Is this normal?

[Wild one]

Why would the pressure sensor randomly take a **** on me? Is there any connection you can think of between the oil pressure and the compression test, Seafoam through intake work. I’ve got work in 6 hours ._.

I can't see how you could screw up the oil pressure sensor by doing a compression test,the oil pressure sensor is down on the front bottom side of the engine,quite aways away from the top of the valve covers.The sensors do go south,and it might just be a coindence that it started to act up at the same time you did the compression test.When the gauge loses oil pressure can you hear the lifters rattling,as they'll be noisy as hell with-out oil pressure

 

[Shtty6point4]

Sounds more like an oil pressure sensor issue,if it starts and runs with-out the lifters rattling big time. Pull the starter relay and jump it,that way you can do everything from under the hood,with-out the key being on,and the truck trying to start.Hook a battery charger to it,so it'll spin over decently while you check all 8 cylinders. A remote starter switch is handy,but in a pinch you can use a short piece of 12G wire to jump the starter relay

Why would the pressure sensor randomly take a **** on me? Is there any connection you can think of between the oil pressure and the compression test, Seafoam through intake work. I’ve got work in 6 hours ._

I can't see how you could screw up the oil pressure sensor by doing a compression test,the oil pressure sensor is down on the front bottom side of the engine,quite aways away from the top of the valve covers.The sensors do go south,and it might just be a coindence that it started to act up at the same time you did the compression test.When the gauge loses oil pressure can you hear the lifters rattling,as they'll be noisy as hell with-out oil pressure

I don’t know if I would call it a rattle. Trying to drive off a busy road it’s hard to hear. I would say that the engine sounds louder though yes, but like a dry loud type sound. Hard to explain but just sounds like air in the motor rather than lubricant.

 

[Shtty6point4]

Oil pressure problem that was occurring got fixed. I removed the oil pressure sensor after draining the oil I put in maybe 800 miles ago. The sensor was getting clogged from sludge and other contaminants. I sprayed some fluids in to break it down. Would let it sit and shake it around a bit, repeater they awhile until I needed it back in. After researching the way the sensors work I quickly realized it was probably my issue. Did the best “flush” I could with the rest of some b12 by sea foam by pouring the b12 in the oil port on top with the drain nut on, shook the truck back and forth for a sec and opened pan up to drain the b12. Sprayed the rest of thr sea foam in the hole for the pressure sensor and let it drain from the oil filter location. Cleaned out the filter I had just bought, Napa Gold, or WIX from what I’ve been told. Installed that again and then put sensor back on and added new oil. I had some on deck from a previous mistake of not having on hand haha. Oil pressure was higher than ever seen it after the cleaning of the sensor. Drove good too. Still have a loud tap/knock sound that’s easily audible from the cab no radio on. Just sounds like a diesel or something. When I’m under the truck it sounds like it’s coming from the oil pan/ trans area like from the bottom of the truck but when I stick my head in the wheel well on passenger side with the plastics off, it sounds like it’s coming from the top of the motor or passenger side fuel rail area. Either way it’s loud. Just sounds like an older diesel truck that’s best I can explain it. Thanks for the help gentleman

 

[Burla]

Can you post a youtube on the sound? Taken from underneath truck. Usually at speed meaning the rpm is post 2k, you "shouldn't" be getting lifter tick unless there is something really wrong with oil system. Can I ask a question without going back and reading? Why did all of this start? Why did you pop exhaust mani off? You were looking for tick, or had good thought that was the tick? And then it just so happen to see one cylinder off normal? to date you have gotten no codes, and you ran them? sorry for redundant questions, don't mean to be a bother.

I'd be cutting open that oil filter and the next one at a minimum. And pop the pcv, but does that 6.4 have a popable pcv, or is it internal, kinda ends that if it's internal. That and brake fluid, most under maintained part in any engine and equally important. Post 100k miles?

