In a message dated 8/31/16 17 26 15, mbefthomas@comcast.net writes:
I'm trying to figure out why I'm getting a pegged reading on my oil pressure gauge. It will show normal pressure as the car starts, but soon after pegs to the right and stays there. Everything runs fine otherwise. I've swapped out the pressure sender, NAPA OP6091, and it's still pegging, so I'm suspecting the gauge. Anything else I could check?
Calling Bill Taylor! That is, assuming it's an electrical. You can't make that assumption though.
Calling Bill Taylor! That is, assuming it's an electrical. You can't make that assumption though. I *think* I may have stumbled across something. Doing some primitive Google research, I confirmed what I thought I knew, which is that the oil pressure gauge works by taking 12V power in, which runs across the gauge, then out to the sender unit, which is a variable ground. The reading given by the gauge depends on the resistance of the sensor unit; this in turn is determined by the engine's oil pressure. Extremely high readings after a cold start, if they are accurate, mean
I *think* I may have stumbled across something. Doing some primitive Google research, I confirmed what I thought I knew, which is that the oil pressure gauge works by taking 12V power in, which runs across the gauge, then out to the sender unit, which is a variable ground. The reading given by the gauge depends on the resistance of the sensor unit; this in turn is determined by the engine's oil pressure. Extremely high readings after a cold start, if they are accurate, mean the pressure relief valve near the pump and filter has probably stuck. The engine should be switched off or the oil filter could burst. I have a mechanical oil pressure gauge which threads into the hole normally occupied by the electric sender. It is used to 'sanity check' the readings on the gauge. It's the first troubleshooting tool; if the mechanical gauge reads high, you have an engine (or at least oil filter) problem. If it reads normally, you have an electrical problem. I could mail it to you tomorrow and you would have it by the weekend? Let me know if you would like to try it out. Mike In a message dated 8/31/16 17 26 15, mbefthomas@comcast.net writes: I'm trying to figure out why I'm getting a pegged reading on my oil pressure gauge. It will show normal pressure as the car starts, but soon after pegs to the right and stays there. Everything runs fine otherwise. I've swapped out the pressure sender, NAPA OP6091, and it's still pegging, so I'm suspecting the gauge. Anything else I could check? the pressure relief valve near the pump and filter has probably stuck. The engine should be switched off or the oil filter could burst. I have a mechanical oil pressure gauge which threads into the hole normally occupied by the electric sender. It is used to 'sanity check' the readings on the gauge. It's the first troubleshooting tool; if the mechanical gauge reads high, you have an engine (or at least oil filter) problem. If it reads normally, you have an electrical problem. I could mail it to you tomorrow and you would have it by the weekend? Let me know if you would like to try it out. Mike