Internal leak 2002 Jeep GCL v6

This is common issue early sign head gaskets failure for EJ251 SOHC engine for external coolant leak. Second gen 96-99 with EJ25D is worst because when head gaskets failed, it's an internal leak that allows coolant and oil mix together in the combustion chamber to destroy engine.
You can drive it for at least 6 months or more as long as you keep top up coolant since the leak should be small at a slower rate leak. I drove mine for a while before change head gaskets. You're looking at `$1000-1200 job a dealership since you might as well change the timing belt, water pump, idlers while engine is pulled to replace head gaskets.

It is probably is the heater hose or the heater return hose.

if the check engine light is still on..try taking to autozone or a good parts store..ask them to read any other codes..or try to erase them..see what it says..

you mean the evap core you need to pull out the whole dash to get to it at least 6hrs and that having some experence

there are only three places for coolant to leak.external leak to the outside of the motor,internal leak like a head gasket causing the motor to burn coolant(white smoke out the tailpipe),internal leak(coolant leak into the motor oil.)you say that the head gasket was tested and it was okay then this takes care of burning coolant,however it could be leaking into the motor oil.check the oil level and condition.I would think the tech would have checked this,but check it just in case.if the oil level is good and not thick or white or milky looking then this is not the problem.you could have a leak externally like a hose leaking a frost plug leaking,water pump leaking,this should be checked out by having the cooling system pressure tested a carefully inspected for leaks

P0442 (M)
Evaporative Emission Control System Leak Detected (medium leak)
A 0.040 leak has been detected in the evaporative system. (A faulty gas cap may cause this code). Also see TSB 25-001-02A. Note: The respective Powertrain Diagnostic Procedures Manual will direct the technician to determine if the vehicle evaporative system has an external system leak. Examples of some external system leaks are: a loose gas cap, a disconnected evaporative system hose, or a loose hose connection. Remember that the evaporative system may also have an internal system leak. This internal leak may be caused by an intermittent or permanently stuck open Duty Cycle Purge (DCP) valve. This leak source is considered to be internal because any escaping emissions enter into the engine system and not directly into the atmosphere, unlike an external leak. An internal leak may cause one of the above DTC?s. Possible causes of a stuck open (intermittent or permanent) DCP valve are: 1. Corrosion due to system moisture or possible water intrusion into the system

P1281
Engine is Cold Too Long
Engine coolant temperature remains below normal operating temperatures during vehicle travel (Thermostat).
P0455 (M)
Evaporative Emission Control System Leak Detected (large leak)
A large leak has been detected in the evaporative system. See TSB 25-001-02. Also, possible faulty or loose gas cap. Note: The respective Powertrain Diagnostic Procedures Manual will direct the technician to determine if the vehicle evaporative system has an external system leak. Examples of some external system leaks are: a loose gas cap, a disconnected evaporative system hose, or a loose hose connection. Remember that the evaporative system may also have an internal system leak. This internal leak may be caused by an intermittent or permanently stuck open Duty Cycle Purge (DCP) valve. This leak source is considered to be internal because any escaping emissions enter into the engine system and not directly into the atmosphere, unlike an external leak. An internal leak may cause one of the above DTC?s. Possible causes of a stuck open (intermittent or permanent) DCP valve are: 1. Corrosion due to system moisture or possible water intrusion into the system.
P0455 usually a loose/faulty gas cap or cracked or broken hose to the EVAP canister or purge valve.

P1281 The engine coolant temp is too low probably a bad thermostat.

Hope that helps

No, you have either a internal or external coolant leak...

STOP DRIVING.

Go to a shop and ask for a cooling system pressure test.

After they pump up the coolant system,they will point out is there any INTERNAL or EXTERNAL leak(s).


Internal leak is the first sign of blowing head gasket. (NOT GOOD)

External leak can just a small hose.


Start monitor cooling loss.

Start monitor the oil level

Change the thermostat and gasket.

The temp sensor is cheap. Change it at the same time.

Use 60/40 coolant mix is you has high odometer reading like 160,000+ miles


DO NOT ALLOW the coolant and oil cross mix.

As soon as it mix,you are ready for a majot head gasket repair.


Good luck.

It could be the incorrect size on the seal.

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