Yellow engine warning light - Help !

Discuss problems you have had or are having with your Z4
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GuidoK
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Yellow engine warning light - Help !

Post by GuidoK » Sat Nov 18, 2017 1:11 am

Monkeydonkeyratmagic wrote:
Mon Nov 13, 2017 7:43 pm

Does this reset any warning light or just check engine? Does it do airbag etc too?
It resets engine related warning lights.
airbag probably not, airbag lights can be very difficult, even for inpa, depending on the fault.

But it does the same as that previous link, as they're both elm327.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

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ph001
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Yellow engine warning light - Help !

Post by ph001 » Sat Nov 18, 2017 8:36 am

kowsmou wrote:
Fri Nov 17, 2017 11:41 pm
Ok, so took it to my local garage today. Error that came out was P0420 which relates to cat performance but could be a number of causes. He reset it and it has so far stayed off. I got a flat on the way home so now have to fork out £200 for two new tyres !!

I'm picking up some cataclean tomorrow and will give that a go.

Over the last 400 miles I have noticed this weird burning smell coming into the cabin. It lasts a few seconds and goes away. I can't replicate it and it seemed to happen when stationary or in slow moving traffic. It's happened 3 times in all so often, just wondering if anyone might have any ideas what it could be? Rocker cover gasket has been replaced already.
You would think the most likely culprit for the burning smell would be oil dripping onto the exhaust manifold. Do a search for oil leak on here to get some ideas. A few people have had issues when replacing the rocker cover gasket, particularly on the corners. See here... viewtopic.php?f=3&t=100116&p=1464159&hi ... ”#p1464159
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bluepain
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Yellow engine warning light - Help !

Post by bluepain » Thu Nov 23, 2017 4:57 pm

If your getting an oil smell and error code 420 check the vacuum oil pump at the rear of the engine .as a burming smell would indicate oil leak coupled with PO 420 which can be caused by vacuum loss which this pump generates. ..
These 2.0l engines are notorious for error code 420,..
Ive had it ,and get it occasionally when poodling around or stuck in traffic at low revs,no miss fire or rough running,
Just the lovely yellow engine light..
Welcome to the 2.0l club.
Sorry

kowsmou
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Yellow engine warning light - Help !

Post by kowsmou » Mon Nov 27, 2017 9:50 am

So just an update on this, the burning smell was unrelated, the rocker cover gasket was still leaking even after it was changed so that's causing the burning smell as oil occasionally drips onto the exhaust.

The warning light, much to my surprise turned itself off and has stayed off around 300 miles later. I have not changed what fuel I used but I have used cataclean a couple of times, so maybe that has done the trick.. I have the say that cataclean stuff is giving me +4 mpg too and the engine is also performing better. £15 well spent.

kowsmou
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Yellow engine warning light - Help !

Post by kowsmou » Tue Nov 28, 2017 8:57 am

and it's back on again.. :(

Scooba_Steve
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Yellow engine warning light - Help !

Post by Scooba_Steve » Tue Nov 28, 2017 2:42 pm

You either need to pay someone to read the current code and stored code(s) or buy a cable and do it yourself.
Anything else is fumbling around in the dark and a waste of time and money as this could be a different fault. I think your best bet, long term, is to buy the kit for yourself.
3.0si Sport: F10 Illuminated ZHP, Retrofit Cruise, OE Stubby, Gaptech RCH+, Kenwood BT73DAB + Handsfree, HIDs, LED Sidelights, OE LED Number Plate Lights, Custom LED strip bootlight.

kowsmou
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Yellow engine warning light - Help !

Post by kowsmou » Tue Nov 28, 2017 5:59 pm

So I bought a code reader as recommended. It was the same as before P0420,

kowsmou
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Yellow engine warning light - Help !

Post by kowsmou » Tue Nov 28, 2017 6:03 pm

"catalyst system efficiency below threshold (bank 1)"

It stayed off for a good 400 miles, including a 300 mile motorway trip... Then just came on again while I was driving home from work !

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Yellow engine warning light - Help !

Post by Scooba_Steve » Wed Nov 29, 2017 12:11 pm

Once it goes back into spec it will clear. I don't think cataclean or similar actually work. I'm not sure what the cat failure rates are but expect them to be lower than the sensors. Trouble is the post cat are a pain to change, if it doesn't affect drivability then I'd not be too worried, can you clear the code using your reader?
3.0si Sport: F10 Illuminated ZHP, Retrofit Cruise, OE Stubby, Gaptech RCH+, Kenwood BT73DAB + Handsfree, HIDs, LED Sidelights, OE LED Number Plate Lights, Custom LED strip bootlight.

markalp
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Yellow engine warning light - Help !

Post by markalp » Thu Nov 30, 2017 6:05 pm

I would be tempted to pop in quality fuel, and then drive her hard for a good few miles. Clear out the built up crud etc.
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