[gisforgerten]

Hey all, I've tried searching the forum for similar questions but none turned up helpful responses.

Yesterday I changed the oil on my 2014 Jeep Grand Cherokee diesel. After completing the oil change I let the vehicle sit overnight, and in the morning started it up - but after a few seconds the engine shut down, and a low oil pressure warning showed up. I tried starting it a few more times, thinking it might just need some priming, but got the same results. Any help is appreciated - more details below.

My oil change details -
Removed engine cover, loosened full cap, removed drain plug, while waiting for drain I removed the air intake hose and replaced oil filter and o-ring (K&N PS-7042) torqued cover back to 25.5 NM. Reinstalled drain plug, filled with 8qts of oil (Rotella t6 5w-40). Reinstalled the air intake hose, reinstalled the engine cover Reset oil change reminder.
The next day - check the oil level on dipstick - around the 'max' line, despite about 7-8qts drained. Started up engine then experienced shutdown. I removed the oil filter, and it's covered in oil inside and out. I then reinstalled the filter.

 

[isstay]

check this thread, it could be oil pressure sensor, more likely. our died in similar way, we parked the car overnight and next morning got the warnings plus the engine won't run.

Low oil pressure light

 

[gisforgerten]

I've ordered a new pressure sensor - its a real pain in the butt to get to.
I also was able to check via OBD (OBDLink MX+) to confirm that there was no MILs and that when the engine starts it quickly sets a flag for 'low oil pressure with engine running' and then shuts down right afterwards. there is a PID for 'Oil Pressure' but it didn't change, and I'm not sure if it ever does, as oil pressure isn't measured raw value, but rather just a switch.
I'll update this thread when I get the new sensor installed.

 

[isstay]

it is pretty easy to get to it from underneath the car. take off engine and transmission shields and you will be able to see it, lot easier than from above.

 

[gisforgerten]

it is pretty easy to get to it from underneath the car. take off engine and transmission shields and you will be able to see it, lot easier than from above.

I'll give that a try! thanks!

 

[isstay]

did you change it?

 

[gisforgerten]

I have not, I just got the switch yesterday, and I removed the skid plate, and discovered the switch is not accessible from underneath... Nor from above. I'm curious if the entire assembly has to be removed to replace the switch

 

[isstay]

which skid plate you removed?

 

[gisforgerten]

which skid plate you removed?

The one directly below the engine. - 6 bolts. It was more of a molded fiber cover than a skid plate. Ran from the front of the engine to beyond the oil drain plug.

 

[gisforgerten]

As a last ditch effort I stopped by the dealership, talked to the diesel tech (who had a ram eco diesel torn apart for a fuel pump replacement) for some advice. He told me 'low oil pressure ' warning could be lots of things unrelated to oil pressure. He recommended changing the filter to the OEM filter and if that didn't help - have it towed.
I replaced it with the OEM filter.... And now I'm having it towed. I'll update when I get an update from the dealership.

 

[isstay]

The one directly below the engine. - 6 bolts. It was more of a molded fiber cover than a skid plate. Ran from the front of the engine to beyond the oil drain plug.

did i said to remove both, you can probably do it just by taking the transmission one, but you definitively can't access it from under the engine. if you did not tow it already give it a try.

 

[gisforgerten]

got a call back from the dealer today - they suspect its a fuel issue. They replaced the fuel filters, but didn't have any success and now believe its the high pressure fuel pump.
This pump is currently under recall, and they don't expect to have replacement parts until the middle of next year.

Anyone have recommendations on what to do with an inoperable vehicle for the next 9 months?

 

[gisforgerten]

@JeepCares - Any recommendations on how to get back on the road without having to wait 9-12 months for a fuel pump? Can the 'old' fuel pump still be used as a replacement since Jeep's official stance is that it has only a 1% defect rate?

 

[ferntree]

You could always call someone like Banks Engineering and see if they have any suggestions. They have done a lot of R&D on these engines.

Just park it for at least 9 months? This is a crazy situation. I'm no fan of legal action, but it might be time to get some legal advice on this. Really hope you can get it sorted.

