ok first off I've gotten a new thermostat, upper radiator hose, got a flex-a-lite e-fan (working), coolant flush, new radiator caps, (the one on the thermostat housing too), of course their all mazda parts. the lower radiator hose doesn't leak but I haven't pulled it off. and I've added new grounds. AFM, engine block...

my problem is that my car is running warmer than it used to. it runs at about 1/3 to 4/5 of the way up the temp gauge. and varies with how high I go in the rpm band. (warmer higher rpm cooler lower). at Idle it cools off more cause of the fan! when I replace my radiator cap with a cusco one the temp returned to normal. (just below 1/4 the way up) but then about four days later the temp started to rise again. when it ran normal the gauge never moved even if I drove at redline. my water pump isn't leaking either. anything I'm missing? should I pull the water pump? I only have the one belt on the engine (everything else is removed) my car is an 87 N/A. any suggestions? oh the engine is a pineapple rebuild still running strong at 60,000. pull a 15.6 in the 1/4. on the crappiest tires I could find for 25 dollars!! haha um help!!

 

someone please help!!!

 

when is it heating up??? city driving or highway???

You do have all your engine undercovers and bumper directors/panels in, right??

 

I was going to suggest using a dual belt pulley setup. Since everything else is disconnected, at high rpms the belt may not be sufficiently contacting the water pump pulley. Dual belts should take care of that (although its not a guaranteed fix to your overheating problems in any way).

 

Like Mark says. Those covers make a big difference.
Also check for trash between the oil cooler & the rad.

 

i agree with fatty fc3s, switch to a dual alternator pulley right away. The belt contact on the pulley is too small and that was one reason my motor fried (water seals).

Do it now. Its cheap.

 

ok well I'm missing the two covers that prevent air from going over the top of the radiator. (by the overflow tank) but it ran just fine before and the covers weren't there. since I've owned the car. plus I've got that e-fan forcing air through. so I'm not sure that's the problem. I do only have the one belt, but this problem happened as soon as I started the car one afternoon. I do need a new belt but it isn't squeaking. but I'll try that. it's possible. anything else? it's heating up anytime I'm driving highway or city. it's been staying the same. ... the last couple days it's seems to level off... before it didn't matter where I was, it was just moving with the Rpm.it doesn't seem to rise and fall with the rpm anymore. just stays at about 1/3 the way up. oh and no smoke at all!

 

oh here's something else. since I've owned the thing (over two years) it's had a problem with starting cold. the temp and fuel gauges rise to max or about twice the gases true reading. then once it's warm the gauges fall. fast. instantly like someone turned off the car and the gauges drop to normal. last couple of months it would drop then stay at 1/4 over the normal readings then it would finally drop. it makes me think it could be electrical. but I don't know. I've never seen a problem like it!!!

 

As you've looked at everything else. look at the lower radiator hose. I have seen some "weak" hoses actually collapse and not allow proper circulation. Just squeeze the hose to see if any resistance, and take a look when hot if any area sucked down. Other than that, radiator could have been flushed, but could still have blockage in the core.

 

alright I'm going to get a new belt now!! and those dual pullies come with the Jspec turbos sometimes so I'll wait until Corksport gets another one in. (I'm a student... can't afford to spend money) but until then I'll have someone flush my radiator again. I'll look into another water pump too. I think their only like 35 dollars. this is the only thing left to fix!!! other than the fender and a Jspec...

 

Oh the lower radiator hose is ok. I checked it before getting the upper one. thanks for the help!!

 

Oh the lower radiator hose is ok. I checked it before getting the upper one. thanks for the help!!
hey turbonut... or anyone can someone recomend a good radiator flush. I want to get everything out of there!! I did it once for a half an hour (friends work at valvoline) I thought that would have taken everything out! Doh!!

 

ok I've gotten a new belt and put the plastic back in the front. it still overheats!! wtf!! the waterpump isn't leaking but could it be bad?? the hoses R fine Caps r mazda! and the thermostat is new (two of them!!) the hoses both are hot so their working, coolant is flowing. does anyone have any Ideas.

 

1. Buy an aftermarket water temp gauge and install it. Compare temps.

2. If the aftermarket MECHANICAL gauge shows hot, and your not losing fluid, then buy a radiator.

3. A 1987 TurboII will read b/t 160-170 degrees, air conditioner on, at 70 mph constant. Fifteen year old radiator. Mazda thermostat. Mazda radiator cap. 80-85 degree outside air temp.

 

so no one thinks it could be the water pump. the temp has gone back to rising and falling with the rpm again. I don't have a lot of money so I can't just go and but parts... I need some more... all parts are mazda... new... sometimes twice. it was running just fine for a couple weeks then one day it ran warm... anything else?

 

I don't believe it's the water pump. Rarely do you find impellers breaking off as they might have done years ago. You could flush the radiator and still not be able to clean the harden material in the core (tubes). You could have the radiator flow checked, or if you could add water fast enough try it yourself. Add water to the top and see how it flows out the bottom. If when running water into it, it overflows(comes out the top), or you don't see the volumn coming out the bottom, the radiator is clogged.

 

$10 says it's a blocked rad. Check the rad thoroughly for any warm/cold spots (you'll have to take the shroud/fan off and work very quickly because the car will overheat quickly without a fan)

 

Well, I don't think the radiatior is the problem, (remember this is just my gues) But have you ever played with the rich lean screw, timing advace, or anything like that. I think it is running lean and it is causing it to run hotter, listen for hissing under the hood, take you MAF out of the car and make sure that it is opening and closing smooth and easy, if it has oil or tar like a parts car I had had the MAF full of tar crap and it wouldn't let the MAF open so it made it run lean, and crappy, also hot.

 

MAF? Air flow meter? I've played w/the lean rich screw, but not the timing. tps needs to be adjusted though. where is the MAF? the lean rich screw doesn't make it run any cooler. I've tried but Where is that MAF??? Doh!! I'm gonna try another radiator flush. can anyone recommend a good detergent before I flush it? I want to get it all!! thanks for the help... still.

 

you have problems with your other gagues... and now the temp gauge moves up and down by RPM??... I'll guess electrical probably...

buy a aftermarket temp gauge and see what happens.

 

It is the metal odd shaped box that is bolted to the bottom of the stock air filter box, it has a plug running to it, and if you have a cone filter it is right behind it.(and still has the plug) You really can't miss it. I'll get a picture here for you in a minute. And the rich lean screw will make it run hotter if you turn it leaner, or at least by theary it should.

 

www.egauges.com

VDO sells an inexpensive mechanical water temp. Like 40$.

 

haha ok air flow meter- MAF.. why isn't it AFM? oh well what ever. I'll check that. well the water temp doesn't move as fast as the RPM. but under hotter running conditions, (when I give it gas or am above 3000 rpm) the gauge runs at about 2/5ths and the max was reached today at 1/2 but It got warm out. cooler temps and it runs cooler. (night) I'll check the AFMMAF tomorrow and try to get another flush. we'll see thanks again for all the help.

 

I will bet that if you went on a mission to inspect, clean, and re-secure the harness & engine grounds, many of your problems will go away.
The aftermarket temp gauge is a good idea.
The whole car is full of sensors & signals using low voltage circuits with 16 year old grounds & old circuit board to connector solder joints that will drive the gauges, the ECU, and you CRAZY.

 

well all the grounds have been redone. but what about the harness? How do I check it for bad wires?