| Author |
Message |
Mike Dawson (Miked)
Junior Member
Username: Miked
Post Number: 87
Registered: 2-2001
| | Posted on Friday, April 18, 2003 - 8:39 pm: | |
On my 308 GT4 I utilized an extra port on the oil filter stand (opposite from the stock sending unit location) to mount a high quality mechanical gauge. There was quite a difference in the pressure readings between the dashboard gauge and the mechanical gauge even with a new sending unit. The sending unit just varies the electrical resistance to ground with the rise and fall of pressure. Other things such as corroded or broken wire strands in the electrical wiring also vary the resistance to current flow which is misinterpreted by the gauge as oil pressure. |
Andy Falsetta (Tuttebenne)
Junior Member
Username: Tuttebenne
Post Number: 75
Registered: 3-2003
| | Posted on Friday, April 18, 2003 - 8:32 pm: | |
I'd go for the sender too. They don't last too very long before they start reading incorrectly. Funny, but my experience seems to be the opposite. Every sender I have replaced has read lower oil pressure than the new one, but that's only my personal experience. They aren't too expensive and they're easy to change. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 604
Registered: 5-2001
| | Posted on Friday, April 18, 2003 - 6:24 pm: | |
I agree, you have a car that is now 25 years old. The senders and gauges can fail, mostly the senders. I had to replace the oil temp sender on my 78 308. For some reason, when they fail, they start reading high. Don't know why...
Start with the sender...if it is still high, then get the mechanical gauge. |
Terry Springer (Tspringer)
Member
Username: Tspringer
Post Number: 456
Registered: 4-2002
| | Posted on Friday, April 18, 2003 - 4:31 pm: | |
I would lay a wager you have either a bad sender or a bad guage. Both are notoriously inaccurate.
Go to Pep boys or a like place. Buy a $30 mechanical oil pressure guage with all the adaptors. Use it as a tool.... screw it into your car while its up on jack stands and run the car. You can then get a very accurate reading on actual oil pressure.
The guage in the car basically serves to tell you YES or NO on oil pressure. If you need real accuracy.... use the mechanical guage. |
Mike Procopio (Pupz308)
Member
Username: Pupz308
Post Number: 291
Registered: 10-2002
| | Posted on Friday, April 18, 2003 - 12:11 pm: | |
During the past week, I've noticed my steady-state oil pressure readings slowly increasing. It started at the standard 85, right down the middle, and then up to the first mark, and today was just past the first mark. 1978 308 GTS.
Oil level is OK. Mobil 1 15w50.
I plan on getting a new sender, but I wanted to get some perspective first...
1. Is there anything quick to check for in the engine area that could indicate that I've got a high oil pressure condition?
2. If I really *do* have a high oil pressure condition, how bad is that? Why?
Thanks guys... --Mike
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