Car is overheating. Making a hissing noise near throttle body.

My car usually runs cool but today the temp jumped to like the M on normal, which I didn't like at all. It went past the M after I parked the car and let it run. I turned it off and it was making a hissing noise on the passenger side of the car near the two front-most injectors. The hissing lasted for at least 3-5 minutes. I tried wiggling the injectors around and prodding around all the hoses to see if I could make the hissing increase or decrease but nothing really changed it. The upper radiator hose was still pressurized though, it wasn't limp. I'm not sure what that hissing could be coming from... it just sounds like air escaping I couldn't find any coolant leaking and there was no steam.

I just had the same thing happen 2 days ago.Check your heater hose that runs by the injectors on the passenger side.Mine had cracked thus the hising and overheating.when I found that hose it was over a 100$becase it runs into that metal fitting ,Ijust cut the old hose off and clamped a new one on.good luck.

I'll double that diagnosis. Same thing happened to me, it was the 90 deg rubber hose that runs from the metal line (along the valve cover) up to the temperature sensor. You can remove the hose by cutting off the crimped collar and then go to your local parts store to match it up & use a regular hose band to secure it. Also a good time to check the rubber hose at he other end of the metal line, where it goes to the heater core (same condition).

Well the only reason your upper radiator hose was pressurized was because of the hot coolant (which is normal), but doesn't indicate that all is fine. How about the lower hose was it pressurized? If so, that could indicate a stalled water pump. But, I know I'm a noob, so the other guys are probably right, I just wanted to put in my .02.

Edit: Or maybe your thermostat is sticking. If your thermostat is stuck, your bottom hose might be collapsed, but maybe not. I just thought of this since you said that your upper hose was pressurized and that your car instantly was hot. It could be because of 0 coolant flow, thus causing hisses since the expanding coolant has no where to go.

Mikey851 said:

Well the only reason your upper radiator hose was pressurized was because of the hot coolant (which is normal), but doesn't indicate that all is fine. How about the lower hose was it pressurized? If so, that could indicate a stalled water pump. But, I know I'm a noob, so the other guys are probably right, I just wanted to put in my .02.

Edit: Or maybe your thermostat is sticking. If your thermostat is stuck, your bottom hose might be collapsed, but maybe not. I just thought of this since you said that your upper hose was pressurized and that your car instantly was hot. It could be because of 0 coolant flow, thus causing hisses since the expanding coolant has no where to go.

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Thanks guys! I plan on replacing the thermostat this weekend while I change that heater hose. I'll check to make sure the lower hose isn't collapsing either.

Is it difficult to change the t-stat on these cars? I've done 5.0 t-stats millions of times...

Terrible Juan said:

Is it difficult to change the t-stat on these cars? I've done 5.0 t-stats millions of times...

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One of the easier jobs on these cars Replace your by-pass hose while your'e at it.

I'm glad I could help.I think it's the first time I knew what I was talking about I know car quest has the hose with the correct bend, but I do not remember the part #