Hi
Just got an oil change , mechanic used 5W30 synthetic oil ,and I immediately noticed the oil gauge while idling stays on the left then when I accelerate it goes from the center to the right
Is that normal?


the car has 10.8xx miles.

 

Kind of normal.

I would have thought that the 6ltr would have the "idiot switch" for that gauge, as apposed to the "real time" switch of the earlier engines.

5W30 is a tad light??????. but at 10K miles, maybe not. If it were mine I would be using 10W40, either Syn or Mineral.

There will NOT be a pressure issue, or a flow issue, the V12 oil pump is just way too good for that.

 

Terry,

Your sig doesn't say but I'm guessing you've got a 4 litre engine?

I'd also have gone for 10/40 semi-synthetic but each to their own. I suspect 5/30 is ok but it's a bit too thin for my liking. That might explain it sitting a bit low at idle.

A fluctuating pressure gauge is as it should be although with 10/40 I wouldn't expect it to sit under 2 bar at idle unless it's very hot. If it's a 4 litre engine it should be 2.75 bar at 2000rpm.

Cheers

Paul

 

I recently did a oil/filter change and went with Maxlife semi-syn 10W40 and am very happy with how it is running. I have used Mobil 1 0W40 in the past but the V12 really seems to like the Maxlife oil. I have also used 20W50 before and 0W40 and 10W40 did not lower the oil pressure at warm idle. Pressure stays up... Also can not beat the price of $17 for 5 quarts jugs at Walmart... LOL.

 

Hi, guys thank you for the reply, yes , I have a 1996 4 litre engine ,not the V12. I agree that 5W30 is too light.
I'm gonna switch mechanic and have another oil change right away.

 

5W-30 is too light for that engine. Use 10W-40 or 15W-50. I use 15W-50 in my '95 XJS AJ16 and my '90 Majestic AJ-6 in the Florida heat.

 

Ok, so now that we used 5W30 Synthetic and knowing that I only drove the car for 4 miles, do I need to switch to 10W40 right away ,and if so ,is it ok to use mineral oil or do I have to stick to synthetic from now on?

 

NAH, whatever rocks your boat.

 

There is a guy (Vee) running 0w something synthetic in his 96... The AJ16 can take it. That being said, I've tried 5w 30, 10w30 and my sweet spot is 10w40 Mobil 1 synthetic for high mileage in my AJ16. It really keeps my engine quieter, not just psychological as the chain tensioners on this car will make a little noise as they get higher mileage. But yeah, I would certainly stick to full synthetic of your choice.

 

If your gauge is reading erratically then the probe could be on the way out; Grant is right in that it is an idiot switch not a variable pressure sender.
It's a cheap and quick fix.

 

Terry,

If your oil pressure sender unit is original, then it probably is the true variable type. Your comment that the gauge fluctuates seems to confirm this. Jaguar only brought out the replacement unit in response to complaints from US owners of the AJ16 engine who thought it was wrong for the readings to go up and down with engine rpm. If you've got the original type and it's reading correctly, then stick with it. I have the original type in my AJ16-engined car and feel much more comfortable thinking that I'm looking at the actual pressure rather than a false mid-point position on the gauge.

Paul

 

I have tried just about every oil in different weights in many different vehicles. Motor oil/filter changed at 5K or less then conventional oil is the way to go(if you change your own oil, try Maxlife semi-syn red bottle). If you drive 7500 miles in a year, then Mobil 1 10W40 HM might be best for you, especially in a hot climate like Los Angeles... Oils and filters are so much better today then 20 years ago, so any name brand will work well for you. Play it safe and go 10W40.

 

No. That's an old myth.

 

I'm running Millers 10/60 on a V12 and it seems to like it.

 

Steve,

remember that Terry has an AJ16 4 litre engine, so I think most of us use 10w40 in these engines.

Paul

 

Thank you guys. I will change that oil to 10W40. I only drive less than a 1000 miles year but rather be safe than sorry . I will look into changing the oil pressure unit too , but I want to keep the car as original as possible.

 

Terry,

Wait until you've changed the oil and then see what readings you've got at idle and at 2000rpm, hot and cold. I suspect there's nothing wrong with your sender unit.

Cheers

Paul

 

Ditto...

 

Still haven't figured out the argument for not wanting to use the lowest possible number before the W. I've been using 0w40 Mobil 1 for awhile. I'd switch to -40w40 if they offered it.

The thinner the oil at startup, the better it stays lubed

 

I agree. Lubrication of bearings when the oil is cold is about flow through the bearing, NOT pressure before it. As long as there is enough oil supply at the "entrance" to the bearing to ensure the bearing is adequately supplied with oil so its self-lubricating effect can wind the oil through, gauge pressure being a touch higher or lower has no effect at all on the efficacy of bearing lubrication. Oil pressure does not "squirt" oil through the bearings!
Greg