MasterTomos

iTrader: (15)

My buddy's '96 TA loses coolant when it's parked. The temp gauge seems to work just fine, and it idles about 200 degrees, so it's not overheating. The coolant is coming out of the top of the fill/overflow neck. The only time I've seen this is when the car is overheating. The coolant is not overfilled. We havent got a chance to flush the coolant system, check thermostat, ect. but just wondering if there something specific we should be looking for before we dig in this weekend.

shbox

Bad radiator cap or the the steam pipe hose and overflow hose are swapped on the radiator.

I8ASaleen

iTrader: (9)

^ Take his word. Somehow you are equalizing pressure with the outside air, these 2 are the first things you should check.

SS RRR

iTrader: (2)

What these two said.

MasterTomos

iTrader: (15)

Radiator cap looks new, its one of the ones with what I will call the "locking" red arm on it. We'll definately take a look at the crossover pipe and make sure its hooked up to to the right places...thanks guys!

MasterTomos

iTrader: (15)

Are the steampipe and overflow the two coolant lines that run to the top of the radiator on the passengers side right behind the fill cap?

gregrob

iTrader: (8)

It hooks to the filler neck. The steam pipe should go to the bottom one, the overflow reservoir hose should go to the top one.

WS Sick

Ive never had good luck with the locking caps.

SS RRR

iTrader: (2)

I have. Between the Stant lever cap and a GM one the Stant seems to fit far better.

camar0corey

iTrader: (22)

Yep probably swapped hoses. I did that once and proceeded to scratch my head.

MasterTomos

iTrader: (15)

Thanks for the info guys, I know the car had some lines replaced recently before the car was bought, sounds like this very well could be the issue. Thanks!

jasonz28camaro

iTrader: (13)

I know this is an old thread but I wanted to see if someone could explain why mixing up the overflow and steam lines cause the coolant to blow out the overfill?

I just had this happen to me and found this thread doing some searches. I put them back where they belong but I'd still like to understand the problem. Thanks!

hrcslam

The steam pipe routes hot coolant from the back of the heads to radiator, it is under system pressure. The over flow (reservoir) line is not under system pressure and routes to the radiator on the other side of the radiator cap.

The radiator cap is designed to release fluid (or pressure) once it reaches a certain amount. If those two lines are swapped, then the reservoir would be getting the expansion of the cooling system which would allow it to over flow. The steam line wouldn't have anywhere for the fluid to go (the radiator cap is a check valve of sorts). The poor flow at the back of the heads, that the steam line is there for, would result is steam build up in that location. That steam build up will expand in the system even more and cause more overflow.

jasonz28camaro

iTrader: (13)

Thanks

ninjai_ruken

Not to bring back a somewhat old thread but I have also started having this problem as well. I logged my coolant temp at right around 180 parked my car and went inside. When I came out there was a puddle of coolant underneath my car. Im going to shoot for a new radiator cap this afternoon. I have a throttle body bypass and I know my Steam Line and overflow are not swapped because I checked them just to make sure. Ill report back if the new cap fixes it...fingers crossed


Ty McBride
Team Leader/Owner
McBride Motorsports

https://www.gofundme.com/vk5peys8

EDIT: Just wanted to let everyone know I am going to pressure test my system tomorrow should the cap not work. Cap looks beat up, so I was going to replace it any ways. Ill post an update

EDIT2: Radiator Cap seemed to fix the issue so far.

neilferguson

Here are some additional tips to help prevent coolant overflow:

• Check the coolant level regularly and add coolant as needed.
• Replace the radiator cap every 5 years or 100,000 miles.
• Replace the thermostat every 5 years or 100,000 miles.
• Replace the water pump every 10 years or 100,000 miles.
• Have the radiator flushed and cleaned every 2 years or 20,000 miles.
• Inspect the hoses for leaks every time you change the oil.

By following these tips, you can help to prevent coolant overflow and keep your engine running cool and safe.