Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Rods2 on 22 November 2010, 22:06:53
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It has been an on / off project for the last 6 months on my 3.0 V6, where I suspected the head gasket had gone on the near side bank of cylinders . It had, the near side gasket around the exhaust ports on both front and rear cylinders. The gasket had disintegrated in this area on both cylinders, with some slight pitting on the head. The offside gasket was also not in great condition, but has not been leaking.
I've had both heads lightly skimmed, so they match and rebuilt the engine. All new top end gaskets and stretch bolts for cylinder heads. I've also redone the oil cooler gasket, new thermostat, water pump, plugs, leads, new stretch bolts for the cam sprockets, new cam belt and tensioners (I found the oof cambelt dvd excellent and very helpful). :) :)
However, all was well on starting up apart from a engine rattling sound on tickover, which largely disappears from about 1500rpm when you rev the engine. I don't want to drive the car until I have identified the problem, in case I done something stupid on the rebuild which causes major engine problems. :o I thought it might be a lack of oil in a cam follower, but after leaving the engine running for about 30 mins to get rid of air from cooling system and checking the running temperature was ok, the knocking sound is still there. :( :(
I've run the engine a couple more times but no change to the knocking sound. I tried going around the engine listening with a screwdriver with no definite conclusions, but think it might be from the near-side bank of cylinders, towards the front.
Any help or suggestions would be much appreciated?
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SO you fitted the original heads and fited the original t vents?
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a knocking or rattle. could be a lifter if more of a rattle.
knocking?. did it get timed up correctly
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Thanks for the replies.
Yes, original heads refitted, not sure what you mean by T vents? I would appreciate more information.
It is more of a rattle, than a knocking sound. I fitted the cambelt and tensioners. I bought a Laser locking kit and oof DVD and took my time to get cam timing on both banks spot on, but this is he first time I've done a cambelt. My previous experience with valve timing is ohc and pushrod motorbikes! ::)
I was very careful on disassembly and assembly in this area and made lots of notes and sketches as I appreciate getting this wrong wreaks an engine. On disassembly as there are two lines on each sprocket, I marked the correct one with Tippex with crank at TDC, before I backed off to 60deg before TDC and removed cam belt and unbolted the sprockets. I made a drawing of cam peg position (so cam was approximately in the right place on assembly) and sprocket number, and labelled all of the cams and sprockets so they went back in the same place. I then made another diagram of cam bearing cap numbers before removing the cams. Likewise with the cam followers (I found egg boxes with labels ideal for holding the followers) so they all went back in the same place.
On rebuilding I refitted the cams, cambelt backing plate, then refitted and torqued up the sprocket bolts (new as they are stretch bolts) with the wife locking the cam with a 24mm spanner. :) With the angle gauge torquing for the cam sprockets. I used one of the sprockets holes to lock the angle gauge, so if the cam moved a bit it would not matter as the angle turned was referenced to the cam. Next I positioned the cams and locked them with the red and green locking keys. I then turned the crank towards TDC added the locking tool and turned the crank the rest of the way so it was locked on water pump. The 'Gates' timing belt had white and yellow markings for crank and and cams 1 and 2. I compared to single marks on the old cam belt (just visible) and found the yellow were correct ones to use. The white won't line up anyway! Started to do the cam timing using the DVD, realising I couldn't get away without a 30mm spanner I left it for a couple of days, until one had been delivered by post (watched DVD a few more times so totally familiar with what I had to do :y) and then timed up cam belt. Torqued up the tensioner bolts to 40nm while locking with 30mm spanner and set tensioner to edge of marker where a new belt. I couldn't get a socket on this with the allen key I was using so I could only tighten this up with a open ended spanner. Not ideal, but done up tightly!
Once I had done everything I double checked the timing with the Laser kit tool four times with 720deg rotation of the crank, with everything spot on each time. :y
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I've made a video of the engine which can be viewed and listened to with the following link.
http://www.swtec.co.uk/omega.php
The video is about 16Mb so it takes a few minutes to load.
Any help on resolving this would be much appreciated as I need to get this sorted and the car back on the road ASAP.
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The link doesn't work for me i'm afraid :-/
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that deffo sounds like a stuck cam lifter to me :y
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It is a .mov file so you need to have Quicktime installed.
Sorry can't help with the noisy engine but I don't like the sound of it. :(
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Thanks for the help, sounds like I'm going to have to remove nearside cams again and give all of the cam followers a service. :( :(
This was the only job which I decided not to do as part of my engine rebuild on the premise, if it ain't broken don't fix it.
Just goes to show Murphy and his law is forever vigilant! :o
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Take it out for a good run :y
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Will do once I got it reinsured, a new MOT and Tax which I should do next week.
Today stripped down NS back brake and handbrake, reassembled and adjusted. Too along time where it was sooooooooo cold. Will do offside tomorrow, so ready for MOT. :o :o
Except for maybe where I've got a split drive shaft gaiter on the wheel end nearside drive shaft, is this an MOT failure point or just an advisory as I'd rather leave it until the weather is warmer if possible? :(
How difficult is it to change?
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split gaiter is a fail im afraid not sure how easy to change though what about swapping shaft from a breaker.
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Thanks for the advice. I've looked on Ebay and can get a secondhand drive shaft for under £15 + carriage, so this looks like the best option.
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split gaiter is a fail im afraid not sure how easy to change though what about swapping shaft from a breaker.
are you sure...if fwd then yes it would be as its with the steering, pretty sure the rear is advisory, without the rules have changed that is. ::)
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Only the outer front gaiters are testable so you'll be fine .
Lee (mot tester)
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Thanks for all of your help it is much appreciated.
I will wait for the weather to get warmer before I fit a new drive shaft. :y