 

[gisforgerten]

I have no interest in getting lawyers involved - I just want to get the vehicle back on the road.
I've told all of my friends/co-workers an others when they ask about the Jeep that it is my most favorite vehicle ever owned... but don't buy one. When it works, it is awesome and I love it, but I've never had a vehicle at the dealer as much as this vehicle.
At this point, the vehicle only has 70k miles on it, so I don't really want to sell it, but I'd be willing to if I have to wait 9-12 months for parts.

 

[JeepCares]

@JeepCares - Any recommendations on how to get back on the road without having to wait 9-12 months for a fuel pump? Can the 'old' fuel pump still be used as a replacement since Jeep's official stance is that it has only a 1% defect rate?

Thank you for tagging us. We would be happy to look into any part delays you're experiencing further. Send us a private message to get started.

Kate
Jeep Cares

 

[Seakir]

Couldn't you order an aftermarket replacement off E-bay, then get them to fit it?
(Just looked on my E-bay- there are different variations available, and I got no idea which is yours.)

The problem is, if its under warranty the dealership will have to use their supplier's parts and not parts from E-bay, no doubt, as it would break their own guarantees if it fails in the future.

The only way you could get this back on the road before that 9 months, as I see it, would be to get the job done yourself and pay for it. Otherwise, it's save those dollars and play the patience game?

If you did go for it yourself, there's going to be tons of stuff on these forums and on the 'net/YouTube, along with the guru's here, to help you with advice.

 

[gisforgerten]

I've yet to find an aftermarket replacement for the cp4.2 pump. Beyond that - even used parts are fetching over $500.

 

[Seakir]

Just a few thoughts to consider:

Have you had the vehicle checked somewhere else for the issues you describe? At an independent garage or by a mobile mechanic with a decent scanner and an eye for these issues, for example?
Sometimes it's best to get a second opinion, or else in 9 months time that pump might be swapped over and the issue may still be there, proving that it might not have been the pump in the first place. How many stealer-ships throw parts at issues, when the home mechanic thinks WTF?

When you pop the ignition on before starting her up, can you hear the fuel pump buzzing/priming itself? (That is, if it's the fuel tank pump we're discussing.)
If so, then get the fuel pressure tested as it means the pump is working, but nothing is coming through.
You could have a pin-prick/join seal failed in the line that is sucking in air and blocking the fuel behind it. Check underneath where the solid fuel lines have a connector to join to the fuel tank system. In my WJ, that connector sits above the rear axle.
In time, those fuel connectors can fail and pipes can corrode. The easiest way to check is get under neath- can you smell diesel at any joints? Are any of the fuel pipes looking corroded or not sitting tight into their connectors (is there any play when you wriggle them at the joints?), or do any areas look wet/greasy/rusty? Cutting bad sections out using a small pipe cutter and jubilee-clipping in a section of equal interior diameter fuel hose is a quick fix for any defected fuel piping issue beneath the Jeep. I had to do that a few years ago when I had no fuel being drawn up in my variant. It has a manual primer system to draw fuel through into the filter housing in the engine bay. When no fuel was coming through, but I could hear the fuel pump priming, it led me to investigate the lines underneath and I found the issue being that rear connection, above the axle.

If you can't hear the fuel pump priming on ignition- try wriggling a few wires underneath the Jeep that lead to the pump and see if that works. It's just a quick test to see if there's any loose connections. You could get a multi-meter and test the loom for power, in case a relay or fuse has blown. Also, check those relays and fuses first if you do not hear the pump buzzing/priming. Sometimes, fuses can be shared and if something else craps out, it might knock out another component at the same time.

These checks will cost nothing and also satisfy your own curiosities.

If its a fuel pump type that feeds the injectors themselves on the common rail feed, then that would entail a fuel rail pressure check at the injectors, I would guess? In case an injector or two may be at fault? (But, surely you would've felt this issue before the oil change was done?) I'm unfamiliar with the diesel common rail injection system, as mine has the old independent lines with a nut at the end of each join, so I just have to crack that to see if the line is causing an issue after the pump. Would such a problem in yours, therefore, show up in a fault code scan?

 

[gisforgerten]

The electric pump is definitely running. To check the pressure at the injectors - does that require much disassembly to access?