Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: adey2 on 18 May 2013, 19:05:18
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as you all heard my missis killed the engine in 3.0 elite a few weeks back by running it down m6 with siezed tensioner pulley on aux belt, tensioner melted and so did the belt,it still ran but not very well, well today ive been outside trying to get it running, on initial investigations i found a chunck of aux belt inside timing belt case, this had caused timing belt to jump by 6-8 teeth on bottom pulley, i corrected this and timed it up properly as have a snap on timing kit for the v6, put back together and it ran really well but you could still see it was miss firing somewhere, stripped it down again and did compression test,now this is what boggled me, cyl one front drivers, 13 bar, cyl 2 front passenger 13bar, cyl 3 drivers middle 12.5 bar, cly 4 pass middle 13 bar, cyl 5 drivers rear 3 bar, cyl 6 pass rear 13 bar, how come if belt was so far out it only made contact with one set of valves yet id had running for ages like it was, and 2nd do you need to replace both head gaskets if one is disturbed
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you can damage one set of valve as piston going away from valves and on one piston hit as approaching -does that help? also really you should do both gasket's but up to you mate :y
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Advisable to do both I would think,but it probably depends on your budget to some extent I suppose.Not that much extra work to do both while you have everything else apart.
If you need a head or heads,give me a shout.I have a spare pair for a 3 litre here. ;)
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Advisable to do both I would think,but it probably depends on your budget to some extent I suppose.Not that much extra work to do both while you have everything else apart.
If you need a head or heads,give me a shout.I have a spare pair for a 3 litre here. ;)
OP might need the heads-bent valves can crack head :'(
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And wreck valve guides etc.Also,new valves expensive,so another head may be worth considering ?
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dont need any bits as i do have a complete 3ltr engine sat in garage, just for sake of a couple of valves seemed a shame to strip it down, cant be that bent as it still holding preasure just not much
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dont need any bits as i do have a complete 3ltr engine sat in garage, just for sake of a couple of valves seemed a shame to strip it down, cant be that bent as it still holding preasure just not much
Bet they are-3 bar is nothing mate- :'( at least you can swap heads :y
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will find out tomozz how bad when head pulled off
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as you all heard my missis killed the engine in 3.0 elite a few weeks back by running it down m6 with siezed tensioner pulley on aux belt, tensioner melted and so did the belt,it still ran but not very well, well today ive been outside trying to get it running, on initial investigations i found a chunck of aux belt inside timing belt case, this had caused timing belt to jump by 6-8 teeth on bottom pulley, i corrected this and timed it up properly as have a snap on timing kit for the v6, put back together and it ran really well but you could still see it was miss firing somewhere, stripped it down again and did compression test,now this is what boggled me, cyl one front drivers, 13 bar, cyl 2 front passenger 13bar, cyl 3 drivers middle 12.5 bar, cly 4 pass middle 13 bar, cyl 5 drivers rear 3 bar, cyl 6 pass rear 13 bar, how come if belt was so far out it only made contact with one set of valves yet id had running for ages like it was, and 2nd do you need to replace both head gaskets if one is disturbed
I imagine that some of the valve heads might bend back again with a bit of heat and combustion pressure behind them. Just as likely to snap off altogether or result in an S shaped valve stem though :(
"the question is do you feel lucky?"
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I'd run it for a while and see how it goes. I had a V6 with the cams all to kilter. One was 4 teeth out, 2 were 2 teeth out and the last one was just 1. It's still running now and that was 4 years ago. They seem to need to go a long way out before the valves bend.
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General opinion on here has always seemed to be"more than two teeth out and valves will kiss piston crowns". :-\
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With 3 bar, I'd say the valves are OK TBH.
Pop half a teaspoon of oil in that pot, and remeasure.
I suspect you just have a misfire on pot 5.
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ive decided to leave the right bank alone, everything disconected bar the cam pulleys on left bank due to snapping torx bit, lots of swearing thanks to the poxy water pipe and certain heat shield that went by the by with a hammer and chisel as bolts fubared, but she repented and i belted my hand with hammer, ooo was so close to finding that can of petrol thats in shed for mower and torching it, was surprised i didnt snap any manifold bolts though, tb it was blowing back up the inlet trumpets so something is bent, work is now on hold till i get torx bit and pull head off fully
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I just happen to have a 3ltr engine in bits at the moment.
The heads are straight and flat. All valves lapped in by loo-knee about 15K miles ago so no problem there.
pm me if your interested in the heads :)
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anyone know of a good recomended valve supplier, fai/camtec(both same company) are rubbish as used them before on the 2.0ltr vectra, lpg wears them out after 36k, on the bay of eees got febi bilstien,bga never heard of them, my initial theory was right, inlet valve from front no4 and no 5 both slightly bent, roll around a flat surface and they dont stop on the heavy area, but put in a drill and spin you can see crowns just off centre
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anyone know of a good recomended valve supplier, fai/camtec(both same company) are rubbish as used them before on the 2.0ltr vectra, lpg wears them out after 36k, on the bay of eees got febi bilstien,bga never heard of them, my initial theory was right, inlet valve from front no4 and no 5 both slightly bent, roll around a flat surface and they dont stop on the heavy area, but put in a drill and spin you can see crowns just off centre
As said mate :'( hope you get it sorted ok-pity 2.5 valves not same-got a few-left over from coffee table ;)
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all the valves the same, just ordered genuine vaux ones as know they harder wearing on lpg