jeremyb

I eliminated my AST and swapped the radiator cap neck with an 86 cap neck. I flushed the system twice then replaced with 70/30 coolant. I filled the system through the cap neck and TB line. I also filled up the overflow tank to a little over minimum. Then I ran the engine up to operating temps and let it cool down to bleed a little more. I repeated that process several times. When I decided to drive around for a bit the car was at 82ºC according to my commander. As I drove around, the temps dropped to 74ºC. I felt that this was normal since colder water in other places of the system have reached the temp. sender. Then I began to raise up to 76ºC and so on, so I was thinking that everything was ok. As I continue to drive(going to Albertsons to make a deposit), the temps began decreasing! It dropped to 72, then 70, then 69, 68.... and so on till I reached 64º!!!(where I had to park). I was like . When I got back to my car from making my deposit, I checked under the car for leaks(I know nothing overheated or blew up, it was just an instinct kind of thing?). When I started up my car it was at 85ºC and stayed there all the way home. It's now sitting in my driveway cooling down. Any ideas to why it decreased so much after decreasing ALREADY and then began warming up?

Jeremy

KaiFD3S

iTrader: (37)

I had a similar problem, I found that the previous owner had drilled the t-stat with 6 holes..since I changed it with a stock non-drilled one temps stayed at 83c and never goes below that since that is when t-stat opens up...

you might still have to purge the system, you might have not done it enough

jeremyb

I changed my thermostat twice so I know there's no holes. My temp stayed at 85ºC when I got back to my car. But did yours drop down after already having dropped down?(Sorry if that sounds confusing lol) Purge like bleed? If so, then I sure will.
How's your turbo set up coming along Kai? Sorry if you don't remember me lol. I had the green FD that one time you went to Chuck's shop with Dylan. The short filipino guy .

Jeremy

KaiFD3S

iTrader: (37)

I remeber you...car is still in progress just waiting on parts....my temps at that time would go all the way down to 67c and that is not good, I like my temps above 83c before boosting...just try to purge it some more..purging is like how you mentioned on your post run the car, let it cool down and add coolant as needed...

DaleClark

iTrader: (55)

Well, I guess it's better to be over-cooling...

Did you use a Mazda thermostat? If not, you may have a T-stat that's sticking open slightly.

I would just drive the car for a bit and keep an eye on it. It might clear itself up - could have been a fluke.

Dale

jeremyb

Yup my thermostat is straight from Mazda! Well, I ran the car 3 times since I started this thread and every time I added water after cool down, I'm adding about 1/8 of a gallon every time. Doesnt that seem like alot? Also, I'm using the 0.9 pressure cap that came with the 86 filler neck. I turn the cap mid way to see if water gets pushed into the overflow tube, but no overflow? Then I loosen the cap all the way and water gushes out so I close it back up. At this point the motor has been cooled for about an hour and a half. Should water be pushed through the overflow tube when the cap is loosened half-way? Or does the pressure have to exceed .9 bar to go through the tube?

Jeremy

iluvmy3rdgen

Keep getting all your air pockets out. Sometimes air in the system will lock the water and the sender isn't getting the right reading. Get the funnel that attaches to the neck so you can run the car and have it bleed itself out. Did you turn your heat on when filling the system?

https://www.rx7club.com/showthread.p...ghlight=funnel

jeremyb

I have a funnel but haven't done that yet. I guess that's what I'll be doing next. My heat was all the way along with the fan at speed 3.

Jeremy

iluvmy3rdgen

You don't need the fan to be on, you just need the valve to be open so the heater lines fill up with the coolant mixture. Becareful getting air pockets can overheat your motor if you're not aware of them and don't fix the problem.

TwinTurbo93

I also had coolant issues after I eliminated my AST, I seen temps go from 86 to 92 and back pretty fast, and the worst thing was that after driving long like 2 or 3 hours highway or local after I let the car cool of weel and than start again to continue I would realize I loose coolant b/c the buzzer would come on, didn't see any leaks anywhere.

I changed the cap few times thinking the cap might be bad and it still keept hapening the same thing all over again.

I put the AST back, bang, NO more...

jeremyb

My temps stay at normal temperatures now. But along with TwinTurbo93, I'm always adding coolant till now. No buzzer cause I grounded it, but checking coolant level every morning makes me add a bit of coolant every time. Now I'm getting boggy *** start ups and a huge amount of white smoke till I'm warmed up. But I think we ALL know what THAT means .....

Jeremy

TwinTurbo93

If you have a digital water temp. gauge or a PFC with commander it would be easier to find out if your temps go up and down without the AST constantly as mine did.
I have an aftermarked temp. gauge + the commander, the aftermarket one didn't show much diference as is harder to tell but as soon as I installed the PFC I monitored the temps more closely I realized the temps. changed few degrees up and down.

What freaked me out the most is that, where the hell the coolant goes if is not leaking out? Is the motor sipping it slowly? , You think coolant seals have had they're better days.
I don't get any white smoke or a boggy start up...

jeremyb

I have a PFC and the commander is what I use to moniter my water temp. Screw the stock gauge! I do think that my motor is sipping to slowly due to my boggy *** start-ups and white smoke frenzy at cold start lol. When I bought my car from the previous owner, he held in to tell me that he poured alumseal into the radiator system. How did I find out you ask? My buddy thought my overflow dipstick looked weird cause of the way the water fills up the holes and noticed shiny silver traces of alumseal. And the car was at 75k when I bought it. Last night I couldn't even start my car for liek a good 6 minutes last night after eating Jack in the Box. My coolant seals have seen better days. I just wish they were with me instead of that bastard that didn't tell me he poured alumseal into the radiator!

Jeremy