IS300h flashing engine light

[pcteam]

Since this morning I'm seeing this yellow flashing engine light on the bottom left of my panel. It's constantly turning on and off. 

Any ideas as to what this could be?

Many thanks.

[Mr Vlad]

Hi. Have a look in your handbook to see if there's anything in there to help. You could phone a dealer to get an idea. When it flashes does your car judder or miss a beat?

Yellow engine lights usually stay on and are a serious problem but since yours flashes it could be a dodgy connection somewhere. 

[pcteam]

Hi, yes the car does judder, like an internal shaking.

Will try and dig out my handbook.

[pcteam]

Btw, this is the light that keeps flashing:

[Mr Vlad]

I've just googled it and it stated a severe misfire which dumps unburnt fuel into the catalytic convertor causing premature overheating causing a big expense. 

Ok it may cost you quite a few quid but best phone your dealer to deal with it.

Is your car less than a year old or does it have a warranty? 

In any case Don't use it till its sorted I'd suggest and possibly save a grand or more.

How many miles on your car and how old is it?

[pcteam]

2014 plate, around 20k miles I think.

Oh great, another catalytic converter issue?!  I had the same light pop up on my previous Lexus 220d, but I thought since this is a petrol hybrid, a similar problem surely wouldn't rear its head.

 

[Mr Vlad]

Mmmmmm that's interesting. To be sure do contact your lexus dealer.

[rayaans]

Symptoms you describe seems to suggest a misfire rather than anything else

[Carl1983]

I'd put my money on this being either a spark plug or coil pack issue. Same happened on my mates car 

[pcteam]

2 hours ago, rayaans said:

Symptoms you describe seems to suggest a misfire rather than anything else

 

46 minutes ago, Carl1983 said:

I'd put my money on this being either a spark plug or coil pack issue. Same happened on my mates car 

Funny thing is, after googling this, some other guys are saying just take it for a spin and rev it hard. Just did that and the juddering is gone.  So, apart from the yellow light, I can't tell anything is wrong with it. 

(Edit: actually there is another yellow light which looks like tyre pressure, but I'm guessing must be unrelated.)

[Mr Vlad]

Yes an Italian tune can work wonders. Either way get your car on a good diagnostic machine even from a dealer to get to the bottom of the light.

[Martin F]

10 hours ago, Mr Vlad said:

I've just googled it and it stated a severe misfire which dumps unburnt fuel into the catalytic convertor causing premature overheating causing a big expense. 

Ok it may cost you quite a few quid but best phone your dealer to deal with it.

Is your car less than a year old or does it have a warranty? 

In any case Don't use it till its sorted I'd suggest and possibly save a grand or more.

How many miles on your car and how old is it?

This is a really big assumption without reading the fault codes!!

Engine lights can flash for any number of different faults and the first thing to do is get the fault codes read. 

[rayaans]

Could even be carbon build up. Not known on these engines and I believe it's not supposed to happen but you never know

[wharfhouse]

On my last Honda Accord I had what sounds like the same problem - it was one faulty coil (there was one coil per spark plug and I guess it's the same in the IS but haven't looked). The engine fault light lit and it felt like a misfire. It may come and go a bit if the coil is starting to fail. I also know others with different cars who have had the same problem. Replaced the one faulty coil (it was an easy DIY job on the Honda) and it was good until I sold it (with over 160,000 miles on it -  fault occurred at about 80,000 miles) - seems that an odd coil can fail on any car - I've known some go when the car age/mileage is similar to yours. Although some people say to replace all of coils at the same time I didn't do that and can't see why you would with a relatively new car (and they cost some £120 per coil) and all the rest of the coils worked fine until I sold the car. However, only way to be sure it to read the fault codes. If it is the coil the engine will be dumping raw unburnt fuel into the catalytic convertor which will destroy it so best not to drive the car until the fault is understood and fixed!

[pcteam]

1 hour ago, wharfhouse said:

On my last Honda Accord I had what sounds like the same problem - it was one faulty coil (there was one coil per spark plug and I guess it's the same in the IS but haven't looked). The engine fault light lit and it felt like a misfire. It may come and go a bit if the coil is starting to fail. I also know others with different cars who have had the same problem. Replaced the one faulty coil (it was an easy DIY job on the Honda) and it was good until I sold it (with over 160,000 miles on it -  fault occurred at about 80,000 miles) - seems that an odd coil can fail on any car - I've known some go when the car age/mileage is similar to yours. Although some people say to replace all of coils at the same time I didn't do that and can't see why you would with a relatively new car (and they cost some £120 per coil) and all the rest of the coils worked fine until I sold the car. However, only way to be sure it to read the fault codes. If it is the coil the engine will be dumping raw unburnt fuel into the catalytic convertor which will destroy it so best not to drive the car until the fault is understood and fixed!

Thanks for the info.  By coil. you're referring to an ignition coil right?  Like this:

https://www.ebay.co.uk/itm/Ignition-Coil-for-LEXUS-IS300h-2-5-13-on-2AR-FSE-GSE-Saloon-Petrol-181bhp-ADL-/311874044728?hash=item489d244338

[wharfhouse]

Yep that's what I was talking about - beware cheap non OEM ones though - I would buy from Lexus or make sure it's from one of the major providers - I have had Blueprint components in the past on older cars though and they seemed to be good quality 

[wharfhouse]

If you have a spare /new coil but don't know the diagnostic code (which should tell you which cylinder is the problem) you'll need to swap out the coils one at a time with the spare / new until the misfire stops. Once you have done that the check engine light may still be on but should clear itself after a number of restarts / miles if indeed it was the coil - otherwise you will need to get the code cleared through the OBD. 

[200h]

the easier way if you dont know which cylinder is effected is to remove a plug lead

and the revs will drop on a good cylinder and the engine will run rough ,on the bad cylinder

there wont be much if any difference in the running.

[wharfhouse]

15 minutes ago, 200h said:

the easier way if you dont know which cylinder is effected is to remove a plug lead

and the revs will drop on a good cylinder and the engine will run rough ,on the bad cylinder

there wont be much if any difference in the running.

Ah yes - you're right - now that you mention it that is what I did rather than swap them one by one! It was some years ago and so had a bit of a hazy recollection... I had the cylinder from the diagnostic codes but wasn't sure which end to count from so used that method to confirm which was at fault!