Coupe pinking

[Inline 6]

I’ve been to see a Coupe si. It’s in very nice shape, drives well and has a good MOT history.
However under loads (hills in higher gears) at low revs circa 1.5k there are signs of pre detonation or pinking.
Is this a common characteristic of these engines? I know they have knock sensors and should adapt.
The plugs and oil have now been changed and I’ll see if there’s been any change.
I seems the car had been stood for a number of months with now old petrol so I guess this could be a contributing factor.

 

[mmm-five]

Sounds more like you're straining the engine if you're flooring it in high gears & low revs - it's not a diesel

 

[Inline 6]

Maybe I should have described ‘under load’ better. I’m not flooring it but staying in gear and for instance a hill gets steeper just applying some more right foot. The engine doesn’t feel stressed, it feels though the lowish torque of the motor should carry it.
I would change down if in my MX5 but that isn’t a torque rich motor.
Can’t remember my old e36 328 wouldn’t pink in a situation like that.
I guess maybe I’m looking for fault as a big purchase and want to make sure I get a good un.

 

[mmm-five]

It could be loads of things...plugs, coils, air leak, bad fuel, faulty MAF, low battery, etc.

Have you scanned it for any fault codes?

 

[bakes100]

It could be loads of things...plugs, coils, air leak, bad fuel, faulty MAF, low battery, etc.

Have you scanned it for any fault codes?

Agreed, specifically fuel deterioration. I would request a fresh tank of fuel and a reasonably long test drive, if there is still an issue it may be something more involved.

 

[pvr]

My first Z4 3.0 did that though, only ever used Shelll fuel V power as well.

I sold it just before 3 years old, but it had done it from day 1. Never had a car do that before or after.

 

[Deepseaskateboard]

I’ve been to see a Coupe si. It’s in very nice shape, drives well and has a good MOT history.
However under loads (hills in higher gears) at low revs circa 1.5k there are signs of pre detonation or pinking.
Is this a common characteristic of these engines? I know they have knock sensors and should adapt.
The plugs and oil have now been changed and I’ll see if there’s been any change.
I seems the car had been stood for a number of months with now old petrol so I guess this could be a contributing factor.

Best thing to do, is test drive another car.

If it does not have that issue, regard the first as a lemon.

My first 3.0si’s engine broke after me having it for 10 mins.
I had a refund! There are some lemons out there…

 

[Mr Tidy]

I don't remember either of my 3.0Sis doing that, but to be fair in a 2 seater with a 6 speed gearbox and a 7,000 rpm redline I would have probably down-shifted anyway!

But my 330i daily has the same N52 engine and while I'm much more likely to potter in that I have never noticed pinking. But I do run it on Super Plus fuel.

Although stale fuel may be a factor I'd agree trying another example might be helpful.

 

[Rockhopper]

Could also be a rattling heat shield or similar.

 

[Inline 6]

I saw the car again yesterday. It’s since had an inspection 2 plus other attention like new gearbox oil, new brake discs/pads and lines although not strictly needed. Also it was scanned for any fault codes and there were none.
Took it out on a 25 minute test drive and really tried to provoke any symptoms.
It behaved impeccably! No untoward sounds
The car drove as good as it looks and I think it’s a beaut
So I drove it home !

However.... after about an hour of driving I did hear some odd sounds, a bit like a brake disc scrapping.. a metallic sound?
I’m going to get it checked out.
Heat shield certainly a good one to investigate.
Other than that I’m smitten, it definitely looks and drives the best of quite a few I’ve driven now.

 

[Mr Tidy]

So I drove it home !

Great news - welcome to Coupe ownership.

But don't forget the photos. :lol:

 

[Zedebee]

Took my coupe out this evening just to check for pinking (any excuse). Pulls cleanly in 6th from 1,000 rpm, so pinking as OP describes is not normal. Good luck with car, I hope all goes well.

 

[Inline 6]

So I drove it home !

Great news - welcome to Coupe ownership.

But don't forget the photos. :lol:

Yes will do soon