coolant foaming
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From: Mayaguez, Puerto Rico
coolant foaming
I recently bought a 1995 bronco w/351 and installed new radiator, water pump, hoses, eliminated the heater hoses and have been noticing that coolant foams up and overflows in the reservoir. There are no leaks. When I open the radiator cap, the coolant level is normally just above the transmission cooler. Is this normal? Any ideas?
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It doesn't really sound normal to me. It is normal for a cold coolant system to push some fluid into the overflow bottle as it warms up. But as it cools down it should draw it back in. You might have your radiator cap tested or replaced. It is possible it isn't holding enough pressure and also not allowing fluid to be drawn back in.
Or it could be a blown head gasket. If you start the engine with the cap off and the coolant just over the trans cooler, does it get frothy right away? If so then this could be combustion gasses getting into and pressurizing the cooling system. Might also want to do a leakdown or compression test.
Or it could be a blown head gasket. If you start the engine with the cap off and the coolant just over the trans cooler, does it get frothy right away? If so then this could be combustion gasses getting into and pressurizing the cooling system. Might also want to do a leakdown or compression test.
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Joined: Aug 2004
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From: Central Texas
Go back to WHY you put all that new stuff on there. What was the probem that you thought you were fixing.
The radiator should be totally full at all times... No air in there! The reason for thecoolantcontainer is to keep AIR out of the system air helps rust form inside the cooling jacket.
Now the heater hoses. Why not use the heater? I am not looking at that engine...does one of the heater hoses heat the intake manifold? If so it is NEEDED and should be reinstalled.
Your test for head gasket leaks is to fill the radiator to the top and start the engine withthe cap off and watch the fluid in the radiator neck for bubbles if the fluid level gets lower than the neck you must add fluid to keep the level in the neck if there is a stream of or ANY bubbles you got problems.
Big Jim
The radiator should be totally full at all times... No air in there! The reason for thecoolantcontainer is to keep AIR out of the system air helps rust form inside the cooling jacket.
Now the heater hoses. Why not use the heater? I am not looking at that engine...does one of the heater hoses heat the intake manifold? If so it is NEEDED and should be reinstalled.
Your test for head gasket leaks is to fill the radiator to the top and start the engine withthe cap off and watch the fluid in the radiator neck for bubbles if the fluid level gets lower than the neck you must add fluid to keep the level in the neck if there is a stream of or ANY bubbles you got problems.
Big Jim
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From: Central Texas
Why would anyone lower the boiling point of their coolant? The radiator guy is a plum complete unquestionable IDIOT!! That may be the stupidist thing I have ever heard an automotive guy say to a customer..
Big Jim
Big Jim
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From: Kansas
You do not need a 7 lb cap. The coolant foaming is a issue. I agree with 76supercab2 that there is the possiblity of a blown head gasket.
Time for a compression test or at least a pressure check of the system.
Time for a compression test or at least a pressure check of the system.
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From: nevada
I thought the same thing about lowering cap pressure. I wonder exactly how much the 13 lb cap raises it? Also, on the foaming issue, I once read of using a detector to see if there were exhaust gases in the coolant to confirm head gasket probs, but foam would lead me towards that too. I would drain and flush the system and see if it did it again. Maybe just contaminants in coolant? Anyone noticed lately how much anti freeze has jumped in price?
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From: Central Texas
Exhaust gasses in the coolant will cause overflowing and overheating.. Drain all that old foamy stuff out and install good new clean coolant.
The 13lb cap raises the boiling point of water to near 250deg. Adding ethylene glycol (antifreeze) will raise the boiling point! At 100% ethylene glycol the boiling point is near 350deg. Without a cap! However pure antifreeze will start to freeze at near -10deg. So it is not advisable to use pure stuff in the far north...we do here in central Texas.
Big Jim
The 13lb cap raises the boiling point of water to near 250deg. Adding ethylene glycol (antifreeze) will raise the boiling point! At 100% ethylene glycol the boiling point is near 350deg. Without a cap! However pure antifreeze will start to freeze at near -10deg. So it is not advisable to use pure stuff in the far north...we do here in central Texas.
Big Jim
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I had that problem with my 78 when I got a new radiator because my tanks seperated on the old one. it would "froth up" and thier would be while foam in the top of the radiator with the new one. My stepdad "mechanic" 25+ years said ya a blown head gasket. But I changed the coolant out for a second time and was hoping for the best, and guess what no more frothing, Might be worth a try but not a personal garentee. Have a brand new 16lb Stant cap on it and a 160* t-stat and it's been working great ever sense
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