 

[Shtty6point4]

I popped the exhaust off bc I saw a missing bolt and did a test with soap and water and found multiple leaks at the mani and flanges. It helped with the noise but the noise prior to the exhaust leak is still there and if not louder. Guy at dealship also said yea you got an exhaust leak forsure, good thing it’s not a bottom end knock. Me not knowing what that is exactly just agreed with him. I fixed the mani leak. Found more problems went to fix that and made more problems. Now my oil psi is reading 99. I’m going to get a new sensor. I will post a video on YouTube asap. Maybe around 815 I can post it. @Burla

 

[Wild one]

I popped the exhaust off bc I saw a missing bolt and did a test with soap and water and found multiple leaks at the mani and flanges. It helped with the noise but the noise prior to the exhaust leak is still there and if not louder. Guy at dealship also said yea you got an exhaust leak forsure, good thing it’s not a bottom end knock. Me not knowing what that is exactly just agreed with him. I fixed the mani leak. Found more problems went to fix that and made more problems. Now my oil psi is reading 99. I’m going to get a new sensor. I will post a video on YouTube asap. Maybe around 815 I can post it. @Burla

Spend the money on the OEM sensor,most cheaper aftermarket sensors from say Napa /Autozone etc,don't play nice with the trucks computor quite often.Stop by your local auto supply store and pick yourself up a mechanics stethascope,it'll help you isolate / pinpoint the noises you're hearing. Glad you got it running again.

52500 Mechanic's Stethoscope

Unique Sound Chamber and Super Thin Diaphragm Greatly Amplifies Sounds.

www.lislecorp.com

 

[Spsully]

Ok.... you have different issues here that aren't related other than right now you are you're sensitively to all the things you would normally ignore.

That valve has a problem. Eagle hemis being known for cam and valve train problems, I can't say enough how important it is to find this before you keep driving and cause irreparable damage.

Oil pressure I said sounded like the sensor. You would KNOW if the truck wasn't getting oil.



The order I would attack this is as follows.

1. Compression test all 8 cylinders and jot down each result.

2. Report this numbers back here.

3. While waiting for guidance conduct a leak down test on cylinder 4 (if I'm remembering correctly that was the one with the bad valve and spark plug.

AFTER the valve issue is diagnosed and fixed get a long screwdriver or a stethoscope and start listening to the heads then block. But listening for oil problems with a known valve issue causing improper combustion will be like trying to whisper at a concert.

 

[Wild one]

Oil pressure problem that was occurring got fixed. I removed the oil pressure sensor after draining the oil I put in maybe 800 miles ago. The sensor was getting clogged from sludge and other contaminants. I sprayed some fluids in to break it down. Would let it sit and shake it around a bit, repeater they awhile until I needed it back in. After researching the way the sensors work I quickly realized it was probably my issue. Did the best “flush” I could with the rest of some b12 by sea foam by pouring the b12 in the oil port on top with the drain nut on, shook the truck back and forth for a sec and opened pan up to drain the b12. Sprayed the rest of thr sea foam in the hole for the pressure sensor and let it drain from the oil filter location. Cleaned out the filter I had just bought, Napa Gold, or WIX from what I’ve been told. Installed that again and then put sensor back on and added new oil. I had some on deck from a previous mistake of not having on hand haha. Oil pressure was higher than ever seen it after the cleaning of the sensor. Drove good too. Still have a loud tap/knock sound that’s easily audible from the cab no radio on. Just sounds like a diesel or something. When I’m under the truck it sounds like it’s coming from the oil pan/ trans area like from the bottom of the truck but when I stick my head in the wheel well on passenger side with the plastics off, it sounds like it’s coming from the top of the motor or passenger side fuel rail area. Either way it’s loud. Just sounds like an older diesel truck that’s best I can explain it. Thanks for the help gentleman

If it's got enough sludge build-up to plug the oil pressure sensor,you might want to do a couple oil and filter changes every couple hundred miles,and run an engine flush of some sort through it on each change.Sounds like that thing got oil changes every 50,000 miles whether it needed it or not,and did it's fair share of idling,lol. It's also probably due for new fluids in everything including transfer case , diff/s and the transmission,and as Spsully stated the brakes to

 

[Wild one]

While you're at your local parts store picking up a stethascope,grab yourself a remote starter switch ,and a couple of 12G 0.250" blade connectors.Then you can pop out the starter relay,and push the blade connectors into #30 and #87 terminals of the relay socket,then hook the remote starter switch to the blade connectors,and use the switch to turn the engine over to do a compression test,with-out pulling the fuel pump relay/fuse or worrying about the truck sending power to the coils and trying to start on you,as you leave the ignition inside the truck off. You don't have to mess around with the fuel pump relay,or have somebody inside the truck hitting the start button,if you jump the starter relay,as the only thing getting power is the starter when you jump the starter relay

https://www.amazon.com/Remote-Starter-Switch-Heavy-6V-12V/dp/B08XBP69Q5/ref=sr_1_5?keywords=remote+starter+switch&qid=1677511915&sr=8-5

You only need 2 of this style blade connectors though,i'm just using this to show you the connectors that you can push into the starter relay contact points in the fuse box.Use a lighter to heat the plastic part of the connector,and it'll pull right off,leaving you a bare metal connection point to hook a remote starter switch to.

