1. What is the'heater trick"?
Not sure what "trick" you are refering to, but if you are not getting heat or getting inconsistant heat the first thing to check is the coolant level and then make sure that ALL the air is bled out of the system...At about 1 pint low the coolant level drops below the heater core and you loose heat, especially at low RPMs
2.What is the compressor or leak down test?
Leak down test is a procedure that pumps compressed air into each cylinder and measures the pressure it will hold for a period of time..Also identifies where the air is escaping such as worn rings, head, valves, etc...You use this test after a compression test if a cylinder fails...If compression test results are OK there should be no reason for a leak down test..
3. Could the ticking sound be related to cold weather and or pulley bearing?
The first thing to check for ticking sound is the 2 front belt pulleys..A lot of times they sound like they are comming from inside the engine...Either remove the belts 1 at a time and, run engine briefly and see if it goes away or spray the bearing with white spray spray lube and see if it gets quieter...Cold weather makes them more evident when first started...Other typical 2.7 ticking locations include ; timing chain and tensioner; valve lash adjusters; A/C pulley and clutch; leaking exhaust manifold (usually goes away after warm up)..
4. What to look for if it is a gasket or rod bearing?
Gasket failure or leak typically does not make noise (head gasket may??) ..A bad gasket will usually leak something somewhere; such as coolant, oil, air , fuel, steam; either externally on the ground or engine or internally inside the engine like a head gasket or water pump gasket....Rod bearing is more of a knock or "double" knock sound coming from the bottom of engine
Start with the basic easy things and rule them out as causes first, before condemning the ole 2.7!!
Good Luck!.
I have been so careful with trep taking care of the oil changes and regular servicing as tune ups etc...I would just hate to have to turn this around to a 3.5 3.2,, and in this economic times, Im not quite sure to spend the money on that....yet.....
