96 5.0 Bronco ticking at idle

Pull each spark plug wire one at a time. If the noise stops on one cylinder, it's may be a rod bearing. More RPM increases oil pressure and may stop the noise.

I've tried that and it made no difference in the sound.

Check the tightness of the spark plugs...sometimes they come loose.

Gerard TS 14

I think I would do a bit more diagnostic before I considered any internal work. You call this a tick - not a knock. A bad rod bearing would exhibit a double knock. The 5.0 has a history of cracking exhaust manifolds. I would look very closely for any trace of a cracked manifold or a bad manifold to head seal. It is also possible that the head gasket has a leak to the outside. How is your compression? I have had several 5.0's over the years. My last two have had what sounds like a piston slap when hot. They went well beyond 200k with no problems with many miles of towing. My current is around 193k miles with the loudest knock yet since new. It hasn't given any signs of failure which is exactly when it will be repaired unless I notice a change for the worse ahead of time. You might also consider that the roller lifters may tick a bit if the roller pin is a bit worn. Nothing to worry about. Enjoy the truck. At the mileage and age of your truck, a new engine will not make it worth that much more and the cost of fixing whatever is wrong will be pretty much exactly the same now or when it fails - either way, the whole thing will have to be rebuilt.

Did you check the tightness of the spark plug like I told you to while you have the wire off?

Gerard

Yes I even tried a different plug in it just in case there was something wrong with the plug. If its a rod I should be able to hear it loader through the oil pan with a scope or at least that¹s what I'm thinking. I'm going to try that today. I would think it would be a lot louder if it was a rod but the valve train would still make the click regardless of the plugs and this goes away as soon as I unhook number 2. Now that I know what cylinder to be looking at hopeful I can narrow it right down before I start pulling the motor apart.

I've very particular with this truck, its mint inside and out so I want to keep it that way.

I had the valve train all a part and everything looks great, even the cam I took out is perfect. If it was the valve train the noise would still be there when I remove the plug. I agree that the sound would be a knock if its a rod and not a tick so I'm still hoping its an exhaust leak or something else foolish. I'm sure the motor will last for a long time with this tick but its a bit of a show truck so I can't have that. :)

Thanks for the advise I'll be looking more closely to that area around number 2 cyl.

FWIW, I have dropped the oil pan and replaced the rod bearings on my Astro van (4.3 V6), and there was a big improvement in oil pressure and engine noise. I used some 1600 grit emery cloth to dress the journals and stock size bearings, since the bearings take most of the wear I figured that even if the crank ended up under sized it would still be tighter than it was with the worn bearings.

This is also how I redid my 302 a few years back, except with the engine out I did both the crank and the main bearings. I've put maybe 40K miles on it since then and it still runs smooth. I wouldn't want to do this job with the engine installed since the 302 has to be raised to get the oil pan off, and the front crossmember and driveline doesn't give me the kind of clearance I like to work with. I've had the engine out several times so I'd rather pull it to work on it anyway.

Whatever you choose, spend the 40 bucks and get a real Ford oil pan gasket. It's a single molded piece with molded-in metal supports, and properly installed will never leak.

Sean

Thanks for the reply, That¹s what I'll do, I'll replace the bearings but I'll be doing it with the motor in the truck, its not going to be easy but it can be done. Yes I like the ford oil pan gasket so I will run out and get one of those. Should I get the bearings from ford or go after market? The oil pressure is still great on my truck so it must of been a peace of dirt to hurt just this one bearing? Will be a week or two before I have a free weekend to do this but will update once completed.

thanks

I just used the standard Clevite 77 bearings that you can get at any parts store.

Did you check the oil pressure with a mechanical gauge? The stock oil sender on yours is just an on/off switch with "on" putting the needle in the center of the gauge.

You can use pipe cleaners soaked in kerosene to clear the oil passages in the crank. Use lots of assembly grease, it's worth it. When I did the van I made sure the new filter was full when I put it on, and did my best to prime the new oil pump before putting it on. When I first started it, it was smooth as silk and only took a couple of seconds to build oil pressure.

With the engine in the truck I think the rear-most bearing is going to be tough to replace, and you can forget about replacing the rear seal. Personally I wouldn't touch the main bearings without pulling the engine. I just think there's too many things that can go wrong, and most of the time the main bearings are in much better shape than the rod bearings anyway. Just my opinion, of course.

Sean

Ok did a little more research on the motor and tracked down the noise a bit better. The noise is coming from the rubber hoses that feed the DPFE sensor and the Orifice tube that goes to the EGR feeds those small rubber hoses. So I unhooked the EGR from the Orifice Tube and I can hear the same click or tap as clear as day as I was hearing before but very laud. The Orifice Tube goes right into the lower intake right next to the number 2 injector. If I disconnect the number 2 plug the noise (Click or Tap) goes away. So number

2cyl still plays some roll here and I'm wonder if this is what's feeding the orifice tube?

So I'd have to say now that its not the rod bearings.

That connects to the exhuast via a passage in the cylinder head, but that doesn't really help much. I think you need to pull that cylinder head, soon, and get to the bottom of the problem.

Sean