Ray Magliozzi
Dear Car Talk:
I recently visited a major, national oil-change business. I was shocked to see them run a hose down my dipstick tube and suck the oil out. This is instead of removing the bottom plug and letting the oil drain out.
They said that’s how they do it now because of aluminum oil pans. I think they are scared of stripping the plug threads. Of course, they had an answer for every question I asked, but I still feel this can’t get all the sludge out. What do you think about this shortcut in car care?
— Jeffrey
I’m all for it, generally speaking, Jeffrey. As long as you have a car with a dipstick (newer cars often use sensors instead), this is a good way to change oil.
You’re right that they’re afraid of stripping the plug or the oil pan. And they should be. Even if they notice it when it happens and confess it to you, it’s still a time-consuming expense for both of you. And if they fail to notice that they’ve stripped the pan, or don’t want to deal with the consequences of having stripped it, that becomes an expense for you next time you try to get your oil changed.
And while all the guys at my shop are great people and I love them to death, not many of them just missed the cut for making it into medical school. So, removing some of the human error risk is a good idea. It’s also a good idea in medicine, and I trust they’re doing that, too.
These “oil exchange” machines simply make it impossible to strip the oil pan — regardless of the skill or lack of skill of the technician. They eliminate spilled oil, which has to be “caught” in a pan under the car when the oil is drained. And they eliminate burned arm hair from when you loosen the drain plug and get a sluice of hot oil down your arm (on its way to your elbow, armpit, and eventually, your shorts).
The machines are faster, too, which is good for business. And for you, if you’re waiting.
Does it get all the sludge at the bottom of the oil pan out? Well, you really shouldn’t have sludge in your oil pan. If you do, you’ve been taking very poor care of your car for a very long time. Plus, sludge is not going to drain out through the oil pan either. It’s just going to sit at the bottom of the pan with either method. So that’s really not an issue.
So, these machines work well, Jeffrey. Aside from the investment the shop has to make in the machine, this is a shortcut that really has no downside and lots of upside.
Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.
