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[billfxtwo]

Hi,   Had the head gasket done a month ago on my W Reg omega 2lt, recently it has started to pink when it’s up around the 90 degrees,  the fan is coming on and off ok  I had the radiator  checked and its fine, I took the thermostat out and left it out, and flushed the system out still seems to be pinking and getting hot never going above 92 ish ,  if I bridge the fan and the fan stays on the temperature gauge comes down  showing just above cold but no pinking and seems to run fine, CAN ANYONE HELP   Cheers,   Bill  

[Kevin Wood]

Firstly, put the thermostat back in as it doesn't appear to be faulty and running without one is bad news.

Doesn't sound like it's overheating so it makes me wonder if something like the ECU's engine temperature sensor is playing up. Have you checked the ECU for codes?

Kevin

[billfxtwo]

Hi Kevin, dont suppose you could tel me were i can find the ECU's engine temperature sensor   Cheers Bill

[Martin_1962]

What petrol are you using?

[billfxtwo]

Unleaded

[Martin_1962]

Tesco Shell BP ect ect?

[billfxtwo]

Im a taxi driver in Plymouth so i tend to buy it anywhere

[Kevin Wood]

Don't know the 2L very well but I believe the sensor is to the rear of the cylinder head. ECU sensor is the one with 2 wires into it. I would still say check the engine ECU for codes though, as it should have stored a fault code.

The other option is that the head has been too heavily skimmed so the compression is a bit high now. Do you know if it had a skim when the head gasket went and if so how much they took off?

Kevin

[mkaminski100]

Something like that? http://uk.youtube.com/watch?v=z1TOgzP83PA
I belive "pinking" is a knocking noise it makes and you can hear it when the engine reaches 90 degrees.
If I am right - tappets.
Solution? Rev it to 2000 for a few seconds, then to 300, and up to 4000-5000, then do down do 2000, and again. It will take a while to fill tappets again.

[Martin_1962]

Try a tank full of BT ultimate or the Shell equivalent

[Kevin Wood]

Something like that? http://uk.youtube.com/watch?v=z1TOgzP83PA
I belive "pinking" is a knocking noise it makes and you can hear it when the engine reaches 90 degrees.
If I am right - tappets.
Solution? Rev it to 2000 for a few seconds, then to 300, and up to 4000-5000, then do down do 2000, and again. It will take a while to fill tappets again.

Classic pinking is pre-ignition or detonation not related to the valves. My thinking is that if the temperature sensor is indicating that the engine is always cold it may be giving too much ignition advance.

Alternatively, compression ratio could be too high. :-/

A lean mixture is a possibility (MAF / air leak) but the Lambda sensor should correct this or light the EML.

Could be a duff knock sensor but again, I would expect an EML.

I'd be really interested to know if there are any stored codes.

Kevin

[mkaminski100]

Something like that? http://uk.youtube.com/watch?v=z1TOgzP83PA
I belive "pinking" is a knocking noise it makes and you can hear it when the engine reaches 90 degrees.
If I am right - tappets.
Solution? Rev it to 2000 for a few seconds, then to 300, and up to 4000-5000, then do down do 2000, and again. It will take a while to fill tappets again.

Classic pinking is pre-ignition or detonation not related to the valves. My thinking is that if the temperature sensor is indicating that the engine is always cold it may be giving too much ignition advance.

Alternatively, compression ratio could be too high. :-/

A lean mixture is a possibility (MAF / air leak) but the Lambda sensor should correct this or light the EML.

Could be a duff knock sensor but again, I would expect an EML.

I'd be really interested to know if there are any stored codes.

Kevin

Are we sure that in this case it's the pre-ingition?
If billfxtwo is sure, I would suggest to check cambelt setting.
Knock sensor should show an error.
Is it possible to put a video of you running engine on youtube or gogle video?

[Marks DTM Calib]

Cambelt setting would be my first port of call to......

[rickyboy]

Don't know the 2L very well but I believe the sensor is to the rear of the cylinder head. ECU sensor is the one with 2 wires into it. I would still say check the engine ECU for codes though, as it should have stored a fault code.

The other option is that the head has been too heavily skimmed so the compression is a bit high now. Do you know if it had a skim when the head gasket went and if so how much they took off?

Kevin

When this is disconnected it doesn't bring an engine code up - the temp guage warning light will come on and the rev counter stops working as well.  If it is not connected properly it will give incorrect readings so definitely a place to check if you don't believe it is giving the correct temperature reading.

Here's a picture of it when it was out the car...  



You should be able to reach down the back of the egr valve, at the rear of the cylinder head to feel it.  It will have a spade connector on it.  Make sure it is on correctly and the wiring has not been split or is worn.