I have a 1967 gran sport with a 76 455. I replaced the oil pan and well lots of things. Anyway. I got the oil pan all fitted everything is great there now. But when I start it cold it has oil pressure and runs great (sounds great) after it warms up It will die just suddenly stop. When I go back to start it again there is zero oil pressure and it will not start. If I let it cool down and it's cold again it will start right up and then rinse and repeat. I'm using 10w40 if that matters but it never was a problem before. Only other thing I noticed was as it was getting warmer the oil pressure would get lower. Any help is appreciated.
1. When you try to restart does it turn over normally? 2. It is normal for oil pressure to drop as motor warms up. You like to have 10-15 psi at warm idle, and oil pressure jumps up as soon as you touch the throttle. You want 10 psi for every 1000 rpm. 3. How low does the oil pressure get just before it stops? I do not think it is an oil pressure problem causing it to stop unless pressure goes to 0 while running. Most common problems are ignition. Coils can work fine cold and short out when hot. If running a points ignition check point gap or just go ahead and do full tune up. Check to see if you have fuel in the carb after it stops.
Couple more questions - are you using an oil pressure gauge? How long does it run before it stops? It ran well before you did some work? What did you do besides the oil pan?
Well as an up date I had a leak at the oil pan and the thermostate wasn't opening. I changed the thermostat for a 180 fixed the oil pan leak. Now runs great stays at temprature and i have oil pressure. Also guages were bad put new water and oil press gauges in they seem to be working correctly. I drove it to work today about 30 min drive to the base. Every thing seems great and i had no issues. The only thing i noticed was the oil pressure gauge. When driving it is showing good oil pressure. But when i stop at a light and am idling at about 500 to 700 rpms the oil pressure is showing zero. If I rev the engine above idle the oil pressure moves like it should. Is this bad or could the gauge maybe not be picking up 10 psi or what?
What is your current oil pressure while driving down the road? This is seeming more and more like an oil pump problem. Hey guys on the board, does this seem like his oil bypass valve is sticking?
I'll have to take it for a spin but it fluctuates higher as I accelerate. While cruising at steady speed it stays put but don't remember where although if I'm moving and my foot is off the gas like 25 mph basically idle it will be at 10 psi. Only when I stop and its warmed up does it sit at zero. When I first start up from cold it will idle stopped or moving at 10psi. Is the oil py pass valve where the oil filter screws on? I suspect a oil leak because there is oil crud all over the oil filter mount.
To sailbrd. It has all new spark plugs and wires. Will these engines shut them selves downnifbthey get to hot? If so I think that's why it shut down before. The old thermostat wasn't opening and gauges was reading to hot. So when warmed up at idle sitting still it will be at 0 oil pressure. It doesnt shut down and it seems fine acts fine anyway.
Dang you need more pressure, if I’m rolling down the road idling I’m a little under 30. Unscrew the large nut on the front of your oil pump with the engine off. There is a valve in there that should move behind a spring. If that valve if hung open, you will have very low oil pressure, or none at all. I’d think it’s likely that your pump pooped itself a little. You may need to pull the pump cover off and inspect. It is no longer safe to drive your car
Ok so I drove it home and when I parked it I checked the engine bay. Ok back track started it and oil pressure idled at 55 psi drove and warmed up on the way home. When warm oil psi stay at 20 accelerating now only fluctuated to like 25 but pretty much stayed at 20. Whenever I stop it idled like 800 and oil psi always went to 0. As soon as I get going it stayed at 20. Ok so got home. Looked at the engine. I have oil thrown all over the passenger side mid battery and down oil all over the front of the mount that you screw the oil filter into but it's dry on the rear side. The oil appears to come from that housing or behind the balancer and its shooting over the housing and battery and passenger side. This oil pump nut where is this located? . First pic is the oil filter housing suspect one and a little in the back of the picture is the balancer suspect two. The second picture is the mess it made all over the passenger side.
Oil is good it was like it didnt lose much if anything. But obviously it did. I have cleaned it all up and today I'm going to have a buddy start it and run up the rpms to see if I can see where the leak is coming from
20 psi while cruising or highway is low. When you overheated the engine, did it stop on its own, or did you shut it off?
