Loud engine in GMC pickup is normal

DEAR DOCTOR:

I recently purchased a 2014 GMC Sierra pickup with approximately 30,000 miles. I really like the styling, ride, and the quietness of the cabin. All is good with the truck except the noise from the 5.3-liter motor:

It has more than enough power and runs very well, but it sounds like my mother’s old wringer washing machine. The dealer told me that the noise is from the high-pressure fuel injectors and is normal. This seems correct, since other similar trucks sound nearly the same. I am the kind of owner who tends to keep vehicles to over 100,000 miles. What has your experience been with these GDI engines?

— Tom

DEAR TOM:

The General Motors’ LS engine family is one of the best engines ever produced by any manufacturer. The injectors and upper valve train do create some noise, but this is very common and some noises are louder than others.

Some other manufacturers have had serious carbon build-up problems around the intake valves that can sometimes require cylinder head removal for vale cleaning. Using a good-quality gas additive once a month is a good idea, in my opinion. Quickly accelerating (called “blowing out the carbon” in the old days) — is still a good practice.

DEAR DOCTOR:

My TPMS light was on for quite some time on my 2009 Hyundai Elantra. The mechanic scanned each tire pressure monitor but indicated they were functioning correctly. The mechanic was able to “recalibrate” the system and the TPMS light went out. After a short ride, the TPMS light turned “on” and then quickly went out. What could have caused this? I know the lifespan of the TPMS batteries is approximately seven years. How do you troubleshoot the system?

— Mike

DEAR MIKE:

I see a lot of vehicles with TPMS lights on. Tire monitor batteries last five to eight years, depending on driving habits and temperature. A good tire pressure scan tool, such as the Bartec brand with the latest software, will in some cases check battery power. (The small monitor inside the tire has a battery the size of your watch or remote key fob.) The technician can program a vehicle with weak battery sensors, but weak batteries cannot send a clean clear signal under some driving conditions. Tire monitors go to sleep when the car is stopped, and take a two to four miles at speeds above 30 mph to fully wake up.

Many aftermarket universal tire pressure monitors are available on the aftermarket, though the batteries in the aftermarket monitors do not last as long as those in the factory monitors; factory monitors have also come way down in price. On some vehicles, the new monitors do not need to be programmed at the time of installation. The installer will have all the information on hand at the time of the tire monitor replacement. I do recommend replacing all the monitors at the same time if they are five years or older.

Junior Damato is an ASE-certified Master Technician.

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