Mechanics

ENGINE ROUGH IDLING

1998 Toyota Corolla • 1.8L 4 cylinder 2WD Manual • 131,578 miles

Hi! I have a 98 corolla which has started to idle roughly after warm up. The car used to have a bad canister (P0441 and P0446) CEL but I've already replaced it thinking it would fix the problem however, it didn't. Car is usually serviced every 1500 miles for oil and engine filter change. There are no CELs anymore and no performance issues so far either, the idling is just annoying and would usually occur if I'm in neutral at a traffic light or just parked
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Joseph2498
June 7, 2014.




If you are experiencing a vibration when sitting still that may get worse when in drive and holding the brake, it may be due to deteriorated engine mounts that are not insulating engine vibration sufficiently any longer.
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Wrenchtech
Jun 7, 2014.
Hi Wrenchtech!

Thank you for the prompt response : )!

I've recently replaced the engine mounts after a few months of having this issue, the car does become worst if I pump the brake but when I stop pumping it comes back to normal idling. Basically the issue only happens when the engine is recently warmed up and it fades away as I drive for a couple hours.

Tiny
Joseph2498
Jun 7, 2014.
Try pinching off the vacuum hose to the brake booster and see if the vibration improves, but don't go anywhere that way. If it improves, you may have a leaking brake booster.

Wrenchtech
Jun 7, 2014.

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