Toronado76

Greetings all. My 76 Toronado Brougham is having an overheating problem I reckon. Every-time she is idling for more than 10 minutes the coolant starts bubbling violently in the reservoir.


I had a garage check it and they told me that the fan RPM was not enough, so they tweaked the fan and have it running at full capacity at all times. To the extent, when the car is idling and you stand in front, you will feel a slight suction from the radiator.


I live in the UAE where the summers are blistering. Currently we are at 50 deg Celsius during the day. My car is no daily driver, but even the weekend drives now seem cumbersome. The coolant bubbles, overflows and when I shut the engine down and let it cool, all the overflow from the reservoir somehow makes its way back to the radiator....


am confused. Please help!


Thanks.

scottv442

Greetings and welcome

Sorry to hear about your overheating issuses.
Firstly, is this a new issue or has this happened before when the weather turns hot outside?
If you can feel the fan sucking air thru the rad and condensor when parked then your airflow probably isn't the issue. At 50C your 455 would be hard to keep cool without a large capacity radiator.

Do you know the size of radiator you have now? Is it a 3row or 4 row and how old is it? Chances are the radiator is undersized for your climate.

FYI...the coolant overflow tank is to catch the coolant that escapes past the rad cap when the pressure in the rad exceeds the cap pressure rating. (15-16lbs) The coolant is then sucked back into the radiator as it cools after the car is turned off, so this is normal operation.

Have the coolant temperature checked at a radiator shop when your having this issue. If it's under 200deg. I wouldn't worry about it, but if it's higher than 220, I would suspect the radiator. Assuming of course your water pump is in good condition too.

oldcutlass

Is your overflow tank filled to the proper level when cold? Did your mechanic verify it was not a head gasket problem? Do you know what temp your engine is getting to at idle?

CRUZN 66

I would recommend a simple block leak check... Kits are available almost anywhere:

Gary M

Autozone and Oreilleys auto parts will lend you the test tool but you buy the fluid that tests it. The fluid will change color if you have a head gasket problem but will not tell you which side or if both are leaking. It's a start.
Some things to check;
radiator cap
fan clutch ( if has one)
check flow thru radiator
check if debris is blocking air flow thru radiator finns

oldcutlass

He lives in the UAE.

CRUZN 66

That's why I posted an AMAZON listing..