2001 GMC Sierra 1500 Q&A
2001 GMC Sierra 1500 Question: my 2001 gmc / 5.3 has an antifreeze leak.
I have put in a new water pump, flushed coolant and put in new antifreeze. There has not been any water in the oil. The cooling system was tested. There was no co2 in the coolant and it keeps pressure. I am lost as to where the antifreeze goes. The surge tanks stays fine for days then will start going down. - roxanne2001
No "C0" in cooling system, that is good. Have system pressure tested, may have to let pressure stay on for a while. Maybe with engine running, poss. intake gasket. But this eng. isn't known to have any intake H20 leaks. Also while under pressure look closely at radiator! No water in oil is also a good thing as that means no cracked heads or gaskets! I say external leak. - pushrod
some of these eng have defective cyl heads and crack around valve springs which will cause this issue. pull the valve covers and look around valve springs for cracks or a wash area that is clean from oil residue - globalhelper