Hi, my truck has been weird lately and id like to solve the problem on it. So here are a few symptoms...
1- Couple of weeks ago, ive noticed some kind of golden metal shaving in my coolant, did some research and found out that someone might have added stop leak. At this point i didnt have any heating issue.

2- its cold as hell here in canada so i use a remote starter in the morning to heat it up, temperature gauge shows that the engine is warm but no hot air comes out of the heater until at least 2 minutes drive.

3- yesterday i was stuck in trafic, again the heater stoped working and i noticed the engine temp was above than normal until i got out of the trafic, then the heater started to work again.

so this morning i looked at my coolant level when the truck was cold and it was low so i added about 1/2 gal.

So my question is where all that coolant went if irs not leaking ? It sounds to me like a head gasket is going but dont really know how to be sure. Also ive noticed a gas smell in the coolant. Doesnt make white smoke. Thought it would be the waterpump or thermostat but since my coolant level was low and it smells like gas im think it could be a headgasket. Any idea how i can tell ?

 

There are at least a couple of ways you can determine if the head gasket is leaking. One way would be to purchase at combustion gas detection kit for the cooling system, or find a friend/shop that already has one. With that you can determine if combustion products (exhaust, etc.) are making it in to the cooling system. You can also use a cooling system pressure tester to pressurize the cooling system to confirm there is a leak somewhere (if the pressure drops). This makes it easier to track down a cooling system leak without having to work on a hot engine.

The lack of heat as you described in lines 2 and 3 above could both have just been due to the low coolant level. Have you checked the passenger and driver's floors under the floor mat to see if they are damp with coolant?

-Rod