walterh

It seems that my engine temperature increases with my engine speed. The faster I go or the harder I push the engine, the temp increases. It gets up to over halfway at highway speeds and just driving around town it stays around halfway. One thing I was wondering is how long it should take for the radiator to get hot at normal temp? My radiator seems to get hot pretty quick which is making me think that I may have a clogged radiator or a slipping water pump. I plan to get the radiator rodded out soon. Anyone else ever had their radiator rodded out and seen an improvement in cooling? I am in the process of flushing the system to see if that will help. BTW, I just replaced the thermostat with a mazda one and I have the underbelly tray attached. Too bad I can't afford one of those $400.00 Koyo or Fluidyne radiators. Any help is appreaciated.

1987RX7guy

iTrader: (3)

My vote goes to the pump either slipping under load. OR getting old. Mine finally went out about amonth or so ago and that was one of my main problems. The other problem was a small crack in the top tank(plastic) of my radiator.

walterh

So, just because the water pump doesn't leak, doesn't mean that it is working properly?

Barwick

I would guess it's the water pump slipping, because it's not pumping much at higher speeds. Put a double belt on it. http://www.1300cc.com/howto/how2/belt.htm

walterh

I still have my air pump. I see this is used when removing the air pump. Still think it is the water pump? Anyway to check for sure, or do I just have to buy one and put it one?

Scott 89t2

do you have all your plasic panels under / over the rad?

edit never mind says you do

check for leafs etc blocking the rad.

Barwick

it still could slip if it's a worn out belt (or both belts are worn out). Especially if you get coolant on the belts.

Try tightening both belts properly (as the manual says) and if that doesn't work, might need to change them, not sure though.

Fingers

Hmm maybe that's my problem. I know for a fact that the damn air pump belt is slipping. Stupid peice of crap is as loose as a 50 year old hooker. I imagine my water pump pulley is slipping as a result of it then.

walterh

I'll try tightening the belt. I just replaced it not long ago, so I really think it is the water pump, but its not leaking. That is the only thing besides the radiator being clogged that I can think of that could cause this problem. Do I really need to buy a Mazda water pump, or would one from NAPA suffice?

walterh

ok, i tightened the belt and flushed the cooling system. no help. anybody else know how to tell if the water pump may not be circulating enough water?

Spawn VII

maybe cross circuit? between temperature and speedometer?

boosted1205

iTrader: (9)

A water pump is just a wheel driven by the belt or belts.
If the seal is leaking, there will be coolant leaking from the weep hole. In extreme case, one or more blades from the water pump could have broken off from corrosion but I've seen that happen only once.
Many things need to be considered for the cooling system to work *PROPERLY*. All ducts should be in place. I don't understand why people take those things off. It's plastic!
Check your lower hose. When you rev the engine, see if the lower hose collapses.
Check between the radiator and a/c condenser if anything is lodged in there.
If you recently opened the cooling system, bleed the air out.
If the belts are slipping , that's an obvious sound you can't miss.
If you've never changed coolant, well, now is the time. You should do that yearly and ALWAYS use distilled water.
You shouldn't tighten the belt too much or else it will put too much strain on the water pump. If it's still slipping after tightening it, you need new belts. Get OEM Mazda belts . Don't even mess with the other belts.

walterh

cross-circuit? can you explain spawn? I flushed the cooling system last night and drove to work and the needle was reading 3/4. ouch!! I haven't checked the lower radiator hose yet. I notice that the radiator get hot pretty quick. Another thing is that I am not spitting coolant from the overflow, so maybe it isn't getting as hot as the gauge says it is. Anybody else had this problem and what fixed it. Belts are good and tight, OEM thermostat, underbelly is on, no leaking water pump, but when I open the cap, the water seems to be moving really slow in the radiator even after it warms up.

walterh

^

1987RX7guy

iTrader: (3)

walterh- Chances are it is the pump just being OLD or a small crack in the radiator's plastic tanks.