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Blown hole in coolant tank, surging temps, need some advice

13K views 3 replies 3 participants last post by  2ndchancemalibu 
#1 · (Edited)
To make the story short........

2 months a go I had my intake manifold gaskets replaced b/c I was losing/leaking coolant, at which time I replaced the T-stat also. Problem solved.

A few days after I started smelling antifreeze every time i turned my heater fan "on". I'm assuming I have a pin hole leak in my heater core, but that's for a different day.

Yesterday I was driving home on the highway. During the winter months I usually leave my temp control on max heat to keep my toes warm and to dissipate engine heat. However with the unusual warm days lately I turned me temp control to max cold which is what i believe to have started the problem. Mind you this is all with the ac and fan off. Got home and hear a hissing noise from under the hood. Popped the hood and coolant is squirting out of a small line of holes in the side of my coolant tank. THE OVERFLOW TUBE WAS BONE DRY. Take the cap off, and fluid is VERY low. Filled back up, drove 5 mins, and fluid is gone again however none blowing through the holes.
Here's a picture where the holes were blown through.



Temporarily now i will fill her up everytime i drive the car, however the low coolant light still comes on. With my heater set to max heat, the output wil go from hot to outside temp back and forth randomly.

I've ordered a new coolant tank & cap. I'm thinking that b/c my overflow tube was bone dry the cap could have been malfunctioning; and now I have air pockets in my system since it is not pressurized; causing the low coolant sensor to go off along with fluctuating heater temps.

Any thoughts?
 
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#2 ·
I'd be inclined to think you're getting combustion pressure in the cooling system. Blew holes in the tank? Never saw that yet, saw radiators split the tanks but not an overflow tank, though I would say it's possible. When the overflow tank is full and the light is still on, the switch is just stuck in the tank. Where the sensor connector is, towards the front, there's a two wire connector. Take a screwdriver and rap that area a few times and usually the sensor frees up and the light goes out. Doesn't matter in your case, you need a new tank. If you don't see ANY outside signs of coolant loss and the tank is dry, it's possible the system has air in it, it's probable the head gaskets are bad though. Heater going hot to cold is a sign of that. The coolant odor could be coming from the heater core or from under the hood and the fresh air intake is just picking it up and sending it through the car. I suppose for now you should fix what you see, the tank has a problem. BUT, before you drive too far, see how fast system pressure builds up. Get the car running and quick drive it a half mile or so and lean on it a little. Then pull over and pop the hood and feel the upper radiator hose, can you squeeze it and it gives or is it solid feeling? If it seems okay at first, do that same sequence a few times as the engines warms up. Cooling system pressure should rise gradually. If it rises rapidly, there's a combustion leak most likely. If there's a bad head gasket or cracked head or block, it may be the cause of any heater core problems you may have as well.
 
#3 ·
UPDATE: put a new coolant tank and cap on. The 2 different sections of the new cap spin freely. I never had any idea that my old cap spun, it must have been locked together?

It's also a heck of a lot easier to go on now, vs. my old cap that was stuck together.

Everything has been well since and have not overheated once.
 
#4 ·
It's kinda funny I was adding coolant to the overflow tank on my 99' because I have a small lower intake gasket leak. I thought about this thread and noticed I have 2 little holes in my tank, just above the side tab. Must be a weak point in the plastic. My car doesn't overheat or spew coolant out them holes though. I can now add another part to my long list of things to replace.
 
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