Car oil pressure / Engine oil question

AFKABartram

Know there are a few engine savvy peeps on here, so grateful for advice as I’m useless on this stuff. 

Got an 8yr old Qashqai, been getting intermittent warnings lately for low oil pressure. Appreciate it might not automatically mean it needs more oil, but that was my first thing to try topping it up (even though I think the level is ok) .

When I did the oil search of my Reg with Halfords last year it said to us 5w40, and I’ve got some of that left. But when I put in my reg this year, it says 5w30.

With 5w40 already in the car, am I best continuing to top up with that? Is it a no-no to ‘mix’ viscosity, or will it make no difference? Should I switch to what is now recommended (the car handbook tech info I can’t make head nor tail of)

Reading online it might be the oil pump not circulating it properly. Would a new oil pump an expensive change? Am I best taking to the Nissan dealership or just an independent garage and asking them to scan and replace?

thanks in advance 

ps. Car isn’t driving great so something isn’t right

eastterrace6168

If me, I'd take it to the main dealers and let them do an oil change, could be old oil which will break down over time, always saves a lot of time and potential expense in fannying around allegedly cheaper alternatives, anyway that's my take...🤷‍♂️

Valiantphil

5W / 40s is the Winter / Summer temperature for which the oil is designed. 

Mixing the viscosity won’t make any major difference. 

I would get an independent garage to check the oil pump, and also the sensor which often goes faulty. 

MuttleyCAFC

I did similar once a few years back, but the other way round, due to looking it up online and getting the wrong info but was told it won't make much difference although you should use the oil reccomended. It probably isn't the cause of the problem I suspect. I think the 30/40 is the viscoity when at operating temperature, the 5 is when cold. I did change to the reccomended oil though as it was on my mind.

tangoflash

I'd personally be leaning more towards your oil pump could be on it's way out. The difference in oil viscosity is minimal and really shouldn't be an issue. Other (obvious) symptoms of a failing pump would be the engine temp getting higher than normal and a change in the engine noise, as a faulty pump won't feed the oil to the rockers/lifters and this will cause major engine damage. I'd recommend taking it to a garage and getting the pump tested.

Rob7Lee

The two different oils will make no difference to the pressure the 5w is the cold the 30/40 is the hot, if it's not losing/burning oil then there's something else wrong, need a mechanic to check it out. Could be the pump but also could be things like bearings although it's likely burn oil too.

Billy_Mix

Viscosity grade is ever more important with more modern engines that operate to finer and finer tolerances
The sophistication of lubricant quality goes beyond just the 5w30 10w40 ratings
Several manufacturers, Mini & Toyota to name but 2, have specifications far tighter than just the familiar viscosity grading.

If the oil level on the dipstick is between the min and max but you're still getting a warning light, you're going to need further investigation
Any gunge under or around the oil filler cap on the top of the motor?
If you haven't observed the recommended oil service intervals the lubricant will likely be deteriorating even without other issues.
If the level is low and certainly if it is below the min then topping up with what you have is probably better than not.  But only as a very temporary measure.
Full replacement with the correct spec and a new filter will be needed post haste
Oil changes feel expensive but they're £000's cheaper than the alternative
Skimping on oil changes and the quality of oil used is usually false economy

If the car's not running right anyway then biting the bullet and have someone competent check it out is advisable
Shop around, there are independent specialists whose labour rates won't be quite as extortionate as the franchised outlets - parts prices will make you cry. 

Redrobo

Makers of my car suggest a service every two years. Fine. But I don’t include oil in that.
I have an oil change and filter done every year with MOT. If the engine goes the car is worthless.
When you check the oil level does the oil on the dipstick look good or is it a dirty black? If it is you need an oil and filter change. Intermittent oil warning is another sign. As is losing oil.
Don't leave it hoping a top up now and then will do. It is urgent.

Covered End

Do you still need an oil and filter change if you've only driven 1,000 miles in the last year?

bobmunro

Covered End said:

Do you still need an oil and filter change if you've only driven 1,000 miles in the last year?

