Originally Posted By: Nick1994
Merk, please take off a valve cover on your Buick and post a picture of what it looks like. I'm dying to know since you tell us all that our extended OCIs are making a filthy engine. I'd like to see what an engine that has been overly-serviced looks like under the valve cover.
Well, I just purchased a 1991 Chevrolet Silverado, 4.3 V6 engine, 85550 miles. The school I work for purchased it in 1995 with about 58k on the odometer. I was able to obtain the service records. The oil used was Amoco 10w/30. OCIs were every 6-8 months, Napa Gold filter. The average mileage per OCI was 1500-1800 miles, with some OCIs as low as 1000 miles. The engine shows heavy varnish at least. I cannot see any signs of sludge, but I cant say the engine is spotless. Around 27k miles in 20 years.