2001 S10 chevy crew cab. I hear a bubbling sound in heater sometimes, cranks for a few Seco Ds b4 starting? I smelled the oil cap, smells like gas. This truck was just bought from older lady, an only has 60k miles on motor. But I've been reading that these Vortex motors (6cyl.) have alot of these common problems. Any advice? Ty in advance!

 

If you hear bubbling in the heater core, it would seam likely you have an air pocket there. With the engine cold, and the heater turned onto it's highest heat setting, start the engine and fill your radiator until it is full. It may take a few minutes for all the air to be purged. When you say it cranks for a few seconds before starting, are you meaning 2 or 3 seconds which is normal or do you mean 10 or more seconds?

 

The radiator is full. When starting cranks for about 5 to 8 seconds b4 starting.

 

Typically when you hear bubbling in the heater core your cooling system is low. Is there any coolant in the reservoir jug? Remove the radiator cap when your engine has cooled for several hours. (Never remove the radiator cap on a warmed up engine). The radiator should be full. If not then you have a leak somewhere. Fill the radiator with the engine OFF first. Let it settle for a minute or so. The level may go down and you will have to fill a little at a time. When it's full, put the radiator cap back on Then make sure the reservoir has coolant in it at the COLD level. Start the engine. The heater setting is irrelevant on this vehicle. Let the engine run until it is fully warmed up. Shut it down and see if you can see any leaks. The cooling system should have pressure in it now after running it so it's the best time to look for a leak.