Recentlyconverted

thanks, figure any info I gain I'd want to relay to the rest of the members, I don't want what's happening to my car happen to any of the other members. whatever little I can contribute to keep these cars alive I'm willing to put in

Ok, so nother update, just checked the forum on what it takes to replace the t-stat, and I guess I didn't realise I need to pull the water pump off to get to the t-stat, which I am going to do but not this weekend because I didn't buy a replacement gasket for the t-stat (I also read that depending on =how long it's been since thelast replacement, the gasket could be in very bad shape to the point of when you pull the water pump off the gasket might fall apart, but the gasket would be fine unless something screwy happens or the water pump is pulled off).

I'm going to change my oil to 20w-50 as well and try doing what I did again. I'm also going to pull the ac fuse and see what happens. will keep you guys posted.

Recentlyconverted

ok, new update. found out that the thread I read had false info. I didn't need to take the water pump off to get to the t-stat. so I started pulling stuff off and got to the t-stat housing, got off the t-stat housing, and found what looked like a not new, but not old, thermostat (definately wasn't a 12 year old t-stat at least). Now I've got a new problem, what I think happened when the old t-stat was put in, the person working on putting the t-stat housing back on tightened one of the bolts down too hard. cause when I tried to remove one of the bolts, with very little force the bolt broke, now I have a 1/4 thread to try and grab on to and get the rest of the bolt out (it's like the damn thing is welded in there). So I put some wd-40 on the threads of the bolt and am leaving it overnight to sit (also plugged up all of the holes exposed at this time to prevent the lube from the wd-40 to spread into places it shouldn't be).

So since i couldn't do anything else today, I decided to test the new and old thermostat in some water. Using a temp controlled electric pot, I filled it with water and set the temp to 180F, put the new t-stat in there and it opened partially within about 30 seconds. Then set the water temp to 210F, and the t-stat opened fully within 30 seconds again.

So when I decided to work with the old t-stat, I set the water to 180F, put the old t-stat in there, nothing happened. Ok, so I set the temp to 190F, it opened, but took over a full minute to open partially and did not appear to open partially the way the new one did. So I set the temp to 210F, put the old t-stat back in there, and it opened full just like the new t-stat, but it took about 45 minutes this time. Ok, so I took the t-stat out, kept the water at 210F, and then put it back in, and now it opened up fully again within the 30 seconds just like the new one. When I turned the water temp back down to 180F, now the t-stat opened partially within the 30 seconds like the new one. Hmmm, guess the old one must have been gunked up or something. So I'm gonna try to get the rest of that bolt off tomorrow , put it all back together, and see what happens.

OneRotor

iTrader: (3)

WD-40 won't do anything for those bolts, get some PB Blaster and soak the **** out of them like once an hour tomorrow to loosen them up before you **** up the broken bolt any more by trying to get it out. for your overheating issue, i can't help you because i don't own a FD yet, but don't try and take that bolt out with just WD-40

Recentlyconverted

gotcha, will pick up some and spray the bolt down, thanks dude

jeffrored92

Sounds like your gettin there mate, good job. It's so nice to see a forum member taking advice and getting stuck into the troubleshooting rather than posting a heap of questions, then buggering off never to be heard from again.

A pair of vice grips might come in handy for getting that bolt out after you've soaked it with whatever you end up using.

Spirit_Rotary_7

When you turn your fans on with the a/c switch, it automatically sets fans to run at 100 percent. I am enjoying your thread. Please continue.

GoodfellaFD3S

iTrader: (213)

This latest development isn't good. A new t-stat housing may be in your future.....

wstrohm

For general info regarding use of an OEM Miata thermostat, my 1990 Miata factory manual says the characteristics are as follows:

Type: Wax, two-stage
Opening temperature: Sub-valve = 182 - 188°F; Main valve = 188 - 193°F
Full-open temperature: 212°F
Full-open lift: Sub-valve: 0.06" min.; Main valve 0.31" min.

vs. my 1994 RX-7 factory manual which says:

Type: Wax, bottom bypass
Opening temperature: 177 - 182°F
Full-open temperature: 203°F
Full-open lift (min.): 0.31" - 0.39"

Don't know about physical compatibility, but the Miata opening temps look higher to me, not lower.

Recentlyconverted

ok, guys, another update. working on the broken bit today, I was using some carbide bit extractors to remove the rest of the bolt. The friggin bolt broke the damn carbide bit! I don't know what the friggin last person that worked on this did to that bolt, they've gotta have some kind of binding agent in it or something (I shot it like 9 times with wd-40, liquid wrench, and pb blaster each and the damn thing still won't budge. Ok, going back out to try and get that damn carbide bit out. Wish me luck.

keynote22

Koyo rad, vented hood, power fc with fans turning on high at 89/192. New thermostat, new coolant.

