bigdaddyp

Hello peoples. I have been having a wierd problem with my 86 for a few weeks now. It started as a blown heater hose, car never overheated. I fixed it, and now it moves the antifreeze over into the overflow, but doesnt suck it back. I have tried getting all air out for 2 weeks, cant be any air left. I replaced cap, and that didnt fix it. I have heard that 86 cars have a problem with this, and that I should put an 88 radiator in it and that should fix my problem. Car doesnt over heat, and it doesnt smoke a lick, and there are no bubbles in the resivoir. It just backs thru the resivoir and doesnt come back out of it, and once enough comes out of the resivoir, the buzzer goes off and the temp will climp to about 3/4 way, but will not pass this, it will go back between 3/4 and 1/2 way. I was wondering if I should change the radiator so I will have a cap on it, and if so, what all do I need to change with it. Thanks for any help.
Chase

classicauto

iTrader: (3)

There's go to be some other problem...be it air (I know you've tried hard and for 2 weeks but you *may* not have gotten it) or a coolant seal or some odd placed leak or something not installed correctly....

The point is I've had several S4 cars with S4 rads, Ive flushed coolant, changed coolant, changed T-stats and it IS possible to make it all work with S4 stuff. Something has to be wrong...

Sum up everything you've done and tried, removed and installed, etc. to this point and we'll see if we can figure it out.

bigdaddyp

I have replaced the hose that blew, and the cap. I filled it according to the FSM procedure. I then drove it around and topped it off whenever the buzzer came on. I had a small leak before this hose went, and never had this same problem. This car has been an excellent running, well taken care of car, until this hose went. I dont think it is the coolant seals because it doesnt bubble thru the resivoir and it doesnt smoke or sputter any. I noticed that there is a small hole in the resivoir cap right beside the outlet tube, but I assume it is supposed to be there, that is where the antifreeze comes out when it gets too full. The night the hose went, I pulled over soon as the buzzer went off, and the resivoir was low, so I topped it off, and it hasnt pulled any out of it since. The car runs about 1/4 guage, untill enough comes out for the buzzer, then it slowly gets up to the temps stated above. I dont know what to think. I guess I will try the thremostat. I need to buy a new water outlet because I pulled the resivoir hose off of it yesterday, and the plastic the hose slides over broke off. Also, I went out to change the thremostat this morning, but the old one seems to be stuck in the hole, how do I get it out? It looks sealed in there. thanks the help so far.
Chase

wthdidusay82

iTrader: (15)

Should be able to put a flathead screwdriver in the middle of the the tstat where it pops up u should fit the screwdirver under that and be able to pry it up, its probably just sealed from some sealer so its harder to get out.

If you dont have another tstat to replace it yet, run it with no tstat and see how it does, make sure you get a tstat from mazda oem tstat not a cheap autozone or anything like that.

Also, your problem may not even be coolant related. Check your clutch fan and see if it spins freely or stops quickly after being manually spun with your hand, if it keeps spinning around like its on a bearing it probably has a bad clutch in it causing it not to work properly and make the car overheat.

If it quickly stops spinning then it probably isnt the fan but I'm willing to guess your clutch fan is bad, I think it will probably spin freely.

My clutch fan was bad on my car and I was thinking there was air in the system or the coolant seals were bad, turned out the clutch fan was bad, I replaced it and my car never overheated since.

classicauto

iTrader: (3)

First......

What exactly did you do to fill it? Describe each step you took....

Second:

Does your heater blow hot when the car is warm, or no?

bigdaddyp

I took the cap off and the bleeder screw out. Topped the antifreeze off. Let the car warm up to operation temp with the heat on wide open. When the tstat opened, I hit the throttle a couple times to let it pull the coolant thru engine, then topped it off, replaced bleeder screw, toped it off again, replaced cap, then filled resivoir to full line.

The heater does blow hot.

The fan will spin for about 3 more blades past my hand when I let go before it stops. I can turn the waterpump with my hand no problem, doubt that matters but, just saying.

wthdidusay82

iTrader: (15)

Sounds like the fan is still good, but maybe its not. I actually got a watertemp gauge to see what the car is actually running at.

A fan from the junkyard wont cost much to get , if that was the problem it would be an easy fix...but it sounds like the fan is ok, if you spin it hard after the car is shutoff after reaching operating temp does it still stop quickly (1/4 - 1/3 of full rotation).

If it spins more than that it is likely the clutch fan, it sounds like thats the only thing it could be other than a clogged up radiator.

