Hello,

This is an emissions post. I bought this car in Oct 2017 with 127,000 unknown service history miles. Since then I've driven 13,000 "trouble free" miles with an engine that is leak free and on a cross country trip of 6,000 miles with 800+ mile days "used" only ~1/2 qt of Mobil 1 synthetic. I consider this outstanding. But, the whole time the check engine light has been on.

Right off the bat in went new plugs, coil packs, and upper and lower intake gaskets. This addressed the misfire DTC codes. Next up was new cats and O2 sensors. The car was driven south of the border so between crappy gas and the misfires it was no surprise these parts needed replacement. Bye bye a few more DTC codes and on to the last one - DTC 00183 right VVT sensor.

Off course if the right sensor was indeed bad, this meant taking off the intake manifold again and risk an air leak somewhere in the chain of gaskets and hoses which would have to come off the engine. I tried a 0W-30 oil and same 1383 code. I then added some Lucas oil additive to this for 500 miles, no change. Okay, so maybe it's not a clogged solenoid. Next up was a 0W-40 oil, same old code.

So for a very reasonable $45 I dropped the car at a local older model Jaguar specialist to diagnose this DTC code. Here is his what I feel is thorough diagnosis although I did not get to talk to him afterwards. Hence this post to pick your collective brains.

1. Both solenoids @ 12 ohms. No change when jumped at hot idle.
2. Can see functioning VVT whencold, once warmed up they turn off and throw fault.
3. Ruled out faulty solenoids. Oil pressure concern.

Here in Maricopa County this car needs to pass the OBDII standards. I'm drawing the conclusion that since this engines oil consumption is negligible, the cause of its low oil pressure is a weak oil pump. Unknown service history, an engine with VVT sensitive to oil quality, and who knows how much sludge, supports this conclusion. My next emissions isn't until Oct 2019. Octobers are still warm but not 110+ like right now.

So, let's talk oil pump. Great car but already spent more than it's worth. As I see it my only hope of an easy fix is a thicker 50 weight oil at emissions time. For "low oil pressure" this seems logical but for a weak oil pump. Will it struggle even more? All thoughts are welcome.

Regards,
Ed

 

Ed,

Can you please elaborate on the care and feeding of your money tree? How does it do in the hot Arizona climate? I'd like to get a money tree myself, but need to get the best variant for the temperate Oregon climate.

All seriousness aside, you're on the right track to suspect an oil pressure issue, but don't go after the oil pump right away. From what I've observed, the VVT faults sorta behave like a canary in a coal mine, signalling an oil pressure issue before any other symptoms are noticeable.

However, in my highly overrated opinion, the oil pump is not the fix. Here are my three top suspects for low oil pressure, in no particular order:

1) Excess clearance at the rod and main bearings.
2) Excess clearance at the rod and main bearings.
3) Excess clearance at the rod and main bearings.

You mentioned you suspected the pump because oil consumption is negligible. That just means the valve stem seals and piston rings are still sealing well (oil isn't being burned) and you've got no external leaks. Most likely you've got oil being dumped back into the crankcase due to one of the three reasons listed above. Oil is not being consumed, just getting a little extra recirculation.

My suggested fix? Run a little bit thicker oil. You mentioned 0W oil. Heck, I didn't even know they made such stuff. Is that like water but with an oily sheen? Isn't that what you'd want in an Arctic climate? Seems like the opposite of what you'd want for Arizona. I run good old 10W-40 in my '02 V6 (almost 300K miles) with no issues here is Oregon.

Good info in this thread about oil viscosity and VVT codes:

https://www.jaguarforums.com/forum/s...bad-vvt-68687/


In particular, please see my comments in post #31 about whether to use thicker or thinner oil for VVT codes. The discussion was going both ways, not that there's anything wrong with that. Since you are already running very thin oil, thicker sounds like the way to go.

 

Hi Karl,
Your top 3 reasons make perfect sense. And I forgot to mention in the 1st post it had the reflash for sensitivity to this particular code (S303-09). Even in 115+ heat, the temp gauge never waivers from the straight up position. And the AC does quite well.

I bought the car for $2500 off of CraigsList. That was then......

Since I've owned the car,
- New spark plugs, NGK Irridium (6)
- New direct ignition coils (6)
- New lower intake manifold gaskets (6)
- New intake manifold gaskets (6)
- New IMT sealing rings (2)
- New breather hose (1)
- New synthetic transmission fluid (7qts)
- New synthetic rear differential gear oil (2qts)
- New air filter
- New cabin air filter
================================
$1500 (local mechanic)

- Remanufactured 18" Jaguar OEM wheels (ZERO curb rash)
- New Michelin Pilot Sport tires (18")
- New chrome lug nuts
- New Jaguar OEM wheel center caps
================================
$1860 (On-lne and local tire mount)

- New brakes (rotors, pads, hardware)
- New cats (Eastern Catalytic)
- New O2 sensors (Denso)
- New coolent (European Car orange $$)
- New DCCV (Ford PN)
================================
$1300 (on line and me as the mechanic)

Everything works. It's really quiet, the small back seat is perfect for my dog, and it keeps the mileage off of my other cars.

Thanks for the smiles,
Ed

​​​​​​​The bridge on Lake Roosevelt Arizona.

 

Update: When I last posted, I had used 30W and 40W Mobil 1 oil in the hopes that a heavier oil would help with low oil pressure. The low oil pressure causes the right bank VVT solenoid to quit working at operating temp triggering the 1383 OBDII code. I purchased Mobil 1 15W-50 for an upcoming cross country trip to see if a 50 weight would help with the code. Then much to my delight, the CEL winked out the other day and has stayed off for multiple trips. All before the oil change. And it's still hot in Phoenix so ambient temp is not a factor. I think just driving the car with a high quality oil is helping to dissolve any sludge that might hinder the oil pump pumping. I'll post again after the 50 weight oil and trip to the east coast. No one commented that I had the state of Arizona paint the bridge Sea Mist Green to match the Jag.

 

Try putting a bit of ATF in with your oil. (Sub 1qt of oil for ATF) Auto Trans Fluid has high detergent qualities. Had both a P1383 and 1388 on my 4.0.

That did the trick along with high quality motor oil. Those small passages are prone to clogging.