Author Topic: Bit of a jerking when pressing the gas at lights, sparks? Some vibration idling.  (Read 1487 times)

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Offline Polaris

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Hey everyone, took the old thread down to add some more info and realized it would've been easier to just edit my old thread.

Anyways, when starting the car up in the morning it occasionally will "jerk" when I give it some gas. When starting the car up sometimes there's a weird noise from the engine too but the car starts up fine, like a "cha cha cha" sound LMAO, don't know how to describe it. As well, sometimes when I give the car gas when the light turns green it goes for half a second, "jerks", then keeps going like nothing happened. When idling, the RPMS are at around 500rpm or a bit below 1000rpm, but there's a fair bit of vibrating when idling at a red light. I'm thinking that it might be spark plugs, but wasn't sure if I should pay for the $100 or whatever bucks and get my mechanic to do a diagnostics test on it and see if there's any other problems, like maybe MAF sensor or something. Advantages is that I'll know if anything's wrong other than spark plugs, downside is if the test really does come out saying that the spark plugs need replacing like I originally thought, I'd have wasted like a hundred bucks just for peace of mind.

I guess just not sure if I should pay for spark plugs to get changed, which I'm pretty happy to do so with my lack of knowledge/space/tools/laziness, or get the diagnostic test done and maybe it turns out the MAF sensor needs cleaning and that's all I need to do :P

Thanks!!

Offline jellynuts

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Cleaning the MAF is easy to do. Try that first.
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Offline Stehle

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If it's idling odd I would definitely clean MAF first. Cleaner is about 15 bux so I would start there.

Offline SlowLGT

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If you put the transmission in neutral when you are waiting at the light, does the vibration go away?

Offline cmyles

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Just replace the spark plugs, and clean your MAF. Will make a nice difference, whether or not it fixes the problem.
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Offline Mendozer

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Cleaning the MAF is easy to do. Try that first.

Any pointers on how to do this? 

Offline jellynuts

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The MAF sits right after the intake filter



Disconnect the plug and screws and take it out.  Spray it down with some CRC.  Some people suggest wiping with a Q-tip.  You don't have to, but be gentle if you do. 

Spray both in where the arrow directs, and where the circle highlights in the following picture



(It's actually both your MAF and IAT)

Lastly, reinstall and reset ECU.

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Offline Polaris

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Hey guys sorry for the lack of updates. Will be doing the MAF cleaning sometime this weekend hopefully. Went to my mechanic to flush the power steering fluid and they tightened the belts without charging extra, steering wheel feels silky smooth now and no more whining. I brought the hesitation issue up with the mechanic and he took a look at it but he didn't feel any jerking or hesitation, he said I might be feeling the turbo lag rofl. And he said idling wasn't as rough as I made it sound, basically typical of any 11 year old, 150k km car. Told me to hold off on spark plug change until a bit later.

Thanks for all the help everyone!

Offline Canuckrz

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Well at least he sounds honest, albeit a bit ignorant of turbocharged cars.

Offline Mendozer

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The MAF sits right after the intake filter



Disconnect the plug and screws and take it out.  Spray it down with some CRC.  Some people suggest wiping with a Q-tip.  You don't have to, but be gentle if you do. 

Spray both in where the arrow directs, and where the circle highlights in the following picture



Thank you for this Jellynuts!  Seems like a simple thing to do as preventive maintenance.



(It's actually both your MAF and IAT)

Lastly, reinstall and reset ECU.