Also would mention I found one of those plastic oil change interval stickers provided by Jiffy Lube stuck to an oil pickup while changing the oil pan gasket. Glad I did it and found it by chance!
I had that same issue on my Grand Cherokee . it started leaking oil & a shaky needle on the dash . Sure is not much inside that for what they cost . Great share , ENJOYED !!
I have had mixed results with Amazon ordered sensors. Sometimes fitment issues or functional issues - especially troublesome since one may erroneously eliminate the sensor as the source of the problem after changing it. Many times they have worked for me though.
Nice job as always Dave! Congrats on the 50K subs. I have seen more low pressures than I can count and it’s only ever been two causes ever- a bad sensor or worn bearings. Never seen it be anything else though of course it’s possible. People especially like to blame the oil pump but in reality it’s almost never the pump and even if it was, if the pump is worn the bearings are almost guaranteed even more worn so the new pump will make no improvement. Of the bad sensors it was only 3 times I saw that. One of those times was the replacement sensor that was bad out of the box and gave the reverse problem you had- pressure was normal until engine warmed up and then pressure went to zero. Actual pressure still showed over 40PSI though so obviously a failed sensor out of box.
Hi thanks for your info, I have the same problem on my boat engine it a old bmc. On start up it’s close to 40psi then drops to zero. I used the old sensor off the engine so you think the sensor could be the issue? it increases psi with throttle thanks
Ticking lifters are an annoying quirk of LS engines. Many make noise on first start, even when oil delivery is fine. My lifters have intermittently made a little noise for over two decades. Fortunately most do well, even over the long run. Thanks for visiting my humble site!
I threw in seafoam before an oil change trying to release any gunk. Then I've stuck with ams oil and premium gas. Now it only ticks on cold mornings until warm or until I give it some gas. It seems like the oil just needs a little oomph.
Hi mate. Spooky we were just saying today that we had not seen anything from you for a while. Great explanation. If you know how it works you know how to fix it! We have built and raced some big V8's Off road stuff long story... Bikes too, big ones. Oil pressure sensors have not kept pace with available technology. Measuring resistance with moving parts that contact just seems so yesterday? We have an upcoming video on a rudder position sensor that uses a 10 K ohm 10 turn pot. Totally inappropriate for longevity on a sailboat. We change it out for a product with a magnet and haul effect sensor. No touching parts. It seems that that in our experience that, as in yours its the way the pressure is monitored is more an issue than the actual pressure? When we raced we had old school tube and gauge. You nailed it in the last 30 seconds. $50 vs $150. Sail Safe mate. stay in touch. Ant, Cid & the pooch crew.
I had no oil pressure after rebuilding a Pontiac 428 ci for a 69 Lemans. Had a friend who knows engines well go behind me and double check my build after removing the engine. I did everything right. Total mystery until several months later and told me his 383 Stroker had the same thing happen but his had run for a while after rebuild. Come to find out, we both had a cam bearing spin. Hole in cam bearing now sealed hole in block that hole in bearing should line up with for lubrication. To this day, 35 years later, I would have a hard time believing total pressure loss could result from such an issue.
*@**9:23* Nearly identical to the fuel sending unit in the tank, except this _transducer_ uses a wiper & cantilever attached to a diaphragm instead of a float. It is, in general- a "variable resistor" like a rheostat, potentiometer, volume control, dimmer switch- all the same principle. The usual fail point of these type of sensors is the insulation between the liquid (oil) and the electrical connector. It used to be Bakelite, but even those cracked from heat, vibration, oil.
Well done with the repair :-D, it's very likely that you have prevented the engine being ruined. I have to admit that i never really thought much about pressure, Volume delivered per second with an output restriction . Makes sense. I bet there is a kind of ohms law triangle/circle for pressure, but i would have to be put under pressure to remember to look on the internet lol.
Good point, that relief valve at the bottom of the filter is really stiff. It will take a lot of pressure to open it, and by that point pressure beyond may well be too low. And if pressure on the pump side gets too high, the pressure regulating valve in the pump will open, letting oil bypass directly back to the pan. So they must manufacture these to the correct opening point so that poor maintenance doesn't kill a vehicle. It is a little disconcerting that there would be no warning if the filter relief valve were to open too soon, sending dirty oil through.
Could a poor sealing o-ring on the pick up tube cause an engine to occasionally start with low oil pressure? Revving the engine slightly brings the oil pressure up quickly.
Yes, possible, though not diagnostic. Notice how in this case the same thing happened with a bad sensor. If you get air in the intake tube, you need to inefficiently draw all that 'spongy' air up before you restore a good siphon and the oil pump works normally.
Oil sensor screen is a common failure and is the first thing you check, then you check oil pickup tube o-ring. Nevertheless, for me it was neither hence i was looking for a more comprehensive video covering the long tail of less frequent oil pressure issues, but this was not it.
With key on engine off, for any car, the system does a self check of all the dash lights as a check that the bulbs aren't burnt out. If it flickers for more than a second or so you may have the beginning of a failing sensor. Oil pressure varies with rpm as well, so the 500 rpm at starting may not be enough to turn the light off. Oil filters are designed with antisiphon valves to prevent siphoning after the engine is turned off, but beyond the filter there may be a small amount of line that needs to be primed of air before the sensor turns itself off.
@@spelunkerd Thank you for your reply, never comes on when driving, always seems to come on if left over night and it’s been a cold night, been doing it for a few months now had oil changed oil filter too very recently.
I have a 2013 avalanche 5.3 l replaced oil pump with high volume pickup tube replace oil sensor and screen have oil pressure running down the road step on it really hard let it come back down to cruising speed oil pressure starts to drop put it in neutral turn off engine restart oil pressure is back what is going.
@@spelunkerd it has a brand new pressure sensor in new screen the only thing I didn't do is block off the pressure release valve in the oil pan I wish I would have bypassed that now when I was in to it but I don't know if that's causing my problem..
@@kevintinaodman4943 As an engine warms up oil viscosity goes down, allowing oil to squeak through narrow passages more easily. When engines age the gap at rings and bearings tend to increase, which reduces overall resistance to flow. So, if the problem is low pressure with a warm engine, I'd wonder if the engine is getting to the stage that you want to start using more viscous motor oil, like 10W40 natural. Synthetic oils tend to have a little lower viscosity in my experience, and in these old engines you aren't so worried about clogging timing phasors.
@@spelunkerd yes I have over 50 lb of oil pressure when it gets up to 210 running temperature I idle at 3233 and run at freeway speeds of 40 lb of pressure so it's still a little low I do have over 200,000 mi on this motor but it doesn't make any noises no lifter taps no rattles nothing even when the oil pressure says it's on 0 and tell me to turn off the motor still sounds smooth and quiet.
@@kevintinaodman4943 If pressure is going so low it reads zero, I'd look again at the oil pressure sensor circuit. The oil pressure sensor is a simple variable resistor leading to ground, I believe grounded through the threads to the motor (0-100 ohms). So you can substitute an actual resistor to check out your gauge if you think it might be the gauge, or a bad connection at the gauge. Failing that, I'd wonder if your new oil pressure sensor is bad.
Yeah, a couple of years ago I had a little sludging oil come out during an oil change on a cold day, so I put a little seafoam into the clean oil and I did a few oil changes over six months. I think I had used some discount oil before that, since I wasn't late to change the oil. It's a reminder that you want to change oil when the engine is hot, to allow even sludging oil a better chance of making it out the drain hole. Thanks for dropping by!
Thourough investigation with easy to understand English spoken explanation, and even correct technical linguistics mister ! Also no hideous, overdriven musical introduction or goofy jokers
