changes were anything BUT frequent for this vehicle. The engine has 140k on it and I am OUT of the recommended 5w30 oil. In fact, the ONLY synthetic oil I carry is 10w-40 and VR1 20w-50 for the race cars I build. I used 10w-40 upon re-filling the crank case. Could this be a problem? Also, I used a run of the mill oil filter (canister). To my knowledge, there is no drain-back feature attached to any oil filter for this vehicle. Could I be wrong again? Thanks for the help in advance, Josef.
