1984 Fieri Base Iron Duke 2.5L 4 Speed Muncie. No mods
The Fiero develops this random tick that follows RPM and sounds exactly like a lifter tick. Except its completely random when it occurs. Sometimes its at startup and goes away with heat, sometimes its on the highway after 30+ minutes of running. Sometimes at the stoplight when the car is idling. It always ticks for about 5 minutes then dissipates to nothing. I have never seen a lifter been this erratic when ticking. Also something to note, when I feed her the onions while the lifters ticking the ticking never seems to change pitch or volume, it just gets drowned out by engine noise.
Is this just a stuck lifter, or maybe an exhaust leak? Just looking for a second or maybe third (or fourth) opinion
Maybe valve train... Check exhaust leaks including the manifold for cracks. Check ignition, Iffy secondary wires etc can like ticking.
Both can be Intermittent problems and gets hot/cold, engine moves at load changes, etc.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
How so? Even if the metal probe was stuck into the high voltage end of the coil (who would do that?), the voltage is not going to travel up the rubber hoses to your ears.
Obviously, a stethoscope is not the tool to be used for diagnosing ignition issues.
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Originally posted by Dukesterpro:
Is this just a stuck lifter, or maybe an exhaust leak? Just looking for a second or maybe third (or fourth) opinion.
How so? Even if the metal probe was stuck into the high voltage end of the coil (who would do that?), the voltage is not going to travel up the rubber hoses to your ears.
Obviously, a stethoscope is not the tool to be used for diagnosing ignition issues.
[QUOTE]Originally posted by Dukesterpro:
Is this just a stuck lifter, or maybe an exhaust leak? Just looking for a second or maybe third (or fourth) opinion.
[/QUOTE]
After an unfortunate incident with a Ford 302's coil and a metal belt buckle, I no long wish to find out what can and cannot isolate enough to stop a spark to a venerable area haha.
Thanks for the advice Ogre, I'm looking into it now. I am definitely leaning exhaust leak as for some reason when I rev the engine to say 3500 rpm when the ticking occurs, when the rpms fall, I get this slight wisp of smoke coming from the exhaust side of the engine, which I have never seen before.
I wouldn't expect ignition to be the issues as I just installed new plugs wires and coil and this intermittent ticking was happening before and after in the same way
After an unfortunate incident with a Ford 302's coil and a metal belt buckle, I no long wish to find out what can and cannot isolate enough to stop a spark to a venerable area haha.
Safest thing to do then, other than to completely negate the use of a valuable diagnostic tool, is to remove the ignition coil from any engine you happen to be troubleshooting.
For the faint of heart, the rubber trumpet can be used in place of the metal rod (although I've found the metal rod to be much more helpful in localizing a noise).
Look closely around the joints between the exhaust manifold tubing and the exhaust manifold flange at the cylinder head. The joints crack and let noise out that you would think would be consistent but isn't.
A fresh oil change to Rotella T4 10W-30 seemed to have stopped the ticking, but it is unfortunately coming back after about a week and 1500 miles (I daily this car). I think I can write this off as a lifter. Ordering some new ones from the fiero store soon!
A fresh oil change to Rotella T4 10W-30 seemed to have stopped the ticking, but it is unfortunately coming back after about a week and 1500 miles (I daily this car). I think I can write this off as a lifter. Ordering some new ones from the fiero store soon!
Seems like a good diagnosis. But why am I thinking that new lifters with an old cam will not last very long??
Seems like a good diagnosis. But why am I thinking that new lifters with an old cam will not last very long??
Well, a couple of things.
If it indeed is flat tappets, you can absolutely add new lifters, (as I have been doing to my 550,000 mile 302) It is just essential that you perform the correct break-in procedure. (Break in oil, start, immediately rev engine to 2200 rpm, fluctuate between 2200 and 3500 for 30 minutes without letting return to idle, drain oil, refill with 1200ppm zddp oil)
If its rollers, just run good oil and they couldn't care less.
At least that's my experience in the small block Windsor world.
), the voltage is not going to travel up the rubber hoses to your ears.
