Tom,
Q
I have a 1992 Ford Bronco full-size with 116,000 miles. It has a 5.0-liter 302 engine. My problem? Oil is getting into the air filter. Can you tell me if this is blowby or a PCV problem? I checked the EGR valve and found that there’s a lot of carbon buildup in the intake manifold. Why do you think this is happening? Thanks for your input.Joe—Buffalo, New York
Joe,
A
Beneath the grommet (that the PCV valve pushes into) on the back of the intake manifold is a pellet-style mesh vapor filter. This filter has a tendency to plug solid with sludge. Once plugged, the crankcase does not properly ventilate. The resulting pressure forces the oil-laden engine vapors backward through the air cleaner hose and fills the air cleaner housing with oil. Replacement of the filter screen beneath the PCV valve will take care of this problem in the majority of cases.Good luck. Tom
Tom,
Q
I have a ’79 Dodge van with 98,000 miles. When I start the engine it runs a little rough, but when I put it in gear and try to move, it splutters, pops, and stalls. I wondered whether I was just out of gas because I don’t use the vehicle very often, and I suspected the gas gauge was lying. So I put a couple of gallons in, but it didn’t seem to make any difference. Someone suggested thetiming chain sprocket (which I understand is nylon) is worn and needs replacing. If it is the sprocket, can I replace it without having to reset the timing? Any suggestions would be much appreciated. Thanks for your help.
Geoff—Fresno, California
Geoff,
A
If you need to replace the timing chain sprocket you will have to reset the ignition timing. I suggest you check the number one cylinder in reference to TDC (top dead center). This will verify if the cam sprocket (nylon gear) has jumped a tooth in timing. If this sounds over your head, then take it to a shop and have it diagnosed. This should cost you roughly one to one and a half hours of diagnostic time at the shop’s labor rate. Good luck.Tom
Q
I had the front and back main seals replaced on my Jeep Cherokee two weeks ago (it has a straight six-cylinder engine). Both seals are leaking again! What could be causing the problem— from a mechanical point of view?Sam—Dallas, Texas
Sam,
A
What other point of view might you expect from me? Metaphysical? Psychological? Lie down on a couch and tell me about your seal problem . . . ommmmmm . . .All kidding aside, I would make sure it is the same leak. A great way to make absolutely sure is to conduct an oil leak dye test. During this procedure, the technician adds a fluorescent dye to the engine oil, and the engine is then run for a few days. At this point, the vehicle is put up on a lift and the questionable area is exposed to an ultraviolet light. The leak can easily be located, as it will show up in a bright yellow color under the light. Another possibility could be that either the PCV valve or the crankcase ventilation system is not operating properly due to sludge plugging it up. This problem can cause excessive crankcase pressure and oil seal leakage.
If the vehicle is of high mileage, check the crankshaft surfaces upon which the front and rear main seals ride. Make sure there isn’t any excessive wear or scoring, as this would result in leakage as well. If wear on the front of the crank is evident, there are sleeve kits that can be installed to take up the gap from the wear, restoring the sealing surface, and most important, averting replacing the crank.
Tom
Tom,
Q
I bought a used ’98 Neon with 80,000 miles. It now has 108,000 miles and needs a head gasket. I plan on replacing it myself. Is the dealer the best place to get the head gasket? Also, has thegasket been redesigned to really fix the problem? What about using an aftermarket timing belt (or should I stick with the OEM)? Should I have the head milled? New head bolts? New water pump? Any tips? Also, should I see if Chrysler would pick up some of the tab?
Thanks,
Steve—Rochester, New York
Steve,
A
First off, forget about Chrysler picking up anything. This is not a safety recall, thus freeing the carmaker of any liabilities. You can try, but I doubt you’ll get anywhere.Buy a Chrysler gasket set, because these gaskets have been re-engineered specifically for this problem (they are laminated). Also, you must use a special sealant from Chrysler, use new head bolts (because the old ones stretch), and yes, have the head checked with a straightedge and milled if necessary (straight, clean surfaces seal better than crooked ones). Make sure you
are inside, replace the timing belt with a new OEM replacement.
As for the water pump, if it has the same mileage as the rest of the engine, replace it. Ask a Chrysler technician who works on these engines about head gasket replacement and what else you should do; however, I think I’ve covered it. I wish you success.
Tom
Tom,
Q
My Honda Accord needs additional oil every 1,000 miles. Is it possible to change oil less often since I have to add it at such a fast rate?Jack—Brooklyn, New York
Jack,
A
The questions you should be asking are: “Where is the oil in my engine going? Why does the engine lose enough oil that I have to add it every thousand miles?” Have the engine diagnosed for an oil leak or internal consumption. If you leave it alone, it will get worse and could result in engine damage.Tom
Tom,
Q
Our 2003 Chrysler Sebring has a DOHC sign on the engine. What does this stand for? Gabbie—Montreal, QuebecGabbie,
A
This stands for double overhead cam. Your engine has two camshafts, one for each cylinder head. Each camshaft controls the valvetrain on each cylinder head.Tom
Dear Tom,
Q
Can you help me understand how it happened that I drove my 2000 Toyota Camry to a quick lube for a simple oil change and came out needing a water pump? I had to have it towed home and then towed to a repair shop where they said I need a new engine. You might ask if I maintain the service on my car and the answer is yes, every six months.Barbara—Philadelphia, Pennsylvania
Barbara,
A
Wow. There are too many variables here to accurately assess your situation. What do you mean by “I maintain the service on my car every six months“? What service? Oil changes? Tirerotation? Sparkplug replacement? This information is too vague for me to help you. That said, I would go through the maintenance records to see what exactly has been done in recent months to determine what happened. Sounds to me like the car had a bad water pump, causing the coolant to leak out, which caused the engine to overheat and blow the head gasket. This, in turn, caused engine coolant to mix with the engine oil, damaging the engine’s road and main crankshaft bearings and necessitating engine replacement. That’s the best I can offer. Sorry for your woes.