coolant overflowing out of reservoir

[GSX503]

dang...I'm starting to think that my car is possessed just like wiseman ddavisaf mentioned on http://www.dsmtuners.com/forums/articles-engine-fuel/200575-help-im-overheating-heres-how-fix.html ..........

Anyways, my coolant overflow started after installing an FMIC and I've tried most of the stuffs mentioned on that thread but nothing seemed to work. I've been looking at threads that have same or similar problems for a couple months now but couldn't find a solution. Anyone have suggestions, let me know. Thanks!

Whats been done and checked:
-Replaced thermostat
-Replaced stock radiator cap to 18.5 psi cap
-Flushed radiator and engine block
-80/20 coolant mix
-Radiator fans running great
-water pump and radiator is 1 year 1/2 old (newly installed during rebuilt)
-belt tensions are fine
-checked a/c refrigerant level (still full)
-check compression (results = 187, 185, 185, 187)
-Heat wrap exhaust manifold and o2 housing (reduced heat 20-30%)
-raised the back hood 1/4 inch

(All i know is that the FMIC is blocking the air flow that used to go up to the radiator.)

 

[lccynmbr13]

Coolant puking out of the bottle under boost is generally a sign of a blown head gasket.

 

[fwdmaster]

I think it's your radiator cap, change it back to stock 13 psi cap, the 18 psi cap your using might be holding to much pressure causing coolant to overflow but your cap might be messed up and not holding pressure, this also makes your coolant reservoir overflow also

 

[copper]

Since you said it started happening after your fmic install, I'm going to have to suggest that you put a shroud around the fmic so that the air will be forced to go through it and through the radiator. Also, an 18psi cap might be too much, and under that pressure, could be causing more coolant to go into the reservoir than if you had used a stock 13psi cap. Another thing you could do is to take the radiator cap off (while the engine is cold of course) and have someone start the car while you look at the coolant. If it bubbles, that most likely means you have a blown head gasket which is causing air to go into the coolant passageways and pushing it into the reservoir while under boost. Of course if that happens the next thing you're going to have to do is a compression test to verify that its a blown head gasket. Good Luck

 

[siceclipse]

agree with copper

put in some kind of shroud or duct to direct air to the radiator for better cooling and put in the normal radiator cap.

 

[GSX503]

No head gasket issue here. compression is 187, 185, 185, 187. and no signs of oil and coolant mixing.

13psi radiator cap only makes it lose coolant faster

duct sounds good but what doesn't make sense is my brother's car doesn't have it on and no issues. I'm sure there are plenty others that don't have duct on it and don't have issues. I'll look into it though. thanks

 

[DSM1G90]

I have a boilover earlier this month from a weak cap. Pulled the radiator out, flushed the junk and rust out real good. Got rid of the condensor since it was cracked anywhos. Flushed out the block and heater core. Got a 13lb cap, put things all back together and been keeping good since.

Big issue also is where the front plate is mounted. If it's in the airstream, it acts like an air dam pushing air away from going into the radiator...

Seriously, I think that DSM radiators are a tad bit small for a turbo setup...

 

[GSX503]

thanks for the input dsm1g90. I've been hesitating about pulling the heater core out to see if its damage or clogged because it takes a lot of time. We'll see what happens this weekend. I'll post up if works or if I get the problem fixed.

update...

still no work done on the car. haven't been able to do anything since I've got legal issues to deal with.

update....6/2/09 >>>FIXED

problem fixed a few months ago. I just didn't have the time to log on to update this.
Ok...all i did was replaced that autozone thermastat with an OEM one and problem solved. I hope this help someone having a same or similar problem.