My problem is similar to the recent NO OIL PRESSURE post.

Here it is: 91 TBI 305 RS

My oil pressure reads 30 at idle or maintaining speed, but upon acceleration it drops into the red. Block seems to be bleeding like a sieve as I put in about a quart every 2 wks.

I sprayed some engine cleaner up down all around the engine and rinsed it off, I have minimal seepage from the valve cover bolts, no worse than normal.

I looked under the carriage this morning and the front bottom end of my bell housing is covered in oil, from driving/dripping at same time. The oil pan is also covered in oil. I havent had a chance to throw it on the jacks to really get a good look. What are some possible causes of this. The valve cover gaskets have been ruled out.

One more thing, i dont know how to do a manual oil pressure check.

blain

 

To manually check the oil pressure you need to hook up a gauge with a dial to where the oil pressure sending unit hooks up. Top off the oil and do this first. That way if your pressure is low and you have to replace the pump, you can also do the oil pan gasket and rear main seal (most likely what's leaking).

 

Usual leak is the valve cover gaskets. Doesn't matter whether you've ruled them out or not, until you have no more leaks, they're suspect. Other than those, check your front seal and the joint between the timing cover and oil pan.

You haven't by any chance recently removed your smog pump, have you?

More than likely, your oil pressure issue isn't the prseeure at all, it's just the gauge. Don't bother with all that hooking up stuff, it's a waste of effort. The sending unit goes bad alot; just replace it. No sense in taking it off, then fitzing around with another gauge, then going out and replacing it anyway, since it's almost certainly bad; just bypass all that, and go directly to replacing it.

 

RB, I understand your comment, but I have thoroughly checked the valve cover gaskets, with a terry cloth and running it beneath the seam of the valve covers and the heads. I'll check again to ensure it though.

And i will heed your advice on changing the sending unit, it seems to be commonly posted that the sending unit almost always needs to be replaced.

The only portion of hoisting the engine out that i look forward to is the opportunity to install a new EGR equipped manifold that will compliment some vortec heads i have my paws on.

any more advice is welcomed, y'all.

 

How would removing the smog pump affect the problems described?

 

One of the most common mystery oil leaks on a SBC, especially on a new motor or one that someone has been "modding" by taking stuff off of, is that the upper of the 2 bolt holes on the front surface of the block, where the smog pump bracket bolts to, goes into the passage where the fuel pump rod is. If you look in that hole, you can see the fuel pump rod. This will not leak at idle, but will spew profusely a higher RPMs. You end up with the entire pass side of the frame and block just drenched and dripping in oil, but no gasket leaks.

So if you've taken your smog pump off, put a short bolt, no longer than ¾", back into that upper hole, with some silicone or something on the threads.

 

good to know.

Im off from work today so I will be tagging all my hoses, lines, etc. so that when I take my engine out, I can just start pulling lines and putting the bolts in sandwich baggies. I reckon it will save me some real time come D-day.

 

Any recommendations on how to get that oil pressure sending unit off w/o removing headers on a 5 speed car? I assume that's the problem since my oil pressure spikes to the max at anything more than idle.

 

I won't discount any other possibilities...

but when I jacked the car up today, to look for obvious problems...

I put my finger to all the bolts on the bottom end and oil filter and such....

turns out my oil filter wasnt even hand tight..I was able to tighten it another full turn. Couldnt this contribute to pressure loss upon hard accelerating?