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Fuel injectors making loud noise

I recently bought a 94 Ford Ranger XL 2.3L. This is a Mazda engine built for Ford. There was a slight ticking noise from the engine. Two months later it has became worse and louder. I bought a mechanic stethoscope and found the noise was coming from two or more of the fuel injectors. New plugs and wires, fuel filter, air filter was done when I bought it. Cleaner has been added to the gas a few times now. I am about to replace the belts and hoses, Bosch platinum plugs and fuel injector O-Rings. I just don’t know if it will be enough. Does anybody have any thing to add for me to check, replace or should I just smash it with a hammer like I want to do?

Also, the truck starts and runs fine.

If it’s truly the injectors and it is driving you mad then replace the noisy injectors with new ones. I would think a ticking noise that gets progressively worse coming from the top end of the engine would be valves (either too loose or too tight). That’s just an uneducated guess.

You could probably confirm the injector by unplugging it and see if the noise goes away. Some are expensive and some aren’t but if you’re going to the work of pulling them to put O rings on, might as well replace the guilty ones. Looks like $24-$50 each from Rockauto depending on whether new or reman.

Your engine is not a Mazda engine built for Ford. It’s a Ford engine, first designed and put into use in the early 1970’s.

Spark plugs, wires, fuel filter, and air filter would have nothing to do with a noise coming from the engine. Neither would belts, hoses, or fuel injector o-rings.

I suspect a mechanical problem in the valvetrain of the engine. I can’t imagine a fuel injector making enough noise to be heard over the rest of the engine.


OP probably thinks it’s a Mazda engine, because Mazda had a rebadged Ranger around the same time, with the identical powertrain

Fuel injectors do make a noise, but it would usually be described as a “buzzing” rather than a “ticking”. If you could figure out a way to remove the injectors from the engine but keep them hooked up to the fuel rail and electrical connectors, aim them at a container to catch the gas, and get them to go into inject mode while the fuel pump was running, then you’d know for certain. There is a way to do that probably, but it may require some special test equipment most diy’ers wouldn’t have. I’ve done that experiment with a 70’s VW Rabbit (K-Jetronic mechanical fuel injection), and yes, those injectors did make quite a racket in that configuration. But like I say, it was more of a high pitched buzzing noise.

@Bing’s unplugging idea above makes sense as a compromise test. By “unplugging” I guess Bing means to unplug the electrical connection to the injector so it won’t pulse, not unplugging (removing) the injector from the engine intake manifold.

If it isn’t the injectors, probably time for a valve clearance measurement. You may just have a couple of loose valves on your hands needing adjustment.

I think the big question is if the noise is really from the injectors or something else. If it is from the injectors and all else is working just fine, I will leave it alone. Esp on a car with that age, if that is its biggest problem, then just keep driving it.

I agree with asemaster; it’s likely a valve train issue. Off with the valve cover.

Buying a set of injector O-rings is not going to fix anything other than an air or fuel leak.

An engine can start and run fine with valve train noise; not so much with injector problems.

The Ford Ranger 2.3L engines of that era had noisy valve trains and that’s just the nature of the beast. I wouldn’t let it worry me.

Thank you all for the feed back. But first, every thing on the engine is metric. Wikipedia, " The Mazda B-Series became a re-badged Ranger for the 1994 model year…"
I have had lifter, valve problems before with other cars. These are easy to spot because the noise changes with the RPMs. This noise is more of a rattle. I put the stethoscope on top of the engine, side of the engine, front and next to the injectors on the engine… nothing. The engine sounds smooth. On the injectors, I need to rip the stethoscope off my head the noise is so loud. Not really, but it is loud. I will try unplugging them and see if there is a change. Thanks Bing. This poor thing was sitting unused and unwanted with bad oil, filters, wires the works just collecting moss. Now it is under my skin, I want to fix it. Thanks again all. I’ll let you know how it turns out.

Here’s an idea. Ask your local auto parts store if they have a test gadget you could borrow or rent, where you remove the electrical cable from the injector and plug-in that test gadget instead. Then you press a button to tell that gadget to pulse the injector. You could then verify the injector is the problem, b/c you could do this without the engine running. You might have to fire up the fuel pump first though, to test the injector’s actual noise level.

you’re talking about this

But first, every thing on the engine is metric. Wikipedia, " The Mazda B-Series became a re-badged Ranger for the 1994 model year…"

So you need some metric tools (the whole truck is metric by the way) and the truck was made by Ford and sold with Mazda emblems on it? What does that have to do with an engine noise?

Can you post a video file of the noise so we can get you headed in the right direction?

Yeah, that would work @db4690 as long as there’s a way to connect it to the injector, and the output voltage and pulse width matched up to the vehicle’s injector design.

One thing it is not is injectors.

I never said it was injectors, because I didn’t believe it, anyways

I’m just posting a picture, to show what George was talking about

Does NOT mean I believe injectors are the problem

I’m also leaning towards valvetrain noise :smiley:

I doubt it is injectors either, but the OP above says they used their noise isolating method to isolate it the source right on the injector where they clearly heard it, then used it on the intake manifold immediately adjacent to the injector and didn’t hear it. Sound can travel in unexpected paths but eliminating the injector as the sound source I think would be useful to the OP’s diagnosis in this circumstance.

I forgot that I posted this. I was starting a new job at the time. I did figure out the problem that was making the injector rattle. I had just tuned it up with new spark plug wires. I went cheap which is fine but I forgot to make sure all connections were good and tight before installing so the injectors were receiving bad signals. I tightened up the wires and the noise was gone the truck ran fine… Then shit hit the fan and I have been working on it ever since. Clutch, transmission, radiator, tires, bearings, timing belt, hoses, seals, ARRRG! Now I have a new problem… Another post perhaps. But thanks for the input from everyone.