FUNKY OIL GAUGE

[kfoz]

On my '78 350 Silverado, after installing a NEW oil pump(stock volume), my oil gauge is acting funny. It fluctuates(is that spelled right?) When parked, warm and idling it's at 15psi. When warm & driving it's around 45-50psi. When I come up to a stop sign,etc. it plummits to less than 10psi!  What's going on here??? There is no knocking and the engine is running fine. The oil pump is NEW and the gauge has been checked,etc! Maybe a sending unit is in order??

Please advise and thank you all!

kfoz

[Captkaos]

What you posted is normal.  The only question mark is the drop at stopping, is the oil level correct?  By below 10 are you saying below normal?  you only need 5-7 at idle when hot.

[kfoz]

THe oil level is correct. It just has never fluctuated like this before. All I did was replace my oil pump with a NEW Melling compltely stock pump for a completely stock  '78 350.

[kfoz]

ok, now even warm and cruising it reads maybe 20psi!  Should I try replacing the oil sending unit??

kfoz

[Captkaos]

Is it the factory electrical?  If so, you could try that.

[kfoz]

I believe it is Capt. My other truck('74 C-2500 454) has a factory mechanical oil gauge. I assume for a stock '78 half ton C-10 it is electrical. I will check!

Thanks again,
kfoz

[Captkaos]

If it is the stock setup it is electrical.  Swap the sender.

[kfoz]

Is the sender located near the back of the block? There is one on the Driv. side but i assume that is a temp sender?

[choptop]

On most of mine, the sending unit is behind the distributor. The one on the side is for the electric choke

[eventhorizon66]

Seems like about once a week we have this discussion about oil sender location.

[GoatBeard]

When mine is first started it gets around 50 - 60 psi.  When it gets warm and I'm driving it (moving) I register around 30 psi.  When it is warm and stopped (idle) I get about 8 or 9 psi.

I have had this same reading on 3 different 305s.  So I feel that it's perfectly normal.