2004 passat engine sounds like a deisel all of a sudden and has some engine lag
Hi, depending on engine fitted it is most likely the cam chain tensioner has collaped or failed. On a twin cam engine like a 1.8 t or a 32 valve V6 there is a chain driving a second chain in the rear of the cylinder head. These chains are tensioned by a oil pressure pressurized piston pushing on a bridge under the chain.
If it collapses, the chain/s become very loose and you will hear a loud clacking noise. It can also collapse due to low oil pressure.
VW is familiar with this problem and the repair involves first checking oil pressure, cold thro' warm. If it is around 85 to105 psi cold and 28 to 35 psi warm at idle, then this indicates tensioner piston is faulty or tensioner guide has broken off.
If oil presssure is good and engine is running synthetic oil...as it should ...then tensioneris suspect. I have also seen these engines with the screen under the tensioner partly blocked . If on removal of valve cover prooves tensioner has collapsed or guide shoe broken or warn then a new tensioner must be installed.
If oil pressure is too low at under 12 psi at warm idle then oil pump is worn and/or engine is worn. Also low oil pressure can be caused by fuel in the oil making it very thin.
If the screen under the tensioner is partly plugged up, then the oil pan must also be removed and cleaned out otherwise plugging will happen again.
To remove and install the tensioner a SST ( Special Service Tool.) is required to compresse the tensioner piston to allow it to be removed from under the cam chain and again compressing the new tensioner to be installed. Cams or chain do not need removing on this job.
Most import shops can handle this as long as they are equipped with the SST tensioner tool.
Nov 01, 2013 |
2003 Volkswagen Passat