Some of you may be feel familiar with my friend's recently aquired '94 Omega 3.0 Elite and the problems with a leaking rocker cover gasket.
www.honestjohn.co.uk/forum/post/index.htm?f=4&t=61...5
He has had both rocker covers and gaskets replaced at local garage (from the good garage list). At the same time he took the opportunity to replace the HT leads and spark plugs and have the auto box's oil changed. The rocker covers/gaskets were sourced from Vauxhall's and the HT Leads and sparks were from Autovaux. All parts were supplied after the engine number was given so he's confident they were correct. However after the work has been carried out the car seem to suffer from a slightly lumpy and noisy idle.
The Lumpy Idle;
The lumpiness is enough to gently vibrate the car and is felt inside. My first impression was that it was misfiring. One thing that stuck in my mind was that the mechanic apparently said that the 2 HT leads (for each bank) weren't marked with a side. On visual inspection they seem to fit neatly with no excess. Is this the case and could this be the problem?
The noise ;
I can only describe as a "clacking". The exact source is difficult to identify, when you listen it seems to be coming from the various wheels and pulleys that the cambelt goes round - why would they start making a noise all of a sudden? (cambelt been changed at 40K and 78K, current mileage 93K). It also sounds similar to "noisy" tappets. Would replacing the rocker covers have something to do with this?
Before the work was carried out the car idled very smoothly and near silent when the bonnet was closed - it was hard to tell from inside the car whether the engine was started or not.
I feel really sorry for him - he was so looking forward to getting the leak fixed and "enjoying" the car. He's not looking for someone to "blame" - he just want's to get this sorted.
Any ideas or thoughts would be greatly appreciated.
Chad.R
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Lots of possibilities here but a few that came to my mind -
(i) you mentioned your friend had the automatic gear box fluid changed, I assume it was done properly and the levels topped up after driving the car for a while and warming up. Does the "lumpiness" change when the car is in neutral, drive (stationary) or park? Is it possibly in the transmission?
(ii) After replacing gaskets and rocker covers, was the engine oil changed and if so, was it the same grade as used before? Check oil level!
(iii) Were the new spark plugs multi-electrode types, or single electrodes.. the single ones have to be carefully adjusted and are not recommended.
(iv) Obvious one, but check the plug leads are connected correctly and in the right order! Also make sure connections are secure, all plugs were fitted tightly to correct torque and that "hopefully" nothing was dropped down the plug holes when they were changed accidentally!
Thats about all I can think of................
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SVPworld (incorporating PSRworld)
www.svpworld.com
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I do NOT Believe it! Mine is exactly the same. Is his car worst when cold - mine is. Within a minute of a cold start the noice starts & then reduces quite a lot when the engine warms up.
Mine is a '98 MV6 with 77k.
In my view its the auxillary drive belt & not the cam belt as the noise isn't fast enough to be anything other then the belt going round. It is engine speed related but only once a second or so.
I haven't had my gaskets done - but I'm wondering if they would have taken the aux drive belt off as part of that repair.
In eager anticipation.
Robert
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During my last service my machanic noticed that the bottom wheel that the auxilary belt goes around was not turning true. He took it all off and measured the wheel using a micrometer (between the edge and a band of rubber within it) and found the whole wheel was "warped", although his opinion was that it had been like this since new (40k approx)
The result of the change (which only cost about £30 for the part, as I was having cambelt replaced so it was coming off anyway) was a slightly reduced noise from auxilary belt - it had, on occassions, started to whine a bit, not clack.
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Hi Smokie,
This is a V6 right? Was it the wheel on the right (looking from the front of the car into the engine). This is the power steering pump pulley. It is about 5 inches in diameter and held on with three torqx screws. How much was the new aux belt as a matter of interest?
Regards ........ Robert
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Just been for a look - no, it was the lower centre wheel.
According to the invoice the drive belt was £19.41 (+ VAT). Quite a bit had to be taken off to get at it, and the first belt which was delvired by the factors was too long (by inches) even though it was the correct one according to the handbook and the mechanic's manual.
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This is the water pump pulley. Its the one that the belt goes up over and makes contact with the smooth side of the belt as opposed to the ribbed side.
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Robert,
I've checked with my mate and his is the same - worse when cold and it "settles" down after a bit. The idle used to be rock solid at 500rpm, now it hovers between 500 and a needle's width above. The frequency seems to be around 1 second too.
The power doesn't seem to be affected, however he hasn't had a chance to extend the engine as he's been pottering around town this weekend.
I'll get him to check with the garage whether they had to take off the Aux drive belt or not.
"...frying pan into the fire...." were his exact words :-(
Chad.R
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Stop press ....
* Oil wasn't changed - level fine (oil changed at service only 2.5K ago - was going to do a kwikfit mobil 1 jobby after repair.)
* The lumpiness doesn't change whatever the gear selected and whether stationary or not.
* The lumpiness is not just at idle, but is discernable at most engine speeds - though most obvious at idle.
* Gearbox oil level was checked with engine running (warm) and box in P.
* HT leads were changed as a precaution - no misfires from the originals but they were "original" and replacing them when the other work was carried out seemed logical.
* The leads seem to be connected correctly; the length of the wires make it difficult to misfit. Only doubt is whether they're different for each bank and they've been fitted incorrectly. They don't have markings apart from manufacturers markings on the actual lead casings.
Thanks in advance.
Chad.R
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Are you sure the water pump is ok? Its quite possible that if the belt was tightened too much (I heared a mention that the pulley in question was something to do with the water pump) that the water pump might be on the way out!
Simon
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SVPworld (incorporating PSRworld)
www.svpworld.com
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The belt has an automatic tensioner - so it can't be overtightened.
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Just found out that the pulleys/belts weren't touched during the repair and that the HT leads indeed had the cylinder number on each end and were fitted correctly.
Chad.R
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Hi Chad,
Send me an email address. I've recorded the sound mine makes when cold - I'll send you the file - you can see if the noise is the same with your friends car.
Regards ...... Robert
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Robert,
Send it to the one in my "profile" - Thanks
Chad.R
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Me again ..... Forgot to ask if changing the plug leads has made any difference to the performance. The two sets of leads are different lengths but the OEM leads are marked with the cyl number @ each end.
Regards
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Hi Chad,
Have spoken to two separate dealers and have both said the same thing. Its a known problem (to Vx dealers anyway) and is almost certainly an exhaust leak which goes away/reduces when hot. It might not be coming from the exhaust pipe system (although could be), but from the EGR valve which uses the exhaust and needs to be removed to change the cam covers as was done recently.
Apparently there have been a number of tech bulletins on the subject - all exhaust joints need to be checked over - which means undoing them and doing them up again.
This problem may not be known to non Vx dealers.
regards ...... Robert
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Thanks Robert for your help on this one. As the culprit is more than likely to be the EGR valve in this case - does it need replacing - or is just a matter of cleaning, re-fixing etc?
Also, are the Vx TSBs available to the public?
Many thanks,
Chad.R
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Hi,
I think its just a case of removing, cleaning etc. and fitting again. The exhaust manifolds are pigs to get at - so lets hope that is it.
I don't think that the Vx TSBs are available outside the dealer network.
Let me know how you get on.
Regards ......... Robert
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Chad,
I've got to the bottom of this - however will be starting a new thread as I think the answer warrants it rather than being burried in an old thread.
Regards ........ Robert
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