It turns out a lot of the new “autonomous driving” safety equipment is not playing well with these car-cleaning tunnels. For instance, a lot of new cars have a wonderful feature called “automatic emergency braking.” If the car senses an object in front of you – like a stopped car or a human dressed as a tuna fish sandwich – and you don’t brake in time, it assumes you’re distracted and it automatically stops itself for you. Now, what do you think it does when it sees a giant spinning buffer heading toward your grille (unless the system disengages itself when the car is put in neutral)?
Other cars automatically apply the parking brake if the car is stopped for more than a few seconds. This also is a great safety improvement. It’s prevented people from stepping out of the car without putting the transmission in park first and running over themselves. Hey, it happens!
So for people like you, with newer cars, you’ll have to check your owner’s manual. More and more of them now have instructions for going through an automatic car wash. It’s more complicated than in the old days, when all you had to do was decline the muffler polish, give the guy your eight bucks and remember to close the window. Now you often have to disable a bunch of safety features, lest you find yourself at the front of the line, unable to go forward through the car wash, with 16 people behind you getting furious while you scan the index of your owner’s manual.
I’m not intimately familiar with the 2017 Buick LaCrosse, but if it’ll stay in neutral with the car running, and it doesn’t have those safety features engaged, you should be fine. Hope you can clean yourself up, Newton.
Performance unlikely to be affected by bad cam sensor
Dear Car Talk:
I have a 1996 Ford Explorer with 164,000 miles. It runs fine, but a year ago, the check engine light came on and indicated a problem with the cam position sensor. The Explorer lives on a very small island with dirt roads and no mechanic. It is driven a maximum of about 40 miles a year, from the marina to our cabin, which we visit once a month or so. After a year with the check engine light on, the Explorer still runs great. Should I worry? – Peter
RAY: No. I'm guessing you retreat to a rustic cabin on a desolate island precisely so you don't have to worry. So don't start now.
The sensor probably is bad, Peter. But the effects of a bad cam position sensor are most likely to be felt at high speed. So just don’t take any dirt highways on the island.
That sensor helps the computer compare the positions of the cam shafts and the crankshaft. And it uses that information to control the timing of the fuel injectors and the spark.
But, like I said, those things become more critical at higher speeds. And if you’re just moseying (and I hope you are) from the marina to your cabin and back, you might never notice any problem at all.
And at worst, if it fails completely, it won’t disable the vehicle; it’ll put it into a so-called limp-home mode – which is what it sounds like. You might not even know the difference! In any case, in the worst-case scenario, you’ll still be able to limp to the cabin.
At that point, you need to befriend a Ford mechanic, and then invite him to spend a peaceful, bucolic weekend on a secluded island. Then tell him to bring a ’96 Explorer cam position sensor with him.