Same issue here.

with ac off...at idle or on the freeway the temp never goes 88 cel or 190 fh. It might go to 91/195 but will quickly cool back down once the fans get going. I can let it idle for an hour and never get higher than 91/195

Once the ac is on....in town traffic will raise the temps to 101/213 and seldom drop down below 96/204. If I am on the freeway the temp will stay at 89 but once I get off, Im heating up. Long term idle will see temps of 105/221

I am experimenting with the reasons why this is.

1st guess. The ac dryer sits on front of the rad. Maybe the heat from the ac dryer heats up the rad or the extra heat in general heats up things in generel. If so, then my vented hood should have helpd the problem. Nope. Same temps with vented hood or non vent.

2nd guess relates to bad wiring in the harness. My ac system only works on 1 and 2. 3 and 4 shut off the ac system--researching that sympton reveals power fc/ wiring harness issues. So it is possible that the wiring is doing somehthing else somewhere else. When the car is cold...turning on the ac turns on the fans so I know it is not related to fan speeds. The car is currently at the shop getting an electrical check up.

Needless to say, I am interested in others findings on this topic. FWIW another guy here with a similar system set up never sees temps above 91/195 when he is at idle ac on.

keynote22

wow. where did I come up with the idea that a motor that sees 110/230 is toast? According to your figures my car is running extremely cool.

what are the coolant seals made of? Buna rubber is only rated for 180 fh before they begin to break down. Viton, the more likely candidate is rated for 275.

Recentlyconverted

ok, new update. started drilling out the rest of the bolt that is stuck in the housing, but the carbide bit that is stuck in there kept eating the bits. Finally, after going through 2 titanium bits, I managed to get past the carbide, but for some strange reasone, the bits are still having a hard time trying to drill through the bolt (I'm starting to think this ain't no normal bolt you put in a spot like that). Gonna pick up some new bits this week and work at it again. I'm about a 1/3 of the way there (after drilling away about a 1/3 of the material, the outer barrle of metal just collapsed and I was able to pull out the top 1/3rd with a pair of pliers). Tested the exposed housing threads with a 10mm bolt, and it fits, so even if I have to send a tap back through the hole after drilling it out, it looks like it will still be in good shape, patience is the key I guess when doing this. Will continue next weekend, can't work on the car during the week. Will see I guess.

Oh, and one other thing I learnt, while the carbide bit will be stronger that most bits, if you intermitently use a sharp tipped punch and a hammer, it will slowly shatter the carbide, but only what is exposed (so it's like, shatter some carbide, drill expose more carbide, shatter that carbide, drill to expose more, and so forth).

Godzilla-T78

well juts my quick 2 cents.. I dont run a thermostat and never really have. If you live up where it gets cold I would, but down here in florida I dont bother. I dont even use the heat in my cars during the "winter" lol. Good luck man.

Mahjik

iTrader: (1)

You should run a thermostat regardless of where you are at. The thermostat (even one with holes drilled) adds the needed restriction for the cooling system:

http://www.mazdamotorsports.com/weba...ubject=cooling

If you are using a stock (cast-iron) water pump, we recommend "gutting" the stock thermostat, leaving just the thermostat casing. Because some "restriction" is helpful, generally removing the thermostat is not as effective as using a gutted thermostat or restrictor.

Recentlyconverted

So wait, it is recomended that holes be drilled into the thermostat?? Is this effective for a street driven car (will holes in the thermostat cause problems when sitting at idle for long or in the winter??). I figure, like one of hte guys said before, the radiator will loose it's cooling efficiency if the water is pumping through the system too quickly (I'm assuming that's why the thermostat only opens to the length it does). Not sure about how fast the water pump is pushing the liquid through the t-stat housing, but it does seem to be a relatively narrow passage of fluid (someone learn me please..........).

