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Chat Area => General Car Chat => Topic started by: JamesV6CDX on 04 March 2010, 14:14:56

Title: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 14:14:56
I know this is a pretty daft question, given they practically run this way ....

My commonrail diesel, is making a prominent "pinking" noise under load.

It sounds JUST like my old  1994 1.4 corsa, when the ignition timing was too advanced.

What could cause this on a diesel, some sort of fuelling problem?

On a bright note, I have found a standard OBDII socket on this pug... so at least I can read the codes when my new device arrives!

Quick edit to add, this is most definately NOT just a bit of diesel knock/chatter, it is a definate, unhealthy pinking sound! combined with lost power.
Title: Re: Can a diesel engine "pink"..
Post by: Welung666 on 04 March 2010, 14:21:16
It's not pinking, that's it's french accent ;D ;D ;D
Title: Re: Can a diesel engine "pink"..
Post by: tunnie on 04 March 2010, 14:25:10
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I know this is a pretty daft question, given they practically run this way ....

My commonrail diesel, is making a prominent "pinking" noise under load.

It sounds JUST like my old  1994 1.4 corsa, when the ignition timing was too advanced.

What could cause this on a diesel, some sort of fuelling problem?

On a bright note, I have found a standard OBDII socket on this pug... so at least I can read the codes when my new device arrives!

Quick edit to add, this is most definately NOT just a bit of diesel knock/chatter, it is a definate, unhealthy pinking sound! combined with lost power.

You have gone from 200bhp to 90  ::)
Title: Re: Can a diesel engine "pink"..
Post by: Seth on 04 March 2010, 14:28:19
Broken valve spring perhaps?
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 14:45:03
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Quote
I know this is a pretty daft question, given they practically run this way ....

My commonrail diesel, is making a prominent "pinking" noise under load.

It sounds JUST like my old  1994 1.4 corsa, when the ignition timing was too advanced.

What could cause this on a diesel, some sort of fuelling problem?

On a bright note, I have found a standard OBDII socket on this pug... so at least I can read the codes when my new device arrives!

Quick edit to add, this is most definately NOT just a bit of diesel knock/chatter, it is a definate, unhealthy pinking sound! combined with lost power.

You have gone from 200bhp to 90  ::)

110 :P

Any anyway, having compared it with another identical model today, of the same miles, that was MUCH quicker, smoother, quieter.... mine aint right...
Title: Re: Can a diesel engine "pink"..
Post by: Lazydocker on 04 March 2010, 15:21:01
Only if the pump timing is out, which you should eliminate with a belt change. Any history of the pump being fiddled with?
Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 15:38:33
Yes they can, if, as has already been said....the pump timing is wrong.
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 15:45:11
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Only if the pump timing is out, which you should eliminate with a belt change.


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Yes they can, if, as has already been said....the pump timing is wrong.

Being a HDi - with electronically actuated injectors.. .there is no pump timing  - as the diesel injection is controlled by ECU? :question
Title: Re: Can a diesel engine "pink"..
Post by: joshwyatt on 04 March 2010, 15:48:54
I've chased up the pug diagnostic man, and he's going to ring me tomorrow with a time he can fit you in  :y I'm sorry it's taken so long, but he seems so busy...maybe because french cars are awful and are always breaking down  ::)
Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 15:53:35
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Only if the pump timing is out, which you should eliminate with a belt change.


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Yes they can, if, as has already been said....the pump timing is wrong.

Being a HDi - with electronically actuated injectors.. .there is no pump timing  - as the diesel injection is controlled by ECU? :question

And the ecu gets its timing info from where......
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 15:54:35
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Quote
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Only if the pump timing is out, which you should eliminate with a belt change.


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Yes they can, if, as has already been said....the pump timing is wrong.

Being a HDi - with electronically actuated injectors.. .there is no pump timing  - as the diesel injection is controlled by ECU? :question

And the ecu gets its timing info from where......

Crank sensor?  ::)

Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 15:55:20
With the help of.....
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 15:56:01
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With the help of.....

Cam sensor  ;D
Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 15:58:06
Correct....also give a thought to what happens if the common rail pressure is low.....
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 15:59:56
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Correct....also give a thought to what happens if the common rail pressure is low.....

If the pressure in the rail is low, then there would be a reduced (or intermittent) feed of fuel to the individual injectors?

Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 16:02:21
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Correct....also give a thought to what happens if the common rail pressure is low.....

If the pressure in the rail is low, then there would be a reduced (or intermittent) feed of fuel to the individual injectors?

Sort of.....as the injection phase starts just before TDC.....the fuel starts to enter and as the compression increases, the fuel flow can drop to xero (due to low rail pressure).....so hence you get less fuel than requried in....

Whats was teh stored codes....low rail pressure per chance?
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 16:04:11
I will be reading the codes tonight, this is the first step I will do in the diagnosis....  :)

If it is fuel pressure low (which I understand is common) what is the cause / fix?

Bu66ered/tired pump?

I have wondered if at any time, the car has been mis fueled  :-/
Title: Re: Can a diesel engine "pink"..
Post by: Sir Popple on 04 March 2010, 16:16:52
I will possibly get shot down for this, i believe there is a sensor that listens for the pinking noise under the bonnet, if this registers it should alter the timing. I know this is common on Large GM Diesels in The States
Title: Re: Can a diesel engine "pink"..
Post by: JamesV6CDX on 04 March 2010, 16:18:18
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I will possibly get shot down for this, i believe there is a sensor that listens for the pinking noise under the bonnet, if this registers it should alter the timing. I know this is common on Large GM Diesels in The States

You mean a knock sensor?

Not sure the HDi has one...

Thanks for the input though - ANY comments gratefully recieved  :y
Title: Re: Can a diesel engine "pink"..
Post by: Sir Popple on 04 March 2010, 16:31:43
No, But if as you say you are doing a test then if a sensor is faulty then hopefully it will show up......
Does it only do it when the engine is under load?
Have you ever heard of the Diesel Bug? We get it a lot over here in the winter, due to Bad Diesel storage. I am for ever having to clean fuel lines and filters for customers.
Title: Re: Can a diesel engine "pink"..
Post by: Seth on 04 March 2010, 17:21:17
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No, But if as you say you are doing a test then if a sensor is faulty then hopefully it will show up......
Does it only do it when the engine is under load?
Have you ever heard of the Diesel Bug? We get it a lot over here in the winter, due to Bad Diesel storage. I am for ever having to clean fuel lines and filters for customers.

Yes, but could the problem be inferior quality diesel?

IME, a 'sharpish' sounding CI engine was usually down to over-advanced injection timing. So could it be that the system, therefore, is over-compensating for poor quality/contaminated juice?
Title: Re: Can a diesel engine "pink"..
Post by: Marks DTM Calib on 04 March 2010, 17:39:54
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I will be reading the codes tonight, this is the first step I will do in the diagnosis....  :)

If it is fuel pressure low (which I understand is common) what is the cause / fix?

Bu66ered/tired pump?

I have wondered if at any time, the car has been mis fueled  :-/

Buggered pumps on the pugs are all to common.....and often results cars the age you have being scrapped or shifted on for low cash.

Title: Re: Can a diesel engine "pink"..
Post by: Debs. on 04 March 2010, 18:16:38
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Yes they can, if, as has already been said....the pump timing is wrong.

Agreed; indeed they can be over-advanced and it makes a horrible noise!
My old landy has a vertical diesel pump (looks like an old -fashioned distributor)....altering the effective timing by revolving it relative to the timing mark has a profound effect on power-output, smoke, noise and engine-heat.
Diesel timing can be tricky to set-up and catastrophically destructive if left in a badly timed condition.
Title: Re: Can a diesel engine "pink"..
Post by: hoofing it on 04 March 2010, 18:58:37
I'm going to get ripped to bits here but would worn valve lifters not cause a pinking :-/
Title: Re: Can a diesel engine "pink"..
Post by: Seth on 04 March 2010, 19:01:15
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Yes they can, if, as has already been said....the pump timing is wrong.

Agreed; indeed they can be over-advanced and it makes a horrible noise!
My old landy has a vertical diesel pump (looks like an old -fashioned distributor)....altering the effective timing by revolving it relative to the timing mark has a profound effect on power-output, smoke, noise and engine-heat.
Diesel timing can be tricky to set-up and catastrophically destructive if left in a badly timed condition.
Ah - the old DPA pump, vertically mounted!
Could be 'touchy' things those, slightest contamination of the fuel, and they'd stop on you. More often than not, it was then over to our pump shop for a replacement!