17 replies to this topic

[minicityE-2008]

Today i swapped my cylinder head and gasket. When i took the head off i noticed that the spark plug tips had a pinking deposit on them as did some of the valves in the head. I have heard of engine pinking, is this what it is? And if so what does that mean?

Thank you

Tom

[minimat]

Pinking is caused by shockwaves in the combustion chambers,usually due to incorrect ignition timing but also by to high a compression ratio but if your engine is standard it is prob just timing.
Don't ignore it though as serious damage can result!
Modern cars have a knock sensor on the block to listen for pinking so that the ecu can adjust the timing to suit.

[Ethel]

All engines get combustion deposits. Pinking is so called because of the pinging sound it makes, it's also known as dieseling because it's caused by the fuel igniting spontaneously, not by the spark plug. Obviously it has to occur before the spark plug gets a chance to burn the fuel (yet another name is pre ignition) which means it occurs sometime before the piston reaches top dead centre so it will try to push the piston against the direction of rotation causing hesitation and a lack of power as well as much higher cylinder pressures leading to temperatures hot enough burn valves and melt pistons.

Don't worry though your engines sounds as if it's healthy, if you haven't noticed it running on or the temperature gauge getting higher than normal.

[tommy13]

Pinking is as described by Minimat. It asually displays itself as a rapid machine gun like frequency of sound like two glass marbles cracking together, usually occuring under heavy load or rapid acceleration. Believe me you will know when you have pinking. As far as I know it cannot be detected by examining spark plugs or valves, the colour of which is usually a result of mixture and any oil being burnt.

[Saxo-Fiesta-Mini]

as said pre detonation can be caused by carbon build up or incorrect timing pinking noise normally down to the ignition being too far advanced

[minicityE-2008]

All engines get combustion deposits. Pinking is so called because of the pinging sound it makes, it's also known as dieseling because it's caused by the fuel igniting spontaneously, not by the spark plug. Obviously it has to occur before the spark plug gets a chance to burn the fuel (yet another name is pre ignition) which means it occurs sometime before the piston reaches top dead centre so it will try to push the piston against the direction of rotation causing hesitation and a lack of power as well as much higher cylinder pressures leading to temperatures hot enough burn valves and melt pistons.

Don't worry though your engines sounds as if it's healthy, if you haven't noticed it running on or the temperature gauge getting higher than normal.

Well my temperature gauge did tend to reach the red zone quite often before the head gasket went. i put a brand new thermostat in today when i changed the gasket and head, but after 5 minutes on the dual carrigeway the temp gauge was hovering just on the red again. Could this be a sign of something bad? Also, when i accelarate from 1st gear and after changing up the gears it loses power before slowly building up speed again.

Im pretty sure its not pinking, just thought that as the deposits were pink that miight be what it is, but my engine certainly isn't happy. If anyone has any suggestions i'd like to hear them. My engine is a standard 998 with standard city e 3.44 final drive 'box. It has a stage one kit with the correct AAU needle in the carb. i had the timing all done about 2 weeks ago so everything was set up as it should be.

Someone please help?

Cheers

Tom

Edited by minicityE-2008, 05 April 2009 - 10:36 PM.

[MiniMonty]

What concerns me is the very first thing you said:
"Today i swapped my cylinder head and gasket".

Did you actually put a new head on the engine ?
Or did you just fit a new gasket and replace the same head ?

This will educate anyone who wants to help you enormously...

Best wishes
Monty

[minicityE-2008]

What concerns me is the very first thing you said:
"Today i swapped my cylinder head and gasket".

Did you actually put a new head on the engine ?
Or did you just fit a new gasket and replace the same head ?

This will educate anyone who wants to help you enormously...

Best wishes
Monty

Hi there, i put a new head on as well as a new head gasket. i got rid of my leaded head and put on an unleaded head. However my lack of power problems and temperature problems were there before i swapped head and gasket. I thought that as my head gasket had gone that might have atributed to the problems. but it doesnt seem to have made a difference.

cheers

Tom

[minicityE-2008]

bump

[minimat]

Incorrect timing will cause the engine to run hot,as tommy says you cannot look for pinking on the plugs etc you can only hear it.Check the timing before you do any more damage!

[MiniMonty]

When you fitted the new head did you do the valve clearances ?

[minicityE-2008]

When you fitted the new head did you do the valve clearances ?

Yep, did the valve clearances, however there is one loud tappet.

[dklawson]

All engines get combustion deposits. Pinking is so called because of the pinging sound it makes, it's also known as dieseling

Dieseling isn't a term I hear used on British boards very often. I am more comfortable when I hear the term applied to what you guys refer to as "run-on". I think the "D" word often associated with pinging or pinking is "detonation", not dieseling.

Regardless, you put on a new cylinder head and you hear pinging so I would suggest retarding your ignition timing a bit. With regard to the high operating temperature you certainly would want to check the mixture AFTER you have set the valves (again) and made sure the points gap and ignition timing are set right.

Don't discount the possibility that the temperature gauge may be at fault. Check the temperature of the thermostat housing and surrounding area when the engine says it's running hot. If you didn't put in a new thermostat when you put the new head on, that's another possibility. Lastly, did you re-fill the radiator after the first time the thermostat opened? If you didn't, you may have very large air pocket in the cooling system.

[minicityE-2008]

All engines get combustion deposits. Pinking is so called because of the pinging sound it makes, it's also known as dieseling

Dieseling isn't a term I hear used on British boards very often. I am more comfortable when I hear the term applied to what you guys refer to as "run-on". I think the "D" word often associated with pinging or pinking is "detonation", not dieseling.

Regardless, you put on a new cylinder head and you hear pinging so I would suggest retarding your ignition timing a bit. With regard to the high operating temperature you certainly would want to check the mixture AFTER you have set the valves (again) and made sure the points gap and ignition timing are set right.

Don't discount the possibility that the temperature gauge may be at fault. Check the temperature of the thermostat housing and surrounding area when the engine says it's running hot. If you didn't put in a new thermostat when you put the new head on, that's another possibility. Lastly, did you re-fill the radiator after the first time the thermostat opened? If you didn't, you may have very large air pocket in the cooling system.

I there, thank you for your contribution. So u reckon i may need to increase the fuel? Also i haven't refilled the rad since putting in the new thermostat. Will go out and check everything now.

Thank you again

[john1.2pearl]

If youve replaced the thermostat you will have lost coolant and will need to top the coolant up after relacing the thermostat