Good day,

My Poor 7 is sick. Little history first. I got the car to replace my gas eating Blazer to dive to and from school (164 Mile round trip 3 to 5 days a week). Did that for 2 years. Along the way I replace the fan (electric), radiator, oil cooler (cost as much as the car), radiator cap and thermostat. All of this months of ago, every thing has been working great. It still needs the carb to be reworked, and a new exhaust. I replaced the parts just to stop from having any issues. The Radiator had a little leak, and oil cooler was starting to crack. I had no issues at any time. I still have my "rats nest" with all new tubing (if it matters). Also lots of other new items that do not matter, like the supension and breaks. I've changed all the fluides when I got the car.

But I bought an Rx-8 (Love this car too) and have been driving it around for the last couple months. The poor 7 has sat in the drive way. Well I guess it got its poor feelings hurt. Now if i try to drive it around the block in cool weather, it over heats.

I got a new water pump, as it was the only thing in the system I had not replaced. I pulled it out after work yesterday, and it looks to be in very good condition. The whole area is free of gunk and rust. And the water pump that is on the car looks better then the new one from NAPA.

So what do you think I should do. Go ahead and replace it, or did i just bark up the wrong tree?

 

Have you replaced the thermostat?

Have you confirmed that it is actually overheating?

 

Yes the thermostat is less then a year old, and was working before I let it sit. How would I know if it was not over heating with out the gauge? Everything but the radiator is hot to the touch. It has strong smell of gas, and a hint of overheating (like burnt oil or something), when normally it just smells like gas.

Also right after the first time it over heated, I changed the oil, right away, and oil came out like water. I burned my hand, as it came out like water out of the water hose. Normally it does not come out like that. It made a stream from the plug all the way over to the tire. Then after I changed the filter I was putting oil in and smoke was coming out of the fill tube. I feared that changing the oil that soon after over heating it was bad, but after cooling for an hour or so I took it for another test drive, and in less then 1/4 mile it was over heating and I push it back home. (It would not start, after letting it cool.) That was when I took the radiator cap off, and got no steam and very little release of pressure. After charging the battery it started right up.

Are you thinking it might be a guage and I took it apart for no reason? At least I know I have no rust. These 12a are bullet proof.

 

Sounds like the tstat is not opening. The radiator should get hot to touch once the car has run for about 15 minutes. Its probably stuck closed since its been sitting. Wack it with a hammer and see if that knocks it loose next time it gets to temperature. When the tstat opens that top hose should start to get hot and then the radiator will also get warmer as the hot coolant runs into it.

 

more importantly, did you replace the thermostat with a new oem mazda unit? and a stupid question, but did you verify that the coolant level was at a normal level and that you werent down on coolant?

 

The closest Mazda place is like 90 min round trip. So I got one from O'Rillys, there less then a mile away. The coolant was at a good level, my sensor that reads the water level is going bad, cause it keeps coming on, so i check it with the oil in the morning. Officially have 0 leaks, nothing is wet any more, and no oil on any thing. Very happy about that.

So I'm going to put it back together tonight or Monday, and hit the thing with a hammer. Sounds fun at least. Any other ideas? If hitting it fixes it is the recommendation to get one from Mazda?

 

Spend the bucks and get a mazda tstat. That'll probably fix your problem.

 

Check your ignition, and make sure that you haven't lost spark on the leading plugs. With only the trailing ignition working, you will generate a lot of heat in the motor, but it usually won't show up in coolant temps. It sounds like you've covered just about every other possibility, so that's all I can come up with for you. Good luck!

 

you can also order a new t-stat and gasket from www.mazdatrix.com. save the gas and order the sucker form mazdatrix.

 

The 7 runs again! New water pump, and thermostat are in and antifreeze level is set! No over heating, I'm so happy. Thanks all for your input, Now I just have to get a new exhaust, and rebuild the carb and it will good as new.

The Mazda thermostat looks much better then the cheap one from where ever I got it. I hope it last me awhile. Cheers and happy driving!

 

Shadow,
You may also want to add a product called Water Wetter...it will drop your operating temp. by 15 to 20 degrees and lube the bearings in your water pump at the same time.
happy motoring

 

When you put the tstat in make sure the jiggle stick is up.

 

I really like hearing a happy ending to a problem like this!!