1982 12a

Can I get some help/advise on this please.

As I was warming up the car I noticed that the car
started to over heat ..some. The temp gage on the car
never passed more than 1/4 before ..just out of nowhere
my temp gage was going up..However I stopped the
motor before she even passed half way on the temp gage.
Even on very hot days..the temp gage never never went past 1/4.

We changed the thermostate..
I noticed that while we had rad cap off ..while
we where letting trapped air/or air bubbles out,
that the coolant wasn't circulating in the rad..
Only once it bubbled and that's when the and air bubble came out..
then after that...the coolant is "still" it's not circulating !!
Shouldn't the collant be circulating in the rad..if not "it must be the
water pump" ??

Notes:
a) The water pump is not leeking.

b) Two days before we had the rats nest removed
but I think it has nothing to do with this
(just a coincidence).

c) The O rings needs to be changed
because recently we noticed some small amount
of coolant on top of the engine (beside the intake manifold)
but from what I read..this shouldn't cause to over heat the car
since it's only loosing a very small amount of coolant per week.

Any suggestions would help..

Regards
Xtreise

 

If you shut it down before the 1/2 mark then the engine should be fine. After you "burped" her, the car has to come up to full operating temp so the thermostat can open. When the thermostat opens then the coolant will circulate through the rad and not until then.

Q: Did you replace the thermostat with a "Mazda" thermostat? If not, do yourself a favour and go get one. Make sure the "jiggle pin" is in the upward position.

 

Thanks my RXBad..
Well this was on Sunday..so I a shamed to say that we had no choice but
buy the t-stat at Cdn Tire....

Why is it that some people say to me that..your suppose to see the coolant
travel when the rad cap is off....and if not..then the water pump is finished..like the fins are worn out they say !!!

 

the fins usually dont wear out like that, very rare and you would probably hear the water pump bearing go out prior. There is a relief valve on the water pump a little hole under the shaft and you can see if there is a long stain from it then usually thats the sign your water pump is bad. Also check to make sure your hoses have not collapsed and take your radiator to a shop for testing, if its not atleast 70% working it will cause your car to run mid range in heat

 

Yeah, lots to check. Like MyRXbad said: You have to wait for the T-stat to open, or you could take the t-stat out and check the coolant flow.

If you were warming the car up, I would look at your fan. Maybe your fan clutch is on the way out. Also, mitigating factors like being parked close to a wall, or on very hot pavement might have an affect.

 

Thanks Feds..well I'll tell ya ...it's was one of a hell of a hot day on Sat..
However, the car never did that before...
The fan seems fine...when off it turns but not that freely...also she on when the
car is started...

Xtreise

 

I'd put my money on bad fan clutch and really hot day.

If not, check the temp on the t-stat you bought, it's probably a little higher and will cause your needle to sit a little higher than you're used to.

 

Radiator could be plugged up. Consider a coolant flush maybe...

 

the fan...if I turn it...it has some resistance......which means the fan clutch should be good...? I've notice that the sensor on the driver side, on the side of the oil pan..the Oil Pressure Sensor I think..well the wire going to that is broken..
I don't think that has anything to do with it ??

Also, I mentioned in my first post re: The O Rings...could that be it ?. I searched and found nothin re: over heating because of small O ring leaks !!

Xtrteise

 

have you gotten a chance to drive the car on the highway?

if you notice considerably lower temps on the highway at speed, it could be the fan and heat soak.

if not, it could be the thermostat or a more serious symptom...

 

No, they don't. It doesn't work that way.

What that means is that you've probably got a leaking coolant hose above the motor. I don't know how 12As are laid out, but I'm guessing that you've got at least one line passing across the top of the motor. It's leaking. Find it and replace it and use new clamps.

This leak will also prevent your coolant sys from pressurizing, which would lead to higher temps like you've noticed. Find the leak and fix it and then see what you get.

 

yeah, there we go, that sounds like a smart thing to do.
do what he said^^

 

there is a pair of Rubber Oil Rings on your intake manifold replace those and the Lower intake gasket, Also sometimes the clutch fans will have resistance till spinned at a certain speed or something so I testing it by honestly grabbing the fan with my hand (OF COURSE I USE SOME SUPER THICK GLOVES) and if the fan is easily stopped its bad, if it doesnt want to stop its good

 

ok, that sounds a little dangerous, lol.

what does the FSM say about clutch fan testing?

 

only way you should be worried is if you have real soft thin skin wearing no gloves and especially if you had a "WHY EVER MADE" Flex A Fan attached....

