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Richard, Jaguar Technician
Category: Jaguar
Satisfied Customers: 15556
Experience:  12 years at a Ford/Lincoln Mercury and Jaguar dealer as technician and shop foreman.
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It's overheating....i have changed the water pump, radiator,

Customer Question

It's overheating....i have changed the water pump, radiator, thermostat housing, coolant tank, auxiliary pump and the fans are working also I have heat when let it sit and idle but as soon as I go a 1/4 of a mile it starts blowing cool air no heat....there is no water in the oil and no oil in the water and the car runs good with no check engine light....its a 2007 jaguar s-type 4.2 no super charger
JA: Does the light stay on, or does it blink?
Customer: What light
JA: What is the model/year of your Jaguar?
Customer: 2007 S-type
JA: Are you fixing your S-Type yourself? What have you tried so far?
Customer: I tried then the dealer had it for about 7 months
JA: Anything else you want the mechanic to know before I connect you?
Customer: That's everything
Submitted: 2 months ago.
Category: Jaguar
Expert:  Richard replied 2 months ago.
How soon after starting does the engine overheat? What did the dealer do to the vehicle?
Customer: replied 2 months ago.
I start it let it run for about 15-20 minutes then take it on a test ride and that when it runs hot...the dealer said they did all these test but could not show us on paper so they it was a head gasket but could not tell us why on paper like a bad cylinder or pressure reading
Expert:  Richard replied 2 months ago.
Ok thanks. Yes a compression and leakdown test can be performed. We would need the tester to do that. I recommend performing a test which detects the presence of exhaust gases in the coolant. This can be purchased at most major parts stored. Follow the instructions on the tester. Solution is added to the tester and if it changes color it means we have a leak most likely a head gasket or head.Let me know.
Customer: replied 2 months ago.
Ok...i will do the test today and get back with you in the morning....on the leak down test what psi do you recommend
Expert:  Richard replied 2 months ago.

Our shop air is about 90 psi but we turn it down with the regulator to about 45 psi