Doing research for my water/antifreeze in the oil found that mechanics and chevy knew the intake manifold gasket is probably the cause.
No warning very lucky to find just before a long trip, last thing before trip had planned to change oil and discovered we had a problem, oil the color of rusty milk.
Tested head pressure all cylinders above 170 psi, tested radiator, cap was bad but pressure testing showed radiator wasn't holding pressure spotted drop of fluid at the #12 bolt for the lower gasket.
Proceeded to isolate radiator and found it held pressure overnight, slowly took engine apart and the upper plenum gasket looked good until it separated on peeling off, removed the intake and found plasitic gasket had deteriorated at both ends, plastic warped and cracked surrounding the water passages.
After replacing gasket, flushed radiator and engine 3 times with distilled water(Florida house a/c has a constant flow of condensate water) sponged up the oil trapped above the cam shaft, replaced filter and had 2 gallons of relatively clean used oil, took a short camping trip 50 miles to test system, monitored motor temperature and it ran 194-199 without tow so on return trip towed pu and temperature was the same.
Used the scangauge to get temp as the dash gauge works but difficult to interpret dial, gauge is marked 100 degree first mark, actual numbers are 160 and the running temp looks like 150 when it is actually 194. Today changed the oil and filter again and added antifreeze. Yes, I replaced the bad radiator cap before the trip, and using antifreeze at 50/50 for 265 degree protection more than it's freeze temp. Pictures will be in next post.
No warning very lucky to find just before a long trip, last thing before trip had planned to change oil and discovered we had a problem, oil the color of rusty milk.
Tested head pressure all cylinders above 170 psi, tested radiator, cap was bad but pressure testing showed radiator wasn't holding pressure spotted drop of fluid at the #12 bolt for the lower gasket.
Proceeded to isolate radiator and found it held pressure overnight, slowly took engine apart and the upper plenum gasket looked good until it separated on peeling off, removed the intake and found plasitic gasket had deteriorated at both ends, plastic warped and cracked surrounding the water passages.
After replacing gasket, flushed radiator and engine 3 times with distilled water(Florida house a/c has a constant flow of condensate water) sponged up the oil trapped above the cam shaft, replaced filter and had 2 gallons of relatively clean used oil, took a short camping trip 50 miles to test system, monitored motor temperature and it ran 194-199 without tow so on return trip towed pu and temperature was the same.
Used the scangauge to get temp as the dash gauge works but difficult to interpret dial, gauge is marked 100 degree first mark, actual numbers are 160 and the running temp looks like 150 when it is actually 194. Today changed the oil and filter again and added antifreeze. Yes, I replaced the bad radiator cap before the trip, and using antifreeze at 50/50 for 265 degree protection more than it's freeze temp. Pictures will be in next post.
0 commentaires:
Enregistrer un commentaire