Need Help Fast!!!!

[Sygerwulf]

Alright, I know this should probably be in the tech forum, but since it isn't a Nissan I wanna get as much feedback as possible.

My girlfriend's 94 mx-6(v6) is overheating. About 2 months ago the waterpump went out and we replaced it, so I'm assuming it isn't that. What's happening is the coolent is just backing up into the resovoir and coming out of the overflow hole. It was so bad it would start overheating a minute after you put coolent in it, so I figured the thermotstat had completely closed up. so yesterday I replace the thermostat. Now it will drive for about 15-20 minutes before it starts to overheat and force water out of the overflow tank again. What's going on here?! I've heard that sometimes you need to boil a new thermotstat before you put it in to make it open up. I'm getting very confused. I checked the oil for coolent and coolent for oil and there was none. Its had a rough idle for a while, but the mechanic told us that it was a back crankshaft sensor. Any and All suggestions will be GREATLY appreciated!!!!! A bad headgasket wouldn't make it overheat this fast would it????

[Mr1der]

you'd b surprised what a bad head gasket can do.

check your oil and see if it looks milky from coolant mixing in it

[PROJECTRB240SX]

ARE THE ELECTRIC FANS TURNING ON? IS THE RADIATOR PLUGGED? THERE ARE NUMEROUS THINGS THAT CAN BE WRONG. I SUGGEST CHECK TO SEE IF THE FANS ARE TURNING ON, AND PULL THE RADIATOR AND HAVE IT RODOUTED.

[flyfishz]

Themostat installed upside down would cause it to close instead of open as engine warms up. Might be that simple...

[Sygerwulf]

The oil looks fine, no discoloration. Yep, the fans come on fine, and the car didn't overheat when I let it sit and idle this morning for about half an hour.

How can I tell if it's in upside down? The thing looks the same all the way around??

[flyfishz]

flip it and see it overheats... watch the temp closley.. let us know how it goes...Also Try taking the thermosat out completley...should take a while it warm up that way if everything is flowing well.

Sometine you just get a bad thermostat in the new too.

[Sygerwulf]

Will it overheat with the thermostat out? lol logically that sounds like a rather stupid question but I just wanna make sure

[UncleBen]

You goon. Sell that stupid Mazda and get her an s13. Its as simple as that.

[UncleBen]

And if you have the thermostat out, no it wont overheat. There is nothing there to stop the coolant from flowing into the motor, so if there is nothing to stop the coolant from going into the motor, then how could it overheat?

[Sygerwulf]

hey I've only slept like 5 hours in the last 3 days gimme some slack, I work 3rd shift That's what I thought but you never know with bass-ackward mazda.

And I would, but now that there is a baby on the way she wants a 4-door.

[flyfishz]

how did it go with no thermostat?

No it will not over heat with the thermostat removed. It will take longer to reach normal operating temp though... if you are in a really cold area, it may not heat up to optimum running temp without the thermostat... if it doesn't overheat with the thermastat out, you have a bad thermostat... take it back and get a new one....

[Sygerwulf]

I dunno by the time I got home it was too dark to mess with it, but I'm going to take it out first thing in the morning and see if it overheats, I'll be sure to let you know how it goes. Thanks a ton for the advice.

So basically if it still overheats then its eitherA)headgasketB)a blockage somewhere in the coolent systemC)bad radiator??

[flyfishz]

I don't know what else it might be, but it eliminates the Thermostat as a possibility

[Sygerwulf]

well thanks for the advice and I'll post what happens tomorrow. I think if it still tries to overheat I'm gonna get some coolent system cleaner and flush it out.

[flyfishz]

Also, make sure your belt is tight on the water pump...check it at higher RPM as well... that might explain why it didn't overheat at idle but did when ou were driving it...doesn't sound like a head gasket to me...

[flyfishz]

Hey 95silviase your car looks great. I noticed you swaped auto for manual...do this yourself or send it out? How difficult was it?

[Sygerwulf]

*Update*

Okay, took the thermostat out yesterday morning and drove it around all day long and never got close to overheating. I'm gonna boil the sucker today and see if it's opening or not.

The only other thing that it could have been was the water pump belt being loose and the thermostat causing too much restriction to flow enough water to cool the engine, but I highly doubt this.

[flyfishz]

Sounds like a bad Thermostat to me. Glad it is working out

[Mr1der]

now then, time to sell the crappy Mazda (take no offense my car has a Mazda transmission) and get her a Maxima or perhaps Altima, or better yet a nice Infiniti

[UncleBen]

Hey 95silviase your car looks great. I noticed you swaped auto for manual...do this yourself or send it out? How difficult was it?

Thanks alot man! I had it done......I would have done it but I had the money, wanted it done sooner than when *I* would have gotten done with it, and the guy that did it is a Nissan Master Tech. so I trusted him. I ended up having issues w/ my clutch (pedal wasn't adjusted right, of all things) but its good now. I love it!!! Oh, one other reason I didnt' do it myself is because NO TIME!!

[flyfishz]

This is a conversion my son wants to do. do you mind telling me what it cost for labor? I am trying to get a good feel for this.

Thanks