[Z06] Oil Cap + coolent
Thread Starter
Instructor
Joined: Jan 2009
Posts: 144
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Oil Cap + coolent
Hello, first post on this forum
Looking to pick up a Z06 in the next while and have checked out and test drove a few local vehicles.
Of two cars (different sellers) that I recently viewed both had some condensation under the oil cap as evidenced by milky oil residue. On the second car I cleaned up the residue prior to the 30 min test drive (included about 10 hard pulls to redline, 2nd through 4 gear). After the test drive I opened the cap again to see that more residue had built up. Observations include that the residue was more watery then usual for coolant, didn't smell sweet or anything and wasn't slippery like coolant. Also, the oil on the dip stick looks clean and the car ran well.
So whats the deal? The dealership says it's just condensation from moving the car in and out of the shop every night. We checked a few other vehicles which are moved around frequently but not driven (motor only runs for a minute or so) and they also exhibited some milkiness.
Am I going krazy here? I've always interpreted this to mean the is a head gasket issue, but I've always owned Honda's and Toyota's in the past, maybe some domestic or LS6 thing.
Temperature was around the freezing market, maybe -5 Celsius. -10 the previous night.
Looking to pick up a Z06 in the next while and have checked out and test drove a few local vehicles.
Of two cars (different sellers) that I recently viewed both had some condensation under the oil cap as evidenced by milky oil residue. On the second car I cleaned up the residue prior to the 30 min test drive (included about 10 hard pulls to redline, 2nd through 4 gear). After the test drive I opened the cap again to see that more residue had built up. Observations include that the residue was more watery then usual for coolant, didn't smell sweet or anything and wasn't slippery like coolant. Also, the oil on the dip stick looks clean and the car ran well.
So whats the deal? The dealership says it's just condensation from moving the car in and out of the shop every night. We checked a few other vehicles which are moved around frequently but not driven (motor only runs for a minute or so) and they also exhibited some milkiness.
Am I going krazy here? I've always interpreted this to mean the is a head gasket issue, but I've always owned Honda's and Toyota's in the past, maybe some domestic or LS6 thing.
Temperature was around the freezing market, maybe -5 Celsius. -10 the previous night.
Race Director
Joined: Jan 2006
Posts: 10,554
Likes: 33
From: Not on either liberal coast.
The dealership was correct. It occurs especially during the cooler/colder seasons. Just starting the car briefly for demonstrations and in/out of the shop doesn't allow the oil to warm up sufficiently to burn off naturally occurring (from combustion) condensation. You should see the same thing at the exhaust with moisture dripping out of the tailpipes.
It's generally recommended not to even start the car during hibernation unless you can take it out for a few miles to bring everything up to operating temperatures. That will reduce or eliminate the condensation problem.
Water in the oil is not good for bearing lubrication, so if it's significant, you would need to change the oil/filter more often. If you end up buying one of the cars, make sure the oil/filter are changed immediately.
It's generally recommended not to even start the car during hibernation unless you can take it out for a few miles to bring everything up to operating temperatures. That will reduce or eliminate the condensation problem.
Water in the oil is not good for bearing lubrication, so if it's significant, you would need to change the oil/filter more often. If you end up buying one of the cars, make sure the oil/filter are changed immediately.
Safety Car
Joined: Jan 2006
Posts: 3,940
Likes: 43
From: shavertown Pa.
If you had a head gasket problem the oil on the stick would be a milky grey, what you found is normal for a car that only moved short distances and never really comes up to temp for a long period of time.
After you drive the car for awhile the mositure will evaporate, even with new oil you will find that moisture untill the car is driven more frequently or brought up to temp for a good while.
If you look under the master cyl caps for the clutch and brake you will find the same thing, I dry my caps out everytime I use the car.
After you drive the car for awhile the mositure will evaporate, even with new oil you will find that moisture untill the car is driven more frequently or brought up to temp for a good while.
If you look under the master cyl caps for the clutch and brake you will find the same thing, I dry my caps out everytime I use the car.
