Oil Consumption - Hyundai i10

[Tedx]

Here's a question.

I've battled with oil consuption on my Hyundai i10 (2015) for years. It doesn't appear to have a leak and it runs great with no tell tale smoke coming out of the pipe.

The Hyundai forums seem to think that 1 litre per 1000 miles is acceptable, which I think I disagree with.

Anyway, I've narrowed it down to a couple or three possibilities.

1. 1 litre per 1000 miles really is acceptable.

2. I've discovered a thing called a PCV valve and I know for a fact that mine has never been changed. Its a small plastic valve in the rocker cover....PCV” stands for “positive crankcase ventilation.” It is a one-way valve attached to the crankcase. Your vehicle's crankcase holds your motor oil, and is located at the bottom of your engine. It produces gases when your engine burns fuel.

https://www.google.com/search?client=fi ... =pcv+valve

Anyway, a potential symptom of a faulty PCV valve is higher oil consumption because if the valve gets clogged it can force gases out of other orifices in the engine - along with engine oil. I think I have that right. But I had no obvious oil leaks....except around the filler cap, which was always 'wet' with a fine covering. I didn't really think much about it until I ordered a PVC valve off the internet from China. Weeks ago.

This is a £5 part. It literally involves taking the airbox off and unclipping a couple of hoses. 10 minutes tops. The bearing inside still moved around, but without the clicking noise of the new one. It was also pretty clogged up with debris.

So I've cleaned up around the filler cap and taken a photo of my dipstick (fnarr) & notes date and mileage. So here we go.

3. The oil viscosity. The manual says 5w/30. The Hyundai forums say up to 15w/40 will be fine. My garage replaced it at the MOT with 0w/20. I'm assuming the lighter oil makes the motor easier to crank when it's cold, so if I use the heavier stuff I'd better make sure my battery is in good fettle this winter.

An online Hyundai technician suggested that the heavier oil would reduce consumption (just by being thicker and not being so easy to 'escape' or boil off I presume?)

....but the 0w/20 would only explain the issue for about 1000 miles until I top it up with 5w/30 - unless that is escaping too?

So maybe I should buy a bottle of 15w and top up using that? I realised Ive just answered my own question (sort of). But hey, replace that £5 PC valve regularly and when you buy one, buy 2 and keep one as a spare.

[DrFfybes]

According to the interweb you have a choice of oils. This normal, and depends on the operating temperatures.

However I wouldn't think 0Wanything was required in a fairly unstressed small car unless you live in Alaska.

https://www.whatcaroil.com/hyundai-i10.html or https://www.manuals.co.uk/hyundai/i10-2015/manual?p=341 seems to agree

Personally I'd stick 10W30 in as it is very common and hence quite cheap.

[bungeejumper]

Hi TedX, you'd be surprised how many cars drink a litre every thousand miles - petrol VWs are well known for it, and I gather Minis aren't far behind. Oh, certainly there are many of the exact same models out there that never touch a drop, and it isn't always easy to say why - some micro-characteristic of the way the piston rings were ground, perhaps? One engine off the production line may not be the same as the next.

If the manufacturer or his evil technical henchmen are telling you that it's within the expected consumption range for the model, that would probably be good enough for me. Just as long as it isn't going up suddenly, or smoking, or leaving tar in the tailpipe. Either way, replacing the placcy valve seems like a simple way to open the investigative proceedings.

There have been a few engines that were noted for over-pressurised crankcases that did spell proper catastrophic trouble - some small diesel Vauxhalls and a couple of small Fords, I think. But I don't think your i10 is one of that club. I'd say be guided by your garage.

BJ

[Tedx]

Cheers guys.

Well the test is on. I don't think replacing the PCV was a bad thing (in fact its probably a good thing).

So I'll check it regularly and if it continues to drop I'll try a heavier oil as DrF suggests.

If it carries on dropping with no obvious symptoms then I'll just keep plodding on with it. It runs well and it's a really cheap way of keeping the rain off (£20 to tax being a fraction of the Caddy van and way less than even my motorbike)

It's on 70k btw. Just been through the MOT with only replacement consumables needed. (Brake pads, 1 x tyre, handbrake etc). I only do about 7k a year now we have the van too, so I reckon it's got some years left in it yet.

I shall report back in due course

[todthedog]

Not a lot of help but our i10 also uses a fair bit of oil. Garage says very small engine, short trips mostly, done nearly 100k, seems an i10 thing.

[Gerry557]

Can't say I have noticed any leak or usage. It's an old car that does lots short journeys maybe the mileage is too low to use it up before each service.

[Tedx]

Bouyed by my PCV success, I thought I'd nip into Halfrauds and pick up a new air filter and some spark plugs.

What the hell has happened to them?

It's all car 'accessories', camping gear and pushbikes.

Oh well. Back to the internet. My goods will be here by the weekend.

....just thinking to the AI thread that's running here. I reckon my car will be able to self diagnose and order the parts by itself before too long.

Oh wait. Air filter and spark plugs? That implies we'll still be driving dino juice motors. Scratch that.

[Tedx]

So a month later after changing the PCV valve and also the air filter and the plugs, the oil consumption seems much more 'normal' - i.e it was about 80% of the max mark and now it's about 60% or maybe a touch more - after about 700 miles. And that's still the light oil (I have a litre of 5W30 in the shed to use).

I also thoroughly cleaned the area around the oil filler cap that seemed permanently coated in a light film of oil and it's still clean a month later - so perhaps the replacement PCV valve is doing it's job?

I'll probably buy a bottle of 10w30 when the 5w30 runs out.

Cheers to all!