FD_dave

hey guys,

i have a '93 R1 w/ mazda reman motor ~1800 miles, aluminum radiator, new AST. i've been having smog problems as i posted in other threads. day b4 yesterday i took it to a mechanic who used to work at tri-point for smog. he fiddled w/ TPS and almost got it passed. we let the car idle the whole time when not running. he dialed up TPS to run REAL rich for the last ~20~25 minutes, at which time i'm sure the cat got real hot. whole session took about ~1.5 hours, w/ car idling most of the time and 3 runs on smog dyno (each ~10 minutes). afterwards i drove home (~47 miles freeway). it was a hot day, and i went 70~80mph the whole way. didn't detect anything unusual w/ car's temperature. car felt fine, tho the rubber cap over the turbo nipple (where the boost gauge tubing goes) somehow got lost along the way, so car idled fast and ran rich (lots of exhaust "popping"), didn't find out 'till i got home. i replaced the rubber cap and the idle went back to normal (b/t 700 & 800) and exhaust "pop" gone

yesterday morning i checked coolant. overflow tank was fine, not low, not high, just right. then i opened the upper cap (not the AST) and i found the level to be lower than before. (a week prior i spoke to john at mazdatrix about my high HC & NO and he said to check coolant level. then it was filled to the neck) it wasn't TOO low, maybe an inch from top at most. but that scared me, so i called mazdatrix again. upon hearing this (i also confirmed w/ him the previous engine overheated, thus reman motor and new radiator), john concluded my cat's dead (original cat 74k miles), thus coolant leven went down. i asked him about the o-ring and he said that shouldn't be the case. i topped off the upper cap (didn't check the AST) and ordered a cat. this morning i checked coolant again. overflow tank was fine, but under the upper cap it wasn't topped off, maybe 1/2~1 inch below top. i opened the AST, and that also wasn't topped off, maybe 1~1.5 inch below top. what the heck? am i losing coolant or should i have topped off the AST the first time too? there's no leak spots on the garage floor. after opening the AST the upper cap level went down some more, overflow tank was still full. is something wrong w/ my car? i'm REALLY deathly afraid of busted o-ring. the motor runs fine. i had compression checked a week ago, both rotors had 100 and 105 readings. i've seen no white smoke whatsoever, not even at startup in the morning. i've smelled the exhaust and got teary eyed but don't think i detect any sweet smell. what's going on? would 1~2 hours of idling and hard dyno runs on a dead cat consume coolant? help!!!

adam c

iTrader: (2)

Sounds like you just have a little air in your system. To remove it, jack up the drivers side front a few inches. Remove the Throttle body coolant line. Slowly fill the AST. Wait to see if it goes down. Watch the TB for over flow during this. If it overflows, put the hose back on, and tighten the clamp. Fill the AST until it won't go down. Cap it and slowly fill at the filler neck. When it stays full, cap it. This should get rid of most of the air in your system. Drive it a few times, and check the filler neck after it cools. You will probably have to add a little more before it stays full.

After this, if it keeps going down, check with your mechanic.

FD_dave

um...which one is the throttle body coolant line?

do the coolant levels in the filler neck and AST have to be completely topped off or is it ok if they're just a bit under the top?

FD_dave

is the throttle body coolant line the same thing as the "water hose" running into the back side (the side facing the firewall) of the throttle body?

when the mechanic was tinkering w/ TPS during smog, he removed this water hose. would this have let the air into the system? i thought of this 'cuz i was reading the shop manual and it said to drain out the coolant before removing the water hose (and throttle body)...