I have less then 3,000 miles on a rebuilt 350. When I start it up cold I get 60 lbs. oil pressure at 1500 rpm. After about 1/2 hour of driving, pressure drops to 0 at idle (900 rpm), 10 lbs at 1200 rpm and about 45 lbs at 2000 rpm. I have the TA oil pump in it since the rebuild. Any thoughts on what is wrong??? Thanks, Darren
Darren, I understand you are a new member, and welcome. Just for future reference, the board is organized into Forums, each Forum dealing with different parts of the car. There are 3 engines Forums, one for Big Block (400-430-455), one for Big Block Race, and one for Small Block. This Forum is for problems using the board. The Small Block Forum is where you could post this question. Posting in the proper forum gets you answers quicker because members see it quicker. http://www.v8buick.com/index.php?forums/small-block-tech.8/ To answer your question, internal clearances in the engine, and oil pump are the biggest influences on proper hot oil pressure. You stated you have a TA oil pump. Did you buy the entire timing chain cover with the oil pump assembled by TA, or did someone else, or you assemble the oil pump? The pump may be brand new, but it needs to be set up properly for correct gear end clearance. If the clearances inside the pump are too large, oil will bypass the gears as the aluminum timing cover expands. The second thing is main and rod bearing clearances, and also cam bearing clearance. Buick engines use tighter clearances than Chevy engines. If the shop that rebuilt your Buick engine was not familiar with that fact, they may have set the clearances up too large. This will kill hot oil pressure, especially at the rear of the engine. The oil pump is at the front of the engine, and pressure will be highest there, but the bigger clearances will bleed pressure towards the rear of the engine. I would not hammer on it until you straighten this out.
Thanks for the reply Larry, I just realized that I posted on the wrong forum as I was trying to find my post. Yes, I have the T/A timing cover but the shop that rebuilt the short block is different from the shop that installed the motor. I don't think the latter knows any particulars on the 350 for setting up the pump. I will check the clearances and start from there. THANK YOU, Darren
What oil pump did you get and did you get booster plate? Did you get a new filter housing? Did the shop replace cam bearings? What oil are you using ( grade? 10-30?) how long was break in oil left in? Has the oil been change?
Where you located? Maybe a Buick enthusiast or a board member is close by and can help you out. I'm ALWAYS leery about any shop that says "Buick, same as a Chevy, no big deal" OR they look at you as tho you told 'em you have a flying saucer that needs repair! I checked out your link, NICE JEEP Don't drive it till you get this sorted out, hopefully its just a clearance issue with the oil pump gears, easily remedied! That's where I'd start first.
