My Pinking Engine!

[chunkz]

my ls 400 has just started "pinking" in the past few days. it does it seconds after starting while revving/accellerating so i dont think its because of a hot engine. outside temp is 7/10 deg. i was putting 95 ron petrol in it and occasionally some redex.

anyone any clues? 136000 on clock fsh etc plus new kwik fit free alternator!

[Haylands]

Hi

Pinking usually only occurs under load, in higher gears. It is caused by pre-ignition, ie the ignition is too far advanced, or the petrol octane is insufficient, or the car has been modified and its not getting enough petrol. As you say it can be caused by carbon build up and a hot spot forming inside the engine, this creates a dieseling effect and ignites the mixture before the spark plug fires. Pinking can destroy an engine.

A pinking noise when you rev up a car at standstill could be very poor quality petrol. I can't think of anything else.... on a lesser car I would say it may be little end wear but not on a Lexus.... Could be something else in the engine complaining, alternator/ power steering pump etc

Have you just filled up?

Does it do it all the time when driving?

Anyone else heard of this?

Pete

[chunkz]

Thanks for replying.

I did put some cheapo Asda petrol in it but I think it's all gone as I put 97 ron in when it got low.

It only happens when I accelerate, it is quiet otherwise. Normally I use Esso / Shell 95 ron

[Haylands]

Hi

It’s usually old petrol that causes problems, unleaded will start to lose its octane after about three months.

Get the car checked A.S.A.P. as pinking is the sound of the petrol exploding within the cylinder instead of the usual burn of the petrol. It puts enormous pressure on the engine and can blow a hole in a piston in a short space of time. Don't drive it unless you have to

Pete

[steve2006]

I would go for Pete's fuel theory as there is a knock sensor on the engine and the ecu would retard the timing to prevent engine damage,have you done a code read as there may be a stored code even if the eml is not lit?

[Haylands]

Steve, are you back now and did you have a nice time?

Pete

[ROYT]

Or is the anti knock sensor faulty......

[Matrixabc]

it might be worth pulling a spark plug and see what it looks like? if is black and sooty then that could be the cause ( carbon build up), but then again the anti knock detector should prevent pinking.

[Dan1]

I think that you should use only the best fuel in your car It may be expensive but I think its worth it, . also you might not notice this but sometimes if you add redex it can thicken you fuel and it might be a bit smokey and juddery,,, every car i have had has done this when redex was added,, should go away after about 200 miles,

I normally use the cheap fuel on my mercedes and thats ok,, but I havent had the lexus on the road yet as its still being fixed.

[chunkz]

thanks for all your replies. before i took plugs out etc i bought some forte treatment off eBay and put it in with half a tank of esso 95 ron. within 25 miles the engine is back to sounding how it was!!!

only hope it lasts.

could it have been something sticking perhaps?

[chunkz]

hi, me again. the sound has returned. i took out the spark plugs and they all looked the same. all ok. i checked the leads and they too looked ok. revving it at stand still out of gear it sounds as though there is a hole in the exaust on drivers side in the down pipe area. is it possible to get a hole there?

would the spark plugs being ok mean its not pinking etc and could be a hole?

its still fast accelerating and gears change smoothly.

please help!!

[Haylands]

Hi again

This sounds like it could be an EGR valve (exhaust gas recirculation) but I don't know if the 400 has one!!!!

These valves, when faulty let out the exhaust gases to the outside, up near the engine, I had an Omega years ago and its one made the sort of noise you are talking about when cold.... Was just thinking if the 400 had one maybe the valve is stuck and you temporarily fixed it with the injector cleaner but now it’s sticking again.

You cannot really tell from looking at plugs if the engine is pinking, if they are very pale and very clean it is an indication of a week mixture, and possible pre-ignition, they should be a light grey with minimal deposits.

Could also be a cracked exhaust manifold, this would make a similar noise...

Anyone else any idea if the 400 has an EGR????

Pete

[ManicMark]

hi, me again. the sound has returned. i took out the spark plugs and they all looked the same. all ok. i checked the leads and they too looked ok. revving it at stand still out of gear it sounds as though there is a hole in the exaust on drivers side in the down pipe area. is it possible to get a hole there?

would the spark plugs being ok mean its not pinking etc and could be a hole?

its still fast accelerating and gears change smoothly.

please help!!

Could be the gasket between the cats and the exhaust ( when these go the engine sounds like its pinking) you normally only here it under load hope this helps Mark

[Dan1]

Im pretty sure the ls has a egr valve, it has a filter in the top that should be cleaned I thunk,,,, but i would replace the pcv valve ,,, anyway see the following site

www.lexls.com-tutorials

[soundchaser100]

Im pretty sure the ls has a egr valve, it has a filter in the top that should be cleaned I thunk,,,, but i would replace the pcv valve ,,, anyway see the following site

www.lexls.com-tutorials

When did you last change your oil and filter? Mine did a similar thing when I first bought it, new oil etc fixed it. Paul

[chunkz]

it was supposed to have been 4000 miles ago just befor i bought it. i was going to change it quite soon when i get a morgage for the oil!

[floggit]

Hi again

This sounds like it could be an EGR valve (exhaust gas recirculation) but I don't know if the 400 has one!!!!

These valves, when faulty let out the exhaust gases to the outside, up near the engine, I had an Omega years ago and its one made the sort of noise you are talking about when cold.... Was just thinking if the 400 had one maybe the valve is stuck and you temporarily fixed it with the injector cleaner but now it’s sticking again.

You cannot really tell from looking at plugs if the engine is pinking, if they are very pale and very clean it is an indication of a week mixture, and possible pre-ignition, they should be a light grey with minimal deposits.

Could also be a cracked exhaust manifold, this would make a similar noise...

Anyone else any idea if the 400 has an EGR????

Pete

Hi all ,, just to confirm the series 3 has a EGR valve, mines blowing and can be heard under load but isnt giving any other symptoms. Its on my list of to do jobs lol.

steve.

[chunkz]

hi, can you tell me where it is please?. i looked at the tutorial but there is a big nothing where that mk1 engine shown is.

[Haylands]

Hi

See this... explains all

http://www.lextreme.com/egr.html

Pete

[Dan1]

check your sparkplugs for a brown ring

[chunkz]

you mean on the ceramic part? there is no marks on them at all. they just look clean.