'09 Auris 1.33 - rough idle

zilog_jones

My brother got a '09 Auris 1.33 petrol (UK import) a few months ago, and I've noticed recently it seems quite rough when idling. I don't know if it was like this when he got it or not, but he doesn't know much about cars so didn't notice anything unusual.

I can feel notable vibration in the cabin when idling, even after the engine has got up to temperature. Seems to be idling around 650 RPM (after warmup), which according to some VOSA document I found online is normal idle for this engine (1NR-FE) in this car (600-700 RPM). It kinda feels like a misfire, but not that rough.

No faults logged, and no engine management light. Nothing else obviously wrong.

I tried cleaning the MAF sensor, and between that and disconnecting the battery it was initially idling even worse - dropping down to 200 RPM! After about 20 minutes of driving it was back to its previous state.

Could one of the coil packs be on the way out, or the plugs? Anything else worth checking?

I understand these engines should normally make a tapping noise when idling, but this is very obvious vibration that can be felt from the front seats.

mullingar

Engine mount? PCV valve ?

zilog_jones

I'm not really seeing any other symptoms of a dodgy PCV valve (no obvious oil loss, no smoke, etc.). Is there any easy way of verifying if the engine mounts are bad?

mullingar

Sometimes opening up the oil cap slightly will help diagnose a pcv problem.

Re mount, try jacking up the engine 1/2 inch to see will it help.

I wouldn't rule out the possibility of weak plugs/leads/coil pack either.

Cee-Jay-Cee

Those engines use long life iridium plugs, when was the last time they were changed? Theyre supposed to be changed every 30k miles I think.

zilog_jones

I have no idea when the plugs were last done, if ever. It's on about 160k km now, which would be about the end of life for them if they are the originals. Toyota say 100k miles/10 years for the iridium-tipped plugs AFAIK (30k miles doesn't sound very long life!).

I just need to get some suitable tools to take out the plugs and check them out - former diesel owner, so I haven't touched them before!

Cee-Jay-Cee

zilog_jones wrote: »

I have no idea when the plugs were last done, if ever. It's on about 160k km now, which would be about the end of life for them if they are the originals. Toyota say 100k miles/10 years for the iridium-tipped plugs AFAIK (30k miles doesn't sound very long life!).

I just need to get some suitable tools to take out the plugs and check them out - former diesel owner, so I haven't touched them before!

You could well be right about the plugs but 100k miles is a friggen long time for any plugs. You can replace them with regular copper plugs if you want and if it eliminates the problem then buy iridiums and if not stick the originals back in again as theyre not the problem.

zilog_jones

I was thinking of just inspecting them first - surely if they're the originals they won't look great at this stage?

Cee-Jay-Cee

zilog_jones wrote: »

I was thinking of just inspecting them first - surely if they're the originals they won't look great at this stage?

Yeah possibly but you don't know how they're performing just by looking at them but yeah inspecting them is probably the first thing you should do.

enumbers

Cee-Jay-Cee wrote: »

You could well be right about the plugs but 100k miles is a friggen long time for any plugs. You can replace them with regular copper plugs if you want and if it eliminates the problem then buy iridiums and if not stick the originals back in again as theyre not the problem.

Wouldnt say 100k is long on iridiums on an engine that is running correctly have seen 150 plus plugs that Ive changed with very little wear and no determinable driving issues.

Frank Drebin

Hi, I have the same problem with my Auris. Did you ever figure it out?

BlakeS94

Had rough idle on my missus car not too long ago, cleaned MAF/MAP sensors with dedicated cleaner, cleaned throttle plate and replaced PCV valve, if stuck closed they will cause the oil loss/smoke issue but if stuck open it will just be a massive vacuum leak that will mess up the idle and you can't really hear it like other vacuum leaks.

Unplug each coil at the electrical connection one at a time and start the engine, if they all make the engine stall when unplugged or sound much worse then they're good, if there's no change then that particular coil or plug is bad. But if one is bad you'd be best off replacing all 4 as they wouldn't be too far behind.

zilog_jones

https://www.boards.ie/discussion/comment/119213411#Comment_119213411

Interesting comment about the PCV valve - the car mentioned in the original post is suffering from high oil consumption - you can see blue smoke when you floor it. I assumed piston rings (seems a common issue on Toyota engines of this era), but could it just be the PCV? How could I confirm this?

BlakeS94

Blue smoke is a result of oil being burned in the combustion chamber. I wouldn't say the PCV would cause that, maybe the rough idle, but not the blue smoke. Unfortunately blue exhaust smoke is never really a good sign, and if its a common issue on that car I'd get it looked at closer by a garage.

There's a possibility in leaking spark plug tube seals which would allow oil into combustion chamber and cause blue smoke, you could check that first yourself just take off the coils and shine a light down the spark plug holes

zilog_jones

Since the original post it's also started logging faults with the cat, P0420 I think. Which I'm guessing is down to the oil consumption. I couldn't see anything obviously wrong with the sensors (looking at lambda values, etc.).

I think the mechanic has already concluded the issue is piston rings, though I'm not certain - I'm going by second-hand information as the owner is not a car person. Seemed like it isn't economically viable to fix, and it hasn't failed the NCT on emissions... yet.

BlakeS94

A Google of P0420 says the issue could be one of the O2 sensors, usually the upstream sensor that would cause rough idle, also says a lean or rich running condition can set that code.

As with most things, start by checking the easiest things yourself and whatever you can manage, then after that ask a mechanic to take a look, while knowing yourself that certain things are not the issue.

zilog_jones

The sensors appeared to be working ok when I checked. My view of it right now is there's no point in fixing the emissions issues while the oil consumption is high, as it's likely the cat is getting contaminated.

ofcork

I had that P0420 code on my04 1.6 petrol avensis for a few years main dealer wanted 800 to change the cat,i left it off passed ncts after.