Hey there, Scotty. I'm currently driving a 2016 Nissan Altima (standard), with just over 100k miles on it. I just had a coolant exchange done for its routine maintenance, and a couple days later I noticed my AC cut off on its own. I looked at my temperature gauge and noticed that the level was showing hotter than normal. The next day I checked the coolant level, saw that is was just above the Minimum. I haven't seen any leaks. Test drove it again the following day, and after about 20ish minutes of total run time, it started getting hot again. Drove my car the next day to a mechanic's shop, and the same thing happened. This time I didn't have the AC, but the heater on to max. I did notice the heater was mostly blowing cold air, for the whole ride (48 minute drive). So far, my mechanic has had it for the last few days. He informed me he hadn't notice the car running hot after having the car idle with the AC on, and test drove it a couple times, though he said he would test drive it again, but for a longer distance to see if there was any change.
Any ideas as to what it could be? Thanks for the advice, and keep up the great work! Your videos have been really informative to a young guy like me!
The AC and heater are separate circuits. If your heater is cold, and it worked prior to changing the coolant, there is air in your system. Jack up the car, or find an incline. Point the nose up the incline. Let it cool down. When it cools down, open the radiator cap and start the car. Crank the heat to maximize heat and put the blower to full blast. Gradually start filling the radiator. It will "burp" as you put coolant in. This is air coming out from the heater core. Once it stops "burping" top off the radiator.
@justin-shepherd thanks for the advice!
Got a few updates from my mechanic. Like you said, there was air in the system, a whole lot of it, in fact. However the gauge is still going above normal slightly, and back down.
He added a new thermostat, a new compressor, and will be adding a new water pump, just to see if that’ll change anything/keep the gauge right at the middle as it should. He mentioned to me that while sitting idle with the heater on at full blast, it wasn’t getting nearly as hot as to when he’s driving it. His words, “definitely hot enough to burn my damn finger when I’m driving it.” His main concern is that I may have a bad head gasket, hence why we’re ‘checking down the list,’ to rule out as much as we can.
Will know more next week once the water pump is installed.
He added a new thermostat, a new compressor, and will be adding a new water pump, just to see if that’ll change anything ... we’re ‘checking down the list,’ to rule out as much as we can.
If your mechanic is loading up the parts cannon instead of doing a proper diagnosis that is cause for concern.
Why did he add a new compressor, and are you talking about the AC compressor?
I am with @chucktobias , throwing everything at it to fix it is a very bad and expensive idea.
Did the same mechanic do the initial coolant change, and also then say that there was air in the system the next time?
If a mechanic didn't burp the radiator when you did routine maintenance, I would never go to that guy again, he is milking you for everything he can get. When something breaks a few days after I go to a mechanic, I get suspicious. It isn't always their fault, but when your maintenance was done on the same system that malfunctioned, that is too much of a coincidence for me.
Situations like that are why I do most of my own work now.
@nlord no, I had the coolant exchange and routine maintenance done by Nissan themselves. The issue happened after I had those things done. My mechanic is the one who burped the radiator and found there was a ton of air in the system.
And yes, I’m talking about the AC compressor. At least, that’s what his assistant told me over the phone. It’s possible I may have misunderstood him, since they both work on multiple vehicles at a time.
His main concern is that I may have a bad head gasket, hence why we’re ‘checking down the list,’ to rule out as much as we can.
Will know more next week once the water pump is installed.
Sounds like you should be finding another mechanic. Worn out water pumps will weep, causing a coolant leak. If the water pump isn't leaking, it was more than likely fine. You could be loading the parts cannon yourself and not having to pay a "mechanic" $80-$100 an hour.
@justin-shepherd I’m just curious as to why the gauge would still be moving pass the halfway point then, even after getting all of the air out of the system?
I’m just curious as to why the gauge would still be moving pass the halfway point then, even after getting all of the air out of the system?
If you're driving and the temperature gauge is right in between hot and cold, but when you're stopped and the temperature starts to rise, that indicates a problem with your fan(s).
Your blower/heater core is is similar to a radiator/fan. When the blower is set to max heat, and the heater is full blast, it takes heat out of the engine and into the cabin, cooling the engine down slightly. If your mechanic isn't apt enough to explain this kind of thing, I would be running away!
@justin-shepherd so, good news, somewhat. My mechanic found the problem. Turns out the drive belt was put on incorrectly/backwards by the dealership, when I took the car for that initial routine maintenance. According to my mechanic, it was causing the water pump to operate in reverse, as opposed to how it should have been, if I understood him correctly. He says you can even see the markings that were made on the belt, showing it was put on incorrectly.
Now she’s running normally, according to my mechanic, with the gauge pretty right in the middle, and holding steady. He said he’s going to give it another test run tomorrow, but he’s sure that fixed the problem. He would’ve never had caught that, if he didn’t start doing anything with the water pump. So, it sounds like we found the issue and it’s been solved, on this front.
Turns out the drive belt was put on incorrectly/backwards by the dealership, when I took the car for that initial routine maintenance. According to my mechanic, it was causing the water pump to operate in reverse, as opposed to how it should have been, if I understood him correctly.
The crankshaft pulley is the thing that rotates the belt. It can only rotate in one direction, regardless of the belt's orientation; the starter only cranks in one direction. If I remember right, the belt runs clockwise.
Putting the belt on backwards (the grooved side on the outside) is terrible for it. I'd consider replacing that belt if that's the case.
@justin-shepherd absolutely. Yeah, my mechanic had went ahead and replaced it, before he called me with the update.
Thanks for the continued feedback, along with @chucktobias and @nlord. I really appreciate all of it from y'all.