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Burning Oil, Pressure drop - byebye engine?


Pritchard

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Sigh.

not my year this one. now my problems turn to the Z.

 

 

54k miles, FSH. Check the oil every several thousand miles as its never used a drop, or changed colour when services are due, in my ownership.

its due (and is booked in) for its next service in a few weeks. following the 45k interval.

 

I noticed about 2-3 weeks ago an occasional smell of burning oil in the cabin, shortly after giving it some welly. but it was brief and not particularly strong. Checked my oil, plenty in there (in fact, looks well over max, but out dipsticks are pretty crap).

However last week i had something pretty fast (M3 i think it was) right up my arse one night as i booted it, and in my rear view mirror i saw smoke between me and his headlights! nice.

 

its been nearly 10k miles since the last service interval. but at previous intervals the oil has still been golden. now its a dark colour but not black or gunky. which ive come to expect in other cars, but its the first time in the Z that the oil has been tarnished. Naturally since getting a wiff i have been very mindful now of the oil 'situation'.

 

tonight i jumped in the car, started it up - and panicked. I check my pressure gauge with every drive and its always a consistent 90psi on cold. However it was just under 60 (half).

I had to make a station run for the missus so i took it extra slow and i noticed at every corner, turn or brake the psi would drop between 0 and roughly 20 (less than quarter). on idle its on 30psi, and when running from 1500 rpm upwards its about 50. however to note on idle the needle is wiggling from about 20-35, it wont stay still.

 

 

so i have pressure, but it has suddenly changed it characteristics. is my oil pump about to go?

admittedly the first time i checked the oil it was a few weeks ago but there does seem to be alot of oil in there, dipstick is coming out plastered, could well be nearly double the max line. (yes literally that much). i'm wondering if at the last service it wasnt drained, and only topped up? might explain why my oil is black for the first time. or do i have a bigger issue? the gauge has been sound for 24k miles of my ownership.

 

 

*also note, car appears to be running fine. not lumpy and no noise coming from the engine that i shouldnt be hearing.

 

 

I'm thinking my car needs to be 'grounded' until service day.

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Black oil after nearly 10k is fairly acceptable I'd say.

 

You could have a faulty oil pressure sensor.

 

As Dan said you could do with finding out exactly how much oil is in it. That much of an overfill could knacker a cat which might explain the smoke.

 

Could be something relatively minor or catastrophic. ....you need to do some investigation first.

 

Also worth putting a small cap of the dropped oil under a light and hold a magnet near the surface to check for metal swarf

 

Sent from my SM-G900F using Tapatalk

 

 

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  • 2 weeks later...

Forgot to update.

 

i hate the Z dipstick. really hate it.

 

It had actually dropped below the Min mark, which was causing the pressure to fluctuate. but where the dipstck likes to scrape oil on its way out it looked like it was swimming in te stuff.

 

all sorted, just needed a top up.

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Difficult to tell. its all hilly in the new house. my road my drive, and every road within a 1 mile walk is on hills! so when i parked up for an hour in a flat carpark (as per above posts) and it was still covered in oil as it didnt have enough time to settle.

 

i put in a litre, and thats sorted the gauge.

If i dip it on my driveway first thing in the morning i get a 'good reading' on the stick (ie it doesnt drag up oil left in the tube), but with the incline the indicated level doesnt mean much.

 

 

Its in for service in 2 weeks. its pretty much grounded until then except for essential trips.

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An hour is plenty of time for it to settle. 15mins is more than enough! I know it's a pain reading the gauge, but it's possible with perseverance.

 

It's hard to figure out where and when you got your good reading, but if it's on your drive which is on an incline then you still don't have a good reading, and adding 20% of the entire sump capacity without being confident on what's in there can be equally or more catastrophic as running around with it a little under the min mark. It's probably fine, but you've no idea at this point.

 

All you need to do it jack it up, remove the sump plug and drain it into a suitable container (something like this is ideal) and then you can measure it accurately. Grab one of these too and you can replace the washer on the sump plug too, we're really talking peanuts here and it's and incredibly simply task. :)

 

 

Given you're only two weeks from a service then there's an argument for not bothering, but at this point you can buy the oil & filter yourself (here) and save yourself that cost. No need to pay the garage to do it then, and you'll know exactly how much you've put in and what that looks like on YOUR driveway, even with the incline you can then measure it perfectly every time.* Hell, come round to mine and I'll do it for you, you only need the oil, filter and sump washer then.

 

 

 

 

 

*No, I know in the ideal world you should always measure on a flat surface, but many people live near slopes and as long as you're confident on what you've put in, there's no harm at all in measureing like this. It's just not best practice ;)

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