yearrgh

I've got a question about reted's procedure. am i supposed to leave the rad cap on or off. it's not overheating anymore so i wouldn't be able to get it to hot without taking it off, but i wanted to double check with someone

Amur_

I did it with the cap on.


I like the idea of doing it with the cap off to reduce the boiling temp. The thing is, this would make a hell of a mess. So I'd suggest leaving the cap on and turned to the first 'notch,' so that's not going to pop off, but it isn't tightly in place, either (the sys won't pressurize as much.) Then put a rag over the cap to keep coolant that does come out from spraying all over the place.

That's my suggestion. I haven't tried it that way myself yet.

yearrgh

Well i did the flush. I tried to get it to overheat, but it would'nt. the guage stayed exactly at 1/2. i'm wondering if i was supposed to leave the rad cap off... anyhow, i did some hard driving up and down the street for a good 20 mins and it performed without a whimper. no overheating, no coolant buzzer, it did blow a very small amount of coolant into the overflow, but other than the upper radiator hose feeling like a balloon, i wouldn't be able to tell there were any problems. so then i drained it, rinsed it, and filled it with coolant. it didn't seem to want to bleed out properly, which has happened before. it doesn't have a steady stream of bubbles, more like sporadic gushing followed by the coolant level dissapearing below the filler neck. after about 20 minutes of this and 2 gallons of coolant, i gave up. i let it cool down, filled it to the brim and retried the geyser test. again, i didn't get a geyser, although it does flow out at a slow, steady pace when cranking. I should also mention that i had absolutly no white smoke during the entire process. anyone have any insights?

yearrgh

anyone?

Amur_

Couple of notes:

- when I did the mod flush, and I had my sys full of Prestone Flush, I drove around for a full half hour and the temp wouldn't go up (like yours wouldn't.) I finally went back to the shop I was using, parked my 7 in front of one of the bays, disconnected the e-fan and waited. Then the temps climbed. I know I reported this in that thread.


- Did you use the bleed screw on top of the rad when you were refilling the system?


- To help get a lot of air out, after you've poured in as much coolant as she'll take place the palm of one hand firmly over the rad cap hole ( to seal it) and then grab and repeatedly squeeze each of the rad hoses, starting with the lower main one. Squeeze each hose up to 6 times, then remove your hand from the rad cap hole and check the level. Top up the coolant as needed and repeat until the level stops dropping. Begin squeezing next hose.


What do you mean by, 'upper rad hose feeling like a balloon?'

Were you refilling the system with the car running? It sounds like you did.

Another trick to get a lot of air out when refilling is to disconnect the hose that goes from the engine to the heater core on the driver's side. When coolant starts coming out of it, reconnect it.

Do you have any interest in trying to do this flush again? If so, PM with me an email address and I'll send you a super-long step-by-step write-up I did for another member a few months ago.

yearrgh

[QUOTE]Originally posted by Amur_
Couple of notes:

Quote:

- when I did the mod flush, and I had my sys full of Prestone Flush, I drove around for a full half hour and the temp wouldn't go up (like yours wouldn't.) I finally went back to the shop I was using, parked my 7 in front of one of the bays, disconnected the e-fan and waited. Then the temps climbed. I know I reported this in that thread.

Now that you mention it, i do remember reading that. I guess the following 7 pages of flame-war turned my brain to mush.

I've got a 90, don't have one.

I'll try your way a little later today.

It's so pressurized that I can't squeeze it at all when the car is running. It also feels like it has air or steam in it when i give it a wiggle.

A mechanic friend of mine reccommended doing it that way since I don't have any bleeder valves anywhere. It worked quite well when he showed it to me. But I'll try your way next.

I'll try it.

Sounds great. I think I need to. I'm guessing it has a restriction since when I put in coolant it rather quickly fills to the neck then glub-glub's its way down (after the first 1/2 gallon or so). This is alot more noticible than any other car i've put coolant in, although I suppose it could be normal for our cars. Thanks for all the help.

Amur_

Waiting for that PM... I'm about to head out for a few hours so don't expect a reply 'til later 2nite.

It takes me quite a while to fill my sys, too. Glub-glub, pour, glub-glub, pour...

That ballooning of the rad hose is kinda weird. To clarify, you're saying that when you were filling the system, with the rad cap off, the hose was ballooning? What were the exact circumstances at the time you noticed this?

yearrgh

When I was filling it with the cap off, it was like normal, since the pressure wasn't held in. I could tell that there was air, not coolant in it. when i put the cap on, it rather quickly gets pressurized to the point where i can't squeeze it at all. I don't mean ballooning like its getting bigger, just that it feels like an overpressurized balloon when i squeeze it, which is the main indication that the system is overpressurized.

yearrgh

Got your email, thanks.

Amur_

Good.


I don't know what to make of the hose ballooning like that. I'll check out my 7 tomorrow when she's warmed up to see if my hose is at all like that. Some comparison is more useful than none.

