Toyota Tick

I have a 1991 toyota pickup with 202k miles. This spring it started making a knocking/rapid tick that came from the engine when going up hills on the freeway if I went over 60 mhp. I was told it has to do with the fuel line and to use highgrade gas and use fuel injector/cleaner once in a while. I tried this and it worked, until now. NOW it is worse. If I go up a hill at about 40 mph the sound is even louder. what could it be?! help my poor truck!

Sounds like preignition. Basically, either the fuel air mixture is combusting too soon. A couple of things could cause this, one being that the timing could simply be off, which would be the first thing I’d check. Also, if you have a lot of deposits in your engine, this effectively raises the combustion ratio, which can cause the FAM to spontaneously combust, like in a diesel. Because octane is the gasoline’s resistance to spontaneous combustion, using premium masked the problem for a while. Some people have had luck using Seafoam directly in the intake to remove them, but if they’re really bad you may have to take the cylinder head off to manually remove them.

Your use of fuel system cleaner and premium gasoline only prolonged the inevitable. Based on the age of your vehicle and the way the symptoms subsided with premium fuel and fuel system cleaner, I suggest you start with the fuel system service that many garages try to sell to so many of us who don’t need it. With this service they pull apart your fuel injectors and clean them manually, along with other crucial fuel system components. Make sure they are not simply selling you another product that they simply pour in the fuel tank. Go to your neighborhood national tire chain and a Toyota dealer or two and get some quotes. This might not completely solve your problem, but if you have never had this service done, it could improve things significantly.

I am assuming that you have done regular tune-ups on this truck. If not, you should consider replacing the spark plugs, spark plug wires, and possibly the rotor (a basic tune-up for a fuel-injected vehicle). These are all relatively low-cost procedures, especially if you do the tune-up yourself. If you do it yourself, be careful to connect the new spark plug wires in the proper order. The easiest way to do this is to only change one at a time.

These items are just inexpensive maintenance procedures that might solve your problem if this truck hasn’t been maintained very well. However, nothing beats a diagnosis from a qualified mechanic.