50 PC(10-12)GAUGE 0.250"YELL0W NYLON MALE ELECTRICAL WIRE CONNECTOR DOUBLE CRIMP | eBay

We did our professional part.

www.ebay.com

 

[lobo]

Ok.... couple thoughts but no real train to carry them together.

Newer motors across all makes are seeing a considerable increase in carbon build up. Thinner ringlands and rings to get better efficiency and better fuel economy are likely the cause. They are also getting thinner oil. So it all adds up increased blow by and carbon build up. It is almost required now to do some sort of carbon cleaning i.e. Seafoam, BG cleaning.

This is a running 5.7 with 80k on it
View attachment 514668

Since you are already in that far, I would 100% say a compression test is a good idea. Also a leak down test would be wise. If for no other reason than having that peace of mind.

I never saw too many 6.4s come in with typical hemi issues compared to the 5.7, but there are so many more 5.7s out there that the numbers would be skewed even if every single motor came into the shop.

This is some of the best carbon cleaner on the market.

505 Pour-ins | ATS Chemical

Manufacturer of the engine carbon cleaning chemicals for the auto industry produced by Automotive Test Solutions, Inc. in Albuquerque New Mexico. 505 CRF, 505 CRO, 505 Pour-In

www.atschemicals.com

 

[Shtty6point4]

If it's got enough sludge build-up to plug the oil pressure sensor,you might want to do a couple oil and filter changes every couple hundred miles,and run an engine flush of some sort through it on each change.Sounds like that thing got oil changes every 50,000 miles whether it needed it or not,and did it's fair share of idling,lol. It's also probably due for new fluids in everything including transfer case , diff/s and the transmission,and as Spsully stated the brakes to

I’ve got most of the tools you mentioned and wiring components. Yes, you are correct about the oil changing before I owned the truck. Honestly when I bought the truck, I went to change the oil and there was nothing to change. I think that the truck is honestly not worth the money it would cost to fix the issues. I’ll report numbers back like sully asked and also a YouTube video link of the sound. Thanks for trying to help guys.

 

[Wild one]

I’ve got most of the tools you mentioned and wiring components. Yes, you are correct about the oil changing before I owned the truck. Honestly when I bought the truck, I went to change the oil and there was nothing to change. I think that the truck is honestly not worth the money it would cost to fix the issues. I’ll report numbers back like sully asked and also a YouTube video link of the sound. Thanks for trying to help guys.

As long as all cylinders are with-in 10% of each other,you're usually okay,but if one cylinder is way down from the others,odds are you have a bad ring or valve issue on that cylinder.The bad valve issue can also be related to a bad/flat camshaft lobe.If the cam is going south,it won't be lifting that valve as much,and it won't build as much compression test psi.The easiest way to check valve lift is to pop that sides valve cover off,and watch the rocker arm movement on that cylinder in comparision to the other rockers.That's where a remote starter switch comes in handy,as not only can you use it for the compression test,but you can also use it to bump the engine over to check rocker arm movement. Once you find the starter relay in the fuse box,put a dab of paint on it,that way it's easier to find,the next time you need to remove it.

 

[Tominator223]

To many additives. & maybe a week fuel pump

 

[El Huapo]

The classical method of filling the crankcase of an old engine with 50-50 oil and diesel often caused more problems than it fixed---per my old Dad.

 

[Marshall]

I took a break so may have missed some posts, looking at your spark plugs, #4 look terrible, oil slug, gap looks way too wide. Coil OK on #4?
Did you plane the manifolds or just put gaskets in? Plane them if still off. But sounds like they are back on.
think next job may be pull valve covers off and check out lifters, cam, after compression check.

 

[Spsully]

Did this get fixed?

And to answer your question about the oil pressure sensor. Sometimes monkeys die. There is a reason I have 3 or 4 sockets in my toolbox for those things. They are also called sending units. I'm sure if you do a Google search it will give you a Google (yes that is a number) hits on all the ways they go bad.