Hi, all: 1969 GS 400 - I had my car in the shop a while ago due to some...exciting...brake issues. While it was there, I asked for an oil change, which was done. Can't tell what oil was used, not on the receipt or the 'change by' tag. I've noticed that when starting cold, I hear a knock for a second or two and it seems to take second or two longer for the oil pressure to come up - I'm thinking that the oil weight the shop used is off? After starting, everything's fine, and the shop is run by a guy who was a Buick dealership mechanic for a lot of years, so I would think he'd know what to use. Any thoughts/insights/ideas appreciated. Absent that, I suppose I'll try swapping the oil and see if that helps at all.
Could be the filter as well. The filters for Buick engines must have an anti drain back feature because of the filter position. Most filters do. 10W/40 is the thickest oil I'd use. Hopefully, you have an oil pressure gauge, a real one? What kind of filter did they use? Hope it wasn't a Fram.
Good point - I'll replace both the oil and the filter with good brands. I have an actual pressure gauge added below - not a big fan of relying on the warning lights in a 50 year old car. John
You may also want to get in the habit of spinning it over for a few turns before starting it (as when its cold to get the juices flowing). Maybe the kid at the gas station was revving the crap outa it when it first started? Hate to say it but you may consider dropping the pan and changing the rod bearings (esp. 7&8 before it becomes "an issue"). "Last oiled, first foiled". ws
I turn mine over for a good 30 seconds from cold first start before I even pump the gas so as to get the oil moving and up where it’s needed. After about 20 seconds of cranking the mechanical sounds get quieter and the oil pressure gauge jumps.
