Why didn't my Durango 'hold on the hill'? The Car Doctor responds

Q: I drive a 2016 Dodge Durango — my company car. It has 88,000 miles on it. I am retiring soon and looking to purchasing this vehicle off the lease. I recently noticed that while I was on a hill with my foot on the brake, when I took my foot off the brake, the truck started to roll backward. The transmission didn’t hold on the hill. Any thoughts?

A: This is referred to as HSA-hill start assist, and it uses the brakes, not the transmission, to keep the vehicle from rolling on a hill. According to the vehicle owner’s manual, this is a feature that can be turned on and off. Check to see that this features is engaged, if it still isn’t working some additional testing will need to be performed.

Q: When delivering mail years ago, I enjoyed listening to the “Tappet Brothers” out of Boston area. I would like to know if your station would be available to be heard in the Southern Rhode Island area.

A: Tom and Ray (aka Car Talk’s Tappet Brothers) were one of a kind, both funny and informative, and I still run into Ray from time to time (Tom died in 2014). My program is a bit different and not as funny, but you can listen on northshore1049.com or download the app.

Hundreds of past Car Doctor programs can be found on johnfpaul.podbean.com.

Q: I have a 2012 Chrysler 300C and recently came home and found antifreeze on the floor of my garage. The car was not overheating. I had it towed to the dealer and paid $149 to diagnose the problem. The next day they called and said they pressure-tested the system and found no leaks. After driving the car 20 miles and retesting the system, still nothing wrong.

I picked the car up and — after driving about 20 miles — the car again lost some fluid (very little) although the temperature gauge was reading normal. I keep an eye on the fluid level in the reservoir and it is good. Do you have any thoughts on the source of the leak?

A: Pressure testing a cooling system is the typical method to find a leak and generally works OK. However, sometimes the source of the leak will seal itself when under pressure. This is especially true with water pump seals.

Since there is an external leak, one way to find it is by adding a dye to the cooling system. Run the engine for a while and let it cool. Then use an ultraviolet light and special glasses to trace the coolant leak. I have seen DIY kits sell for as little as $20.

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Q: I have a 2012 Dodge Grand Caravan with 175,000 miles. In the past few months, it has developed a metallic rattle in the rear axle when hitting bumps or driving on uneven surfaces. I recently replaced the rear shocks (one was bad) and thought that had fixed the problem, but it still occurs.

A: The rear of the Grand Caravan is pretty simple. The rattle could be from a worn bushing in the track bar, control arm bushings or spring insulators. I have found the best method to find these noises is to have the vehicle on a drive-on style lift where all the vehicle weight is on the tires. This method allows for an easier view of worn suspension parts rather than a traditional lift/hoist where the tires hang.

Q: I know you have answered this question before. With winter storms, is it best to allow the wipers to rest on the windshield or raise them up?

A: Raising the wipers up keeps them from freezing to the windshield and allows for easier cleaning.

With my own cars I leave the wipers down, for a couple of reasons. I worry that during a storm, the wipers could spring back against the windshield and crack the glass. Lifting the wiper up to the “service” position repeatedly puts additional stress on the wiper arm spring and over time could cause wiper chatter.

Over the years, I have read hundreds of vehicle owner’s manuals and have never seen one vehicle manufacturer recommend lifting the wiper off the glass. And it looks silly.

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AAA's Car Doctor, John Paul
AAA's Car Doctor, John Paul

John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email jpaul@aaanortheast.com and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.

This article originally appeared on The Providence Journal: John Paul: Thought as to why vehicle 'didn't hold on the hill'