To make a long story short I got a great deal on a 95 z28 from the back lot at a car dealer,they said the motor was gone but it sounded like just a blown head gasket.It run but had a miss and the oil looked good at the time,on the way to the garage the gasket blow competely leaving the oil milky.I replaced the head gaskets had a local shop did check them and worked the valves.Everything checked out great but I noticed after starting the car ,letting it warm up and driving down the street.When I checked the oil level it looked a little milky,is it just some of the old mixed with the new oil and how many back to back oil changes should I do before I start to worry something else is wrong?

 

I would do it at least a couple of times, but be very careful and not let the engine run to long without checking your oil for coolant. I wouldn't even drive it, would let it run a little bit and check the oil, hopefully it gets better after each change.

 

Should I have the coolant system flushed.When I had the heads off I looked into the coolant passage ways the best I could and they didn't look bad.I don't want to pay to have it flushed if it don't need it.Not know the history of the car I don't know what else I am going to have to replace.

 

if you had antifreeze in the coolant your bearing will be going soon. should take one rechange of oil if that. the water will burn off when motor warms to operating temp so if you are seeing coolant after a rechange im gona say there is probly still an issue.

 

After the gasket change,It was ran about 10 min. And it looked milky but I changed it one more time ran it a few minutes and had to go but I started it today and ran it about 10 minutes,looked at it and it had a very slight milky tint but not near as bad as the first change after the repair.Now I am wonder if I should have the coolant system flushed and pressure tested.I put a new thermostat in it too.I not sure why other than the last guy wanted a cold motor at all times but when I went to put in the new thero it didn't even have one,how long should it take for a lt1 to start to warm up?

 

Depending on outside temperature, from 2 to 30 minutes. Like at 17* F. it takes longer than if it is 60* F. outside.

 

At this point you should just changing the oil seveal times. Your garage should have warned you the motor could be damaged from the coolant in the oil.

Do a pressure test on the coolant system hot and cold. You can borrow the pressure tester from most cahin type parts stores. If the oil keeps getting milky either the shop screwed up or the block is cracked. The shop should have done the pressure test after the headgaskets where installed.

 

Which side of the Rocky Mountains are you Cody.

 

I in va,I didn't have a shop do the repairs I changed the head gaskets but I did have a shop rework the heads and it's a 95 z so what's the chances of a cracked block.I thought the iron block was less likely to crack.I asked about warm up time because it's been years since I had an lt1.With already having issues when I bought it,like thermostat missing, blown head gasket,radiator cap seal broke,when putting it back together I found the coolant sensor was missing,I am just trying to still figure out what is wrong with it.It sounds great ,runs good now just trying to get all the water out of the motor without trying to spend 200$ in oil changes ,so you think I should change it again for the second oil change?

 

Even trace amounts of coolant in your oil can cause damage. I would change the oil and fliter until there was no trace. But only after the pressure test. Use the cheapest car grade oil and filters you can find. Once everything is sorted out go with the better oil and filter.

GM says 20 mins at idle to reach full temp. That whould be atleast 2 fan cycles. The engine will reach its hotest point about 1-2 minutes after it is shut down.

Yes Cast iron blocks crack. We had blocks cracking long before GM started making them out of Aluminum.


Note: I said car grade oil because I have seen cheap 5 quart jugs of API SA oil. This should not be used in any internal combustion motor. I am not sure what is common now but any letter greater then SE would be fine for idle.