Quote Originally Posted by Itoldyouso View Post
I just had the same thing happen to the sbf in my 27. The gauge started dipping to zero only occasionally, but would go to 40 psi when I raised the rpms. I removed the sender and screwed a mechanical pressure gauge on there and when I started it the gauge read 50 psi at idle and would go to 70 when I revved it up. I bought a new sender and the gauge on the dash started reading the same as the mechanical one...........my sender was only a year old but had gone bad.

I'm starting to lose confidence in electrical gauges. My water temp gauge is 20-30 degrees off of what the actual temperature is (I have shot the engine with an infared gun and also have a Mr Gasket radiator cap with a thermometer in it. Both the gun and the cap read 180 when my dash gauge reads 200-210.

I would suggest you do the same test I did, screw a mechanical gauge in where the sender goes and see what it reads. They are cheap enough (you don't need a top of the line one for the test) and will confirm you have or do not have a problem.

Don
Thanks Don! I will give that a try. I don't hear any tapping or anything so I was kinda of leaning towards problems with the gauge, etc.