Ok so I have a 305 in my 22 year old GMC pickup truck. Overall the engine runs extremely well and only has 87,000 original miles. I plan on keeping it for a long time.
I did the lower intake manifold gaskets recently and when I had the intake manifold off the valley of the block was sludged up. I think part of that issue was coolant was getting in there which was most likely contributing to the issue. I very carefully cleaned what I could but didn't mess with any of the larger chunks since I didn't want that clogging up the oil pump.
I did an oil change with some semi synthetic castrol 5w30 and the lower end purolator filter with the plan to do an OCI at 500-1000 miles to get whatever gunk that was left over from the intake gasket replacement.
When I had the valve covers off to change the gaskets, the top of the heads/rockers looked really good with minimal carbon deposits. I was actually impressed with how clean it looked after 22 years of unknown OCI's.
Anyway I am wondering if I should do another very short OCI with cheap oil and filter or if i should get an oil that has more of cleaning detergents in there next (like PUP)
I did the lower intake manifold gaskets recently and when I had the intake manifold off the valley of the block was sludged up. I think part of that issue was coolant was getting in there which was most likely contributing to the issue. I very carefully cleaned what I could but didn't mess with any of the larger chunks since I didn't want that clogging up the oil pump.
I did an oil change with some semi synthetic castrol 5w30 and the lower end purolator filter with the plan to do an OCI at 500-1000 miles to get whatever gunk that was left over from the intake gasket replacement.
When I had the valve covers off to change the gaskets, the top of the heads/rockers looked really good with minimal carbon deposits. I was actually impressed with how clean it looked after 22 years of unknown OCI's.
Anyway I am wondering if I should do another very short OCI with cheap oil and filter or if i should get an oil that has more of cleaning detergents in there next (like PUP)