rotating sound behind dash
Thread Starter
Melting Slicks
Joined: Apr 2001
Posts: 2,119
Likes: 213
From: Pittsburgh PA
rotating sound behind dash
I'm getting what sounds like a pinwheel spinning behind my oil pressure gauge and the needle vibrates a tight span. Only when fully warmed up, and increases with speed and/or rpm. I'll need to study it further and report back, but I'm looking for initial suggestions as to what it could be.
The car is an 81 coupe in very good condition, always garage kept and very clean. Is the 81 oil pressure gauge still fed with a plastic straw pipe, like my 72 had? Could it be the speedo instead? No rocking needle.
Thanks.
The car is an 81 coupe in very good condition, always garage kept and very clean. Is the 81 oil pressure gauge still fed with a plastic straw pipe, like my 72 had? Could it be the speedo instead? No rocking needle.
Thanks.
Le Mans Master
Joined: Oct 2005
Posts: 6,247
Likes: 471
From: Glen Allen, VA
My first thought before I read your entire description is speedo. It's easy enough to disconnect the speedo cable from the speedo and see if the sound goes away, it just clips into the back. I'd do that first and then focus on the oil pressure gauge if the speedo isn't it.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Your oil pressure gauge is electric and has a signal wire coming from a sending unit plumbed into the engine's oil circuit. I suspect that the sending wire is fraying somewhere (most likely under the hood and at the connection to the sending unit). That would yield an erratic signal which would tend to drive the oil gauge 'nuts'. If the 'pinwheel' sound seems to match the movements of the gauge needle, that's the problem. You just need to find the offending wire/connection and repair it. (If no problem with the sender wire, check the power and ground feed wires, too.)
Racer
Joined: Dec 2014
Posts: 374
Likes: 42
From: Coldwater Mi
AND.....if U do that, it's not that much more hassle to pull it back into the engine bay area, raise it up & lube it at that time!
Thread Starter
Melting Slicks
Joined: Apr 2001
Posts: 2,119
Likes: 213
From: Pittsburgh PA
will do. i was at Carlisle today and bought a new cable in case that's the problem i'll start with the oil pressure wiring. where is it on the engine, top rear like my 72?
