FuturePerfect

I had taken my FD to a local rotary shop when I incurred a massive coolant leak that happened when I was installing my aluminum AST/ Blitz SMIC (the latter of which I failed to install). Thinking I had mistakenly knocked something loose and frustrated with a failed install, I had my FD towed to a reputable local rotary shop.

Their diagnosis reported that failed coolant seals caused excessive pressure in the coolant system, thus causing the leak. I wasn't clear on where exactly the source of the leak was, so when I had my car towed back to my place, I did some investigating and found this:

The source of the leak was from the capacity tank, coming from a hole, or spout, that looked like it should be capped off. Here is a photo where I've circled this "spout." Mind you I'm looking straight down from my hood at the capacity tank.



Was there supposed to be a cap or seal there, or is it some exit hole to relieve excess coolant?

Also, when I looked directly under the coolant capacity tank, I noticed a plastic "catch pan" directly under the tank, placed on top of the mud gard. Here are photos of the "catch pan" and the mud guard which was dripping with coolant.





Is this "catch pan" supposed to be there?

Input would be appreciated, especially in regards to the spout in the capacity tank.

Thanks in advance.

perscription 7

U saved my day. Mine just did the same thing. I'm going to check out that spout

sevensix

iTrader: (1)

i have never seen that catch pan before or even mentioned.

however i know that the hole u found is supposed to be there uncapped. how did they diagnose the blown coolant seals? by the symptoms? or some type of testing like a coolant pressure leak down test, coolant hydrocarbon test etc.

the overflowing coolant from the tank can be caused by bad caps on your coolant system or even a tiny hole in the coolant return hose. the latter was the cause of my overflow problems(just like yours). once i fixed the hose the overflowing stopped.

r0gu3

That catch can looks like the passenger side bumper openning cover.

sevensix

iTrader: (1)

oh yeah

CantGoStraight

Yep that catch pan is a panel that covers the opening when there's no oil cooler (as in the R-1, and automatic cars) It won't hurt anything to remove it. The spout your talking about is on top of the recovery tank and is there to give the tank a place to evacuate coolant when the resivoir is too full and you don't want it traveling up the resivoir neck. I placed a hose on it to allow the coolant to run out of instead of it just running out over top ove the tank and all over the frame and under belly tray. You need to find out why the recovery tank is recieving the coolant and not allowing it to return to the motor. My guess would be you didn't get all the air out of the system when you did the AST replacement and might have induces the problem your having. It's also possible the AST cap or neck is defective/bent and not sealing properly which will not allow the system to build proper pressure or allow the coolant to return to the motor. If the seals wern't bad before you replaced the AST I doubt it went bad that quickly unless you over heated the car after the intallation of the new AST. ANy way drain some of the coolant out of the recovery tank (normal level engine cold) get all the air out of the system, see how much coolant moves into the recovery tank (hot motor) and them let the engine cool over night and see if the recovery tank returned to the original level it was at when the car was cool. If the coolant remains in the recovery tank then you need to find the leak in the coolant system.

bajaman

^ Wise words indeed.

From personal experience and from viewing many, many posts on this subject it seems that it really comes down to a couple of different things, either you have a bad AST cap or you have a compromised coolant seal (AKA 'O' ring) that allows combustion pressure to force coolant out of the system and into the overflow tank.
There have been a LOT of posts of "Oh ****!!!! My engine is GONE!" only to have the person (sheepishly but HAPPILY!) come back later and say, "Whew! It was a bad AST cap."

I really hope for the best for the original poster. And as others have said, have the coolant checked for the presence of combustion gasses and also do a leak-down test of the cooling system.

FuturePerfect

Thanks to all who responded. I'll go through the air bleeding procedure in regards to the coolant. One thing that I didn't mention in the first post was that my "add coolant" buzzer is triggered, even though there is more than enough coolant in the system. Does this change anything that was mentioned above?

Also, the AST has a 13PSI cap. Is this correct?

CantGoStraight

The add coolant sensor is in the thermoastat housing (filler neck next to air pump) and if it's not completely covered it will set off the alarm. The wire could also be damaged if you have plent of coolant in the thermostat housing. The 13 psi cap is fine if it actually holds 13 psi.

FuturePerfect

Fixed! For good measure, I flushed the coolant and properly burped the coolant (only had to do it 3 times). I figured out that I incurred air pockets in my coolant system when I installed my AST (I didn't drain the coolant). This is what triggered the add coolant buzzer. All I really had to do was burp the system, but I did a flush for the hell of it.

It also didn't help any that I was trying to fill the coolant at the capacity tank.

Thanks to Can'tGoStraight and everybody else for chiming in.

Harold93

hey guys,, i just went through the whole thing that you talked about, the only differance was that no matter how well we evaced all the air we were loosing coolant and we could not find a leak any where excepth the over flow port in the top of the resivoir. here is what we found the coolant seal had starte dwith a small crack in the oring, this was allowing the exhaust gasses in the chamber to enter the jacket water preasurizing the system. the preasure would force the coolant into the resivior but not allow the engine to draw more into the system so it would over flow. the more we filled her and ran her the worse it got. ffially it was to the point you could smell coolant in the exhaust. FUTERPERFECT, i am hopein gfor yoursake that it is not the same problem keep an eye on the coolant level over the next few days mine started realy slow if you did blow a coolant seal and you catch it before you realy over heat you can save alot of the engine components. it will be better for you in the long run. also remember that if you are low enough to get the coolant level light you are below the heat sensor also so you can be running alot hotter than you think if you are just using the stock gauge you need to be careful. any way good luck if anythign else happens just ask i am in the middle of it right now. i will help any way i can good luck