Temperature higher than expected

[snoopios]

Hi guys,

I’ve replaced my thermostat now and like all of the ones I’ve seen/been told about, it’s rated/set at 82 degrees.

Now, my car is definitely cooler than it was before (it was at around 93 degrees before) and is now sitting at around 88. Is that an issue or is there something else that could be stopping the temperature from sitting at the 82 degree rates temperature of the thermostat?

Cheers

 

[Myocardial Infarction]

Thermostat cracks open at 82c and should be fully open by c.95c

 

[GAVBEY]

Normaly Crack open 80 and fully open 86 from my kettle test lol. what kind of radiator / ast setup do yo have? No air locks?

 

[MKZ7212]

Where is your aftermarket sensor? Or are you going off the PFC?
I have a sensor in the thermostat housing so I can monitor temps going in (helps to show fan or rad issues) and also engine (PFC)

 

[snoopios]

Well, the picture attached shows my rad/intercooler/AST setup.

Im pretty sure I don’t have any airlocks but how could I tell?

Based on your comments, it doesn’t sound like mines running badly anyway. Maybe it was just my expectation after speaking to a few people with theirs running at 82, I was expecting the same.

 

[snoopios]

Where is your aftermarket sensor? Or are you going off the PFC?
I have a sensor in the thermostat housing so I can monitor temps going in (helps to show fan or rad issues) and also engine (PFC)

I’m going off the PFC. What’s the sensor at the front of the housing for? The one with the rubber cap.

There’s the other water temperature sensor below the back of the alternator (see attached photo - I stole the picture off the internet).

 

[Richard.C]

There will be two sensors on the back of the water pump housing behind where the thermostat is. One of these is a simple one wire to ground switch that controls the fans at a set temperature and the other is the temperature signal to the ECU. They are both measuring the coolant temperature as it exits the engine.
88C still seems a little high to me if it's consistent, prior to installing an electric water pump I was mostly 82C in normal road driving with occasionally hitting 84C if I was hard on the throttle.

 

[GAVBEY]

That dosnt look like a mazda sensor? I wonder if its offscale a bit as you can calibrate new sensors for coolant on the PFC,
Might be worth a look into. the fuel temp sensor is the same ass the coolant temp.

Also add a bit of ducting to seperate your cold air feed from radiator, air flows through the least resistant pass possible and at current its going to flow into your bay rather than through your radiator.

do you have an undertray?

Cheers

 

[Caine_1989]

Hi guys,

I’ve replaced my thermostat now and like all of the ones I’ve seen/been told about, it’s rated/set at 82 degrees.

Now, my car is definitely cooler than it was before (it was at around 93 degrees before) and is now sitting at around 88. Is that an issue or is there something else that could be stopping the temperature from sitting at the 82 degree rates temperature of the thermostat?

Cheers

When are you seeing these temps at idle or driving? And id definalty make some side ducting for your rad/intercooler as the air wont be as effective with the big gaps and check the gap at the rear where they meet

 

[snoopios]

When are you seeing these temps at idle or driving? And id definalty make some side ducting for your rad/intercooler as the air wont be as effective with the big gaps and check the gap at the rear where they meet

I see this when I’m driving but it’s the same when I’m idling as well.

 

[snoopios]

That dosnt look like a mazda sensor? I wonder if its offscale a bit as you can calibrate new sensors for coolant on the PFC,
Might be worth a look into. the fuel temp sensor is the same ass the coolant temp.

Also add a bit of ducting to seperate your cold air feed from radiator, air flows through the least resistant pass possible and at current its going to flow into your bay rather than through your radiator.

do you have an undertray?

Cheers

I’ll see if I can get a picture of what’s going on in that area.

Ducting sounds like a good plan but like I mentioned above, I do get the same temps when idling so surely when I’m stationary, ducting wouldn’t make a difference?

I do still have an under tray. It’s a little bit mashed but mostly in tact.

Would new rad fans help? I don’t think they’ve ever been replaced.

 

[snoopios]

Also, in case it makes any difference, I’ve got an early spec front bumper.

 

[Caine_1989]

Your temps shouod definatly come down when driving ive got a koyo rad and a large fmic and see temps between 150-185f the higher are idle and can be anywhere inbetween when driving depending on speed and hard or normal driving

 

[snoopios]

So these are my PFC read outs when stationary after the car is warm.

 

[Caine_1989]

Ive been having a look on the rx7 club forum apparently your temps are ok https://www.rx7club.com/general-rotary-tech-support-11/rotary-water-temp-range-125839/

 

[snoopios]

I didn’t think it was bad it was just that when I have friends with theirs running at 84 tops, I thought something might be up with mine. I’ll monitor it for a bit and see if anything changes.

Thanks for the help so far though.

 

[MKZ7212]

I’ll see if I can get a picture of what’s going on in that area.

Ducting sounds like a good plan but like I mentioned above, I do get the same temps when idling so surely when I’m stationary, ducting wouldn’t make a difference?

I do still have an under tray. It’s a little bit mashed but mostly in tact.

Would new rad fans help? I don’t think they’ve ever been replaced.

The stock fans are very good if working correctly, looks like you have no ac?
Try hitting the ac button this should trigger the fans or step them up, if it doesn’t there is a write up somewhere so you can still do this, I use it to help cool down or on a hot day it traffic to just help before temps go over 88

 

[Mid Night FD]

Just for comparison, mine runs usually 86-90 when driving on the temp sensor in top rad hose, pfc the same. On idle its gets to around 93 but fans cool it down quickly, can get to 96 if ive just pushed it really hard. Pfc reads a bit above sometimes, due to heatsoak i guess. This is on a completely stock (cooling ) setup with no undertray.

 

[Spendyrx]

Yeah mine drives at around 85 and seen my idle go to 99 in the hot weather

 

[snoopios]

Sweet, thanks guys. It looks like mine is running alright then.

There was a time when I picked it up from the garage and driving back it hit 104 but since changing my thermostat (picture of the old one after taking it out attached), it's not getting anywhere near that temperature.