1994 Ford Explorer with 176,000 miles. Runs great except for a vapor lock when fuel is lower than 1/4 of a tank, and a tapping sound in the valve system when I drive uphill. I have recently had the oil and filter changed, had it lubed, and all checked out. I want to sell it but now after this has happened, I don't want to sell a lemon, but cannot afford an expensive valve job.
2006-08-13 03:09:27 · 9 answers · asked by ladypriest 1 in Cars & Transportation ➔ Maintenance & Repairs
sounds like you have engine "ping" which is pre-detonation of the fuel in the combustion chambers, what happens is the air/fuel mixture ignites prior to the spark plug igniting the fuel, you end up having dual ignition of the fuel in the combustion chamber, when the 2 ignited fuel sources hit each other it causes the ping noise. this can cause damage to your engine, usually a higher octane fuel will lessen or eliminate the ping, octane ratings in fuel is the anti-knock or anti-ping rating, the higher the octane the slower the fuel burns and less likely to have pre-detonation
2006-08-13 03:18:04 · answer #1 · answered by Kato 3 · 0⤊ 1⤋
Most likely, with it being a '94, the valves are not adjustable. They are the hydraulic type that adjust themselves. Valve noise can happen when putting an engine under load. I bet you are hearing the noise with the A/C on, and the transmission in overdrive. The question you need to ask is how much noise is abnormal? If it's just a tick tick tick before the transmission downshifts, then I would not worry about it. If it happens all the time, at any RPM, then you have a problem. Go ahead and sell the car as you were wanting to, but be sure the prospective buyer knows your concerns.
2006-08-13 03:26:27 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Does it sound like marbles rattleing around in the engine?
If so that's caused by detonation in the combustion chamber.
That is usualy caused by this new crappy gas. As mentioned above. Buy better gas. Higher octane.89 or 91
If that doesn't help, the you may have a timing problem, or faulty knock sensor.
Oh, and wait till you're almost out of gas to refill your gas tank, then for the first time refilling us the high grade gas.
2006-08-13 03:23:44 · answer #3 · answered by Mr. KnowItAll 7 · 0⤊ 1⤋
Hats off to all the folks answering the question. Like everyone has said try a higher octane fuel and see if that helps. If so try a fuel additive that increases the octane.
2006-08-13 03:34:02 · answer #4 · answered by Can do it man 3 · 0⤊ 0⤋
you are probably using a low octain gas try a higher octane gas and this will solve your problem check on the gas pump it will tell you what octane it is such as 87or 89 ect you may also want too check your owners manuel for the recommended octane for your engine if you don't have it call your local ford dealer they will be glad too help you using the wrong octane may harm your engine.I am sorry for the two part answer Hickey
2006-08-13 03:22:36 · answer #5 · answered by ? 4 · 0⤊ 1⤋
Maybe the valves have to be tightened, they can get looser with age or your drive train may be stretched from wear. Put higher octaine fuel in your car, that will stop the pings and nocks.
2006-08-13 03:14:31 · answer #6 · answered by Anonymous · 0⤊ 1⤋
I agree with the higher octane answer. My 96 Taurus does the same thing and the better gas seems to stop the knocking.
2006-08-13 03:16:15 · answer #7 · answered by Anonymous · 0⤊ 1⤋
I'd make sure the oil level is topped up again.
2006-08-13 03:13:32 · answer #8 · answered by 'Dr Greene' 7 · 0⤊ 1⤋
might consider haveing egr system checked
2006-08-13 06:18:23 · answer #9 · answered by pale face 1 · 0⤊ 1⤋