# 2001 Nissan Sentra 1.8L Overheating



## avellone5 (Apr 20, 2015)

My 01 Sentra has been overheating more and more rapidly every time I drive it (haven't driven in a week out of fear of making it worse). A few months ago, it wouldn't start and we had a mechanic replace the crankshaft position sensor, fuel pump, spark plugs and put fuel injector cleaner into the system, and it finally began starting again but it overheated after a 15 minute drive when I got it back. The heat was blowing out cool and it overheated fairly quickly. We replaced the thermostat but that didn't solve it and now I'm wondering if it is the water pump? There don't seem to be any leaks on the hoses, and there was coolant in the radiator, also the water pump was making a sort of whining noise when the car was running. Again, I haven't driven it a lot at all recently so the coolant hasn't leaked, and the radiator fans were working. I've been having problems with this car for a solid two months now so I'm desperate to fix it, but don't have a ton of money to work with :/ oil looked fine and there didn't seem to be any white smoke from the exhaust either so should I rule out a blown head gasket?

Also the heater makes a whining noise when on full blast


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## icu1954 (Feb 11, 2011)

*overheating*

blown head gasket


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## avellone5 (Apr 20, 2015)

icu1954 said:


> blown head gasket


Any reason to believe that? I don't want to jump to conclusions that it's the most expensive repair


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## icu1954 (Feb 11, 2011)

pull your spark plugs when the engine is cool and shine a flash light into the spark plug holes and if you see where it is wet in there and plugs look damp or wet then it is a blown head gasket.You said the heater was blowing out cool air well that is for sure a blown head gasket.I had all of these same problems on my 02 sentra,i replaced the head gasket and no more of those problems.


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## avellone5 (Apr 20, 2015)

I'll have to do that this week (it's raining pretty hard today), but when I got my car back a couple of weeks ago, it still wouldn't start. The mechanic told me to bring the plugs in so he could clean them and when I put them back in, it started right up. If it does end up being a hg, around how much would it cost? I don't know if I could do it on my own :/


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## icu1954 (Feb 11, 2011)

any where around 300-500 dollars for a decent all around mechanic.Not a stealership,because you would be looking at $1200 up.


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## avellone5 (Apr 20, 2015)

That's no where near as bad as I thought it was going to be


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## SPEEDO (Jun 9, 2003)

you should be able to tell by looking at the plugs


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## SPEEDO (Jun 9, 2003)

air pockets in the system??


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## avellone5 (Apr 20, 2015)

It's STILL raining here lol, if I can I'll try tomorrow or thursday, but after that I'll be out of town for the weekend. Does it matter if it's been sitting for a while (to check the plugs)?


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## SPEEDO (Jun 9, 2003)

pull the plugs when you can, check the color


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## avellone5 (Apr 20, 2015)

I pulled the plugs out today when it wasn't raining, and it seemed pretty dry, but I haven't run the car in a week. Should I start the car and let it run for a few minutes before checking, or does it not matter?


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## jdg (Aug 27, 2009)

If you've got a blown head gasket, and it's leaking water into the cylinder, generally speaking, one (or two if the leak is between cylinders) of those plugs is going to be a fair amount cleaner than the rest.


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## SPEEDO (Jun 9, 2003)

what color are the plugs??? blk, brn wht etc


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## avellone5 (Apr 20, 2015)

They were white if I remember correctly. It started to rain as soon as I pulled them out, I can't check again until tuesday because I'll out of town this weekend


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## avellone5 (Apr 20, 2015)

Sorry it took me so long to get back, while I was away, my dad bled the cooling system, drove it about 7 miles and said it didn't overheat at all. We skipped over that in the first place lol, so that is the first place to start next time something like that ever happens. Tomorrow, I am going to do a flush and put new coolant in


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## rogoman (Dec 16, 2004)

avellone5 said:


> I've been having problems with this car for a solid two months now so I'm desperate to fix it, but don't have a ton of money to work with :/ oil looked fine and there didn't seem to be any white smoke from the exhaust either so should I rule out a blown head gasket?


A good test to run for a blown head gasket is called a cylinder leak down test; it consists of a gauge set. You'll need a large air compressor for an air supply. By applying compressed air to each cylinder in turn (with that cylinders intake & exhaust valves closed) you can isolate the faulty cylinder. ***{make certain to open your cooling system (radiator cap etc.) so you don't over-pressurize it & blow a radiator, seal,etc.}*** LOOK FOR BUBBLES. 

You can also perform a block test, Many auto parts stores sell this kit. It looks like a big ear dropper, it extracts vapors from the radiator filler neck, if the blue solution that you add to it turns yellow then that indicates a blown head gasket or coolant entering your engine.

As an alternative, take a sample of the coolant and go to a local radiator shop and request that they analyze the coolant for the presence of hydrocarbons. If they are present then it is most likely that you have a blown head gasket.


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## avellone5 (Apr 20, 2015)

I drove it yesterday after my dad bled the system; went 25 miles without overheating at all, and then my brother drove it another 25-30 today with the same results, thanks the for the help though!


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