Q.

 I have a 2020 Honda CRV (touring) the question I have is regarding temperature gauge. Once the car warms up the gauge sits halfway while driving, but when I sit and in park, the gauge goes down in temperature towards the cold marking. Is this normal fluctuation?

A.

 In most engines once they come up to temperature, they tend to stay at that temperature using a combination of the thermostat and cooling fan. For some Honda models, they tend to cool a bit when sitting and return to the normal zone when on the road. I would consider it normal. 

Q.

 I have a 2016 Subaru Forester. Recently, the GPS stopped working, and I hardly used it. I do not want to bring it to a dealership. Do you know of any place I can bring it to that can fix it for me? 

A.

 Any auto stereo store should be able to help with this although depending on what is wrong a complete replacement may be cheaper than repairing what you have. The other issue may be the Subaru Starlink System, if it ran on the older 3G cellular network there is nothing you can do other than upgrade the system, at your expense. 

Q.

 In 2017 I bought a new Chevrolet Silverado with the V-8 engine and 8-speed transmission. Within a year, the transmission started to “bang” and “thud” when slowing and stopping. The frequency of this increased with more miles on the truck. At 30,000 miles, the Chevy dealer drained and refilled transmission with Mobile One “blue” at no charge. This has lessened the occurrence but not eliminated the bang and thud. The Chevy dealers’ service department will flush and refill for $311.00 if I want to give that a try. An internet query reveals numerous problems with these GM 8-speed transmissions and why hasn’t GM ordered a recall to install new transmissions? 

A.

 The 8-speed transmission has been quite problematic with shift quality the bang and thud as well as a slight vibration is pretty characteristic of the transmission that being said it does seem to last a long time with owners reporting more than 200,000 miles without any repairs. This is most likely the reason that Chevrolet has not come up with a replacement plan. It would not be a typical recall because the transmission is still operational and does not affect the safety of the vehicle again, I would continue to work with the dealer. Let them do the fluid flush if they feel it is worthwhile and also check to see whether there’s any software changes that will improve the shift quality. Later model vehicles are using a 10-speed transmission that has been jointly developed with Ford, time will tell if it is better. 

Q.

 On 12/15/23 I purchased a 2017 Ford Explorer with 70,000 miles and on 1/17/24 the engine started making bad knocking banging sounds and stalled out. I did not try to restart, but rather waited until it cooled and found no oil on the dipstick. Could the engine be blown? Is the vehicle salvageable? I was told it spun something, what would this other than no lubrication?

A.

 The engine in the Ford Explorer has had some issues, but typically at much higher mileage. The idea it had little or no oil in the engine after a little more than 30 days is certainly a problem. At this point, the engine needs to be completely inspected to find the cause of the failure. I suspect the timing chain may have failed which resulted in the knocking banging sound. I assume there is no warranty. At this point a used engine may be the best solution to get your Explorer back on the road. 

Q.

 Can you please explain how the dashboard feature of telling me the tire pressure works? Are the readings that are displayed on the dash cluster accurate? My tire pressure gauge and the car’s reading never seem to match up. Also, can you recommend a good tire gauge? I have four of them, and I get a slightly different reading from each one.

A.

 The direct style pressure sensor uses a pressure sensor transmitter/transducer built into the valve stem that sends information to the on-board computer. These systems are typically pretty accurate, powered by a non-replaceable battery with about a 7–10-year life. Regarding tire gauges, a quality pencil gauge Dill/Milton/Ingersol Rand are usually accurate within one PSI, some digital gauge and dial gauges do a little better at 1.5 percent accuracy which on a tire that uses 35 PSI is about ½ pound. The fluid filled gauges are very accurate. But for typical vehicle use almost any gauge that is accurate to 1 PSI is fine. Now if it were aircraft, racing (bikes/motorcycles/cars) or other extremely critical needs then a fluid filled or digital gauge that is periodically checked with a “master gauge” is what you would want. Overall, I have found the TPMS sensor, and a quality gauge agreed within one PSI. Even though a TPMS can deliver accurate alerts when properly maintained, it is not a replacement for manual air pressure checks, which you should do monthly.

John Paul is AAA Northeast’s Car Doctor. He has over forty years’ experience and is an ASE-certified master technician. He will answer readers’ questions each week. Email your questions to [email protected]. Follow John on Twitter @johnfpaul and friend him on Facebook at mrjohnfpaul.