My friend's car has recently started losing power upon accelerating. He took it to the garage to have it checked, but that got me wondering if the timing belt slippage could be a reason for that?


  • 1
    Timing changes will cause a change in power, but if the change is too much then damage is often the result.
    – Solar Mike
    Oct 6 at 10:06
  • One possibility is the exhaust gas regeneration valve, for example on the VW TDI engines when accelerating (or climbing a hill) a sensor can cause the turbo operation to be cancelled until the engine is restarted, with consequent loss of power. Oct 6 at 12:36
  • Is it lighting "Check Engine"? Do you have access to an engine scan tool? (Nowadays that looks like a little dongle that syncs with your phone, be wary that the cheapest of these require paying a monthly fee for an app). Oct 6 at 18:47
  • Do you have a reason to suspect timing belt slippage, like having replaced the water pump or belt or done something else that involved loosening the tension idler? Slippage is not something that would "just happen" without such a change or catastrophic breakage, since it's a toothed belt. Oct 6 at 19:05

It's possible but extremely unlikely that the timing belt is the culprit to a power loss. The timing belt (or chain in some cases) synchronizes the movement of the pistons and valves in the engine. Most modern internal combustion engines are interference engines, meaning the piston at top dead center will hit any open valves, so a failure of the timing chain will usually result in catastrophic engine failure.

A power loss is far more likely to be fuel or ignition system related, there's far too many possibilities to list.

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