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VT is jerking when accelerating above 80kph

DoubleX

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Hey guys,
I need help with my VT V6. My car is jerking when I accelerate at 80-90kph. I can feel the jerking noticeably about 2-3 times then it goes away when I drive with a steady speed. It is also jerking when driving uphill at 70-80kph.
I have checked the transmission fluid when it is warm, it is a bit above the maximum hot line on the dipstick. All spark plugs were replaced in 2016. The fuel pump was replaced in 2017. Also had the last regular service on 11/2018.

Thank you in advance :)
 

accentstencil

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You haven't mentioned changing spark plug leads, so I suggest you try a new set. It may not be the problem but there is a good chance that it is.
 

immortality

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Agree with the leads. Possibly a lean cruise miss. How many km on those plugs?
 

mpower

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another vote for leads, after i got my car back from getting extractors installed i developed a miss - it was leads thankfully i could just reseat them not shell out for a new set as they weren't that old. so yeah try a reseat first.
 

_R_J_K_

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Time to change those plugs. Would also look at the fuel filter as it sounds like it happens when the engine needs the higher fuel flow and the filter could be partially clogged.
 

DoubleX

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So I had a look at the leads, there were corrosion around the plugs and the coils. I used WD40 to clean them. Now my car is good and the acceleration is more responsive than before. Thanks heap guys!

I've tried to replace the spark plugs but they didn't budge at all. Looks like the mechanic who put them last time didn't use an anti-seize agent. I'll leave them for my next service.
 
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_R_J_K_

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I've tried to replace the spark plugs but they didn't budge at all. I'll leave them for my next service.
That's not a good sign. You should start using penetrating fluids now over a few days to a week to try and get them to free up, otherwise they're liable to snap off in the head and then you'll be in a world of hurt.

If the heads on the spark plugs are also corroded, just use a wire brush till you get them silver again.
 

DoubleX

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That's not a good sign. You should start using penetrating fluids now over a few days to a week to try and get them to free up, otherwise they're liable to snap off in the head and then you'll be in a world of hurt.

If the heads on the spark plugs are also corroded, just use a wire brush till you get them silver again.
I sprayed WD40 on those plugs and left them for a night but still no luck this morning.
 

Juice3

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Mine had exact same problem I replaced all 6 leads and plugs and that fixed it
 
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