Car cuts out sometimes immediately sometimes after 30 seconds etc.

If I hold the key on the starter position engine keeps running and stays on.

I know this can be caused by a faulty ignition switch.

However I’m suspecting/asking if this same behaviour can be caused by a damaged resonator as I have read In one article it can. I have been experience reduced performance and sound for a while since I bought my low car from a garage. Recently I hit the resonator on a speed bump and the sound and performance improved immediately. Days later I hit it again and the sound and performance went bad again. This suggests the resonator is damaged and is causing the sound and performance issues I’ve had ever since I bought it back from that garage. Obviously they hit it and damaged the resonator while in their posession.

I had recently changed a faulty ignition switch with another used one so could be replacement switch is at fault however it when I hold it to keep car running it feels very different from first ignition switch. First one also used to start and run more often.

In any case could the current symptoms be due to a damaged resonator or is it more likely the ignition switch. How should I approach this, replace resonator first or would it be better to open and check if the ignition switch is corroded?

You can already see why I think the resonator is damaged but is there another way to diagnose that it is bad?


  • Did you not solve the ignition switch correctly here: mechanics.stackexchange.com/q/80648/10976
    – Solar Mike
    Dec 24 '20 at 6:19
  • @Solar Mike No. wasnt caused by keys. As I had a faulty ignition switch previously I know how it feels and sounds when I hold they key to keep it running. This time it mimics the same behaviour but sounds and feels different and for reasons mentioned I know I have a reduced performance due to a faulty resonator. I also read a faulty can cause stalls and no starts so I’m wondering g how to diagnose this: google.co.uk/amp/s/repairpal.com/resonator.amp Dec 24 '20 at 11:06

Yes, exhaust clogs can cause a stall after a short time. It has to be a very complete blockage such as mud or snow, or a clogged catalytic converter. You can try to blow air through the resonator or temporarily remove it to check.

Your problem is ignition.

Separate question, really.

  • This answer is correct. Clogging, however, does not go away if one manipulates the key. The OP's situation indicates that a clogged exhaust is not the cause. Dec 26 '20 at 18:37
  • @DavidSupportsMonica isn’t me holding in the run position just the starter constantly being engaged? And so the stalling could still be the resonator but manipulating the key is just causing the starter to continually be engaged? Dec 26 '20 at 22:19
  • When the starter is engaged, the engine isn't running. You said "When the starter is engaged, the engine keeps running." The engine may be turning over, but it isn't running. Dec 27 '20 at 1:38
  • Let's not get semantic. I understood running to mean "keeps rotating". The point is that in "Start" we get rotation, which ceases when the key returns to "Run." Still sounds like ignition and not exhaust.
    – geoO
    Jan 27 at 13:57

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