Overheating..sometimes

[Unicornasaurus]

Recently my Festy has had a bit of an overheating problem..nothing too severe. It gets up to about 3/4 on the temp. gauge, then the fan kicks in for about 2-5 seconds..and it begins to fall back down to 1/2. I've replaced my T-Stat, put in all new fluids, changed my oil (not really related..but I thought it might help cooling it). The radiator in the car is probably only over a year old as it was replaced not too long ago.

Occasionally when the temp gets up high, I can see a bit of steam coming out from under the hood. It doesn't do it every time, only every now and then.

Also, it seems to do it more often if I've been idling for a while. I could be red lining it doing 140 and the temp will sit at 1/4.

Anyone have any ideas? Next on my list would be a cooling system flush..and if that fails then possibly the water pump. I'm just hoping its not like a tiny crack in the head gasket or anything.

[anomoly40]

I just called the local Mazda dealership and had them quote a 1988 Mazda 323 non turbo.
They said the P/N is 8AK1-15-171-9U. He didn't know if it was a dual or single stage, but as stated on page 2 it is mazda's dual stage. $19.17 Mazda, here i come!

You have one of these t-stats?

[Unicornasaurus]

Is that the one I should have? I have a 91 EFI. I had just gone to Lordco(parts store) and asked them for a tstat for a 91 and they gave me one. Are they the wrong one?

[WmWatt]

I was sold a single stage as a replacement by a parts store. He just looked it up in one of his supplier parts books. I put it on and have had no problems. Actually I think the original is still good as the problem was a dirty EGR valve (high NOx in emissions test).

[hotfordcat]

I have three of the Mazda T-stats listed above, and all are dual stage. I have the Ford one also, it's a bit different than the Mazda, but they both work fine. Switching from the generic Stant made a world of difference in my 91 GL

[jglutz]

Cooling system flush is never a bad idea.

I can not give any specific data (°F's) but the temp indicator should hoover around 1/2 way up.....fan kicks in around 5/8 up and will cool down to 1/2 or slightly less.

The sensors/fan switches...go bad.

Your symptons could be a bad fan switch....sluggish t'stat...inefficient water pump or clogged radiator. I would go after the fan switch because every thing you claims seems perfectly normal and follows a dogging fan switch.

[ejp2fast]

Is that the one I should have? I have a 91 EFI. I had just gone to Lordco(parts store) and asked them for a tstat for a 91 and they gave me one. Are they the wrong one?

see the very top sticky of the repair section about heating....

If you don't have a dual stage, get one... this is one of the ONLY times that OEM is good.. mazda or ford. Go to the Mazda dealership and tell them you have a 1988 Mazda 323 and then match the P/N as stated.

like others mentioned, a good flush won't hurt...