Gday all,

Advice needed please.

Have a prob with my VX 6cyl auto, have noticed at over 80 kph and up to freeway speed it feels like it is shifting down and back up, very slight feel and lasts a second and does it a couple of times a minute. It's the same deal with cruise control on or off and the tranny oil level is spot on.

Thanks in advance.

Thanks for that, checked the tacho and it drops about 400 revs and the fault occurs much more rapidly under load ie up inclines.

Ive had this car since new, the leads are the originals from aug 01.

Doesnt feel like a miss because its not constant, just drops and recovers probably 3 times a minute on the flat and more often depending on the load. Only seems to be noticeable in 4th gear.

Dunno if this is part of the prob, but have also noticed that the idle rpm is steady but sits on either 1000 or 600, feels slightly rough when its on 600.

Just need a heads up before I approach the transmission guys.

Edited by user Wednesday, 12 August 2009 7:53:21 PM(UTC)  | Reason: Not specified

petaus is on the money. Get it scanned & fit new leads & spark plugs. This fault is very common.

Dr Terry

Took the punt and fitted new plugs and leads, good as gold now.

Does anyone know if Holden dealers use GM branded plugs as service replacements? This also means that Ive possibly been ripped off by the local bloke who has serviced the car for the last 2 years.

Edited by user Sunday, 16 August 2009 11:35:42 PM(UTC)  | Reason: Not specified

Why do people assume its the last service which caused the problem, in this case a simple ignition misfire.

I would say that an HT lead has gone open circuit, why is that the technicians fault? If they looked & measured OK, at the time of servicing, then why would you replace them. You would then complain of over servicing. If they looked daggy at the last service, then sure, they should have been replaced. When did the fault start to appear, last week, a month ago? How does that make the last 2 years of servicing a rip-off?

The spark plugs that Holden use are made by Denso, which are every bit as good as NGK or Bosch. Those prices you are quoting are to the trade, in quantity. If you want to save some money, buy some, it would be cheaper than retail prices at the spare parts counter.

Dr Terry

the v6 has allways in my opion been hard on plugs and leads, my vp i used to change plugs every 20,000 after that k,s you could feel performance fuel economy and idle quaility start to decline.
in the end i used platinum or eridium plugs got a good run from them.
so i guess it pay to follow the manufactures recommendation on plug changes even if the car has gone past the service book km,s, if you look you will see it ever 20,000 40,000 60,000 etc depending on car.
as terry say,s you can only look at the leads and test them, even testing them with a multi meter does not allways show up the fault, your dammed if you do and dammed if you dont.
denso are good plugs cheap as well, i would often use them servicing a commodre.
holden would quite often have a service sepicial oil filter fuel air filter and plugs and belt for under $50 (parts that is).
pete.

quote:

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Originally posted by 80569K
Dr Terry, In no way do I seek to offend anyone here, and from what Ive read from you over the years I very much doubt that you would condone what I think has gone on here. Also, it was gts308 who put the prices up, not me.

I asked if Holden dealers use GM branded plugs to see if they have actually changed the plugs since new, checking my service receipts shows that I have paid for new plugs several times. I have been charged by my local guy for new plugs twice in the last two years, and I cant see him using GM branded plugs when his shop is part of his own spare parts outlet.

I dont mind paying for what I get, if plugs are good they should just charge me for looking at them, I dont mind that but paying for new plugs when they obviously have not changed them really gets up my nose.

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Yes, I missed what you were getting at.

I cant see the local guy using GM branded plugs either.

I would be asking a few questions in that regard. I do feel however that the fault was a crook lead not a bad plug.

I have found the opposite to what petaus has found. I get 40,000 to 50,000 km out of V6 spark plugs (in Ecotecs anyway).

Dr Terry.

i could not see the dealer using anything other that genuine denso plugs, they would not have a parts warranty to back em up.
i say the miss would of been a a lead more so than a plug.
if you look at modern engine plugs there so much cleaner than say a old carburetored 202,
guess from new engines running so much cleaner than old days, running hotter fuel injection.
i have seen ba lpg engine with over 800,000 still with the hones marks in the bores
pete.