riptor

gota question for you cooling gurus. ok yesterday it was 107 out side. i was on my way to look at cars...(bored). was doing about 80mph's. so pull into the mazda dealer ship and turn off the car.. turbo timer counts down from 1:15. at like 0:02 the temp gauge jumps up a little bit and the add coolent buzzer comes on.(stock water temp gauge)at first i freak out then i calm down and start checkin for leaks. there was water coming from the overfill ( think thats what its called, little plastik tank on passenger side,) and the fans stayed on for like 2-5 min after car and ignition was off.( i remember in reading in the fsm that they will do that but i cant remember why.) so my question is wil i need a new rad, water pump, or thermostat. it did this once before like almost 3wks...ago, i know the rad nees a flush and new coolant but would it be that severe..for the fans to stay on..?
it is still at the dealers gettting a diag. but i was just courious as to what im getting into here. thanx in advance.
steve

David Beale

It seems to me that would be a normal thing for the outside temps. Having the turbo timer idle the engine is not really necessary, and IMHO not a good thing to do for that long when it's that hot outside. 30 sec. would be enough to remove the extra heat. Just about any vehicle will actually boil coolant when you immediatly pull off the highway and shut it off when it's that hot.

There was probably boiling coolant in the system and the pressure that caused forced some out into the resevoir (the only vent for the system). Your resevoir (passenger fender) was probably overfull. The neck doesn't really seal to the tank, it just sort of sits in there. So you ended up with more coolant in the tank than it can hold and it leaked out.

Moral, when it's that hot slow down for the last mile or so. Set your turbo timer to around 30 sec. Make sure your coolant resevoir is not too full, though loosing coolant from it isn't a problem, if you know it's too full and expect it.

Be aware that when the engine cools down it sucks coolant from the resevoir back into the engine. If you have a pooly sealed cap (either one) they will leak -air- into the system which will stop this refill from happening. This is one reason the resevoir can get overfilled. When the engine heats up it forces some coolant into the resevoir, but the air leak (under vaccum conditions) stops it from being sucked back. You will not see a coolant leak from the faulty cap as they usually seal under pressure, just leak under vacuum. The fix is new caps - not really very expensive. Make sure the one without the spring goes on the engine and the one with the spring goes on the AST - if you don't have an AST the one with the spring goes on the engine.

a3dcadman

iTrader: (1)

do a search. most diagnostic processes and solutions have been discussed and elaborated upon.

here are a few basic things to consider.

1. reduce engine well temps - do you still have a precat? clean engines run cooler.
2. check coolant levels - check for leaks - burp cooling system - coolant to distilled water mix ratio?
3. do the fan mod - allows you to turn the fans on manually and at shutdown.

chuck

riptor

here are a few basic things to consider.

yes i still have a precat..hopefully not for long..

to burp the cooling system is there a tool i can borrow from autozone?
def on my list of things to do.

chuck[/QUOTE]

potatochobit

iTrader: (1)

its never normal for the coolant buzzer to come on though... so u may have a small tiny leak in the cooling system.


but yeah, if its hot outside, turn off the a/c and do not boost for the last 3-5 mins of your drive when reaching your desitnation. if you hear your turbos making the 'gurgle' noise, u know the car is very hot.

Sgtblue

iTrader: (16)

http://homepage3.nifty.com/norihon/muffler/muffler.htm
A recent post (from scotty305) with an overview of the cooling system and links that might be helpful.

riptor

cool...like i asked earlier can i get the pressure kit thingy from autozone. or do i have to go buy one..?i normally dont drive w/ a/c. i think that it decresases my gas milage..dosent it. or is that just another myth of the automotive world?

Sgtblue

iTrader: (16)

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/cooling-system-flush-info-441967/

Edit: Sorry, posted wrong link. This is the one I referred to above.

POS7

Whens the last time you replaced your thermostat? It may be failing, so you might want to change it as a "reliability mod". Note: thermostats don't instantly fail usually, they'll stick open or closed or open or close partway (at the wrong temps).

IMO for the fans to kick in after the car is shut off, the car is running abnormally hot. The only time I ever had the fans kick in automatically after shutdown was when I had a bad thermostat (Water temps 105-108C)

Also IMO turbo timers are unnecessary. Just let the car cruise for a bit before you park it and let it idle for maybe 30 sec or so. I never understood the purpose of turbo timers. Who walks away from the car with the engine running? What if it malfunctions and keeps the car running all day?


Isn't it better to run your A/C (as it will keep your fans on). I've noticed that keeping the a/c or a/c fans on either on freeway or city driving will help reduce water temps and heat soak. If its hot outside and I turn off the a/c or the a/c fans (city driving) I notice the water temperature rise almost immediately.

David Beale

If you turn on the A/C, the fans run one speed higher than if the A/C is off (I think it's one speed higher, anyway). It's listed in the shop manual, as I recall. That's the main reason turning A/C on seems to make the car run cooler.

Some vehicles get better mileage with the A/C on compared to opening windows. An example is my Nissan Pathfinder. In fact they state that in the owners manual. I didn't believe it and tested and found it was correct!
I don't know if the RX-7 falls in that catagory though.

the_glass_man

iTrader: (2)

If in doubt I replace the thermostat and go from there, they are cheap enough. When I used my turbo timer it would make the temp increase because the car would be running in a sitting position and with no incoming air the radiator would heat soak. Does your car have the fan modification?

RX7Wishing

dont let the car idle when its that hot outside... period..


The turbos are watercooled. So unless you were WOT the entire time. just shut off your car.

riptor

no i dont...what is it just a switch inbetween the relay and the fuse or what..?

whitehill

this happened to me yesterday too. I thought I had a radiator leak and I took out my radiator and tested it, but no leak. I think my coolant was just boiling and that is why **** hit the fan. I had just come off the freeway sitting in traffic and let me car cool down for 30 sec then when I started up again the water temp quickly jumped to 112 degree celsius...

Sgtblue

iTrader: (16)

http://rx7.voodoobox.net/howto/fanswitch/fanswitch.html
http://www.scuderiaciriani.com/rx7/fan_mod.html