NEED HELP! 04 liberty NightMare

2004 Jeep liberty limited 99k miles

The day I bought the Jeep ( started over heating) 2x weeks ago.

List of service performed:

1.) New Reman complete heads
2.) New timing chain
3.) New water pump
4.) New head gaskets and intake gaskets
5.) New radiator
6.) New radiator cap

After the above its still overheating! No check engine, no trouble codes, everything looks good on scanner. If I don't close the radiator cap all the way it runs smack in the normal range. The minute I put the cap on tight it overheats 15 mins later.
I bought this as a Christmas gift for my wife and I'm running out of time. Any advice greatly appreciated.

Wild guess given your list of replaced parts, what about thermostat? These engines pretty much only like mopar for thermostat.
Unless the deck was warped the heads and gaskets should be good. Maybe try swapping the old radiator cap.

Other than the obvious engine mixture running lean and clogged cats can cause overheating.


Sent from my iPhone using Tapatalk Pro

Other than the tstat etc mentioned above, maybe air in system. Do both hoses get hot? Do you have heat? What is the evidence that it is overheating? Gauge or boilover?

Forgot to mention it has a new Thermostat as well. I know it still overheats based on the following:
1.) Gauge
2.) coolant Boil
3.) Scan tool.

Yes, both hoses get hot. I had a shop do the work for me, since this is beyond my wheel house. Ive read about a PURGE valve on the upper inlet. ive tried both radiator caps. same result.

I dont feel the cats are clogged, it passes emissions test with flying colors, has plenty of power. No lean conditions see to be present. ( according to live data scanner)

yes, heat works fine. It will melt your face.

The thermostat maybe stuck closed. I would test it in water and then slowly bring the water up to temp and see where the thermostat opens.

thanks! I'll test it in water.

Is the thermostat in correctly. I've heard of people reversing them. If that were the case it may never open but then both hoses wouldn't likely get hot.

These things can be a real bugger to get all the air out.

whats the process for using the bleeder? Do you bleed until there's a constant flow of coolant coming out? I assume you remove the radiator cap as well? How long should this process take to bleed? I'm new to these 3.7 Engines.

04limitedliberty said:

whats the process for using the bleeder? Do you bleed until there's a constant flow of coolant coming out? I assume you remove the radiator cap as well? How long should this process take to bleed? I'm new to these 3.7 Engines.

Click to expand...

Engine shut off,remove bleeder,remove pressure cap,fill engine through bleeder,once full put bleeder back in(tighten),fill tank,start engine(with cap off) and monitor level till t-stat opens.

Only ever open that bleeder with the engine off and cold and only fill through it.The orientation of the t-stat requires the engine to be filled or the t-stat will not open.

Is the radiator fan running?

kage860 said:

Is the radiator fan running?

Click to expand...

That's a good point.

Thanks everyone for the quick replies! That may be the money reply right there. I bet they never filled the engine though the bleeder. After all the services were performed. Infact I've never heard of filling a system though the bleeder, after the system has been drained. The fans work, and function normally. In the morning, I'm going to do as advised above. Keep you all posted

Don't sweat the minor problems. When you get this one fixed, another will soon pop up to replace it.:happy175:

These liberties are really that bad? God I should of got her a C.J with the 4.0 liter

Thanks Bob. Normally I would laugh. however, given the fact that it's my wife's Christmas present... Go F***k yourself.

So I refilled the coolant system, per TKJK2002's instruction. Placed thermostat in water, and it started to open around 206 degrees. Obviously I did this before refilling the coolant system. Started it up and slowly fed coolant until near full. Hed Rpms around 1200 for a few mins, added more coolant, and let run for 15 mins.

Now you can drive it without getting in the red, however the heater must be on. It will run very warm 3/4 up on gauge or a little higher. So it's better but still not right.

So your thermostat is bad. You will need a new thermostat. It should open around 195.

renegade 04 said:

So your thermostat is bad. You will need a new thermostat. It should open around 195.

Click to expand...

A properly operating t-stat for the 3.7 KJ should start to open at 195 degrees and be fully open at 218 degrees.

The electric cooling fan(main cooling fan) does not even turn on till 219 degrees or so.

Putting a t-stat in water then bring to a boil is not a good test since there is no water pressure present.With static flow(IE no flow) opening at 206 degrees might be correct as it may start to open at 195 degrees with water pressure present like it would if installed.

I get a 100% properly functioning t-stats to open at 70 degrees all the time at work,it's called water pressure(13-21psi to be exact).