the only proper fix is to replace the head gasket, a fast and easy fix is to add packet of ground black pepper to raiator , that will stop the leak untill u have time to get it fixed
Your transmission fluid is probably leaking into your coolant
Leaking coolant, making noise or engine overheating.
Bad thermostat, Low on engine coolant--( coolant leak ) Cracked head, Leaking head gasket,
You may have a bad head gasket and it may be leaking from that. Why when cold i dont know, but if you are losing coolant it may be the head gasket.
If you are sure that it did not freeze and crack the block, Then the intake manifold gasket is leaking. That is a common problem with the vortec Chevy engines. You need to replace the gasket with a factory Chevy gasket from the dealer.
Sounds like the head gasket may be leaking to allow the coolant to get in the oil but it it still sealing well around the cylinders. Yes, lower intake manifold gasket is probably leaking. Very common in 1997 and 1998 models. Good engine, just needs sealed up.
Two main causes for this on a SL's SW's or SC's are 1) a leaking PCV hose from the valve cover to the intake 2) a faulty coolant sensor ( yellow and black wires) by upper coolant hose Other possible causes are a leaking intake gasket or throttle body gasket. Hope this helps-
Bad head gasket
The intake manifold are very bad about corroding a hole in them which means that you will have to replace it.
it might be the intake gasket
usually that problem is caused by a leaking head gasket. The only way to find out is to have a mechanic do a leak down test on all cylinders. This will tell you which cylinder is leaking.
Blown head gasket.