The engine is well designed, but very "picky" as to the lubrication and oil filter. Originally 5W30 was specified, later changed to 5W20 and 5W20 synthetic blend. The oil filter also has a specific anti-drain back valve and for good reason.

We are seeing a good many of these engines with a costly problem. The timing chains are relatively long. They are supported by plastic guides and kept tight by hydraulic tensioners. With the proper lubrication and oil filter this works very well for a great many miles. Problems begin when improper viscosity oil and substandard oil filters are used.

If oil drains back to the oil pan and does not properly tension the chains on startup, the plastic guides can be broken.

Symptoms can range from noise on startup (not always) to rough idle to a check engine light.  This engine was fitted with a Motorcraft filter in a hope of helping with the problem.  Unfortunately it was too late.

When the guide (1) breaks, the tensioner (2) attempts to take up the excess slack. The piston extends out and the chain is pushed tight. Moving this slack to one side of the chain also causes the cam sprocket (3) to rotate.

Rotating one cam sprocket disturbs valve timing. The rough idle can set diagnostic trouble code (DTC) P0300 and codes for lean and rich. Many times these engines come to us, after having been mis-diagnosed elsewhere.  Needless part replacement has often been a further waste of money. Repair involves timing cover removal and the chains, guides, tensioners, etc. being replaced.

We find the chances of this problem can be greatly decreased by a few simple steps:

Use the proper viscosity of oil specified for the engine

Change oil according to the severe maintenance schedule

Use synthetic blend or full synthetic where specified

Use an OEM oil filter on the engine

Proper service prevents problems. Preventing problems is always better than fixing them, that’s the AGCO way.