Pumped

the cap on the metal canister part, NOT the ast,
I bought 16 psi rad cap but it has spring mechanism on it while the stock coolant filler cap doesn't is it ok to put on, or is that cap not a rad cap....??

Johnny

isn't 16 kind of high.....I thought 13 was the one to use....I can never remember

rynberg

You're right, stock pressure is 0.9 bar ~ 13 psi.

Bacon

iTrader: (12)

the one on the thermo neck dosent need a spring type cap hence how the stock dosent have one...the one on the ast is the press cap...(the one with the spring) put your new cap on the ast not on the thermo neck...the thermo neck should just have the flat cap on it...

Pumped

can this cap go bad?? because, I have a coolant overflow problem, and pple recommend me to replace the caps with 16 psi ones, but I wasn't sure if I needed to replace the cap on the thermo neck with a 16 psi one...

rtryrktrx7

Not that this is your problem but it could help some one. After I had my motor replaced my over flow tank kept throwing up after a drive. Turns out the caps were swapped.

Bacon

iTrader: (12)

i guess theres some way it could go bad but its not goonna effect coolant over flow @ all
if you had a leak coming directly off the thermo neck i guess it went bad but if the overflow is your problem... just replace the one on the ast...

whats your simptoms of over flow? how many miles on the car...any white smoke @ startup?

Pumped

My car is a 93' 100k kms ~ 60k miles, on a cold start i'd get a initial puff of white smoke then I get a less condensed cloud that will last within 10 - 20 sec, mind you it was pretty cold up here these past weeks, we actually had snow 2days ago smoke does not smell like coolant..

recently changed oil.., no coolant in oil nor oil in coolant,
changed spark plugs typical brown residue

But I did find a tiny bit of mayonaise type gunk on my oil cap...

mods are DP, MP, SMIC, intake, exh., pettit unlim ecu, pettit ast, greddy profec b, @ 11.36psi

coolant just started to spew out from the rubber purge hole from the overflow tank 3-4 days ago, and continues to do so every once in a while after a drive

hope its not my seals

Bacon

iTrader: (12)

is the coolant going out and not gettign sucked back into the system?

if not it may just be you over flow over full
dosent the pettit ast have a 16 psi cap on it alredy?
and they use those saftery valve ones..

user 84205

Hey bro,
Im here in Japan and have heard this problem a million times. Flush the system, if coolant runs threw the motor and radiator just fine GET STOCK!!!! the stock ones are the best, this has came form many companies around here, even the companies that sell the caps HKS, COCKPIT, AUTOBACS. ON the RX7 stock is best for those, both my are spring loaded, 1.2 and 0.9 on the plastic box.
LATE

97' FD Type R
55,000 km= around 30,000 Miles i think
HKS T04-E
Full straight pipe (Hyradshokai)
Speedline gold wheels
JUN FRP hood
Trust New type front mount intercooler
All aluminum piping, trust straight piping, Polished
battery in truck
Roll cage Cusco
NO back seat
Apexi power FC
Blitz Fuel/ Boost guages
HKS pro boost controller
MOMO 30' steering whell
4 point racing harness
Cusco strut bars
HPI engine torque brace
AND STOCK COOLANT CAPS

PEACE OUT!

Pumped

my pettit ast came with a 13 psi cap with a red release lever.
i just changed both the ast and the coolant filler cap with 16 psi. but its still spewing coolant from the overflow tank, just a little though

Bacon

iTrader: (12)

is it holding coolant or is it loosing coolant?

like is the coolant level sensor goin off?

if it is..time to get a press test..i think the seals may be goin :sorry:

badass7

From a cold start (in the morning) take your filler neck cap off and start your car. You will lose about a cup or so of coolant but what you want to do is look for "Champagne Bubbles". If you start it up and run to look and find bubbles coming up....that means you have a coolant seal failure and need a rebuild. Try it out and report back.

Pumped

Bacon: its only losing a bit of coolant like maybe a few tablespoons. its coming from the little black hole from the reservior tank by the passenger headlight.
and no, the coolant sensor has not gone off.

badass7: thanks for the idea, ...i'll try it tommorow morning.

Pumped

Ok I did your trick this morning and what I found was

Tiny specks of fizz type bubbles, they were not very noticable, they would come up for a bit then stop,... maybe 4-8 specks per second when active, the size of the bubbles are nowhere near the size of sodapop bubbles which are roughly .5 ~ 1 mm,

the bubbles I was getting were more like .01mm

I had to use my maglite to spot them...

so does that mean I have a small leak, or is it ok...

dammit I was hoping the car would last me at least another year

rx7speed811

if you eliminate the ast, then you can use the 13/16psi cap on the water pump housing.

stock 1993 fd's use a 13 psi cap
stock 1993-1995 fd's use a 16 psi cap

rotorbrain

hey guys, i just did that morning coolant test too. how long am i supposed to wait. all i saw was that the coolant aslowly rose to the top. i didnt see any bubbles at all. but when i start my car and let it warm up for a while i notice coolant purging at a very slow rate out of the overflow tank. its a very slow drip. i have a 16 psi cap on it and my ast has been removed. im not getting the light so much anymore. im gonna change the thermostat out this weekend just to be on the safe side. the only thermostat i could get was the 195 deg F one though. i was wanting the colder one. . . just to be safe. do you think it will be okay?

rynberg

Wrong.

The original coolant pressure was 1.3 bar which is 16 psi. The recall and changes in 94 reduced pressure to 0.9 bar or 13 psi.

rynberg

No, you need to get the OEM 180 deg thermostat.

rotorbrain

POO!!!

rotorbrain

oh yeah, when i had the 0.9 cap in there i had massive purging. it was bad. i put the 16 psi cap back on and all that purging quit. . . well, it slowed down a lot. whats the deal with that?

rx7speed811

oops, i meant what he said.

Pumped

so anyone know if its rebuild time???