Weird noise garage can't find

[HaylesTu]

Hi all. I have a 2009 auris who has been good as gold the last 6 years. Always passed her MOT never cost much money etc. 

However about a month ago it started doing the weird noise like a rotational chug. Which also judders the car. Seems to be when i slow down to pull in or at lights. If I do the old IT trick of switching on and off again it goes back to normal. The Toyota garage can't replicate it even with the video for reference they don't know. Then last night it wouldn't switch on again but after half an hour it was fine. 

It's had a couple of quirks before like when I've had to slam the brakes on which then meant all the lights on the dashboard lit up like Christmas. Again the garage couldn't find anything wrong and referred to the car as a 'spooked' animal. 

I'm just worried this is an actual problem but I don't know why the garage can't find it. Anyone else had similar?

[TonyHSD]

Hi, 

what engine and transmission and what is the current mileage? 
Any videos to share ? 
Thanks 

[HaylesTu]

2010 model hybrid electric 1797 cc. It currently has 78428 on the clock. Took to the Toyota garage and they did the health check and it didn't show anything but I'm still getting it.  

 

 

[TonyHSD]

10 minutes ago, HaylesTu said:

2010 model hybrid electric 1797 cc. It currently has 78428 on the clock. Took to the Toyota garage and they did the health check and it didn't show anything but I'm still getting it.  

 

Thanks for sharing your video. 
The knocking noises are from the clutch damper springs and they comes up as a result of engine misfire. 
The most common reason for these are blocked egr system, poor fuel quality, bad spark plugs , coolant into combustion. 
If the car doesn’t have any faults stored in the ecu, no coolant consumption, , been serviced or within service intervals, then most likely it’s for egr system cleaning.
This is a mechanical work that takes a few hours labour and can cost around £300. Needs to be done as preventative maintenance every 10 years or 100k miles, sometimes earlier or sometimes can be slightly later and the engine knocking noises are a good sign of this work needs to be carried out. Toyota main dealers knows about it but they aren’t interesting to carry on this type of work. What they do is just replace egr valve which is only half work done. This may fix or may not. You can try add e5 premium fuel and injector cleaner wynns , and keep using the best petrol available around but mechanical egr cleaning is highly recommended. 

[Gerg]

Just as some background, Tony has the exact same car as you, but it's covered about  200,000 miles more!

He is very thorough about keeping his car running 'just so', and does all his own maintenance.

The EGR clean (confusingly, EGR is a valve, but also a cooler and its pipework - it's all the EGR!) he has done himself a few times.

This EGR problem is the 'Achilles Heel' of this engine. Yours has this happening a little early at around 80,000 miles, that might be because of the engine having driven a lot of very short journeys from new, as suggested by the mileage/age of yours.

The baked-on muck that needs cleaning out is not due to the car being a hybrid, only in so much as the engine stops and starts in traffic, which can prevent it getting quite as hot (getting hot is a good thing here!) as a regular petrol car; in it's efforts at good fuel economy. This is an engine problem, it's not a failing of the hybrid-y bits.

Cleaning the EGR is done from above the engine, which makes the job easier and quicker. Replacing the EGR valve itself may help the 'gunged-up' system back into functioning, but the gunge will have settled into all of the EGR parts, not just that one valve! So someone offering just to replace the valve is rather looking for the quick fix.

This problem affects all cars (eventually!) with this exact engine, so:

Toyota Prius gen3

All Toyota Auris Hybrid

Lexus CT200h

To sum up: your engine is probably intermittantly misfiring because its narrow inlet-ducting has become clogged up with baked-on carbon. It's intermittant because the EGR plumbing is not so important at different engine loads and engine temperatures.

(Broadly speaking, the EGR system exists to reduce air pollution and improve fuel economy. But the hardware controlling this is directing stinky, dirty, engine vapours - it's a tough life in that part of the engine!)

And for higher-mileage drivers, this is very much of a known problem, your dealer response is perhaps because the fix involves lots of very thorough, intricate cleaning, which won't be a popular job with the technicians, and won't be making much use of their servicing skills.

You can replace all the gunged-up bits with new ones, but the cost will be stinging. The old ones can be cleaned, we're talking solvent sprays, wire brushes, even oven cleaner and dishwasher powder for some of the more experimental DIYers amongst us. And quite a lot of time scraping and poking the muck off.

But, as Tony says, it could be a head gasket failure. A garage should be able to diagnose that quickly, easily and cheaply - there are even simple DIY testing kits for this. (Google: sniffer test head gasket).

A head gasket replacement is an expensive job. Losing radiator water from the header tank is the common clue to that one, but there is an overlap of symptoms with the ones you have.

Excuse the long post: it's a big topic.

HTH.