The car:
96 Saturn SL1 manual transmission, $800 used car with a little over 100k now showing on the odometer. The oil change history is unknown.
It was burning more than a quart per 1 thousand miles in "average" driving conditions, and getting noticeably worse.
Driving at "interstate speeds" resulted in consumption of 1 quart or more in 500 miles or less.
At WOT anything over 4 K RPM was leaving behind a blue haze from the exhaust.
Thicker oil (15W40) didn't measurably reduce oil consumption.(surprise for me)
There was considerable blow-by from the PCV opening in the cam cover at idle.
Opening the throttle resulted in a LOT of white blowby out the PCV opening (no missing coolant).
Yes I know about the cracked SOHC heads.
Treatment:
After cleaning around the spark plug openings with compressed air then carb cleaner I removed the spark plugs.
The plug electrodes were heavily contaminated with greyish black deposits.
I used an aerosol can carburetor cleaner and extension nozzle to spray a liberal dose of solvent into each spark plug hole. I used almost the entire can for this.
Next I poured a tablespoon of MMO through a suitable funnel into each spark plug hole.
The MMO is to replace the oil washed away by the carburetor cleaner.
After this I cleaned, re-gapped, and loosely reinstalled the old spark plugs.
After allowing the pistons to soak for about an hour I used the accessory drive belt to move the crankshaft a few degrees in both directions.
I repeated this each few hours to loosen carbon and distribute the solvents.
After about 10 hours I removed the spark plugs and placed shop towels across the spark plug openings. I weighted the towels down with a small tool box.
Using the starter I turned the engine over for about 8 seconds or so until the solvent was expelled.
I noted that the shop towels had a considerable amount of carbon "chunks" deposited on them afterwards.
Replacing the plugs and plug wires I cranked the engine at WOT until it caught and gained RPM.
Then I let it idle until it came up to operating temperature then changed the oil and oil filter.
After the first treatment there was a noticeable increase in low RPM torque.
Hills that had previously required WOT or a downshift to 4Th could now be pulled at 1/4 throttle in 5Th!!
Blow-by was noticeably reduced as was oil consumption.
After @ 2 K on the oil change I decided to repeat the piston soak with Berrymans B-12 Chemtool substituted for the generic (WalMart brand) carb cleaner.
This was done with with all else being the same.
After the second treatment blow-by is down to nothing.
Oil consumption looks like it will be less than 1 quart in 2 k with 10W30 Defy oil in the sump.
A small portion of the consumption is from an oil pan gasket leak (no oil spots in the driveway, pan stays a little oily).
The jury is still out but I believe I see a significant improvement in gas mileage now as well.
Overall a worthwhile improvement in oil consumption and engine performance.
Your mileage may vary. (pun intended)
Rickey.
96 Saturn SL1 manual transmission, $800 used car with a little over 100k now showing on the odometer. The oil change history is unknown.
It was burning more than a quart per 1 thousand miles in "average" driving conditions, and getting noticeably worse.
Driving at "interstate speeds" resulted in consumption of 1 quart or more in 500 miles or less.
At WOT anything over 4 K RPM was leaving behind a blue haze from the exhaust.
Thicker oil (15W40) didn't measurably reduce oil consumption.(surprise for me)
There was considerable blow-by from the PCV opening in the cam cover at idle.
Opening the throttle resulted in a LOT of white blowby out the PCV opening (no missing coolant).
Yes I know about the cracked SOHC heads.
Treatment:
After cleaning around the spark plug openings with compressed air then carb cleaner I removed the spark plugs.
The plug electrodes were heavily contaminated with greyish black deposits.
I used an aerosol can carburetor cleaner and extension nozzle to spray a liberal dose of solvent into each spark plug hole. I used almost the entire can for this.
Next I poured a tablespoon of MMO through a suitable funnel into each spark plug hole.
The MMO is to replace the oil washed away by the carburetor cleaner.
After this I cleaned, re-gapped, and loosely reinstalled the old spark plugs.
After allowing the pistons to soak for about an hour I used the accessory drive belt to move the crankshaft a few degrees in both directions.
I repeated this each few hours to loosen carbon and distribute the solvents.
After about 10 hours I removed the spark plugs and placed shop towels across the spark plug openings. I weighted the towels down with a small tool box.
Using the starter I turned the engine over for about 8 seconds or so until the solvent was expelled.
I noted that the shop towels had a considerable amount of carbon "chunks" deposited on them afterwards.
Replacing the plugs and plug wires I cranked the engine at WOT until it caught and gained RPM.
Then I let it idle until it came up to operating temperature then changed the oil and oil filter.
After the first treatment there was a noticeable increase in low RPM torque.
Hills that had previously required WOT or a downshift to 4Th could now be pulled at 1/4 throttle in 5Th!!
Blow-by was noticeably reduced as was oil consumption.
After @ 2 K on the oil change I decided to repeat the piston soak with Berrymans B-12 Chemtool substituted for the generic (WalMart brand) carb cleaner.
This was done with with all else being the same.
After the second treatment blow-by is down to nothing.
Oil consumption looks like it will be less than 1 quart in 2 k with 10W30 Defy oil in the sump.
A small portion of the consumption is from an oil pan gasket leak (no oil spots in the driveway, pan stays a little oily).
The jury is still out but I believe I see a significant improvement in gas mileage now as well.
Overall a worthwhile improvement in oil consumption and engine performance.
Your mileage may vary. (pun intended)
Rickey.
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