What is that sound?

Hi guys! I have a 1996 Ford Explorer (please hold the Ford jokes, lol), it’s a V6. I have regular maintenance done on it, so it’s good to go with oil and tune up. The problem is that when I am on a hill, even a little one, going up the hill makes a knocking sound start in the engine, it’s really hard to make it go faster and the harder I push on the gas pedal the more the knocking persist. Any idea what this could be?

There are two types of knocks. There’s valve knock and pinging, which can sound like marbles in a can. This is common with older cars and gummed up or sticking valve lifters or an engine with carboned-up valves and pistons. Ask your mechanic about running some top oil to help free sticking lifters and cleaning the induction system with a product like ‘Seafoam’ to de-carbon the valves and pistons. It may help. If the knocking happens, the knock sensor tells the computer to retard the ignition timing to reduce the problem, but if it persists, then the timing gets retarded to the point you loose power. This is in order to try and save the engine.

If the knocking sounds more like a hammer on a block of metal, you may be looking at a rod about to be thrown, and destroying the engine.

I am guessing that the in 96 Ford did not have knock sensors in this engine because some others did not get them until after 2000. Maybe Busted knows better because I don’t know for sure. I would like to add insufficient EGR (exhaust gas recirculation) to the short list of Ping-inducing problems. The EGR passages could be clogged up or the valve gone bad. Do you have a check engine light on? Does the check engine light work?

Have you tried higher octane gasoline?

The check engine light has been on since we bought the truck. We’ve had it in multiple times for it and they’ve replaced censors, fuses, nothing makes it go off and they couldn’t find anything that was wrong. This was years ago though, before this sound started. So no, that light doesn’t work. So should I use that gas cleaner you get at the gas station? Sorry to sound like a ditz, I’m a blonde, lol.

I read the owners manual and it says I need to use 87 octane, or that’s what they suggest anyway. You think upgrading would make a difference maybe?

One way to find out - put a tank of premium in it, see if the knocking goes away. My '95 Suburban needed mid-grade because of carbon buildup. If the knocking does go away with premium, you might try putting a good dose of fuel treatment (I used Techron) in it. It would help my Suburban for a few months.

I’m going to print this and take it to the mechanic because I will never remember it all, LOL. The sound is more like marbles in a can, in fact that’s the perfect description, when I was trying to make the sound for my Dad I sound like a dummy because I couldn’t figure out how to describe it, LOL. Thank you so very much for your help, I really appreciate it. :slight_smile: