overheating problem

I am trying to figure out an overheating problem with my dad's 98' crown vic.
The car only overheats when in traffic. I have replaced the thermostat. We took the car to auto zone and the fault (I forget what the p-code was) said that the possible causes are broken belt (isnt) low coolant (isnt) or the head temp sensor. I installed a new head temp sensor and the car is still overheating.

Are there any TSB's anybody knows for this issue? Any advise would be appreciated.

OK. I had the P code checked out myself. The code is P1299 (cylinder head overprotection active) I realize now the the sensor was not the problem. The idiots at autozone told my dad it was, so i just threw the part in without seeing the code.

I know the car is overheating, and there is no coolant leaks. Normal driving will not cause it to overheat, just long idling (traffic)

This leads me to believe that it is not the water pump, there is flow, and there is not any blockage and these things would cause it to over heat all the time. Once again any help is appreciated.

Hi, and welcome to the forum. I'm not familiar with the Crown Vic so I won't be able to offer any specific help on this one, but I noticed that you haven't mentioned the cooling fan - have you checked to verify that it does switch on when the temperature rises above normal? A failure in the fan circuit would account for the car having a normal temperature on the open road but then overheating when sitting in traffic.

Have you checked the radiator for cold spots? Do you have an infrared thermometer?
The vanes on water pumps wear and therefore will not be able to circulate enough coolant. How old is the water pump?
Bugs and debri can restrict airflow through the radiator. Make sure the fins are clean.
Radiator can be partially blocked internally restricting cooling capacity.
Make sure the fan is working.

I have 2005 crown vic. at 70,000m I changed the coolant.Since then,when in heavy traffic the car runs very hot only when I have the a.c. on high.I dont have any air pokets.The car is a NYC Taxi so I spend a lot of time in traffic,no problem if the a.c. is on low or off.Any suggestions?:banghead::screwy:

I have 2005 crown vic. at 70,000m I changed the coolant.Since then,when in heavy traffic the car runs very hot only when I have the a.c. on high.I dont have any air pokets.The car is a NYC Taxi so I spend a lot of time in traffic,no problem if the a.c. is on low or off.Any suggestions?:banghead::screwy:

taxigis-

First off, start your own thread instead of hijacking someone else's. It makes it easier when a thread is about one car's problems.

Now for your car

What is the ratio of coolant to water did you use? Are the fans working correctly? Are the radiator fins clear of debri? Is the thermostat fully opening? What is the condition of the radiator hoses? Spongy hoses can collapse, restricting the flow of coolant. Last would be the water pump. The vanes on the water pump can wear away over time reducing the flow of coolant.

What is the ratio of coolant to water did you use? Are the fans working correctly? Are the radiator fins clear of debri? Is the thermostat fully opening? What is the condition of the radiator hoses? Spongy hoses can collapse, restricting the flow of coolant. Last would be the water pump. The vanes on the water pump can wear away over time reducing the flow of coolant.
I'm suffering the same thing, on a '99 CVPI w/197,700 miles. The fan is working correctly, thermostat is new (along with the intake manifold - 2 weeks ago), hoses look good, and do not appear to be collapsing, though the one from the overflow tank shows some swelling and a softspot, but this shouldn't effect cooling (?). car has been running great since the mainfold change, until yesterday, when it got very hot after a 20 mile run @ 60-65 (normal engine temp at speed, 80-85* F ambient temp), then caught at a stop light- It just started steaming like mad.
I don't feel this is 'hijacking a thread' as we both have the same origional issue, and I've checked everything mentioned above, yet the problem persists.

The cooling fans have 2 speeds. If both speeds are not working, the engine will overheat at idle. So you need to check to be sure the fan is operating at both speeds. It is easier to use a diagnostic scan tool to test.