I have a 2003 Jeep Liberty 3.7 L. Engine. It lost compression on both front Cylindrs (1and2). Do You know of any specific cause for such a problem?

SOURCE: 2003 Jeep liberty

There are lots of reasons for a car to over heat. To say why in particular in your case is a vague question and vague answer.

If you are not capable of working on the vehicle and diagnosing it you probably should take it to a shop.

The following are possible reasons for your Jeep overheating:
1. Bad radiator fan/clutch
2. Clogged radiator.
3. Low antifreeze level
4. Waterpump leaking
5. Faulty Radiator Fan Relay
6. Failed Thermostat
7. Bad coolant temp sensor
8. Clogged antifreeze resovoir tube
9. The list goes on and on....

It's best to get it diagnosed by a professional

SOURCE: Cylinder location

Standing in front of your jeep and facing the engine. The number 1 cylinder is the one closest to you on your right (the drivers side of your jeep). The middle cylinder on the drivers side is the number 3 cylinder.

Driver Side Front to back is 1-3-5
Passenger side Front to Back is 2-4-6

SOURCE: 2003 Jeep Liberty heater fan problem

It is the blower motor resistor. Look under the passanger side dash and locate the fan housing (looks round and black in color. Then locate the resistor it will be in that housing usually withtwo ten millimeter nuts or two simple screws holding it in. unplug the harness to the resistor and remove the resistor. Part store price is approx. 50.00. Note: on aftermarket (not Jeep) resistor sometimes you have to modify the housing a little to get it in. Hope this helps.

SOURCE: Install a 05 Jeep Liberty 3.7 in a 02 Liberty

BEFORE you put the engine in you must convert it with your old engine's crankshaft position ring and it's pick-up sensor. This ring can ONLY be changed with the engine upside down and out of the car. All rods must be disconnected, all mains are part of a cast saddle that must be removed, the front engine covers and all the timing chains must be removed, and finally the crankshaft must be lifted out and the ring must be hammer-unscrewed (impact screw driver, but I forget now if the taper-headed screws are allen, hex, star or phillips). DO NOT WASTE YOUR TIME REMOVING THE HEADS. The ring is ENTIRELY different than the one the computer system on the 02 Liberty can recognize (this is what triggers your spark timing). Next is the magnetic pick up 'wheel' located on the front of the passenger's side of the over-head camshaft. This magnetic cup wheel triggers the '02 fuel injection system (don't un-magnetize it). Lastly, the '02 plastic intake manifold (w/ O rings for seals) for the '02 has an additional port, this is an easy swap-out. Mostly there are no gaskets- the finish is so fine they just use a factory sealer (comes in a tube). Buy it, it's cheap enough and it matches the factory's specs. Taking the engine back out/in is NOT fun, but with the engine on a stand, and with no time constraints it's managable (but still not fun). I made that exact engine swap myself and went through a lot of anguish learning all of this. By-the-by, these engines will NOT tolerate dirty oil. DO NOT EVER try and stretch out your oil changes, because they run really hot (due to the windage tray that prevents oil mist from coating the engine's internals) an ash will form and goop up the insides. The fine oil pick-up screen (drilled plate) will always clog up. If it's been a long time since the last change and your engine is still running fine, when you get around to putting in new high detergent oil it sorta un-sludges the goop and REALLY coats the pick-up. DEATH BY SUFFICATION. If you're ever at this point (no damage yet) I would suggest doing the oil change (before there's any knocking or signs the engine is failing) and I would do 2 more oil & filter changes @500 miles each; hopfully you'll dislodge the ash/sludge and get it out of the engine. Once damage has started it progresses very quickly- this engine is not very tolerant. Your oil will be gold color, and yet your enging will sieze because it can't 'get to it'. BEST OF LUCK- this is very do-able, but you might first investigate if you can swap out the engine management computor and wire harness and maybe avoid all of this above mentioned wrenching. No back ground info here, plus I didn't have access to the vehicle the 05 engine was snatched out of- sorry, and good luck again. One last bit of advice- I bought a zero miles engine from a National Highway Admin. crash/test vehicle. When I broke the engine down ALL the timing marks on all three chains were not aligned and had to ALL be set- I guess they might do that to prevent the parts from re-entering the 'system'? Or, some dumb s__t at the factory was new and/or pi__ed-off and this engine was just plopped in the donated/untitled crash vehicle rather than ripping it back apart and re-assembling it. The damn Jeep fired on the second crank and is running fine now (2 years later). Ciao4Now, Brian Fahey

SOURCE: firing order diagram 2003 jeep liberty which is #2

You didn't supply the engine size,so I include both options.