A good friend just called and his son in Texas called him with this problem. His 03 Silverado OP has been fine but this evening it suddenly spiked to max(like 80PSI) and is staying there. He shut the engine down and re started it and the PSI stayed the same. I suggested it may be a false reading but to inspect the oil filter to see if it has expanded. I also told him he may need to put a mechanical gauge on the engine to verify the pressure. Any other thoughts.
Problem: Very high oil pressure
- Thread starter tig1
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you are several states away, no way you can diagnose the problem. Tell him to get it into a shop ASAP
probably a bad oil pressure sending unit. I've had it on GMs also.
Bypass valve in the oil pump is sticking. I had it happen on a Pontiac 301.
I just found this on You Tube. Notice the OP gauge is at *0, the same as this problem. I e-mailed the link to him. I will also mention the bypass valve. Here is the link.
http://www.youtube.com/watch?v=y8fRT4PhCq0
http://www.youtube.com/watch?v=y8fRT4PhCq0
Bad sending unit.
Originally Posted By: NHGUY
Bad sending unit or sludged pressure spring.Has it had intake gaskets yet?
This truck has a dry intake manifold, no coolant flows though them. No intake gaskets to fail from dexcool here.
It could also be the gauge step motor is failing as they will do strange things when it happens. Common problem with these trucks.
Bad sending unit or sludged pressure spring.Has it had intake gaskets yet?
This truck has a dry intake manifold, no coolant flows though them. No intake gaskets to fail from dexcool here.
It could also be the gauge step motor is failing as they will do strange things when it happens. Common problem with these trucks.
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Originally Posted By: tig1
Originally Posted By: NHGUY
Bad sending unit or sludged pressure spring.Has it had intake gaskets yet?
His engine has always had M1 5-30 so sludge won't be the problem. Leaning to the sensor.
I'll bet $1.00 its the sensor,keep us posted.
Originally Posted By: NHGUY
Bad sending unit or sludged pressure spring.Has it had intake gaskets yet?
His engine has always had M1 5-30 so sludge won't be the problem. Leaning to the sensor.
I'll bet $1.00 its the sensor,keep us posted.
Stuck relief valve.
Could be the sensor, a common problem on Corvettes.
To check, turn on the ignition, without the engine running, if it shows high oil pressure it is most probably the oil pressure sensor (could also be wiring or gauge).
To check, turn on the ignition, without the engine running, if it shows high oil pressure it is most probably the oil pressure sensor (could also be wiring or gauge).
Pressure sensor or gauge cluster issue is by far the most likely. A mechanical gauge on the engine will rule out both in one fell swoop (or point to the next most likely culprit, the stuck bypass valve).
Another vote for a failed pressure sending unit. Had one fail on my last truck ('05 Chevy with the 6.0). Like Corvette Owner suggested have him see if the gauge stays pegged with the ignition on but the engine not running.
Update?
Testing with a mechanical gauge is likely the best idea to try first. Then go from there.
Originally Posted By: daman
Update?
UPDATE!!
I just called my friend and his son replaced the OP sensor last weekend, but had a terrible time doing it. It's buried at the back of the engine and he broke the first one putting it in. Second time around fixed the problem and the Oil pressure reading was fine. I think he spend 6-7 hours on the repair. They sure don't make em to work on.
Update?
UPDATE!!
I just called my friend and his son replaced the OP sensor last weekend, but had a terrible time doing it. It's buried at the back of the engine and he broke the first one putting it in. Second time around fixed the problem and the Oil pressure reading was fine. I think he spend 6-7 hours on the repair. They sure don't make em to work on.
Originally Posted By: tig1
Originally Posted By: daman
Update?
UPDATE!!
I just called my friend and his son replaced the OP sensor last weekend, but had a terrible time doing it. It's buried at the back of the engine and he broke the first one putting it in. Second time around fixed the problem and the Oil pressure reading was fine. I think he spend 6-7 hours on the repair. They sure don't make em to work on.
Good to hear,i knew that was the problem and yes they can be a bear to get at.
Originally Posted By: daman
Update?
UPDATE!!
I just called my friend and his son replaced the OP sensor last weekend, but had a terrible time doing it. It's buried at the back of the engine and he broke the first one putting it in. Second time around fixed the problem and the Oil pressure reading was fine. I think he spend 6-7 hours on the repair. They sure don't make em to work on.
Good to hear,i knew that was the problem and yes they can be a bear to get at.
Glad to hear it's fixed.
That's one of those jobs where you really need the right tool. If you have the specific socket that's made specifically for that oil pressure sender it's a ten minute thing: unplug two connectors, unscrew it, repeat in reverse. Alright, if you have big hands or thick forearms maybe a half hour. If you don't have the specific tool then you get what your friend and his son just went through.
Edit:
Of course, he probably could have shaved a couple hours off by removing the intake (very easy to get off and on) but that's one of those things that looks like such a big deal to do you end up killing yourself to avoid it.
That's one of those jobs where you really need the right tool. If you have the specific socket that's made specifically for that oil pressure sender it's a ten minute thing: unplug two connectors, unscrew it, repeat in reverse. Alright, if you have big hands or thick forearms maybe a half hour. If you don't have the specific tool then you get what your friend and his son just went through.
Edit:
Of course, he probably could have shaved a couple hours off by removing the intake (very easy to get off and on) but that's one of those things that looks like such a big deal to do you end up killing yourself to avoid it.
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Right on
There is certainly something to be said about mechanical gauges.
I bought a 3 gauge c-pillar mount for my mustang. I plan on both auto cross and drag racing this upcoming season. Oil temp and pressure are both invaluable to know when autocrossing and the 3rd gauge is for line pressure for nitrous.
Gonna be a great summer.
There is certainly something to be said about mechanical gauges.
I bought a 3 gauge c-pillar mount for my mustang. I plan on both auto cross and drag racing this upcoming season. Oil temp and pressure are both invaluable to know when autocrossing and the 3rd gauge is for line pressure for nitrous.
Gonna be a great summer.
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