first off all, most of the time, my idle is smooth and regular. At about 750rpm and running like a champ. but all of a sudden sometimes, the idle will start to be rough, the idle will oscillate between 600-750rpm (I can really feel the engine struggle). After a couple seconds, I’ll see the idle go up to 1000rpm and slowly go back to 750rpm(like when it’s cold outside and the idle is higher) and once it did that, the idle will be back to normal and smooth.
So far i’ve replace the wires, cap, rotor, PCV valve and the O2 sensor was replace last year. I’ll replace the spark plugs soon but they have like only 40,000KMs (25,000 miles) on them…
Anyone have an idea on what could cause this? (I also have a bad hesitation near 3K rpm)
It is probably caused by your cooling fan kicking on. That drains a lot of power and if your idleing you would notice it.
If your having a bad hesitation at 3k then it is probably caused by your O2 sensor. Considering the fact that your plugs have so many miles on them, it could definately be those causing this problem.
Have you tried changing out your fuel filter??
Spark plugs and fuel filter are next one the list…
And I don’t think it’s the cooling fan because I can hear it start and it does not create the idle problem, It does draw a lot of power(I can see the lights dim a little when she kicks on) but the idle problem isn’t related to the fan starting…
I’ll try the fuel filter and plugs first, and the O2 sensor after… When are we supposed to replace the fuel filter?
another thing that you might wanna check is the idle valve, it uses engine temp to control it sometiems it will cause a flucuation in engine rpm…its on the back of the intake manifold. take it a part and clean it out, that should fix ur problem if not its somethin else
It almost sounds like there’s some dirt getting past the fuel filter, and I think you’re supposed to change that every 12,000km? Maybe 20,000? Not sure on that though. I think usually they recommend you change it once a year or so.