ss04: it does seem that i am having more issues than you are, but give it a chance and push the car a little. sometimes my car will go several weeks with no problems and like you i think WOW finally i got it and then just as you gain confidence back it comes and bites you in the ass again! i will try a different rad. cap, but the one on it currently is brand new as we suspected this as well.

again as i stated earlier i have been fighting this for almost 3 months now so that may also appear why i am having some more issues than ss04.

i am very open to more options on this subject. keep in mind i have already done a LOT of things to figure this out, but shooot me the suggestions any how. its always good to talk things out!

 

Your problem is very unusual, 3 months is crazy to still be pulling air from the system. If you had a point in the system that was allowing air to enter you would also have a leak, and as you stated you don't.
Im a little curios as to your bleeding method, could you walk us through how you are doing it?

 

this is the method i do with my car... jack car to have radiator as highest point. run motor until bottom radiator line is hot. let it cool down and then open radiator cap and pour coolant back into the radiator. that should be the quickest way to bleed system. Do not just start the car after you have bled it, pull radiator cap and see if it needs coolant.

 

You do not have to jack up the car to bleed the system, there are two bleed points. One is on the front of the engine by the throttle body coolant lines, the other is on the fire wall directly over the engine ( little rubber cap w/ a clamp.

 

you are correct, but to make the bleeding process a one time deal, jacking the car up needs to be done. Having bled my coolant system probably 75-100 times already it seems to work the best.

 

AuDM cars definitely need to be jacked up. We don't have a rear bleed point.

 

sure.. as soon as i notice my spike in temp i run home as safe as i can watching the guage to not get too hot. i roll up onto some 2X4's to get a jack under the car and raise the front as high as my jacks will go. pop the hood and start the car. turn the heater on all the way hot and the fan all the way up. make sure the temp guage is at running temp. i crack open the bleeder right next to the valve cover and allow it to spit out the bubbles and air for a while until i get a steady stream. shut it off and allow it to run for a little while longer. i repeat this until i contantly get a steady stream out of the bleeder. after that i shut the car off and allow it to cool down. pop the rad. cap and make sure the radiator and resivoir are full. fill if needed (always does since i just spilled alot out with the air) and then start the car again and allow it to warm all the way up again. and again re check the bleeder real quick for any more air. all this while its still up in the air. this whole process takes me about 30 to 45 minutes.

the questions that i still have not figured out are how is the air getting into the system, and why my resivoir never stays full.

i will be buying a new radiator cap in the next couple of days, hopefully this will help a little

 

if i were to go out on a whim and say that it is the radiator that is causing this problem and buy a new radiator what should i do? i have heard that the Koyo radiator is very nice and i havent heard of any problems comming from it. but i dont want to get it and lets say that it is the aluminum radiator that is causing this issue and buying another one keeps the issue. my question is would i buy stupid buying another aluminum radiator, despite its better quality and less problems, over an OEM?

 

Koyo shouldn't be any better than a Mishimoto... there have been very few problems with these rads....

It could very well be your rad cap. Hell I may still have the same problem as you, there's just been too much snow on the ground so I can't take my car out to push her. We will have to see. Last time I bled my system I did EXACTLY the same thing you listed above. There was a lot of air that came out - and I thought I had gotten it all out before.

 

i think i may have found an issue with your process, the bleeder should never be opened while the engine is running it can and will allow air into the system. in the last 8 years of being a service tech i have seen numerous warnings on all types of vehicles (import and domestic) that state the bleeders should never be opened while the engine is running.

I have found that opening both bleeders up and filling the system on level ground yeilds the best results. warm the engine to operating temp and shut off, reopen the bleeders then remove the cap and top off the system.

but these are just what i have found over the years...... I hope you get things worked out soon