Doug McAllister/Under the Hood:
Within one week we had two cars come into the shop that were very low on oil. When I say low, I mean like one to 1½ quarts left in a five-quart system. In one case the engine was knocking when it came in and in the other, the engine would not even turn over.
After we changed the oil in the engine that was knocking, it seemed to quiet down and was running OK but after a day of driving one of the connecting rods went through the side of the block and that was the end of the line for that car. It didn’t help that it was a high-mileage 2.7-liter engine that was a very weak engine on a good day, let alone running it low on oil.
The other car also started and ran OK after changing the oil, but the jury is still out on whether it is going to last or not. If it does, the client got very lucky; however, I’m sure the life of that engine has been greatly reduced.
I have written on longer oil change intervals before but I want to point out that this is one of the side affects of stretching out your oil changes. Over time there is going to be some oil loss, which is normal. If the interval between oil changes is not in time to catch up with the natural oil loss, you run the risk of running your engine without enough oil in it for proper lubrication.
Most of us are not in the habit of checking the oil in our cars, and based on this low oil trend that I am seeing, this is a problem. May I suggest if you are changing your oil at a 4,000- or 5,000-mile interval or more, you check the oil at least once in between your oil changes, and add a quart when it runs low. This one simple chore could save you a lot of money and aggravation.
There was a day when the oil was checked every time you pulled into the full-service gas station for a fill up. Uh oh, I just dated myself.
Q. Recently I took my car in because I thought I was going to need new brakes. The mechanic told me I need to replace the pads and the rotors. How do I know whether or not I need the rotors?
A. The first thought that comes to mind is, do you have a trusting relationship with your shop? If not, I would suggest you find a shop where you build that trusted relationship, so when the mechanic says to have the rotors replaced you are not left questioning him.
The rotors used today on most cars do not have a lot of extra metal on them so, in most cases, by the time the brake pads are worn down, the rotors are pretty close to discard thickness as well. The problem with resurfacing a rotor down to the discard thickness is it becomes prone to warping. There is not enough metal anymore to dissipate the heat so it will warp like an old record. That is when you get that uncomfortable vibration when applying the brakes. In some cases there is plenty of thickness on the rotor and a resurface is perfectly acceptable. A good finish with a brake lathe will produce a quality brake job and can save you a little bit of money. Rotors are not as pricey as they used to be so if they need to be replaced it is not the end of the world. But be careful, don’t buy the cheapest ones you can find. Remember, you get what you pay for!
Ÿ Douglas Automotive is at 312 S. Hager Ave., Barrington, (847) 381-0454, and 7218B Virginia Road, Crystal Lake, (815) 356-0440. For information, visit douglasautomotive.com. Send questions to underthehood@dailyherald.com.