What is the feel of the lower rad hose like?

yearrgh

Not sure. I'll check tomorrow. I know this is abnormal, since during the brief periods the car was running right, like after i replaced the water pump, I could squeeze the hose and feel it surge back. I don't know if i've mentioned it previously, but the few times I've been stupid enough to open it when it's like that has resulted in a surging geyser, kind of like opening up a well shaken can of coke. (it does pass they geyser test though. i know i mentioned that.)

yearrgh

Well this has gotten a little more bizzare. I was trying to bleed the air out of the system, undid the heater core hose and filled it until it came out there, then went for a little drive. the buzzer came on briefly a couple of times then went off. Once, it stayed on for about 2 minutes. The temp guage is whats weird. It never got past 1/2, and kept dipping to 1/4. (maybe because coolant was getting vented into the overflow. it was at the low mark when i started and full to the brim when i got back.) anyhow, the odd thing is that i noticed that by increasing my rpm's, the needle would drop in a direct relationship to the increase. if i revved it high enough, the needle bounced off the floor and came back up a little. Also, if the buzzer was going off, downshifting to higher rpms quickly made it go away. I'm thinking this means i have a bad waterpump again, or my thermostat isn't opening fully.

Amur_

Okay, did you also do the hose squeezing thing after you had reconnected the heater core hose and topped up the fluid?

Okay, I'm working on this - I should have more to post a little later. In the meantime, here are my thoughts...

- air pockets are passing over the sensor, and so the readings go wonky. I think that this is highly unlikely.

- the sensor is faulty.

- the wire from the sensor to the gauge is either damaged or grounding out.

- the gauge itself is faulty.

- you need glasses. (j/k)


Faulty Temp Sensor - I've never heard of a way to test these damn things. Probably the simplest thing to do is install an aftermarket temp sensor. I did b/c I was frustrated at not knowing exactly what was going on with my coolant. It's one the best mods I've done to my 7, and one of the first things I noticed is that the coolant temp can change by as much as 25F before the stock gauge will begin to move.

Info and pics here about my aftermarket gauge:
https://www.rx7club.com/forum/showth...hreadid=137825



Bad Wiring - I used to have a thing that told you how to find wires that are grounding out, but now I don't know where it is.


Faulty Gauge - again, I've never heard of a way to test the gauge. I get the impression that most people install an aftermarket gauge to remove any concerns about the stock gauge's readings.


If the gauge is reporting properly and there are no faults anywhere (which I really doubt,) then there is some weird-*** **** happening inside your motor.

I did have my 7 out today, both for a quick joyride and to set the TPS, and I forgot to check the firmness of the rad hoses. Sorry.


Well, I guess the point of this post is to encourage you to get an aftermarket gauge. You can get one at just about any parts store. As you'll see in that thread, getting your thermostat housing tapped is both cheap and quick. I'd recommend getting a gauge pod for the gauge. I got mine from www.rx7store.net.

So there you go for now...

yearrgh

I do need to get an aftermarket temp guage... My first guess was that there's a problem with the guage or something, but it's too consistant. Tomorrow I'll check, but it just occured to me that the accelaration associated with downshifting and flooring it might be making the wire move, grounding it somewhere.

Another odd thing is that I no longer hear coolant bubbling and boiling in the rad after I drive it. I thought it might just be because it's been relatively cold here lately, but It was nice and warm today when I drove it and still no boiling when I turned her off.

Anyhow, I finally took it to a shop, and had them use a sniffer on it. Unfortunately, I've got 60 ppm hydrocarbons in my coolant. As far as I know, that means I blew a coolant seal, but I still have two little rays of hope left:

-Is it possible that my beat to hell turbocharger has a crack in it's coolant passage?

-I know i'm running very rich. Is it possible that I have a leaky injector and I've got gas leaking into the engine and working it's way past the coolant seals and they detected that, not exhaust?

I realize that i'm probably just in denial, but that freakin engine only has 5000 miles on it dammit!

Once again, thanks for all the help.

Dvst8

iTrader: (6)

i still dont think you blew a seal.... no white smoke right? I had the same problem with the overflow tank...
you need to change your thermostat and your rad cap..
thats why you've got too much pressure built up in the system and therefore the coolant leaks into the overflow tank ( rad cap is not releasing the air properly )

yearrgh

Thermostate is new from mazda, and been replaced at least 3 times in recent memory. rad cap isn't mazda (i know, i know...) but it's brand new, and shouldn't have failed yet.

scathcart

I am battling the exact same problem. I let the car sit idling for 2 hours today, with the overflow canister empty. After two hours, the canister was till empty. I then went for a 25 minute drive, semi-pushing the car.

At the end of the trip, the overflow canister was filled to the minimum mark, and the buzzer just came on.

I am took out the thermostat last night, it makes no difference.

I get no geyser, and I get no bubbles.

I am putting in a new rad cap and thermstat, and replacing the overflow hose.



I doubt either of these is a blown coolant seal. I will verify for sure with a coolant system pressure test.

yearrgh

I got a pressure test with the test for hydrocarbons. the pressure test was fine. I'm thinking that the hydrocarbons are gas from a leaky injector working its way past the seal. I need someone to verify that being a possibility though, I don't know enough about the test they do to know if that would show up. as far as the pressurization, my turbocharger just caught on fire, so maybe it was overheating and causing localized boiling of coolant.