TSB's

Piston-to-valve kiss?

This TSB refers to all 2008-2012 VW vehicles equipped with the 2.0L engine, where the customer complains of a no-start or rattling noises from the engine, and the MIL on. DTCs 00022 P0016 (crankshaft position vs. camshaft position correlation) and 00808 P0328 (knock sensor 1 circuit high input) may be set.

The 2.0L engine features an interference design. The timing chain tension may be incorrect due to a worn/faulty tensioner. As a result, the timing chain can skip, causing contact between the pistons and valves.

If the timing chain is suspected, complete the DTC entries according to guided fault finding (GFF). Remove the lower timing chain cover and check the timing chain tensioner as follows: Compress the tensioning rail of the timing chain by hand against the timing chain tensioner. If the piston of the chain tensioner cannot be compressed by hand after several attempts, further engine diagnosis is required.

Inspect the intake camshaft and camshaft bearings for damage. If the piston of the tensioner can be compressed by hand, the timing chain tensioner has failed and further engine diagnosis may be required.

If engine noises or no-start condition remains, inspect pistons and valves for contact damage. If damage is noted, the cylinder head and/or engine may need to be replaced or rebuilt.

Figure 1. 1) Timing chain tensioner. 2) Tensioning rail. Arrow: Direction of pressure to be hand-applied on the tensioning rail.
<p>Figure 1. 1) Timing chain tensioner. 2) Tensioning rail. Arrow: Direction of pressure to be hand-applied on the tensioning rail.</p>
Figure 2 shows the timing chain tensioner incorrect (stuck). Figure 3 shows the tensioner in correct state.
<p>Figure 2 shows the timing chain tensioner incorrect (stuck). Figure 3 shows the tensioner in correct state.</p>

Post a comment
 

Comments (0)

 

Post a Comment

Submit
Subscribe Today

Subscribe to Auto Service Professional

Sign up for a FREE subscription to Auto Service Professional magazine

Subscribe