I have had a noise from the engine when cold for a while now. It doesn't sound too threatening and the stock oil pressure Gage reads well within a safe range. However, I want to test it with a more reliable manual pressure gauge.

Where is the oil pressure sending unit on the 302? Also, do you have any recommendations for a cheap manual gauge?

The noise which is a "marble " type of noise has been present since I changed the oil 2x after I bought the truck. I've been using Castrol GTX 10w30. I don't know what the original owner used.

Is there a different type/brand of oil that is still within factory recommendation that I should try?

Thanks.

 

I use one of these
Engine Oil Pressure Test Kit

 

Oil pressure sending unit on a Windsor is up front on driver's side, just above the oil filter. You can put a tee in and run it as well as a mechanical gauge.

 

The sending unit on a 302 should be on the driver side near the front of the engine. It will be close to the fuel pump and power steering pump.

 

As this shows, you are looking for a white wire with a red stripe:

 

Just buy a cheap one from any of the parts stores. I always have good longevity from the cheap pressure gauges, not so much with the cheaper temp gauges. The temp gauges seem to last about 4 or 5 years and then they fail. But they are easy enough to replace.

 

That's what I did on my 84/302. I have the stock in dash gauge, and an aftermarket one.

 

Yep, that's the way I do it as well. But, now that I have a very stable ICVR the stock gauge works pretty well.

 

Ok thanks everyone!

 

On mine, my factory gauge sometimes acted strange, along with the temp gauge. When I put in an instrument cluster from an 86, which had a tach, the problems corrected themselves. Could have been the ICVR, or maybe the gauges themselves.

 

Does anyone have any suggestions what brand/wt engine oil to use? Also, what kind of gear oil for the differentials do I want to use?

 

Asking what brand oil is like asking what brand tires and what brand battery. Everyone has their favorites, just so long as it's clean and has the sae stamp on it, I use it. I usually run 10w-30.

80w-90 gear oil is what you want for the differentials.

 

These trucks were made for 10W-30, so that's what I run. As for type or brand, do a bit of research and you will find that is a heavily-debated question. Some say that your cam and lifters have mated and the type of oil doesn't really matter. Others say that since the amount of ZDDP has been drastically reduced in standard oils you either need to run an additive or a high-ZDDP oil, like those for diesels.

Personally, on an engine with many miles on it, all presumably with a standard oil, I'd continue to run a dino or synthetic oil w/o any extra ZDDP. Like Mobil 1. But, if I were building a new engine with a flat-tappet cam I'd probably start with an oil with extra ZDDP, like some diesel oils, or run an additive.

Confused?

 

10W 30. I find Valvoline usually on sale around here. I also add a bottle of STP, for the ZDDP it has. I figure it can't hurt. 90W in the differentials.

 

So any 80w90 is ok for the differentials?