Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: GastronomicKleptomaniac on 25 August 2009, 15:41:32
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So. I've put the engine back together, and it runs... but it rattles like something ridiculous. When it's idling, it doesn't hunt or miss, just rattles.
Then, put some revs on, and it revs up still rattling - but when the revs come back down it starts missing and almost giving up.
Going to whip the plugs out (particularly interested in no. 5, since that's what gave up in the first place)... if I see nothing there, I'll be stripping it down to the timing marks for a check again...
Only codes on the ECU are related to the throttle position sensor, I've checked its connected and there's no EML so I think that's just old stored codes?
Any ideas as to what might be the fault(s)? :-/
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How far did you dismantle it?
First suspect(s) would be cam followers. 24 of those without oil make a scary noise.... Did you press the oil out of them before reassembly? Has the engine run long enough to refill them?
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Might well take a bit of a run to fill the followers, as said. Difficult to tell from a distance if anything more serious is likely to be up. :-/
Kevin
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How far did you dismantle it?
First suspect(s) would be cam followers. 24 of those without oil make a scary noise.... Did you press the oil out of them before reassembly? Has the engine run long enough to refill them?
Had the cams out of it, didn't take the followers out though... will they have drained themselves in the last five months? I've had it running for a couple of minutes at most - whats worrying me is how it dies once it's been revved...
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I am not totally clear on how the followers work but I believe that there is a little piston inside with a light spring that wants to push the piston out to take up the clearance. Engine oil is fed to the followers and, if the piston does extend, then a little bit of oil is taken in to prevent the piston pushing back in.
It might be that you have some followers that are not taking up the clearance (& rattling) and some that are pumping up too much and holding valves open so causing a misfire.
Like Kevin I am also nervous. If there is no oil pressure then a lot of damage happens very quickly. Alternatively the belts on the front could be thrashing about.
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Well, I have no idea why the spark plug dropped into the cylinder in the first place - so I've been working on the assumption that it was broken, and if it works its a bonus...
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The lifters do need a while to quieten after the cams have been out, IME. If it's running on all 6 and the oil light goes out within a couple of seconds of starting I would hold it at a fast idle for 5 - 10 minutes, monitoring the vital signs, and see if it quietens.
If you're not confident that the cam timing is right, or it's misfiring even when brought off idle, I'd do a little more investigation. Ignition bits can get demp when a car has been standing. Won't make nasty noises but if it's dropping a couple of cylinders due to poor plugs / leads it might explain the poor idle.
Kevin
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Well, I have no idea why the spark plug dropped into the cylinder in the first place - so I've been working on the assumption that it was broken, and if it works its a bonus...
:o
Has it been apart to remove bits of plug then?
Kevin
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I worked on a 83k 2.6 this weekend that had been badly serviced for some time.
I changed the treacle oil and filter for fresh GM stuff, fitted a new cambelt kit water pump, camcover gaskets, and few other bits.
It was really tapping like a good'un when first fired up, but it shut up after about 10 minutes....
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It's got fresh oil and filter, new plugs, so I'll be able to see any problems on them straight away... Will double-check the cam timing tomorrow, then see about running it for longer.
Still looking for a mullered 3.2 to rob the guts out of... :y
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Is the head gasket on properly?
DBW connected properly?
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As suggested check the cam timing first, then if your happy start the engine and bring it up to fast idle.
I had 3.0 cams put into my v6 and when we started the car it sounded like a heard of mexicans in a tin can but within a few mins it started to go quite, and after 15 mins it was back to normal. :y
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IT'S ALIVE!
Ta muchly chaps, stripped, reset timing (just to be certain), rebuilt, and started it up. It struggled at first, oil light straight out, but a bit lumpy. So knocked it off, turned the ignition to 2 ready for the pedal trick, and heard the fuel pump running, so waited until it clicked off. Then pedal-tricked it to check, nothing new on the codes front. Fired it up again, and it sat at a PERFECT idle. Revs cleanly, it's spot-on.
Now all I need to do is grab some more black sealant to seal the cam covers... then get the windscreen fitted, swap the rear dampers, get an MoT... and so on. But, it works, and didn't explode, so :y