Dayton Daily News

Wheels: An e-mail from Craig says, “When I take my 2000 Honda Civic to the dealer for an oil change, they overfill the engine. They seem to be putting 4 quarts in when it only needs 3.5 quarts. I have them check it. Sometimes they will give me a new oil change. Other times they will say it is OK to have 4 quarts in it. What do you think?”

Halderman: I have not checked the specifications from Honda regarding the specified amount of oil. I am assuming that you are referring to the amount needed with an oil filter.

I doubt that overfilling by a half quart will create any problems, but it would slightly increase the resistance in the engine, resulting in slightly less fuel economy. I doubt that the change in miles per gallon would be measurable.

Overfilling the engine with oil can cause air to be forced into the oil by the rotating crankshaft. This aeration could cause a lack of lubrication.

Should it be filled to the full mark and not overfilled? Yes.

Wheels: Al writes by e-mail, “I have a 2001 Ford Ranger with a 3.0-liter engine, and it has 87,000 miles on it. My problem is that the “check engine” light keeps coming on.

I have contacted several different mechanics and when they check it with their computers, it shows the EGR valve as being the problem, but it isn’t because they find that as being OK.

The tube from the EGR to the exhaust keeps clogging up. I clean it and the light goes off for 35 to 50 miles, and then it comes back on and needs to be cleaned again.

I have put new plugs and wires on it, but that has not helped. The shops have no idea what is causing this to happen, and the truck runs fine.

There has to be some kind of a problem, and I just wondered if you could help me.”

Halderman: The EGR valve is fed exhaust gases from the exhaust manifold. The exhaust gases pass through the EGR valve and then through small passages in the throttle plate area.

From your description of the problem, the diagnostic code is most likely indicating a lack of proper flow through the EGR system.

I believe that cleaning the passage between the EGR valve and the exhaust manifold either causes some of the deposits elsewhere to loosen or does not help at all.

The code sets after the computer performs a test of the system, and this would explain why the check engine light does not come on right away.

I suggest removing the throttle body from the intake manifold and cleaning the passages. This should take care of your problem.