Clean the connections and the posts on the battery. It's a sensor, it needs a good ground. Yes it fixed mine.
Oil that’s too thin can also lead to insufficient oil pressure to properly operate your vehicle’s variable valve timing system, if equipped. Low pressure may also result in lifters not staying in contact with cams, causing noise and increased wear
Well, oil viscosity should be determined by temperature range, bearing clearances, and/or oil pressure.Post #20. 5W-30 and 10W-30 sound good, no 5W-20 weakling. Higher output engines tend to use heavier oil for good reason.
It's best to use the viscosity recommended in your owner's manual, but a slightly thicker oil or thinner oil likely won't do lasting harm.blog.amsoil.com
I agree.Well, oil viscosity should be determined by temperature range, bearing clearances, and/or oil pressure.
So as your engine wears out, in theory you should be increasing the oil viscosity to compensate for the increased clearance and reduced pressure.
As for clearances/tolerances being a driving factor, all motor oil is very viscous (high viscosity, thinking molasses) during cold weather startup and engines tend to run cooler during cold weather. Same engines and "operating" oil specs are used north and south. Heat seems to be more of an issue than cold. Consider rocker arm needle bearing failure in the 3.6L engine using 5W-20 oil. Oil film too thin?, needle bearings aren't rocket science Toyota was known for higher tolerance engines for years and still used 5W-30 motor oil. Engines in North America, Ford for example, requiring 5W-20 were requiring 5W-30 in Europe. Go figure, but nothing to do with tolerances.Although it will help improve fuel efficiency throughout the entire oil drain interval, it opens the door for increased wear and tear on critical engine parts. This makes the development of new additives suitable for ultra-thin oils in high power density engines that much more critical.
I have some internal noise, similar to what coolcatcreative stated in post #22.I used to have a 1981 Dodge pick up with a 318. If I changed the oil and used the thin bulk oil we had at work (free!) the oil light would flicker when at hot idle. Raising the engine speed just slightly would turn the light off. The solution for me was to use thicker oil or add a can of STP with the thin oil. There was no singular thing wrong with the engine. It was just old and a bit worn. I sure wish I still had that truck.
I asked the mechanic who measured the oil pressure for me what he thought of my friend's proposal to change the rod bearings. He advised against it, saying he never had long-term success by replacing the rod bearings. The new bearings would perform fine, but some other bearing or internal component would fail within a year. That and I question just swapping the rod bearings, but not the main bearings. Wouldn't they all need to be changed?...the REAL reason was the lower end bearings - rod bearings and main bearings. (In the middle of a cross-country trip, one of the rod bearings went out completely, rod knocking and all...)
I tried to salvage it with new bearings (at the motel we stopped at) but by then the crankshaft was already damaged and after a few of miles of smooth running, the knocking came back...
He should of tested the pressure at higher engine speeds. The minimum pressure is 5psi at idle with the engine warmed up to operating temperature, and 30-80psi at 3000rpm.Thanks for the specs and procedures.
I asked my mechanic to measure the oil pressure and listen to the engine as a second set of ears. These were his readings with the engine at idle (700 rpm):
Oil cold: 15 - 20 psi
Oil hot: 6 psi
I have some internal noise, similar to what coolcatcreative stated in post #22.
I asked the mechanic who measured the oil pressure for me what he thought of my friend's proposal to change the rod bearings. He advised against it, saying he never had long-term success by replacing the rod bearings. The new bearings would perform fine, but some other bearing or internal component would fail within a year. That and I question just swapping the rod bearings, but not the main bearings. Wouldn't they all need to be changed?
Interesting about how some of you suggest abandoning the manufacturer's recommended 5W-20 weight oil and proactively moving to a heaver weight oil as the engine ages.
Unless I'm mistaken, 5w30 actually was the manufacturer's recommended oil weight until ~2004. Yet, the engine internals remained unchanged after that. That ought to tell you it's perfectly fine to use the slightly heavier oil.Interesting about how some of you suggest abandoning the manufacturer's recommended 5W-20 weight oil and proactively moving to a heaver weight oil as the engine ages.
The oil pressure sensor switches at 2-4psi, 5 psi is the minimum recommended pressure at idle, and you allegedly have 6 psi. I've had or seen plenty of old Chevrolet straight sixes and V8s which are the same technologies as the pushrod 3.3L/3.8P V6's in our vans, that idled around 3psi without issues.Since I get the brief noise at the first start of the day, should I stick with a 5W vs a 10W oil? The start-up sound is the same sound I hear after starting the car for the first time after an oil and oil filter change.
The mechanic was of the mind that with internal engine noise at 226,000 miles, there was not much value in checking the oil pressure. I had asked him to confirm the sensor was not kicking off a false reading, and that was about as much as he wanted to do for an engine that he considered a lost cause.
Pretty sure that only applies to the 3.8 and not the 3.3. My 3.3 is almost at 190k and at most, it used maybe one quart of oil within a 5k change interval. And, that was mostly before I fixed some small leaks it had.Something internal changed in 2005, which is why 2005 and up burn oil.
Agreed.The mechanic sounds lazy if he doesn't even want to properly diagnose the issue (run the engine faster to check for proper running pressure). Probably wants the more expensive work of replacing the engine.
I don't blame them. Aside from the oil burning, the 3.8 was a gutless turd in a a Jeep compared to the 4.0. My neighbor had an '07 Wrangler. He ended up unloading it when it had around 40k on it because it was already using a ton of oil, and of course, Chrysler wouldn't stand behind the junk product they sold him.Yes, the oil consumption seems to apply to the 3.8L V6 engine. The Jeep guys wrote volumes on their oil burning experiences with the 3.8L engine in their Wrangler JKs. Weren't too happy that Chrysler changed fron the 4.0L I6 in 2007.
The mechanic was upfront in making it clear hew was not interested in doing much diagnosing or any work on the vehicle. His contention was low oil pressure and the internal engine noise shows an engine at the end of its life. His thinking was engine repair or replacement would be a waste of money on a vehicle with body rust. And even if the vehicle was rust-free, in his experience, replacing rod bearings was a temporary bandage, that a high mileage engine with replaced rod bearings typically failed in the short term when the other high mileage parts on the engine failed, like main bearings.The mechanic sounds lazy if he doesn't even want to properly diagnose the issue (run the engine faster to check for proper running pressure). Probably wants the more expensive work of replacing the engine.
When you say bad lower end bearings, do you just mean rod bearing like my friend suspects are bad? How does one pinpoint which of these three potential problem areas are causing the low oil pressure issue?If the oil is leaking out when shut off such that it runs dry for a few seconds at startup, either you have some bad lower end bearings, a sloppy oil pump, or a bad oil bypass valve.
That's pretty much what I did yesterday. The heavier oil quieted the engine at the first start of the day and got the oil pressure up to where the oil light no longer illuminates.C, so switch to 5W40, or 15W50, and drive on. And your mechanic is correct and certainly honest.