Cooling system
2002 Chevrolet Silverado Overheating PDF Print E-mail

Dear Barbara,

I have a 2002 Chevrolet Silverado 4.8 liter. It has a 3 inch lift on it and the bottom fan shroud is not on, and it has a big slice on the top fan shroud, cut out to fit for the air intake tube that is stock. The problem is when I am sitting in traffic, or at a long light, the truck will overheat with the a/c on it does not over heat when it is off.

I was told that the fan shroud should be put back on and I was told this would not matter. I changed out the thermostat and had the cooling system flushed; and this did not help. What can cause this problem?



Dear William,

The car manufacturers make their makes and models with certain specs of aerodynamics. When you jack your truck up with lifts and alter the design that first came off of the assembly line you will more than likely have issues like you are experiencing.

The best advice I can give you is that you need to get the shroud back on and as quick as possible to keep your Silverado from overheating. It needs to be built up enough to the center of the radiator as much as you can, or build a tunnel like you would see in a Dodge truck/V6.

To get a visual of how your shroud needs to be built, take a gander at the Dodge V6; you might want to even think about buying a Dodge shroud for your truck.

Thanks for the question and writing in!

1998 Jeep Cherokee Classic 4.0L 4x4 Cooling System Issue PDF Print E-mail

Dear Barbara,


I have a 1998 Jeep Cherokee Classic 4.0L 4x4, 150k miles.  For the last 3 years I have had a cooling system running hot problem.  I replaced the all metal two core radiator with an all CSF 3 core.  During the hot Houston summer months I would see the coolant temps rise from the normal 210 up to 230.  If I drove at highway speeds it would shoot up to 230 with in 5 minutes.  I do have oversized tires, lift and 4.56 gear.  I have added an additional 13,000 btu transmission cooler to the factory transmission cooler.  I have a high flow 195 degree thermostat, Flowkooler high flow water pump.  Hoses, belt, all changed.  I have the proper mix of water and Prestone radiator fluid.   It has a pretty green to the fluid color.  It still gradually builds coolant temp while driving 70 mph at 2800 rpm.  I have NOT flushed the coolant system.   In the cooler winter time temps I am lucky to see a temp of 195 on the factory gauge.  I'm stumped.  The additional cooling mods seem to be working as long as the outside air temps are not about 90 degrees.  I do not see any coolant in the oil, nor do I see oil in the coolant.


It has been suggested that I flush the coolant system with CLR.  Is this a good idea?




Dear Tony,


Let’s consider a few things to keep in mind and as possible solutions. 

Make sure the cooling fan clutch is tight as this clutch should get tighter the hotter it is, and at 200 plus degrees it should sound like a tornado under the hood so this is where I would look first.


Secondly, a high flow thermostat may not always be the best thing as the coolant may not be staying in the radiator long enough to cool down.  Also, I do not think the CLR would be necessary if your coolant isn’t rusty or highly contaminated.


Thanks for writing in and let me know what you find,


Water pump warning signs PDF Print E-mail
Dear Barbara,
Could you please tell me, short of waiting for a large leak, is there any other sign I need to look for when to replace a water pump?  I have a 2002 Honda Accord.  Many thanks for your response.
Ardythe Wyke
Dear Ardythe
A leak of any kind is a sign to change the pump if that is where the leak is coming from. This pump along with a timing belt should be changed every 80-100k miles as a regular maintenance item and failure to do so increases your chance of a water pump or timing belt failure which can lead to further engine damage.
Look in your owner’s manual to see what is exactly recommended for mileage intervals on these items for your particular make and model. It is best to do preventive maintenance instead of having to do major damage repair in the future which can rob your bank account dearly!
Thanks for writing in,
Chevrolet Cavalier AC air flow problem PDF Print E-mail
Dear Barbara,
I own a '03 Chevy Cavalier which here lately (last 2 mos.) is not blowing properly. The A/C is operating and so is the blower, but the airflow seems to be coming from the floor board area. Do you have any suggestions?
Thanks for your time.
Dear Chevy owner,
The mode door on you cavalier is cable driven so it sounds like either the cable has broken, fallen off or the mode door has a problem. Usually when the mode door has the problem it defaults to defrost and wont move. The switch on your dash could also be malfunctioning causing the door to not operate.
I would have your local A/C shop check it out
Thanks for writing in,
Dodge Ram fan clutch PDF Print E-mail
Dear Barbara,
I enjoy reading your column in the Houston Chronicle, now I find I need your guidance. I have a 2002 Dodge Ram Quad Cab 4.7L engine auto transmission 70K I purchased the truck new, it has had all the maintenance as required, transmission oil changed, coolant changed new belt along with oil changes every 4000 miles (Mobil 1) this is a good truck, now I find an anomaly which I have not seen on this truck until this year. Example I run the freeway for about 12 miles at 65 mph external temperature 93 degrees F I then exit to the feeder 45 mph, at this time the operating temp increases, it also increases when stop at a red light, once I accelerate the temp goes down but not down to normal or half way mark, if I place the truck in neutral and increase the RPM to approximately 2200 the temp goes down. No coolant loss, the header tank shows the level to be normal when cold. The temperature never goes to the hot mark it goes between the half way mark and the hot mark on the gage mainly when idling, could I have a fan clutch going out? Your expert opinion will be greatly appreciated.
Yours sincerely
Barbara F
Dear Barbara,
Fan clutch if applicable to your vehicle would be my first guess. When the truck is cold and NOT running try and turn the fan with your hand. It should have some resistance to it, so if you can spin the fan and get a whole turn or more out of it then I recommend changing it. 
Also wiggle the fan front to back and check for play, a slight amount is ok. However, if it moves a lot then your water pump could be the problem. Watch the pulley that the fan attaches to in order to see if it moves when you wiggle the fan blade. If it does then have you mechanic check to see if you’re bearing is bad in the water pump
Note: If you change the water pump be sure to change the thermostat also.
Thanks for writing in,
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