So I was driving home the other day and I could hear my car making a whining noise. Its done this in the past but not usually while I'm driving. I then noticed my heat was blowing cold. I reached forward to feel it and as I sat back down, I looked at the gauges and my thermostat was all the way up to 260! I pulled over on the side of the road and there was coolant all over the bottom of the engine. Would be a blown head-gasket? Or could it possibly be my heater core? Please help!

 

Could be coolant elbows that leaked all the coolant out or very bad lower intake gaskets or head gaskets. Either way if it got to 260 in my eyes that engine is toast...

 

Could just be the water pump gasket too, they sit relatively low and near the belt. Was there coolant thrown all over the engine bay at all?

 

There was coolant all over the bottom of my motor. I just went out and filled it back up. Let it run for 10 minutes and it leaked nothing. So I took around the block (6 miles) and I beat it and rode it hard. It didn't over heat or leak anything!!!! What happened!? BTW, I have 186,xxx miles.

 

First step, get a loan a tool radiator pressurer tester. This will let you leak test the cooling system. I would start with ruling out a leak.
If it IS a head gasket, your temp reading could have been false (air pockets mess with the temp sensor). And if it is a head gasket, the cylinder compression gases could over pressurize the cooling system.

I dealt with this on a 3100 on my old Grand Am (which is the same basic motor on your 3400 Monte).

If you are dealing with a blown head gasket, prolonged over compression can cause further repairs (in my case, blew the gasket on the side tank of my radiator).

Letting the car sit over night, when you start it cold, does it have white smoke coming out the exhaust?

 

No white smoke. But I also just found some leaking gas at my fuel pressure regulator. Looking into retiring the Monte and getting a newer Grand Prix series 3.

 

My car once hit the "Hot" message on the dash and she is still running fine so I wouldn't call er done just yet... I did, however, she her down quickly and put a big industrial fan on her till she cooled down. Stupid smog guy is like "does she normally get this hot"; what an idiot...

Your heat was blowing cold? But your temps read were off the charts?

 

That is a sign of an air pocket OR very low coolant. There is no coolant in the heater core when it goes from blowing hot to cold like that. Hot air does not open the T-stat well and causing crazy hot readings on the temp sensor.

The Monte might not be done, but it depends how much work you feel like putting into her. It sounds like possible head gaskets.... But you would first have to do a leak check and make sure something easier is not being over looked.

 

I just drove over 20 miles today and it did fine! No leaking (other than my fuel pressure regulator) and temp didnt over heat and my heat worked. I did, however, have to cut my hose leading from the reservoir to my radiator. Someone had replaced it sometime and didnt trim it to fit properly and it was kinked and not allowing as much flow. So maybe that was it? I dont know. If it acts up again, shes done. But hopefully things turn out and I can pick up a Cadillac CTS this weekend. If not, Ill just fiix her up!

 

A kinked hose is certainly not going to help things. Here's to hoping it was nothing more then that.