5w-30 to 0w-40 oil on a 143k mile engine
Discussion
Hi all,
I've got a 2009/59 E92 N53 330i with 143k miles on the clock. It's been on 5w-30 fully synthetic oil for its life (standard dealer schedules) and since my ownership from 126k miles I've been changing the oil every 9k miles. It gets through around 1/4 litre of oil every 1,000-1,500 miles and for this reason I'd like to switch to a thicker grade oil. I've Googled to death and find mixed opinions on if thicker grades are a brilliant / horrendous idea. Opie Oils and the BMW handbook recommend 0w-30, 0w-40, 5w-30 and 5w-40 fully synthetic oils. I have two boring oil questions which I cannot get a definitive answer to online...
1) Would switching to 0w oil give better winter start protection? Is it too thin when cold for a higher mileage engine? My mechanic thought it could be a bad idea. Is it really necessary for the mild UK winters or is 5w sufficient cold start protection?
2) Would switching to a thicker -40 oil upset the engine? Is it bedded in with a lifetime of -30 grade oil that switching to -40 will upset tolerances, increase oil pressure or cause bad things to happen? Will it disturb an otherwise happy engine and cause bits to behave differently?
Thanks in advance for the help :-)
I've got a 2009/59 E92 N53 330i with 143k miles on the clock. It's been on 5w-30 fully synthetic oil for its life (standard dealer schedules) and since my ownership from 126k miles I've been changing the oil every 9k miles. It gets through around 1/4 litre of oil every 1,000-1,500 miles and for this reason I'd like to switch to a thicker grade oil. I've Googled to death and find mixed opinions on if thicker grades are a brilliant / horrendous idea. Opie Oils and the BMW handbook recommend 0w-30, 0w-40, 5w-30 and 5w-40 fully synthetic oils. I have two boring oil questions which I cannot get a definitive answer to online...
1) Would switching to 0w oil give better winter start protection? Is it too thin when cold for a higher mileage engine? My mechanic thought it could be a bad idea. Is it really necessary for the mild UK winters or is 5w sufficient cold start protection?
2) Would switching to a thicker -40 oil upset the engine? Is it bedded in with a lifetime of -30 grade oil that switching to -40 will upset tolerances, increase oil pressure or cause bad things to happen? Will it disturb an otherwise happy engine and cause bits to behave differently?
Thanks in advance for the help :-)
I will go for 5w-40, looking into temperature ranges 0w is unnecessary for UK temperatures. I'm hoping a slightly thicker when warm oil will reduce oil consumption. I hope that the thicker grade doesn't upset anything else though...
Apart from the coil pack recall it just wants for servicing. I change plugs and oil with a preventative / paranoid attitude, I've replaced shocks / springs / mounts at 130k as the originals were worn and baggy.
It has a cold start misfire for 30 seconds or so, injectors might be to blame, but being a 2009/59 model mine already has the later injector part number (there's three versions, mine is number two so not entirely sure). Coolant temperature sensor and MAF are on the list. Despite the cold start lumpiness I think the N53 issues are exaggerated, typical of most things there are always more angry voices than reports of the many owners who have no trouble at all. It's a great car and the biggest upset is explaining to a friend with an N54 335i that I did not want twin turbo!
Apart from the coil pack recall it just wants for servicing. I change plugs and oil with a preventative / paranoid attitude, I've replaced shocks / springs / mounts at 130k as the originals were worn and baggy.
It has a cold start misfire for 30 seconds or so, injectors might be to blame, but being a 2009/59 model mine already has the later injector part number (there's three versions, mine is number two so not entirely sure). Coolant temperature sensor and MAF are on the list. Despite the cold start lumpiness I think the N53 issues are exaggerated, typical of most things there are always more angry voices than reports of the many owners who have no trouble at all. It's a great car and the biggest upset is explaining to a friend with an N54 335i that I did not want twin turbo!
Manual lists 0w-30, 0w-40, 5w-30, 5w-40 as acceptable grades so 5w-40 will be in use after the February service next year. Got a few litres of 5w-30 left to top up with until then...!
Only sensor I've replaced is the washer fluid level sensor! Judging by forums the N53 issues went quiet in 2012ish after the coil pack recall. Googling the lumpiness finds results ranging from plugs to replacing all injectors but the latter is normally done when there's a problem when up to temperature.
I rarely get a fault code with mine, the EML has only lit up three times in one year. Code is combustion misfire, cylinder varies. It might just be a quirk of the engine, if you look into it you'll see early N53s with starship mileage like me and brand new off the line N53s with the same cold start issue. It's been a niggle for the past 20k - if you find a fix do let me know. I'll message you next year after my Indy has had a look at the car when it's in. New plugs did eliminate the issue but that was only 10k ago so perhaps something is mucking up the plugs.
Only sensor I've replaced is the washer fluid level sensor! Judging by forums the N53 issues went quiet in 2012ish after the coil pack recall. Googling the lumpiness finds results ranging from plugs to replacing all injectors but the latter is normally done when there's a problem when up to temperature.
I rarely get a fault code with mine, the EML has only lit up three times in one year. Code is combustion misfire, cylinder varies. It might just be a quirk of the engine, if you look into it you'll see early N53s with starship mileage like me and brand new off the line N53s with the same cold start issue. It's been a niggle for the past 20k - if you find a fix do let me know. I'll message you next year after my Indy has had a look at the car when it's in. New plugs did eliminate the issue but that was only 10k ago so perhaps something is mucking up the plugs.
Your static theory is interesting, the injectors were known for being finicky. An Italian tune up does work wonders. The misfire is only present on sub-10C cold starts, and last just for 30 seconds after pouring out white smoke at idle. From then on all is good. I'm expecting mucky plugs on next service after 10k miles. Think changing plugs masks the problem but it's better than the cost of a Piezo injector!
bmwmike - thought I'd update you on the oil. Flushed and switched to 5w-40 at the weekend, changed the filter and chucked a bottle of Wynn's Stop Smoke (also in with the replaced oil). Misfire issue is less severe (slight judder under acceleration but less smoke at idle) but this is probably unrelated / coincidence. Noticed +3 MPG from the change, the oil which I replaced was only 6,000 miles old so this is a result (getting 30 MPG on my 8 + 8 to the office and 16 mile home commute). The oil takes a little longer to warm up which is consistent with how the car behaved when I first bought it, I suspect it's been run on a -40 weight oil and switching to -30 is why it was using oil. I'll keep you posted as I rack up more miles, and if I get anywhere with the misfire issue!
Hi Mike. Still using oil on 5w-40, roughly 1 litre every 3,000 miles. The misfire issue is a separate N53 quirk, narrowing it down to a faulty injector. No adverse affects on -40 oil and it has reduced consumption so it's still recommended. There's a minor leak from the rocker cover gasket which is weeping but apparently the N53s like a drink unless run in properly when new.
I've been chasing fault codes. Persistent on cylinder three, swapped coil packs and fault remained, swapped injectors and fault moved. Replaced injector with new and recoded, and fault is better but still happens on cylinder one! Will try your suggestion as it seems the fault codes do not pinpoint beyond the cylinder bank.
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