Recentlyconverted

ok guys, another update. I got the stuck bolt out by drilling out he hollowed area of the bolt, hammering a square headed punch into the center of the bolt, and slowly turned the square headed punch backwards and the bolt came out. One thing I have to say though, I got the pilot hole messed up while drilling because I couldn't get enough clearance even with the air pump rotate all the way back, so what I did is bought a diamond tip cutter/engraver attachment for a dremel and opened the hole up properly using the dremel and attachment (I would not advise this at all for anyone who does not have a steady hand and a lot of patience though, I was panic stricken the entire time I was opening the pilot hole). But needless to say, I got the seized bolt out, got the new t-stat back in there (also put on a new coolant level sensor while I was at it, it looked a little frayed when I looked at it, and when I went to take it off to put the new one in, the wire basically fell apart on the old one), put basically everything back together, the only thin I've got left to put back on is the intercooler and the intake duct and I'll be ready to start the car up. Will have to see what happens.


Also, I ordered an AST cap from the dealer, and what I got was something labeled as a radiator cap, but the design looks like an ast cap (it's got a spring loaded piece attached to a rubber washer). The only thing is the washer looks smaller than the old ast cap I have on the car right now, and when I put the new ast cap on, I don't feel any of the push back resistance that I do with the old ast cap (it basically spins on and locks in place but does not give the pushback resistance that the old ast cap did. Does anyone know if that rubber washer expands after the first time it heats up or somthing?? Are there any other cars out there that Mazda makes that has ast caps??? And if anyone knows that part # to the AST cap, I'd appreciate it if you could tell me so I can cross reference the part number on the bag the part came in. Will have to see what's going to happend tomorrow. Was gonna finish up tonight, but ran out of daylight. Oh well, will have to see tomorrow.

Recentlyconverted

OK guys, here's another update. Seems like in a lot of ways the new thermostat did the trick. Haven't seen too much traffic yet but have noticed that for the most part the water temp seems to move from 180 to 195 and them stay there a lot longer before it moves up again (started moving at about 200F or so). My oil is still heating up when I turn the fans on though. I'm gonna pull the ac relay and see what happens. But it does seem like the thermostat was due for a change cause I've noticed a hell of a lot of improvement from before (while sitting at idle for a while, coming to a stop at 195, I saw my temps drop or the first time to 180 with the fans on and sitting at idle at a traffic light). Seems like I'm getting there. Thanks so much for the help guys, seems like it's working out (keeping fingers crossed though). Will see what happends when I pull the ac relay.

RX7Wishing

i know the A/C fuse affects the Airpump... does the Relay as well?

Recentlyconverted

not really, sure, I know I tried to pull the ac fuse (not the relay, but the blue fuse), and the car worked fine till i came to idle, then the rpm started going into convulsions (pulsing between 500 and 900 rpm). Gonna try and pull the relay and see what happens.

PhoenixDownVII

Really? I did the same thing, with the same results.

When people do the A/C fan-mod trick, are they removing the Blue fuse or the Relay itself?

RX7Wishing

the relay.

trini

iTrader: (2)

dont turn on the a/c b/c that makes more heat. ..
if your running a koyo rad. its hard for air to flo threw it b/c its so thick..
so when driving slow the air probably wont flow threw the koyo rad.
.. use less coolant and more distilled water.
i use 20 50 non syn. motor oil. .. if you can . run a wire from your diag. box
TFA plug to a ground and put a switch on the wire inside the car so you can controle the fans with out turning on the a/c . dat should help with your traffic heating problems..

Recentlyconverted

is that the same thing as pulling the relay??

(haven't pulled the relay yet, don't have the tools for it at my apartment).

mad_7tist

or pull the elec connector off the compressor for yet another ghetto mod/diagnostic tool.....

Recentlyconverted

Holy christ it think pulling the ac relay did the trick. I hadn't pulled the ac relay yesterday and got stuck in some pretty bad traffic (about 45 minutes worth), so my car came close to overheating twice (when my water temp got to about 230F and oil was at like 230-240F I pulled over to the side of the road, shut the car down and let the fans run with the hood up to cool the car off, had to do this twice throughout my time in traffic). So came over to a friends place an pulled the ac relay off (it's in the fuse box in the passengers side of the engine bay under the plastic duct that is right behind the front bumper in the engine bay, the duct is held in place by 2 screws, so basically, open the hood, pull the 2 screws from the duct (the duct is between the intercooler and the front bumper), pull the duct off and you will see the fuse box). I ran the car at idle with the ac relay off for 30 minutes and the water temp did not shift a bit from 185F for the entire 30 minutes I ran the car (the oil temp did rise to 200 from 165 after running for about 20 minutes, but stayed at 200 for the rest of the 30 minutes), which is a hell of a lot different from when I run the car with the ac relay in and the ac on (water will hit like 220F after about 20 minutes). I think pulling the ac relay did the trick. I'll be damned. Thanks guys. (Keeping fingers crossed for the next time I hit traffic though)