starting cold at 60...after maybe 20 miles it'll sink to 20 or even a bit lower. any idea why this would happen? it's got 5 quarts of oil, no leaks, no burning. could it be a pump problem (please god no, i don't need my car out of commission again)
it isn't really dropping on revs, my problem is it's just generally going down over time while cruising/idling, and it's hitting a zone i don't feel very comfortable in. on a hot day, what should i expect in my psi readings with a stock oil pump? (btw, i DO have a plastic cable in my oil gauge.. someone will ask that. but it's leak free and should be reading just fine)
David, For a 350 Buick, 10 psi/1000 RPM is fine. That means at a 6-700 idle you want at least 10 psi. At a 5500 RPM shift point you want at least 55 psi. On the highway at 60 MPH, 35-45 psi should be fine. What are your readings at various RPM's??
Since we are on the subject of oil pressure, I think my oil pressure drops as the car warms up. On a hot day after driving home from work and off the highway I realize I have no power!!!! Not even enough to break the tires loose, but when I use it the next morning to go to work or let it cool down for some hours it has balls to the wall and chirps hard in second. I have no aftermarket gauges to know whats really happening but does this sound like an oil pressure problem?? I thought it was an overheating problem ,vapor lock or something of that nature so I put in a new themostat and spacer for the carb. It helped perform better but didn't help my loss of power problem. Any input greaty appreciated!!!!!!! Thanks Pete
Oil pressure will drop in any engine when it gets warmed up, the oil thins out. In a Buick engine it drops a bit further than most because of the oil pump being housed in the aluminum timing cover. Any engine will be down on power when its hot out and the engine is warm. The best combo is cool air and a warm engine with a 160 to 180 operating temp. Larry70GS is rite on with the pressure specs he gave. If you actually have only 20 psi while cruising on the highway, that does seem low. With a stock pump and a booster plate with the proper gear end clearances (.001-.002) AND proper main and rod bearing clearances you should be able to maintain AT LEAST 10 psi at hot idle (600 to 800 rpm) with 10W30 oil. Heavier oil wont help much if theres wear in the pump or bearings. Mark
i'm not sure what i get at crusing speed. i'll have to get someone to keep an eye on it next time i have a passenger or two...if i try and look at the little underdash cluster i about run off the road. i was just worried about the low reading at idle, but i guess i havn't driven it since it warmed up a bunch...probably a big factor. my power is still quite good. like i said, i'll take a look. now to jsut get that extra cooling i need. (hitting 190+ sitting stiull during midday...a HD clutch and the stock sevenblade should fix that a bit, and an aluminum radiator will help even more)
Pete, Your power drop off when the motor gets hot is normal and in no way indicates a problem with your oil pressure. Like Mark said, optimal temp is 160-180. Hot air isn't as dense and will make less power, that's why most new cars have a cold air package available stock or as an add on. You should have gauges though, first thing I added when I got my car. You may be running alot warmer than you think. David, If you have 20 psi at idle hot, your fine. Check the high RPM pressure.
A good (new) 4 row Modine radiator for a 455 will fit, along with the stock 7 blade clutch fan (new clutch) with the stock fan shroud will provide more than adequite cooling for 95% of 350's out there. There isnt really a need for the more expensive and somewhat universal aluminum radiator, tho they are nice and quite a bit more effecient in heat transfer, but not really nesessary for even a more than warmed over 350. If you dont have a temp guage, install a good Autometer mechanical guage to see where your at temp wise. Mark
i've been there twice, both times it was the oil pump pickup clogged from the fibers off the upper timing gear. hope that helps. by the time i repaired it ,already wiped the cam and lifters.
Thanks guys, I really have to buy those gauges. Im sure it probably holds the key to my issue. Btw, my radiator is newer and Ive put in a 160 degree thermostat. Its so frustrating having tons of power to none. Really have to buy a set of gauges, any recommendations????? Pete
Pete, Autometer gauges, 2-1/16" or 2-5/8". Oil pressure #3321 or3421. Water temperature #3332 or 3432. Those are the Sport-Comp, black face. Or you can go with the Ultra-Lites, silver face, Oil pressure #4321 or4421. Water temperature #4332 or4432. Get a 2 hole gauge panel #2237 or 3232. Get the copper line #3224 for the oil pressure(don't use the supplied nylon tubing-an accident waiting to happen). You can get everything from Jegs or Summit. Good luck.
