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Randy
02-14-2010, 11:16 PM
I have a '90 Outback that overheats occasioanlly. I have replaced the water pump w/new belts and pulleys, the radiator, and the thermostat. The heater blows cold (both lines to heater core are cold) and if I put radiator cap on all the way, the car overheats. If I leave the cap loose it doesn;t overheat so easily. It is 17 degrees in Nebraska today. FYI not a contributing factor. I am at a loss, any suggestions?
Randy

admin
02-16-2010, 04:36 PM
Hi Randy,

You should have a combustion leak detector hooked up in place of the radiator cap. This tester uses a special fluid that changes color if there are any combustion gases in the cooling system, which would most likely indicate a bad head gasket. They are available at most auto parts stores, and aren't very expensive.

Randy
02-16-2010, 06:14 PM
Would a bad head gasket cause it to overheat?

admin
02-16-2010, 08:46 PM
Absolutely. If a head gasket is leaking, hot combustion gases can be forced into the cooling system. Not only would heat be an issue, but pressure is being injected into the cooling system as well - way more pressure than the system is designed for.

Randy
02-17-2010, 06:46 PM
OK, I will check into that. thanks for your help.

admin
02-17-2010, 09:29 PM
You're welcome.

In case you don't have one already, your vehicle is covered in Haynes manual no. 89100 (it's a Legacy Outback, right?).

Randy
02-19-2010, 05:23 AM
I bought a Haynes manual shortly after purchasing my subaru. I have a problem with the doors locking when I shut the drivers door and on the front passenger door I have to hold the lock button to the "unlock" position while opening the door or it locks. If I get the overheating problem fixed the locks are a monor inconvenience.