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rpmdiag, Tech and Instructor
Category: Jeep
Satisfied Customers: 8153
Experience:  Since 1975
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Ok, 2003 GCL 4.0 cooling problem changed water pump radiator

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Ok, 2003 GCL 4.0 cooling problem changed water pump radiator cooling fan radiator cap when it warms up seeing steam at stop or low speed don't see any leaks
JA: What part of the car is the leak coming from? And are you sure it's water?
Customer: No leaks...losing fluid from the steam
JA: What is the model of your '03 Jeep?
Customer: GCL = Grand Cherokee,
JA: Are you fixing your Grand Cherokee yourself? What have you tried so far?
Customer: Yes replaced everything except thermostat
JA: Anything else you want the mechanic to know before I connect you?
Customer: No

Hi, I'm Ron and I will be helping you today.
Stand by for a moment while I prepare your answer.

This all being the case, then you may have a blown head gasket. Please be sure that the T stat is good too. You need to do a compression/cylinder leak down test to confirm it.

Please understand that I don't know your skill level or tools
you have to assist us. Also understand that I can't see, smell,
hear, or touch the vehicle either, so your patience is
appreciated. JA is a great Q/A site, but it does not replace a
repair shop. So please don’t shoot the messenger if I have to
deliver bad news:)
If you are satisfied with my answer, I would greatly
appreciate a 5 star rating now before you leave the site and I
will still assist you after you have rated me too if another
question pops up. I don’t get credit for helping you until
you rate me

Thanks, Ron

Did you have any more questions for me at this time?

Thanks again, Ron

rpmdiag, Tech and Instructor
Category: Jeep
Satisfied Customers: 8153
Experience: Since 1975
rpmdiag and other Jeep Specialists are ready to help you
Customer: replied 2 months ago.
Smell coolant haven't seen coolant in the oil or oil in the coolant

It's probably such a small amount at this point, that you wont see a transfer of the fluids, and I wouldn't wait for that to happen either, or you can hydro lock the motor.

Thanks again and please remember to rate me 5 stars now
and keep this link in case you need me again later on.
I don’t get credit for assisting you until you rate me

Hello, welcome and thanks for asking your question. My name is*****'m a Certified Auto Technician with 30+ years experience. I will do my best to assist you. please keep in mind that I may need to ask questions of you before I can answer. When you reply please feel free to add as much detailed information as possible pertaining to your concern.

I have a different answer. The 4.0 is not common for blowing head gaskets easily. You stated that you see steam and that this is where the coolant loss is coming from. Have you been able to determine where the steam is coming from? Can you tell if it is coming from the radiator?

At this point, I recommend to fill the cooling system fully, drive the vehicle until you can start seeing the steam. At that point, stop the vehicle, leave the engine idling and start looking for the source of the steam. Once you find where the steam is coming from you have found your leak. Most likely it will be the radiator so pay special attention to the radiator area when looking for the source of the steam..

Another thing that leads me AWAY from a blown head gasket is the fact that you didn't mention overheating.

Keep me posted...

Thank you,


Please let me know the results of the tests I told you to do and let me know if you need any more help. I have 42 years experience in this field. Plus you did say you replaced the radiator I believe. Anyway let me know your results so we can move on.

Thanks again, Ron