The Car Doctor Q&A: Intermittent problem, windshield washer fluid and more

by: AAA Northeast

Posted: Aug 30, 2023 / 12:00 PM EDT

Updated: Aug 22, 2023 / 04:32 PM EDT

Q: I have a key fob I need to program for my Honda Accord. It is for a used car that I purchased that came with only one fob. I found an aftermarket fob online for $50, but the dealer wants to charge me $250 to program it; $500 if I buy a fob from therm. I have been looking on-line and found a scan tool from XTOOL, model D8, which would pay for the tool if a program two keys. Any thoughts on this?

A: All I know about XTOOL is what I have seen online, and it certainly appears to offer a lot of features for a relatively low price. For consumer-level scan tools, I like the products from Innova, as well as their Repair Solutions2 companion app (although at this time I do not believe they have a tool that can program key-fobs.) Shop owners tell me that they like the Launch and Autel bi-directional scan tools, in addition to their traditional scan tools from OTC or Snap-On. I will be testing the XTOOL scan tool soon. Readers, have you used the XTOOL scan tool and what do you think? Email me at [email protected]

Q: I have a 2010 Mazda CX9 with an intermittent problem. When turning, I will sometimes get a thumping which I can feel through the armrest. I thought it might be the rear differential, so I changed the fluid but the thump was still there. I checked under the car, and everything looks solid. There are no wear marks on the exhaust from hitting anything. Any ideas?

A: Feeling the noise in the armrest tells us that the cause may be related to something in the rear of the vehicle, although this model has had issues with serious control arm corrosion and ball joint rust. I would look at the struts and the exhaust one more time. Due to heat from the exhaust, the rubber exhaust hangers can get very hard and transmit vibration through the vehicle. In addition, the rear differential mounting rubber may become hardened and cracked, resulting in vibration and/or noise. This is also likely caused by age and exhaust heat.

Q: Your column states that any question gets a personal reply…even dumb questions? My dumb question is what would happen if I put a few ounces of windshield washer fluid (blue stuff) in the radiator bottle? I have been driving the car and all seems fine.

A: To paraphrase Carl Sagan, there are tedious questions and naïve questions, but every question is a cry to understand. There are no dumb questions! What you described is a fairly common occurrence. Windshield washer fluid contains soap, alcohol and mostly water, so a few ounces should cause no harm. Of course, if you put in more than that you could have the cooling system flushed out, just to be safe.

Q: How long can a hybrid battery sit unused without being damaged? I live in Florida but come north for four months in the summer. My plan is to disconnect the 12-volt battery, cover the vehicle and let it sit. But I’ve read that this will damage the hybrid battery. Is this correct?

A: Snowbirds with hybrids have told me they do nothing to their cars; they just head north to escape the Florida head and storms. All cars are a bit different but for most, the best long-term storage procedure is to charge and disconnect the 12-volt battery. However, high voltage battery recommendations vary by manufacturer. Some recommend running it down to 25%, but most others say to store the car with at least 75% charge (which makes the most sense to me). At a minimum, top off all the fluids, change the oil, fill the fuel tank, add gas stabilizer and properly inflate the tires. Keep in mind that once the 12-volt battery is disconnected, you will only be able to lock the door with an emergency key and the alarm won’t work.

Q: My 2018 Honda Accord driver’s side tire has been making noise for some time, which increases the faster I drive. I brought it to a mechanic thinking it was the bearing, but he said the tire was cupping. I had the tires rotated and balanced, but that didn’t help. From what I’m reading it could potentially be the shock, struts or bushings. Wanted to get your thoughts.

A: Since you moved the tire with irregular wear to the rear and the noise didn’t travel, that rules out the tire as the source of the noise. At this point, you should put the car on a lift, block one tire so the noisy side turns, carefully run up the speed and listen with a probe around the wheel bearing to determine if that is the source. CV joints don’t make that type of noise so that rules out the axles, leaving only the transaxle. Based on what you have told me, I would be looking very closely at the axle bearing and surrounding area (brake system, backing plate). Honda did have an odd noise/rattle that could come from the front struts and the diagnosis and repair is quite simple. Open the hood and remove the left and right strut bearing covers (they pop off) and see it there is still a noise. If not, Honda has a newly designed rubber cover you can purchase as a replacement.

Q; We love our 2017 Ford C-Max plug-in hybrid which now has 50,000 miles, I but recently noticed the passenger side carpet being wet even when there’s no rain. I suspect a plugged air conditioner drain-tube, but I don’t where it is located. What would be the best way to unclog it?

A: From your description I believe you are absolutely correct, that the evaporator drain is clogged and the condensation is draining into the car. The Ford C-Max doesn’t use a rubber drain tube like many other vehicles. Their drain is a plastic piece with an elbow that attaches to the bottom of the evaporator case. The drain is a bit difficult to get to, but when the car up on a lift it should be visible. I would start by using a short piece of stiff tubing to clean it out. Once you get the water moving, finish the process with some low-pressure air.

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