330i PINKING BADLY

[Rapido WP]

MY E46 330i IS PINKING BADLY AFTER DRIVING HARD, BUT AA CAPE TOWN CANT FIND THE PROBLEM SO TOMORROW THEY'LL "PUT IT ON THE MACHINE" WHICH I ASSUME IS THE DYNO. ITS BEEN IN TWICE IN THE LAST WEEK FOR THERMOSTAT, SHOCKS AND A NEW DIFF THIS MORNING. BUT EVERY TIME THEY CANT FIND THE PINKING (OR PINGING) - THAT'S WHAT IT SOUNDS LIKE. CAN ANYONE SHED ANY LIGHT?

 

[Hellas]

Do you go for a cool-down lap after some hard driving?

(PS, pls turn off the CAPS)

 

[Jandre]

What brand of fuel are you using currently?

I am trying to screw my brain trying to figure out who I had this exact conversation with last week.

Basically it came down to the fuel. Give me a few minutes, I'm sure it will come back to me soon.

 

[Rapido WP]

It just does it all the time when hot. Am using normal 95 unleaded.

 

[liv]

what octane fuel are you using? Car will detonate (ping) when it is running lean. In which case - the knock sensor should pull back the timing. It could also be Vanos related.

 

[danielscvhamann]

Is the car still stock or have you done any modifications....?

 

[Rapido WP]

Still stock

 

[Jandre]

I just can't remember who I had this conversation with. His dad drove one, and was the owner of a petrol station. As soon as he used petrol from his own garage, his car would ping. Any other brand and the car didn't ping. Now only if I can remember what brand of fuel we discussed.

Damn old age.:cursin:

 

[Rapido WP]

YOU COULD BE RIGHT - LATELY BEEN USING CALTEX - I TEND TO SWITCH BRANDS FROM TIME TO TIME.

 

[danielscvhamann]

I would recommend Shell or Sasol otherwise BP.... I tested it on a few cars already I only use them in that order...

Further have a diagnostics test done on your car by BMW or if you like I can also do that quickly for you, maybe will find something in the system.

 

[Rapido WP]

Thanks - will switch to Shell or go back to BP. But hopefully Auto Atlantic should find the cause tomorrow

 

[danielscvhamann]

Yes do that.... Anyway Auto Atlantic should find the cause, otherwise if you still have some problems just let me know.

 

[BimmerMan]

Could this be a faulty knock sensor? As far as I know, the DME uses the knock sensors to adjust the timing until its perfect with no knocking. It could be that the sensor has failed and the DME is just guessing the timing without that correction factor that the Knock Sensor provides?

 

[SirSparky]

my bet would also be faulty knock sensor

 

[danielscvhamann]

This could well be.... Will be easy to find out once you check it with the diagnostics machine.

 

[Mike1]

It may have been me you had that conversation with Jandre...

As has been said. Pinging is usually caused by poor quality fuel with a poor RON value.

I would suggest that if BMW cant find the fault that you try an Octane Booster (Only R66 Incl. VAT) and see if that gives any improvement.

The other thing is also the knock sensor as has been said... You may want to give the MAF a clean too.

Mike

 

[Rapido WP]

I've put in an octane booster which should stop the pinging completely, but it has not. Will see what AA come up with on Wednesday. Maybe I need a thicker head gasket to change the compression slightly. Thanks for all the input.

 

[BimmerMan]

I've put in an octane booster which should stop the pinging completely, but it has not. Will see what AA come up with on Wednesday. Maybe I need a thicker head gasket to change the compression slightly. Thanks for all the input.

I doubt that you would need a new headgasket. BMW made the car to run perfectly from the factory.

This could unfortunately be many things.

A diagnostic would be your best bet. I mean, this could even be something as stupid as the wrong brand of spark plugs!
What is the lowest octane rating that we can get in South Africa? As far as I know its 92 for LRP and 93 for Unleaded. Neither of these should ever need an octane booster to stop causing pre-detonation...

 

[Rapido WP]

Diagnostics showed nothing last week - I'm still hoping its a faulty knock sensor, but there was no error code.

 

[liv]

Diagnostics showed nothing last week - I'm still hoping its a faulty knock sensor, but there was no error code.

error codes only come up, if the sensor does not read in a certain range (either too high, too low, or no signal etc). The sensor could be providing a false reading due to being faulty - so, sensor tells ECU, all is well. ECU trusts that the sensor knows what he is sending back, so does not pull the timing, and assumes sensor works fine.

I'm sure you can log to see if timing is being pulled. If it is not, then I would suggest swapping a knock sensor (with one you know is working), and testing that out. Alternatively - look at the Vanos. Could be that the ECU requests timing to be pulled, but it doesn't happen.

Other things I can think off which could cause this, is:

MAF is faulty (there are other symptoms which could point to this - for one - the car only doing this when its hot, could be an indication).
Lambda Sensor is faulty.
Fuel System (fuel pump/injectors etc not supplying enough fuel).

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I've put in an octane booster which should stop the pinging completely, but it has not. Will see what AA come up with on Wednesday. Maybe I need a thicker head gasket to change the compression slightly. Thanks for all the input.

Thicker HG will lower compression, which you will only need to do if you are going the FI route. And that too, is required only if you wanna boost big!

Don't touch the HG. If anything was wrong with it, you will definitely know!