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cincigp
06-20-2013, 01:16 PM
I tried the search function, but couldn't come up with anything on this. We recently got an 07Jeep Grand Cherokee with the Mercedes 3.0 Diesel in it. In May, for the first time, the oil pressure light came on for a second on startup then went out. It seems to be happening more frequently now that the weather has warmed up, and even more so since it doesn't necessarily get driven every morning and afternoon now. My theory is oil is draining back from the filter housing through the pump and it takes a second or two to build pressure. Shortly after the first time this happened I changed the oil, so I know both o-rings on the filter holder are good.

Is this common with the NCV3 as well?

Aqua Puttana
06-20-2013, 01:33 PM
...
Is this common with the NCV3 as well?
I'm 99% absolutely 100% certain with the following information.

The NCV3 and T1N Sprinters have no oil pressure monitoring capability. They only have an oil level monitor in the oil pan which will show low or high level. So you likely won't get any NCV3 feedback as to oil pressure problems.

The Jeeps with the MB 5 cylinder diesel engine had an oil pressure monitor. From your description it sounds like that carried over to the newer models also. I wouldn't discount that it could be an oil level related dash indicator. Be certain to check the manual for which icon you are seeing. vic

sailquik
06-20-2013, 02:07 PM
cincigp,
A quick flash of the oil pressure light at start up may be perfectly normal.
The oil pressure light works off a simple pressure switch, and when you turn the key, the oil pressure switch senses that there is
no oil pressure (can't make oil pressure until the oil pump starts turning.....right?) and turns the light ON.
As soon as the pump turns and pressure develops, the light goes out.
A few seconds, at start up, with no oil pressure, may be perfectly normal.
Are you waiting for the filament indicator (glow plug light) goes out before cranking the engine to start it?
What oil (Brand, viscosity, MB BEVO approval number) are you using?
Does you Jeep have a DPF (Diesel Particulate Filter)?
What oil is suggested in your owners manual?
Roger

suzieque
06-20-2013, 03:41 PM
I tried the search function, but couldn't come up with anything on this. We recently got an 07Jeep Grand Cherokee with the Mercedes 3.0 Diesel in it. In May, for the first time, the oil pressure light came on for a second on startup then went out. It seems to be happening more frequently now that the weather has warmed up, and even more so since it doesn't necessarily get driven every morning and afternoon now. My theory is oil is draining back from the filter housing through the pump and it takes a second or two to build pressure. Shortly after the first time this happened I changed the oil, so I know both o-rings on the filter holder are good.

Is this common with the NCV3 as well?

on the jeep forums, the issue was fixed by installing a new oil pressure sensor.

also, some jeep owners have experienced poor quality third party oil filters with incorrect sized o-rings, are you using geniune mopar/mercedes filter?

last thing is some jeep owners have seen their dealer break the small piece of plastic holding the o-ring. hard to explain in text.

the jeepforum is here: http://www.jeepforum.com/forum/f67/

cincigp
06-20-2013, 05:28 PM
I didn't realize the NCV3 doesn't have an oil pressure light. That explains why I didn't find any info on here. Sailquik, we do wait for the glow plugs to cycle, and the Jeep manual says it is the oil pressure light, and not the level (I can confirm the proper amount of oil is in there as well), and that it is acceptable for it to come on for a second or two on startup. I was just wondering if it happened on the NCV3 and what MB says about it since I don't trust the Jeep manual for the engine/trans related stuff on this vehicle. I would rather go by what you NCV3 guys do.

When I did the oil change I used the Mobil 1 ESP Formula M and an NCV3 filter from Europarts SD, so that stuff should all be proper. I can also confirm that the original owner maintained thish thing VERY well, and it has only had Elf MB 229.51 oil in it up until I put the Mobil 1 in.

It does have a DPF but no urea. It also has an Eco tune from Green Diesel Engineering that shuts off the EGR vave and swirl motor, which greatly increases fuel economy (we average 25mpg in town), and power (they claim 241hp and 440 ft/lbs).


Suzieqe, I visit that Jeep forum quite often. The only oil pressure light issue I have found on there is where the light stays on at idle, which isn't what is happening, and hopefully won't happen. I am guessing most people don't pay enough attention to even notice the light come on and go off that fast. Also, reading some of the posts about the diesel on there kind of scares me. There are people on there that will argue that Rotella non-synthetic is the best oil for the diesel. I just shake my head.


While I have everyone's attention I have another question. On the Jeep forums there are people, including Jeep techs, that swear that if you don't pour half of the new oil down the filter housing during an oil change that the pump could lose prime and cause bearing failure. I have never heard of this on the T1N, and always just put my oil in the oil fill. Has anyone heard the same thing about the NCV3?

Aqua Puttana
06-20-2013, 05:51 PM
... I am guessing most people don't pay enough attention to even notice the light come on and go off that fast.
I believe that the dash mounted low oil pressure light operation is slightly delayed upon startup on some engines to prevent the worry that you describe.

While I have everyone's attention I have another question. On the Jeep forums there are people, including Jeep techs, that swear that if you don't pour half of the new oil down the filter housing during an oil change that the pump could lose prime and cause bearing failure. I have never heard of this on the T1N, and always just put my oil in the oil fill. Has anyone heard the same thing about the NCV3?
I have never heard that for the NCV3, or the T1N as you already mentioned.

It doesn't make sense to me.

The oil pump pulls from the oil pan (sump). The oil filter is on the pressure side. How does pouring oil into the the filter canister prevent the oil pump from losing prime? (The filter cannister does completely drain during an oil change. Any oil poured into the canister will just drain out.) That is completely ignoring the fact that a gear pump is self priming anyway. Maybe I'm missing something. :idunno:

vic