The general view is that if the oil change interval recommended by the manufacturer is for example 12 months then irrespective of the mileage it should be changed. Oil degrades over time, whether or not is is whirling around the engine at high temperature.

limeygent

Repeated short trips, where the engine never really reaches operating temperature, results in the oil being "thinned out" by petrol getting in the oil. If you're using your vehicle in this way the first thing I'd do is change the oil and then have a garage check the oil pressure with a proper gauge. You should always use the recommended oil viscosity.

Gribbo

Oil must be feeling the pressure from all the recent protests against it

Lincsaddick

Valiantphil said:

5W / 40s is the Winter / Summer temperature for which the oil is designed. 

Mixing the viscosity won’t make any major difference. 

I would get an independent garage to check the oil pump, and also the sensor which often goes faulty. 

this .. on a Nissan I had a tyre pressure warning light, was a hell of a job to turn the light off after the tyre issue was sorted

cafcnick1992

Stop driving it.

I hate to be a downer, but If you're getting oil pressure warnings, that's generally a very bad sign. Engines can generally get by with little oil pressure but if it's throwing warnings it must be very low. An oil change probably isn't going to fix it the issue (unless it has an oil leak and you just haven't been monitoring it).

I'm going to assume the engine is knocking quite hard as the rockers are starved of lubricant?

If the oil pump or oil pickup tubes are blocked then that's a big job. I really hope it is just an oil pressure sensor, but it doesn't sound like it if your engine isn't running properly.

MrOneLung

Petrol Head Afka, openly admits to hating children's lungs, 

FACT 

DaveMehmet

Lincsaddick said:

Valiantphil said:

5W / 40s is the Winter / Summer temperature for which the oil is designed. 

Mixing the viscosity won’t make any major difference. 

I would get an independent garage to check the oil pump, and also the sensor which often goes faulty. 

this .. on a Nissan I had a tyre pressure warning light, was a hell of a job to turn the light off after the tyre issue was sorted

Have had exactly the same issue with my wife’s Qashqai. Made sure all 4 tyre pressures were spot on but the light still showed. Ended up clearing it by slightly over inflating the front tyres.

R0TW

Is this a pre cover for an insurance claim when my non ULEZ motor suddenly catches fire?
Bloke opposite me suddenly lost his convertible BMW in similar circumstances.

cafcfan

You don't say whether this is mineral, semi-synthetic or fully synthetic oil. Do you even know? I'd say they should not be mixed. Certainly not if your car requires synthetic oil. 
Check on this always handy site https://www.opieoils.co.uk/ precisely what your vehicle needs and ensure your grease monkey has put in the correct stuff.

Edited to add:  just looked up my car on this site and eurocarparts.  Neither has the correct oil for either my last car or the current one!

AFKABartram

Thanks all for you input, incredibly helpful. I’ve booked it in with an independent for later this week 

cafcnick1992

@AFKABartram what was the verdict?

AFKABartram

cafcnick1992 said:

@AFKABartram what was the verdict?

Put the rent up on my BTLs and bought myself a Range Rover. 

AFKABartram

Only joking, they checked it all over, didn’t find a leak or issue,  added 4l litres of oil and will check again next week at its MOT to see if it is burning through the oil too quickly. Fingers crossed all ok 

IdleHans

If they added 4 litres of oil and there's no obvious leak, the engine is burning it. A bit of oil consumption is to be expected but if it's more than about half a litre per 1000 miles (and that's still high) there's something amiss. When did you last check the oil level yourself and how many miles have you done since?

eastterrace6168

IdleHans said:

If they added 4 litres of oil and there's no obvious leak, the engine is burning it. A bit of oil consumption is to be expected but if it's more than about half a litre per 1000 miles (and that's still high) there's something amiss. When did you last check the oil level yourself and how many miles have you done since?

If they "added" 4 ltrs of oil, I would think it was an oil change rather than a top up, or the engine would have seized on the way to the garage, only takes 5 ltrs total capacity...🤷‍♂️