engine is SOHC with 260 km

coolant is at good level. Fan functions properly.

When the engine is under constant load at 4,000 rpm or higher the temprature begins to rise. i.e i'm doing 160 km/h in 5th gear and the temprature starts to rise. Any ideas what could be causing this?

Also just a general question, my normal operating temprature is around 75% on the temprature guage. is this normal?



sorry for all the newb questions, just learning about these engines.

 

I have a 93' 323 and the temp usually rides a little over half way, maybe 2/3 at the hottest. You might need to just flush the radiator and put in new coolant. If that doesnt help let me know I will ask around for you

 

since i'm swapping the engine with a newer 1.8 sohc, I will keep driving with it untill i do the swap.

But if I have time, I'll try to flush my coolant

 

had a temp problem with my car to,

the temp started going all the way to the top of the guage shortly after i would start the car,

but fixed the problem by replacing just the thermostat (i think, gotta ask my bro, car was still his at the time).

 

can you check and get back to me. ITs pissing me

 

i want to check another components before i even think about replacing my water pump.

1. where is the temprature wire located on the engine block? could that be faulty?

2. also could the temprature guage be faulty?


3. If i wanted to measure the temprature of the engine myself, where should i measure it?


4. what is the range of temprature
example: c = ?? h = ??

 

anyone? its getting hotter in toronto and i really don't want to kill the engine with hot temprature issue.

 

my experience on this, might help, but here goes, usually, my gauge will run from dead cold to about half way or slightly more on a blazing hot day (90 degrees outside, probably up to 115 on the road). when i have had it over heat or go real high above 75% as you were saying, my radiator was leaking or the coolant hadn't been changed in so many miles (probably over 30,000 miles) so, simple, open up the drain plug, let it run out into a drain pan, run some distilled water straight into the radiator cap and let it run completely out, fill the resivior with the proper mixture of water and coolant, and that should do it. this should flush out most of the dirt, though not a complete change, should be adequate. if not enough, let the engine run for 10 minutes and flush it again. either than that, i'd go with pseudo's suggestion of the bad pump. hope this helps in some way.
peace

 

thank you. I will try and flush it on the weekend.

 

Re: cruising at 160 km/h and the temp is going up -

You may simply be reaching the heat dissipating limit of the radiator. What do you think got you to 160 km/h (~100mph) anyway? An engine, working fairly hard. The faster you go, the more work the engine has to do (wind resistance goes up with the cube power of velocity, by the way) and the more waste heat the radiator has to get rid of. If everything is working properly, as suggested in things to check in some replies above, you might try:

- air dam/ground effects packages - they can force more air through the radiator and let less of it go under the car
- an engine oil cooler
- larger radiator or auxillary coolers
- plug/tape all extraneous holes in the front end - make all the air go through the radiator and not around it (years ago my brother had an MG Midget with such an undersized radiator that taping every hole finally let him do 55 mph without overheating!).

Hope all this helps.

 

cruising at 100 mph is coming home from gf house, lol or going there, this is late late at night


i have now changed my suspicians to the temprature sensor.
because:

1. as soon as i turn on the car, the temprature is at 75% in 5 minutes

2. under constant load, the temprature goes up past H, like 2500 rpm to 3000 rpm

3. to get temprature down, in neutral I have to keep reving the engine at 3000 rpm and it drops dows to 50%

number 3 is kinda f'ed up. I think i'm just gonna give in and get a diagnostic test from mazda for 44 bucks

but i want to try changing thermostat and flush coolant be4 i do that.

anywho, thank you all, will keep posted

 

if your engine starts cooling down when u rev it at 3000 rpm, it is most likely because of the water pump. sounds to me like its not pumping enough coolant at idle, but when you spin it faster without putting too much load on the engine (ie. reving to 3000 in neutral) it works well enough to cool the engine. also, 5 minutes till ur car warms up is not that surprising considering that it is like 20 degrees out now. And one more thing. To check if ur thermostat is the problem, let ur engine warm up to operating temperature. Then, squeeze the big radiator hose at the top of the radiator that goes into the engine. It should feel rather hard and be under pressure. If not, then that means ur thermostat is stuck closed and is not allowing coolant to enter the engine. Good luck.

 

if you're concerned about the water pump, it's easy enough to do yourself in an hour or more, either than that, the damn part with seals/gaskets comes to bout $40 bucks, you can go ahead and do your timing belt while you're at it for another 40, and even then, you can do all your belts for under 200 in parts. so hell, you have to do some preventative maintenance eventually, so my suggestion, thermostat and flush, no results, water pump at least, $40 bucks, plus labor couldn't be more than 1 1/2 hours on that puppy with a good mechanic that knows mazda's.
peace

 

If you can change the water pump in an hour, you're my hero. It usually takes a lot longer than that.

 

Don't forget to change your radiator cap. It probably won't do anything but you never know! I pressure checked mine and it didn't hold any pressure. Plus it's less than an hour to install