'93 Overheat Question

I have a friend with a '93 Sentra... Her car overheated a couple weeks ago and she took it to a Sears auto to try to discover what was wrong. She was told that the Heater Core was bad and that was what caused the overheat.

This doesn't seem right to me, but I haven't done much work on cooling systems.

There is no coolant in the floorboard of the passenger side. From my research, it seems like there would be if the heater core was cracked and leaking. Also, I've driven the car and cannot find any leaks in the engine compartment. There isn't even any moisture.

I just need to know if it's possible for a bad heater core to cause overheating. Given the nature of the heater core, it doesn't seem like it is and the Haynes manual doesn't mention it as a cause for overheating.

Thanks in advance for any help you can give.

it could be clogged with murky coolant causing it not to flow well, id have your cooling system flushed...

1.6 or 2.0 liter? just that once? was is a hot day?

low fluid in the rad. poor flow will do this too. give some history plz..

Thanks so much for your replies. My friend is a poor college student (is there any other kind?) and wants to get this fixed for as little as possible while still making sure the car will be reliable.

In answer to your question, yes, it was a very hot day (we're in Texas so most of them are this time of year), I'd estimate high 90's. This is a 1.6 liter. So far, it only overheated that one time, but she stopped driving it after talking to the mechanic because she didn't want to permanently damage the engine.

I offered to do some research and take a look at it for her and didn't have a chance until this weekend. However, in my research, I haven't turned up ANYTHING that would indicate that a bad heater core alone would cause an overheat. And everything I've read indicates that if it were cracked, coolant would be leaking into the passenger compartment... it isn't.

I've advised her to do the radiator flush (either I'll do it or we may get it done at a local shop if it's not too pricey).

Thanks so much for your replies. My friend is a poor college student (is there any other kind?) and wants to get this fixed for as little as possible while still making sure the car will be reliable.

In answer to your question, yes, it was a very hot day (we're in Texas so most of them are this time of year), I'd estimate high 90's. This is a 1.6 liter. So far, it only overheated that one time, but she stopped driving it after talking to the mechanic because she didn't want to permanently damage the engine.

I offered to do some research and take a look at it for her and didn't have a chance until this weekend. However, in my research, I haven't turned up ANYTHING that would indicate that a bad heater core alone would cause an overheat. And everything I've read indicates that if it were cracked, coolant would be leaking into the passenger compartment... it isn't.

I've advised her to do the radiator flush (either I'll do it or we may get it done at a local shop if it's not too pricey).

Well you can do a quick test on the fluid to see what temp. it's good
for too. also I Had a iroc with a stuck thermostat . so I also had checked the fans and the relays too. some more Ideas for you ..
good luck. this will help look for water wetter by red line drops the temp by 20degrees. http://www.redlineoil.com/products_coolant.asp
Chip-

i think a mechanic will flush your WHOLE system not just the radiator, get it all douched out so you know youre flowing better, on a car that old its more than likely, sentras are pretty bulletproof though, so flushing that out might fix her right back up