How to test Radiator cap. coolant boiling over

aa_ezra · Post by **aa_ezra** » 01 Jun 2011, 13:09

long story short, car never over heated coolant would come out of the cap. Replaced the cap with a new one OEM and it still poped a few times. Well i replaced the head gasket as exhaust gases were entering the system.

Car sat for a few months turned it on and ran it for a while today before taking it to get smoged. It passed but just as the smog test was over the coolant came out of the expansion tank they guy said.

Do i have a bigger problem here or is my Radiator cap just simply bad now even though it was new because it previously blew a few times?

Regards
J

Post by **jblackburn** » 01 Jun 2011, 13:50

Is the radiator fan working? It should come on after the AC has been running for a few seconds or after idling 10-15 mins.

If not, you might have either a bad coolant temperature sensor, fan relay, or fan itself. Unplug the coolant temp sensor and short the wires together and see if the fan cuts on.

aa_ezra · Post by **aa_ezra** » 01 Jun 2011, 14:44

I removed the coolant temperature sensor( located by thermostat) and jumped the connection on the harness. turned the key on but not the car.... no dice.. turned on the car...no dice... Temperature at normal and i turned on the a/c compressor is cycling on and of so i know its on and.. the fan is still dead.

All unpluging the temp sensor did for me was show that the engine was cold on the instrument cluster

Now what. I see 2 sets of relays above the fan. looks like 3 on one side and 1-2 on the other.

On most cars usualy turning on the a/c makes the fan turn on regardless. DANG!

now what?

aa_ezra · Post by **aa_ezra** » 01 Jun 2011, 15:21

ok found a post on how to check the relay. it cliks when touchign either the white/yellow or yellow wire... grabed the fan it it's locked up its hard for me just to spin it kinda like the bearings got rusted inside

SimLyons · Post by **SimLyons** » 01 Jun 2011, 15:29

Sounds like a new fan is in order....or recycled.