Master
It's a 1969 2a 2.25 petrol. Mileage unknown: odo reads 22700 but the speedo didn't work when I picked it up. Oil is clean, and coolant is green and the level for both is constant.
I've got two noises.
At idle its rattly in the top end, which I think is tappets. The noise doesn't go away with revs. I've got to replace the rocker gasket, so I'll adjust them when I do that.
Then the second noise is a knocking under load, but only really in 1,2 and 3 gear. Its frequency increases with engine speed, but dies away under light throttle.
My immediate conclusion was to to think bearings, either crankshaft to piston (big end?) or crankshaft to engine casing (main?). But having thought about it I'm not so sure because even at higher revs the knock is only 2-3 times a second.
If the crank is rotating at 2000rpm thats 33 times a second - wouldn't a bearing knock appear more like a deep buzziing, or constant roar at higher revs?
So my next thought is it might be the oil pump? Can these be cleaned/refurbed or should they be replaced? Is it as simple as dropping the sump to get at the pump?
I'd appreciate any suggestions.
Cheers
Duncan
Master
No-one?
Havn't had time to do anything this weekend, but I'm wondering whether the knock might be pre-ignition.
I'd always thought 'pinking' with a high pitched noise, but reading this
title_3.gif
it sounds as if it could be more of a knocking noise.
I'll check the timing tomorrow and report back.
RoverLord
Your identification of tappets is probably right.
The other noise id difficult to identify from your description, but it could be timing chain, or is could simply be something loose on or near the engine, possibly loose geenerator mounts or something similar, or the exhaust system loose or touching the chassis somewhere. (or something similar)
John
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
Master
Thanks John, very helpful I wasnt even thinking it might be external.
It could be worn engine mounts allowing something to hit on accel but stop when not under load.
I had a look at the timing chain and set up when I changed the front seal and the chain and tensioner looked fine but I must confess to not actually checking anything. Doh!
I suppose all I can really do is methodically go through everything and check it over
Master
Pinging (pre-ignition) sounds like the noise made by some nails in a tin can being shaken. It's an erratic rattle rather than a regular knock.
The power plant may be lurching backwards under load (soft mounts?) causing something to hit someting?
TopicToaster
Couldn't be something simple like an exhaust leak could it? If on the manifold/head join it'll only sound on one cylinder's exhaust stroke. My County sounded like it needed a tappet adjustment when the exhaust manifold gasket first was breached, my Series has a similar leak but sounds very different again.
Master
Well I started him up this morning and had a look around.
Rattles a bit under acceleration in neutral but not the knock I get in gear. It doesn't feel as if the engine is rocking on its mounts, but I probably need to get an assistant to confirm.
The exhaust is within 3-5mm of the chassis where it goes under the x-member. I'll fab up an additional exhaust bracket to give a bit more gap there.
Also I stuck a timing light on the #1 lead and it showed the timing to be super retarded ~about 10deg. However the engine was cold, it had been running less than 5mins, and hadn't been started for a week or so.
I'm only used to adjusting timing by twisting the distributor, using the light to show the advance on the crankshaft, on a running engine with electronic ignition.
When you adjust the timing on a non-electronic distributor, what are you actually adjusting? The amount of vacuum acting on the distributor, or the position of when the points contact relative to the crank position? I'm presuming the former else how does the advance get auto adjusted. Anyone got a link to 'Distributors for Dummies'?
Should I do the timing with the engine warm?
Is it possible to adjust the timing using a timing light?
Is it possible to tune without having to either remove a plug to find TDC on #1, or remove the rocker cover?
I read this thread http://www.aulro.com/afvb/series-ii-...g-2-25-2a.html but I'm still a bit confused about whether using a timing light is possible, and I'm a bit unsure about John's tuning by ear method as I'm not sure I know what 'good' sounds like on this engine.
Sorry for all the questions, but I like to know the 'why' as well as the 'how'
Cheers
Duncan
Master
Oops, forgot to reply to Mark.
New exhaust from manifold back, but I'll check for leaks on the engine/manifold join.
Cheers
Master
Found one! Demystifying Land Rover distributorsOriginally Posted by Ozdunc
Anyone got a link to 'Distributors for Dummies'
From what I gather I rotate the dizzy as usual to retard or advance the timing running warm at idle.
And the electronic dizzy has just done away with the points and dwell adjustment.
So to set the points I just rotate the dizzy til the point arm is sitting at the peak on the cam lobe, the gap should be 15thou (whatever that is in metric).
Once thats set I can use the timing light to adjust to 6 BTDC, then adjust by ear from there?
What about dwell? Is that just governed by the points gap?
This is probably really painful for you but I'd hate to go in guns a blazin' and then bust something.
Master
Set the timing to 6deg BTDC this morning on a warm engine.
I'd say the revs dropped a little at idle, and I can now hear an erratic 'soft' miss, but no more than I can hear with my 80 series 4.5 1FZ-FE.
Bill drove very nicely ( maybe feeling a little down in torque at low revs), the knocking is still there, but I think quieter, that or the tappets got louder.
But again its very hard to tell, it 'seems' to be emanating from just infront of the firewall.
But the test drive was great, drove ~20km up and down the coast on a glorious winters morning with only a windscreen and beanie as protection. What's not to love about this little truck.
I think what I'll do next is the tappet adjustment and a compression test.
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