MTBSully

Started my car up 2 days ago after i finished my head gasket swap and i let it idle for 10-15 min while i bled the cooling system. Everything seemed good to go. Then yesterday i decided to check my oil real quick and it looked like a milk shake! I dont understand how this could happen, i just put in fresh felpro 1074s, and used arp head bolts torqued to 75ft lbs in three steps. I am going to try and change my oil tommorow and see what happens but i am really hoping its not the gasket again. Otherwise, i will have to take it to the shop to have it done becuase im not going to do this a third time. I have always run synthetic in my car, but if i do 1 or 2 oil changes just to clean the motor out will i be okay to use conventional? Sythetic is awfully expensive just to clean the motor out. Thanks guys.

Stl94LT1

Did you have the heads checked to see if they were warped?

irocbsa

+1. Gaskets don't seal well on a surface that isn't true.

MTBSully

i didnt get them checked becuase the car was never overheated at all. The only reason i took the head off in the first place was to fix a stripped spark plug hole. I cleaned the heads and block with a razor blade, scotch brite and some brake cleaner.

If i change the oil a few times its not going to hurt to switch back to conventional just for an oil change or two is it? (Just to clean the motor out)

Stl94LT1

Oh, thought maybe you had a blown head gasket.

YodiBrodi

others, are LT1 's similar to SBC1 in regards to some of the head bolts go into the water jackets? if they are, then did you seal those particular bolts? that would definitely allow water into the oil.

onebadponcho

OK. You drained the oil before you took the heads off right? I'm assuming you got some antifreeze down the bores when you took the heads off and possibly stayed in the oil pan, and ended up mixing with your new oil.
When you do your oil this time, save some $$ and use regular oil for the time being. Hopefully the problem will be due to what I said.

MTBSully

i hope this is true as well. I used Permatex thread sealant on all of my bolts. Will keep you guys updated.

Andrew@MarylandSpeed

Keep an eye on your coolant level, and the color of your coolant, and the color of the oil after the oil change.

pearlpurple

Hopefully you just contaminated your oil. Yes you can use regular oil to flush the moter. In fact I would use the cheapest oil you can find that is what I did when I did my heads and I had blown a head gasket. I ran it until it reached operating temp dumped it then put synthetic back in.

I have to ask this though: your heads are they cast iron or aluminum, I am assuming they are aluminum and if so I have been told that any time you pull a set of aluminum heads they might require trueing back up (shaving). I think this is even more possible since on the LT1 we bolt aluminum heads to a cast iron block and the two metals expand and contract slightly different in the heat and cool cycles.

I would:

- change your oil to flush the system then change again,, keep using regular oil until you have determined that the problem has gone away
- check coolant levels frequently
- run it lightly and watch fluids closely and note that oil with coolant in it are not bearing friendly
- if you continue to have problems remove heads and have them checked by a reputable shop as if you continue to have issues more than likely the heads are warped as you said you haven't o/heated so cracks in my opinion are less likely.

Kevin Blown 95 TA

He could always retorque them and add some GM sealing tabs in the coolant system like they tell you to in the manual.