Another Coolant Problem

[Mr. Land Yacht]

now that I fixed that coolant leake in the intake, another problem has sprouted.
After the car is nice and warm and I drive it, the coolant starts collecting in the overflow and spewing right out of there.
I replaced my radiator cap and that didnt seem to do much.
I also replaced my thermostat and that doesn't seem to make a difference either.
if it helps at all, my heat is not working well at all...does not warm up.

anything that might cause this issue?
blockage in heater core?
cracked head?

any ideas?

-Colin

[89merk]

same thing happened to me, i kept buying radiator caps thinking i was getting lemons...i took it to the shop where they did a pressure test and told me my head gasket was gone...that MIGHT be the problem if your getting creamy gunk in the eradiator. but before going down that road, i would go to a ford or mercury dealer and get a factory radiator cap, instead of the crap they sell at auto stores..see if the overflow stops.

[87_crown_vic]

have it pressure tested and look on back side of engine for hidden leaks. if you have an air compressor, make a pressure tester. you can make one for $5-$10 opposed to buying one and paying $80-$120.

-take an old heater hose or buy a piece of hose
-buy a truck type valve stem that has the nut to fasten to rim
-punch hole in hose to fit stem into and seal it up
-block other end of hose with bolt and hose clamp to tighten hose to bolt
-disconnect a heater hose on front of engine
-block off heater hose with a 3 inch 3/8 extension in end you removed and connect your home made pressure tester
-where you disconnected your heater hose, connect the pressure tester and add air

that is how i tracked my coolant leak and found bad frost plug in the back of the cylinder head on my car

[gadget73]

I wouldn't hook an air compressor straight to the cooling system. It normally runs 16 psi and should be tested at that pressure. Hooking a compressor up can pump things up to 100+ psi, and that will blow stuff up. Its just not meant for that sort of pressure.


I'd wonder if you don't have a big air pocket in there somewhere, but a blown head gasket or cracked head is a possible. I'd say more likely a head gasket than a head though. If it was that though, you should see lots of bubbling if the motor is idling with the rad cap off, or it might just turn into Old Faithful if you crank the motor with the cap off. Oily sludge in the coolant or an exhaust smell from the coolant would also probably point towards getting compression into the coolant. The bit that doesn't add up though, usually head gasket problems are accompanied by overheating, not excessively cool running.

[1987cp]

Head gasket on that nearly-new engine would be highly annoying. Did you end up having the block decked at all? Just wondering, since that would logically improve head gasket sealing unless for some reason it's done wrong.

Also, what radiator cap are you running? I once noted a few years ago that I could easily obtain a cap in ratings from 12 to 18 psi. At the time, I went with the 18psi cap to eliminate what seemed to be a bit of an overflow problem.

[Mr. Land Yacht]

I have a 16psi cap IIRC.

The block was totally cleaned and machined, there shouldnt be any issue there.

[Mr. Land Yacht]

so in an attempt to force out any air pockets, I ran the car yesterday with the Rad cap off and let the motor get warm until the coolant started bubbling and then I closed the cap back on.
On the way home form that my heat seemed to be ok, but this morning it was back to ice cold even after 5+mins of driving when it would normally start blowing warm.
It actually felt like it was starting to get warm but then went right to cold again.

I think I'll try flushing out my heater core and see if tha helps.

[turbo2256b]

Try checking for vacuum at the vacuum motor that operates the blend door . Its behind the glove box. If the vacuum line to it is plugged and left off is there heat?

[1987cp]

Ditch the ATC. Problem solved!

[86VickyLX]

When you said bubbles Colin, what did you mean? Like little bubbles? Or like big gulps? Last time I had to burp the system, I waited for the stuff to over flow, out of the radiator, and then I closed the cap and filled the overflow thing halfway with coolant, then I revved the motor, the radiator hoses would start to compress, but as I revved it, coolant was pulled through the overflow into the system and the little air that was left in the system was replaced with coolant, making the radiator hoses nice and firm, and no longer collapsing.

[Mr. Land Yacht]

little bubbles.
I flushed the core this afternoon...we'll see tomorrow if it's ok but I doubt it.

Dave, I pulled that vacuum line a while back and plugged it so that I would have full heat.

[cld783]

how full is your overflow when the cars is ice cold? when the cars warmed up can you feel warm coolant in the upper and lower rad hoses? bubbles in in your rad isn't a good sign, it usually indicates a gasket leak somewhere. but you not having heat means it could just be an air pocket.

if you squish the upper and lower rad hoses when the car's warmed up that should tell you the thermostats opening.

[turbo2256b]

Fill the rad with coolant (just water to save money). Start the engine run with the rad cap off, add coolat as needed as it warms up. Once the thermostat opens (you should see the water flowing). If it violently spews water out with the coolant still cold. Do a compression check. If it dosent onece the coolant is flowing have someone turn the engine off while you are looking in the rad fill neck. If you see bubbles comming to the top do a compression check. Thhese symptoms usually are assoated with blown head gaskets. The compression check should confirm it. The compression check should show 2 cylinders next to each other low. Not always. If they are all low and a couple lower possibly blown gaskets and bad rings. Based on these findings I will explain what is wrong.

[Mr. Land Yacht]

I did that Dave.
started the car with the cap off..filled it with coolant while it was running and let it keep running.

[Mr. Land Yacht]

well I took it for a drive today...was real warm out today...like 60s.
drove it around..pretty hard..no coolant overflowing so I guess it's fixed for now.