I have a '95 Bronco with 158k miles and the engine is making a ticking noise that seem to be coming from valve train. Oil pressure is OK since the gauge normally points to the "M" in the word "Normal". The oil in it is a mixture of 4 quarts of 10W30 and 1 quart of 15W40.

I'm planning on removing the valve covers soon and inspect the engine. How do I find out what's making the noise, and how can I fix it without taking the engine apart?

TIA

 

First of all the factory gauges only tell if you have more than 7-8lbs pressure, not an actual value, if it's below that pressure the gauge drops to zero if above it moves to somewhere on the dial. You need a aftermarket gauge to actually know what the pressure is(factory gauge is a glorified idiot light), secondly by a inexpensive auto stethiscope and listen to your engine and see if you can identify exactly where the noise originates(it's probably a lifter) and then it can be repaired.

 

OK, I'll get an oil pressure gauge and get some more accurate reading. As for lifter problems, do I need to pull a head, or is there some other way to fix/replace it without too much of a teardown?

TIA

 

Could be that the lifters are not getting enough oil.
Could also be valve lash. There are adjustments for this on some engines depending on the type of lifters. May also be wear.

Are you sure you don't have any exhaust leaks at the manifold?

 

That's most definitely not a case of a leaky exhaust -- I can hear that the ticking is coming from the general direction of the valve cover. Oil starvation is a possibility, but I'm not sure how to diagnose a blocked passage, for instance. I don't think I can adjust valve lash on that engine.

 

Which side of the motor is the ticking comming from? It could be a PCV valve, or it could be that you have a slightly bent pushrod, or you may have a bad lifter. If you have to replace lifters, you will need to take off the intake, valve covers and the distributor. Then you'll be able to reach the lifters to pull them out. You may just have a loose rocker arm in which case, you'll just have to pull the valve cover. Cross your fingers. Once you have bought the mechanics stethoscope, and determine the location of the "tick", you'll know which valve cover to pull first. Once you pull the valve cover, again use the stethoscope to detirmine the EXACT location of the "tick".(yes, the engine will have to be running and you will likely get some oil on your exhaust manifolds so keep a fire extinguisher handy) Once you have determined that, take the rocker in hand(engine off) and try to move it in a rotational motion. If it moves excessively, you may have an issue with either a bent pushrod(easy fix but not very likely), bad lifter(harder fix, but pretty likely), or maybe a lobe on the cam going flat(very difficult fix, but not as likely unless you race the vehicle or do a lot of 4X4ing). Hopefully, it is just a simple fix. You dont mention how loud the ticking is. Can you hear it in the cab of the truck?

 

It could also be an injector going bad. You'll know more when you get the stethoscope.

 

It's coming from driver's side, and I cannot hear it in the cab, I have to be outside to be able to hear it. As a matter of fact, I need to actually open the hood for the ticking to be really obvious. I'll look around to get a stethoscope today. Thanks for your advice.

 

that light of a tick sounds more like a injector getting dirty. Hopefully!!

 

That could certainly make my life easier , especially since it's cold and rainy outside....

To check if it's an injector, I guess I can just disconnect the wire harness one-by-one, and if the ticking stops, then I found the bad fuel injector. Idle could be a bit rough with 7 cylinders, though.

 

This is true.......but I suppose you could just turn the idle up a bit.

 

If you narrow it down to a dirty injector have them cleaned. Most shops have a system where they screw a can of cleaner to the fuel rail, pop the inertia switch, and run the engine until it dies. Then they reset the inertian switch. It works well according to my father who has done several of them. If it's really only audible after opening the hood then it's not likely a lifter.

 

I just got a stethoscope today and played around with a little (have to hit the road soon, so no time to do much) and listened to the injectors I could esily access, and all of them were ticking. So I'm not sure now since 4 bad injectors seem highly unlikely, so what I'm hearing could be normal.

Once I get back I'll go through all injectors to see if any one is significantly louder than the others, and also do the individual disconnects.

BTW, if I listen very carefully, I can hear the ticking with the hood closed, but I need to open the hood for it to be obvious.

 

It almost sounds like something else other than a mechanical part going bad....like maybe something stuck in the belt or on a pulley or something. Maybe a small rock or something stuck into the belt.

 

No, that's definitely not the case. The ticking is coming from the engine. It seems to have stopped raining so I can hopefully work on it a little tomorrow.