 

This is misinformation. Why do you post if you dont know for sure??

Yes their are 2 o-rings between the manifold and the rotor housings. They are on all 1st gen 12A's and 2nd gen turbo motors. They tend to crack or deform over time which will cause a pool of coolant on the lower manifold. You should replace these if they are leaking since they do cause a loss of pressure in the cooling system and could cause a low boiling point which in turn could lead to overheating. They're a pain in the *** to get to with the stock carb though . When you do replace these, use only the Mazda o-rings, not cheap ones from a parts store. The cheap ones arent made to handle the heat from the coolant and will shrivel up and cause another leak in no time.

 

You guy's are great..many thanks for your help..

Ok..We are changing the water pump either way...good or not..
The rad is not that old.
We are putting in a Mazda t-stat. Remove the Crappy Tire one we bought last Sunday.
We are going to remove the o-rings, and plugg the holes with 20mm frost plugs..
and new intake gasket.
From what I read, we can do that since the rats nest is completely removed, and we have Rb headers (no air pump/cat/ect)...


How hard is it to remove the O-rings ??
Would you JB Weld the frost pluggs in ??
Where would you order your intake gasket?? (besides Crappy Tire)
Any otherr input is greatly appreciated..

regards

Xtreise

 

He asked for comments, he got mine. When he said "o-rings," I assumed he was referring to the o-rings within the keg. Thus the, "It doesn't work that way," comment.

I said clearly that I'm not familiar with the 12A's layout. And there's polite people such as yourself who do know better and who can correct me.

 

Looks like you're replacing the whole cooling system lol. You really dont need to change the waterpump... that will cost you $$ for nothing. The only reason you would change the pump is because the bearings are shot and loud/leaking.

If you only drive in the summer, buy a lower temperature T-stat than even the Mazda one. The stock one is a compromise between winter/summer temps. A lower temp will more effectively cool your engine.

Dont bother with frost plugs, you can use a quarter and JB weld. But with the $ you save from not buying a water pump, buy the Mazda O-rings (10$) and replace them instead. It's not hard to do, they are simply sandwiched in the between the manifold and the block. Make sure you clean all the dried up coolant around in the o-ring slots... The O-rings are there because there are actually 2 coolant passages in the lower manifold. These help warm the carb up in the winter and prevent icing. It doesnt have anything to do with headers/emissions etc.

You'll have to get the new intake gasket from Mazda.

Good luck

 

You can buy the Plugs and its a simple Tap to get them wedged good. Buy a few extras in case you damage a few while getting the hang of it and no they wont just fall in...Also you should remove the radiator and take it to a shop they most times for free check it and tell you how much of it works in a Percentage range...Trust me the radiator should be tested

 

Another tip, get ALL of that old intake gasket off before you put on the new one, even if it means sitting there for hours with a razor.

 

Man... all these suggestions for a simple fix... :S

 

Well...we figured to go all the way...while taking thing apart ..might as well get dirtier..lol...
Actually, Shawn got a new w/pump (and it's not a rebuilt !!) through connections at work for $52.00 + tax. A rebulit was $47.00 + tax. Hell why take a chance ..we don't know how long the old w/pump is...
Also you guys are quite right, Mazda O-ring and Intake Gasget...a little more expensive..but worth it..
We will get the rad checked as well...
We will keep you posted on the results. Waiting for the weather to cool off a bit.

Also thanks Jon (Vipernicus42) re: t-Stat and returned phones calls/patience ect.. as well as, Eric (the Dude).

Just a note: Shawn works at Auto-Wa Upholstery and Glass ( 729-7212) any one you know who needs a windshield/othercar glass repairs...call and ask for Paul (owner)...say you are Shawn's RX-7 buddy and you well get a very good price.
(no Shawn get's no commission)..


Thanks to all again..

regards

Pete

 

i was thinking of getting my front windshield replaced this summer, thanks for the info.
hope you get everything sorted out with your cooling system

- Aaron

 

Well guy's here are the results....

New w/pump was replaced.
News O rings and gasket replaced.
New Mazda T-Stat replaced.(thanks Jon for the T-Stat)

The Temp Gage still goes half way ??

I think we may need a new rad. I noticed
inside the rad it was like a slimy grey colour.
So we might as well has get it rebuilt, cheaper
I think than buying a new one...(I think).

Any clues on this...when we turned on the heat inside
the car...while burping the rad..the temp gage when up a bit
more. There is alot of heat. I verified both hose by the firewall
going to the heater and both are equaly hot.

Any good advise...??

regards

Xtreise