[davscer]

Hi again,

I have a problem with my car, its a 2001 VW Polo GTi 6N2 AVY Engine Code.

When warm the engine starts to knock for a second between 1500 rpm to 2700 rpm when I punch the accelerator, after 3000 rpm its fine and it pulls normally.

It is not a fuel issue for sure as my friends have BMW's, Audi's, Lexus's and other modern cars which do not do this.

I have connected the car with VCDS and there are no faults.

I bought an original MAP Sensor, changed the coil pack with an original pack and its still the same. When I was replacing the MAP Sensor, I opened the Air Box and found the air filter with engine oil in it, it wasnt soaked but there was engine oil.

When the outside temperature is low, like 9 degrees it doesn't knock. During the day when the temperature is higher it knocks.

Can you please shed some light on this as I do not want to ruin the engine.

I have been reading that it could be a rod bearing?

One another thing, when the engine is cold, its sluggish and its not smooth. It will only last for a minute or two.

Thanks so much for your time and help.

 

[boostedJTi]

Do you have a pcv system? On the other side of the pond we don't have your engine so I'm not too familiar with it.

If you do have a pcv, you may want to inspect that as it could be the reason oil was in the air filter.

As for the knocking, have you pulled the valve cover and had a look in the head?

Dual cam motor?

 

[davscer]

Thanks for your reply,

Yes, it has a breather pipe from the crankcase going to the air box in which there is a Sensor inside this pipe. This breather had been replaced.

I have replaced the exhaust valves as they were burnt, it's a common issue with VW in Europe. It has a new set of exhaust valves, new head gasket kit and the head was polished and cleaned.

Thanks.

 

[boostedJTi]

Afraid it may be in the oil pan area unfortunately.

You could always use vcds and log the knock sensor and see if it pulls up anything strange. Maybe check the misfire counter and ensure nothing funky is going there. Of course those would be last minute checks before you drop the oil pan.

Wish I could be of more help.

 

[davscer]

Thanks so much for your help.

Will check the readings of the Knock Sensor and the Misfire Counter.

You have been of help.



Will update you.

 

[boostedJTi]

Curious tho, do you have dual cams in the motor?

A local, to me, has a bad cam chain tensioner and his makes a knocking noise under the same conditions as yours. So all may not be lost.

 

[davscer]

Yes, its a 1.6 16 Valve DOHC VVT Engine.

For the camshafts, it has one small belt which connects to two pulleys for both camshafts and the external pulley which has a belt that drives the camshaft and the crackshaft, along with four tensioners.

Both belts are rubber and not chain.

 

[boostedJTi]

So no individual tensioner for the belt for the cams? But yours wouldn't even make the noise for chain slack so I guess that kind of kills that idea.

Hmm.

What kind of oil are you using?

Petrol?

What's the mileage/kms on the car?

 

[davscer]

It has 4 tensioners in all.

I used Agip Fully Synthetic Oil 5W-40.

Yes its a Petrol engine and using 95RON.

The mileage is 100000 miles.

 

[boostedJTi]

It could be an oil pump issue but I feel like I'm shooting in the dark with that.

 

[davscer]

I doubt it, reason being is that I have seen oil in the breather pipe which is going to the Air Box.

 

[davscer]

I cannot upload any images to help you guys out...

I want to show you how the engine looks in the timing belt area.

 

[boostedJTi]

I cannot upload any images to help you guys out...

I want to show you how the engine looks in the timing belt area.

Try using an image hosting site like www.photobucket.com

 

[davscer]

This the model, its not my personal one.

This is the Timing.

 

[conner]

More or less its all about the engine timing, but take note that type of fuel you are using could contribute with ping and knocks.