Rough Idle (92 f-150)
#1
12-12-2005, 07:12 PM
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Rough Idle (92 f-150)
Hey guys. Nice to find this site, i'm sure it will come in handy in the future. I have a problem with my 1992 F-150 that i just can't seem to figure out. Let me tell you how it started.....
I left college the other day and the truck started shuttering real bad. I pulled over to check things out and after looking over everything i noticed the oil was extremely low. Two & 1/2 quarts to be exact. This is odd because the truck gets all it's routine maintance and more. Infact the oil was changed 1,800 miles prior. The truck has never burned oil before. There was also a noise coming from in the engine....where can not quite pinpoint.
When i got home I changed the oil (5qt castrol, 1 qt lucas) and there was nothing in the oil pan (metal etc...) The truck ticks...like an exhaust leak or possibly and valve. The truck also vibrates a lot at idle.
When i hooked the truck up to the computer it gave me three codes: 327, 328, & 232. They are all EGR codes. Two of them are circuit codes, and one is the EGR valve not opening.
Any idea on where to do with this? One person thought maybe it was the flex plate, or torque converter, but i am thinking it is a timing or EGR related issue.
If you guys can throw in any advise or have any questions i would appreciate it. Thanks, Marc
I left college the other day and the truck started shuttering real bad. I pulled over to check things out and after looking over everything i noticed the oil was extremely low. Two & 1/2 quarts to be exact. This is odd because the truck gets all it's routine maintance and more. Infact the oil was changed 1,800 miles prior. The truck has never burned oil before. There was also a noise coming from in the engine....where can not quite pinpoint.
When i got home I changed the oil (5qt castrol, 1 qt lucas) and there was nothing in the oil pan (metal etc...) The truck ticks...like an exhaust leak or possibly and valve. The truck also vibrates a lot at idle.
When i hooked the truck up to the computer it gave me three codes: 327, 328, & 232. They are all EGR codes. Two of them are circuit codes, and one is the EGR valve not opening.
Any idea on where to do with this? One person thought maybe it was the flex plate, or torque converter, but i am thinking it is a timing or EGR related issue.
If you guys can throw in any advise or have any questions i would appreciate it. Thanks, Marc
#2
12-12-2005, 10:36 PM
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What size engine?
A little info on bottom end engine noises:
Main Bearing Knock:
Main bearing knock is usually apparent when the engine is pulling hard, when an engine is started, during acceleration, or at speeds above 35 mph.
Loose Flywheel or Broken Flexplate:
A loose flywheel or broken flexplate can usually be detected by this procedure:
1) Advance engine idle to 2000 rpm.
2) Turn off the ignition switch.
3) When the engine has almost stopped, turn the switch on again.
4) Repeat this procedure several times.
5) If the flywheel is loose or the flexplate is broken, a distinct knock will be heard every time the ignition switch is turned back on.
Harmonic Balancer:
A separated harmonic balancer will generally produce a heavy rattling noise that can be heard at low speed.
Rod Knock:
Excessive connecting rod bearing clearance noises are usually a light rap or clatter much less in intensity than main bearing knocks and the loudest when the engine is "floating" or running with a light load at from 25 to 35 mph. The noise will become louder as engine speed is increased. By grounding out each of the spark plugs, one at a time, you can determine from which cylinder the noise is coming. The noise may not be eliminated entirely by grounding, but it will be reduced considerably in intensity. The easiest way to ground out the cylinders is by inserting a 1.5" piece of 5/32" vacuum hose on each terminal on the distributor cap, and then placing the spark plug wires over the vacuum hose. With the alligator clip end of a non-powered 12 volt test lamp attached to ground, touch the test light tip to the vacuum hose to ground out that cylinder.
Piston Slap:
Piston slap is loudest when the engine is cold, and lessens or disappears after the engine is warm. When driving the car (at from 25 to 30 mph) the noise will increase in intensity as the throttle is opened and additional load is applied. To detect piston slap, try the following procedure:
1) Pour several ounces of 40 weight engine oil into the suspected cylinder(s).
2) Crank the engine for several revolutions with the ignition turned off. This will allow for the oil to work itself down past the rings and act as a cushion.
3) Install the spark plug(s).
4) Start the engine.
5) If the noise is eliminated, the engine has a piston slap condition.
Piston Pin Noises:
Piston pin noise is usually the result of excessive piston pin clearance. This will cause a sharp, metallic, double-knock sound most noticable when the engine is idling. Sometimes the noise is more audible at car speeds of from 25 to 35 mph. To test for excessive piston pin clearance noise, use this procedure:
1) Run the engine at idle speed.
2) Retard the spark to reduce the intensity of the knock.
3) Return the spark timing to the normal setting.
4) Short out each spark plug, one at a time. The double-knock sound will become more audible at the cylinder with the loose pin.
I'm not saying your noise is coming from the bottom end, but at least now you have the info necessary to determine for sure.
A little info on bottom end engine noises:
Main Bearing Knock:
Main bearing knock is usually apparent when the engine is pulling hard, when an engine is started, during acceleration, or at speeds above 35 mph.
Loose Flywheel or Broken Flexplate:
A loose flywheel or broken flexplate can usually be detected by this procedure:
1) Advance engine idle to 2000 rpm.
2) Turn off the ignition switch.
3) When the engine has almost stopped, turn the switch on again.
4) Repeat this procedure several times.
5) If the flywheel is loose or the flexplate is broken, a distinct knock will be heard every time the ignition switch is turned back on.
Harmonic Balancer:
A separated harmonic balancer will generally produce a heavy rattling noise that can be heard at low speed.
Rod Knock:
Excessive connecting rod bearing clearance noises are usually a light rap or clatter much less in intensity than main bearing knocks and the loudest when the engine is "floating" or running with a light load at from 25 to 35 mph. The noise will become louder as engine speed is increased. By grounding out each of the spark plugs, one at a time, you can determine from which cylinder the noise is coming. The noise may not be eliminated entirely by grounding, but it will be reduced considerably in intensity. The easiest way to ground out the cylinders is by inserting a 1.5" piece of 5/32" vacuum hose on each terminal on the distributor cap, and then placing the spark plug wires over the vacuum hose. With the alligator clip end of a non-powered 12 volt test lamp attached to ground, touch the test light tip to the vacuum hose to ground out that cylinder.
Piston Slap:
Piston slap is loudest when the engine is cold, and lessens or disappears after the engine is warm. When driving the car (at from 25 to 30 mph) the noise will increase in intensity as the throttle is opened and additional load is applied. To detect piston slap, try the following procedure:
1) Pour several ounces of 40 weight engine oil into the suspected cylinder(s).
2) Crank the engine for several revolutions with the ignition turned off. This will allow for the oil to work itself down past the rings and act as a cushion.
3) Install the spark plug(s).
4) Start the engine.
5) If the noise is eliminated, the engine has a piston slap condition.
Piston Pin Noises:
Piston pin noise is usually the result of excessive piston pin clearance. This will cause a sharp, metallic, double-knock sound most noticable when the engine is idling. Sometimes the noise is more audible at car speeds of from 25 to 35 mph. To test for excessive piston pin clearance noise, use this procedure:
1) Run the engine at idle speed.
2) Retard the spark to reduce the intensity of the knock.
3) Return the spark timing to the normal setting.
4) Short out each spark plug, one at a time. The double-knock sound will become more audible at the cylinder with the loose pin.
I'm not saying your noise is coming from the bottom end, but at least now you have the info necessary to determine for sure.