Hey everyone , Im new to this forum. I have two Pontiac vibes. I bought a 07 about 5 years ago and am very happy with it. So in May, I bought a 09 with about 170,000 miles. I'm not sure exactly what is going on with it. It seems to overheat after driving it about 10 miles. I took it into a garage and they ran a coolant diagnostic test. They said it could use a new radiator cap and a belt. So they put that on but I still have a problem. I checked to see if the radiator fan turns on and it does when it starts to get hot. It also has the VSA Off light that blinks along with the vehicle traction light. So I'm looking for some suggestions. Could it be a thermostat or a clogged radiator
Did you buy the car from an individual that you can politely go back to and ask if they or a mechanic ever put in some kind of stop leak solution into the radiator? That stuff seems to just prolong overheating for a few months at best. If you bought it from a dealer, you'll never get an honest nor educated answer. With as many miles as the car has, it becomes an "in for a penny; in for a pound" ownership situation. Your car (obviously) won't run unless you fix it and you have the option to dump it. I think a new radiator is a reasonable solution, although I'm hoping you can contact the individual you bought the car from and get some insight to the problem.
Honestly, to me that sounds like a classic thermostatic relief valve failure.
People call it a 'thermostat', but it's not - it just opens up at a specific temperature, then closes when it cools. (bimetallic spring)
Do you get any relief by opening up the heat in your car on full blast? Does the coolant in the radiator actually get hot?
You can test some of these by opening the radiator cap and running the engine until it hits normal operating temperature. The return line for the coolant should get warm to the touch. you should see the water moving around once it hits temp and the pump can draw coolant into the engine.
To me, a 'coolant diagnostic test' sounds like hokum. Maybe a system pressure test and a check of the coolant to make sure it's not mostly water or mostly coolant.
A new thermostat is pretty cheap, especially if you do the labour yourself. I'm not sure how the valve is placed on the 09 and up; the 03-08 is a stupid placement (to me). (I just looked at a video of a 2010 matrix. It's still in the same stupid location. Below the alternator. If you change the intake manifold gasket at the same time, you can reach it very easily.) At 13 years old, might be worth changing the top and bottom hoses at the same time.
Hey thanks so much for your input! I really can’t go back to the seller and even if I could I don’t think I’d get a straight answer. The mechanic I brought it to said blown head casket but a friend/ mechanic said to look at the oil because it would be a mix of coolant and oil. I’m leaning towards changing both the radiator and thermostat and new coolant. This would cost about 140 if I can do it myself. What do you guys think…. or . I bought the car for 3000 so I can put some money into it but a head casket may break the bank.
It would be a head gasket, not casket. The gasket separates coolant and oil from exhaust gases. A failure can show up in the oil, coolant, or exhaust. Hot exhaust gases leaking into the coolant can cause a spike on the temp gauge. Clean oil is not a sufficient test. Another easy test is a coolant pressure test, and maybe that was done--try to verify exactly what was done. More difficult tests are engine compression and cylinder bleed-down.
Radiator flow can be tested as outlined above. Don't replace if not needed. Don't do any more work if a head gasket leak is suspected.
It's been a lot of years since I blew a head gasket, but _usually_ you see it as white smoke coming out of the tailpipe, if you have coolant leaking into the combustion chambers. Blue or grey smoke is oil moving into the combustion chambers. Black smoke is screwed up fuel/air mix.
Coolant in the oil makes the oil greyish/whitish foamy, and you see it immediately on the dipstick.
(the wispy white smoke at startup is condensation steaming out. This white smoke is a lot more billowing)
I'd do the radiator flow check before anything else - just watch the tailpipe and see what colour the smoke is as well. (or if there is any at all).
(I went through two heads and three head gaskets on my old Ford Escort. )