I had a spare clutch fan with a bolt through it to make it spin at same rpms as the engine constantly, I put that on and my car was running at 165 degrees and before that it was running up to 200 within 2 minutes of driving so then I knew the clutch fan was the culprit.

jackhild59

iTrader: (7)

Ok, I had this identical problem with my S5 vert. What is happening is that somewhere in your cooling system, there is a leak that will not hold a vacuum. When the system pressures up, the expansion tank gains a little coolant. When the car cools and the system goes into slight vacuum, instead of pulling coolant back into the radiator from the overflow, it pulls air in from the leak. Process repeats until the tank is full and the cooling system is low. This trouble get worse if you try stop leak type materials, as they can inhibit the return of coolant from the tank to the radiator.

Do a cooling system pressure test. You may be able to find the leak this way. Remember, it is possible to have a leak that will hold pressure but will not hold vacuum. I pressure tested my system and could not find a leak, but still the problem remained. I had great compression, no smoke, no cold start issues and I could even empty the overflow into the radiator tank and fill it up. I was not losing or consuming coolant, it was just staying in the overflow tank.

As a last resort I changed over my system to Evans NPG+ and now the system runs with 0-psi pressure. It has worked thought one of the hottest summers on record here in Dallas TX.

BTW, I eventually found my leak. It was in my thermostat housing. I have not re-pressured the system because I am pleased with the no pressure approach.

So, find the leak and fix it. If you cannot find a leak, you CAN use Evans Cooling NPG+.

Good Luck.

mort2002

iTrader: (1)

i think your problem is the hose that goes from your radiator over flow to your cap. if you have a hole in it, it will allow water to pass though but not be able to pull it back. it will suck air instead. i would give that a try.. ive had it hapen to me before..

Sideways7

iTrader: (7)

Yep, I agree with jackchild. It sounds like there is a small leak that is keeping the coolant from being sucked back in.

jackhild59

iTrader: (7)

Yes, that is one place that a pressure test would not check...


Remove both ends of the hose and check it. This might be an easy fix.

bigdaddyp

Ok. Me and my dad were looking at it after a little drive. He heard a hissing comming from where the overflow hose connects to the water outlet. He tugged on the hose to pull it off, and the plastic broke off the water outlet. THis could be the problem. I will get a new water outlet tomorrow. Also, is there supposed to be a tiny hole in the coolant resivoir?

jackhild59

iTrader: (7)

Yes, the coolant overflow reservoir should have a tiny hole in the lid.

bigdaddyp

update. I took out the thermostat and replaced the plastic piece that broke, replaced the heater hose and replaced the hose going to the resivoir. It drove great for 1 day, buzzer never came on, resivoir level never rose, so I considered it fixed. Took it out the next day, and the level raised a little in the resivoir. Then took it out later that day and it started over flowing and the buzzer went off.

bigdaddyp

Evans NPG+? what is this, sounds like something that I would like to do. Also, now, after it was fixed for one day. I have noticed that when I get back after a short drive and it is over flowing, I noticed that after I cut the car off it has bubbles going thru the line running to the overflow, and they are comeing up in the overflow container. It wasnt doing this before, makes me wonder if my leak is in a different spot now. Any chance it could be the radiator cap I got from Advance? Any help would be great, thanks for help so far too, helped me for a day, lol.

Goofy

I thought that indicated a water pump failure?

bigdaddyp

does it? I am not sure, it seems to be pumping the water fine when the cap is off, it pulls it thru and such.

bigdaddyp

ok. I finally rechecked my fan clutch. After the car is warmed up, it will spin for about 2 or more full rotations before it stops. Also, it doesnt speed up with engine speed any and it has stopped cutting on when I crank the car. I am guessing this is my culprit. Only thing is my car stays around 1/4 on guage, but then again, I am driving it on open roads, not stopping much, and I am only driving it for 15-30 minutes at a time. How could I run a bolt thru mine to see if that helps? The local junkyard wants $50 for one, and they are being asses about it also. Said they didnt have any when I called, I drove down there and found 6. Asked him how much, he said $50 and I said well it says $25 on line, he said well we are out of stock, I was like, there are 6 down there and I only went thru half the FCs, he is like ok well $50.

SpooledupRacing

here is what I would do buy a oem style cap and thermostat, replace both of those

if the clutch fan when turned will spin for 2 full revolutions it is bad or the pump is bad (is the pump spinning or the CLUTCH spinning)

the fan should NOT spin at the same speed as the engine thats the reason for the clutch

maybe puttin on a water pump wouldnt be a bad idea

I have the cap, t-stat and water pump all brand new all nippon oem stuff I will pm u a price

Dave