trying to track down why its occasionally running too hot

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
Hi guys, I have a 1986 Caprice with a 305 engine, when I put the car under power like climbing a hill the engine wants to get hot.
Sometimes it’s to the point where I really need to pull over. Once you get on a level road it cools back down.
I swapped out the clutch fan but it’s still doing it, any ideas before I start changing more parts.
Thanks

have you tried adjusting the ignition advance curve?
have you replaced the t-stat?
have you checked carefully for vacuum leaks
a stuck or only partly open t-stat would pose an issue with restricted coolant flow rates,
do you have an auxiliary trans fluid cooler? this could make a huge improvement in engine cooling!
have you tried adjusting the ignition advance curve?
its rather common for small changes in the ignition advance to have a dramatic effect on engine temps.
most modern cars have a computer that only turns on the fans once the coolant temps exceed somewhere between about 215F-225F
and under load the transmission fluid temps will rapidly increase, this is very bad for transmission durability, but it also adds a great deal to the thermal heat loads the radiator must deal with, making use of an auxiliary trans fluid cooler almost mandatory when cooling during and higher loads like when towing?
oil coolers and trans fluid coolers can remove a great deal of the radiator's thermal loads.
Id also point out that a clogged exhaust or catalytic converter will cause the engine to run hotter under load,
is your fuel/air ratio ok? a clogged injector or defective oxygen sensors can cause the engine to run overly hot!

these links might help



have you added a fan equipped trans fluid cooler? if towing its a darn good idea!
its rather common for small changes in the ignition advance to have a dramatic effect on engine temps

and you might want to swap to a 190F T-stat and fan sensors that turn on the fans at lets say 200F


http://garage.grumpysperformance.co...low-rates-and-heat-transfer.9880/#post-101711



 
Last edited:
Top