Oil Gauge Jumps at Idle
#1
09-27-2018
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Oil Gauge Jumps at Idle
Sometimes when I come to a stoplight once the engine is hot the oil gauge jumps around for a few seconds and the engine idles kind of rough. I also sometimes get a soft chirp when I’m idling/driving at low speeds, but I don’t think I’ve get these two symptoms at the same time.The combination of the two seems to indicate cam synchro from what I’ve read. Can anyone confirm? The truck is running fine but I dont want to lose oil pressure and ruin the engine. What would be a good place to start? Or should I not worry about it?
2000 3.0L manual 4x4
116,000 miles
Thanks!
2000 3.0L manual 4x4
116,000 miles
Thanks!
#2
09-28-2018
Welcome to the forum
Around 1988 Ford switch over all vehicles to an oil pressure SWITCH, on/off
Switch is OFF, ungrounded, when oil pressure is under 5psi at the switch
Switch is ON, grounded, when oil pressure is above 5psi at the switch
Oil pressure Gauge is preset to read in the Normal Range when Grounded, and 0 when ungrounded.
Any movement within Normal Range would be an electrical issue, i.e. alternator voltage changing with engine RPMs
If needle is jumping then oil pressure could be dropping below 5psi, causing switch to ungound and ground quickly
But it could also be a failing switch or loose wire on the switch, which is more common
At 3psi valve train will start to make "ticking noises", that would confirm actual low pressure
Oil pressure switch on the 3.0l is on the block but behind Passenger side head, so between head and firewall on the block by the bell housing
Yes, chirping noise is most likely Cam synchro tower, the bushings wear out, 80k miles is approx. replacement period for the 3.0l
Yes, it is part of the oil pump drive but cam gear on synchro would have to slip to effect oil pressure, so I would guess these two things are unrelated
Chirping can also come from fan belt pulleys, tensioner and idler pulleys usually
Loosen fan belt and spin all the pulleys by hand, including alternator pulley, see if any make a noise or "feel" odd
Around 1988 Ford switch over all vehicles to an oil pressure SWITCH, on/off
Switch is OFF, ungrounded, when oil pressure is under 5psi at the switch
Switch is ON, grounded, when oil pressure is above 5psi at the switch
Oil pressure Gauge is preset to read in the Normal Range when Grounded, and 0 when ungrounded.
Any movement within Normal Range would be an electrical issue, i.e. alternator voltage changing with engine RPMs
If needle is jumping then oil pressure could be dropping below 5psi, causing switch to ungound and ground quickly
But it could also be a failing switch or loose wire on the switch, which is more common
At 3psi valve train will start to make "ticking noises", that would confirm actual low pressure
Oil pressure switch on the 3.0l is on the block but behind Passenger side head, so between head and firewall on the block by the bell housing
Yes, chirping noise is most likely Cam synchro tower, the bushings wear out, 80k miles is approx. replacement period for the 3.0l
Yes, it is part of the oil pump drive but cam gear on synchro would have to slip to effect oil pressure, so I would guess these two things are unrelated
Chirping can also come from fan belt pulleys, tensioner and idler pulleys usually
Loosen fan belt and spin all the pulleys by hand, including alternator pulley, see if any make a noise or "feel" odd
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