sudden decline in mileage

65,

Is it leaking coolant externally or internally?

What is the actual MPG?

Does the engine light work? Is the engine light on? If so check the codes and post them back here. Most parts stores will check codes for free.

Post back with more info or questions. We'll be glad to help. Thanks.

Thank-you for your reply Drivability-

It is leaking, externally she says it smells more like a wet rock than the sicky sweet coolant smell -(which is present but not the overpowering odor of the puddles she finds under the truck) ... no check engine lights or anything like that... she says the mileage is about half what it used to be-60 miles on a quater tank instead of 100.

65,

The coolant that SHOULD be in the vehicle has a little different smell than the green coolant you might be used to. Also, if it is parked on dirt, rocks, cement or asphalt the "wet rock" smell makes sense. Have the cooling system pressure tested and post the results. Please ask her to address this problem ASAP.

You mentioned that the engine light is not on but does it perform a self test (turn on and then off) when you start the truck. I'm asking because if the bulb is blown you're not going to be aware of any problems. With a gas mileage drop like you are speaking of the computer would normally notice a problem.

On the gas mileage...Elevation changes can cause problems. The computer should relearn and adjust by itself but you might want to reset the computer and let it relearn. Also, I'm not sure about the fuel requirements in Idaho and Alaska but it's possible your truck doesn't like the fuel you are using.

You mentioned the miles per 1/4 tank...You might want to fill the vehicle up, drive the car a 150 miles or so and then refuel the vehicle at the SAME PUMP. Divide the exact # of miles by the exact # of gallons to determine your gas mileage.

Let us know what you come up with. Thanks.

Thanks again-

The light does flash on like it should. I was thinking climate change and possibly the fact that she is mostly driving very short distances in town (its a V8)were probally contributing to the mileage issue. She did a lot of highway driving here.

I am definitely gonna send her to a radiator shop ASAP though-

Thank-you so much for your input-even though she asked me she wasn't gonna believe "just Mom".

Hello 65chevy4x4

In addition to what has already been posted a colder ambient temperature will have a negative impact on fuel economy.

Thank You
Helene

Helene,

Good point. Not sure how I neglected to mention that. I thought I covered that when I mentioned the elevation change but I did not. :-( What you stated would only be compounded by the fact that she is only driving short distances in a cold climate. The vehicle might not ever get warmed up and the gas milage is going to go from bad to worse.

65,

You're welcome and you're right. Driving distance, habits and conditions can make all the difference in the world as far as gas mileage is concerned especially with a gas hog. Also, since you mentioned the short trips, she might want to consider periodically (once a week) driving the vehicle long enough to get the exhaust good and hot to burn the condensation out. This can help keep the exhaust from rusting out as fast.

Keep us posted. Thanks.