My Mk 1a 3 Litre drives really well, the only issue is when it's cold the engine is quite noisy with a ticking sound this will quieten down a bit after short time when it's warmed up. The car has nearly covered 70 000 miles on it original engine, it's had regular oil changes since I've owned the car now 33 years. Does anyone know what this noise might indicate and what should be done to rectify it, many thanks Clive
Post by Phil Nottingham on Oct 5, 2019 21:36:49 GMT
Try SEARCH but apart from the limitations of diagnosing remotely when it cannot even be listened to it could be 1 of 2 things commonly.
Tappets adjustment/flat on cam roller OR most likely blowing exhaust manifold gasket because the manifold has disorted and needs planing flat. It very often becomes distorted because the manifold clamps are refitted the wrong way round and overtightned. Has the exhaust system been disturbed or a decoke done?
Nice to hear you have had it 33 years though - any pictures?
Phil - 1964 P5-Coupe PMB***B & P5B-saloon LHO***L & other classic Rovers & Land-Rovers
Thanks for getting back Phil, I very much doubt it's the exhaust manifold gasket, I had that done some years ago and it's sealed very well. So it's looking like it might be the other suggestion, the tapping noise is very regular and certainly coming from under the rocker cover and increases with speed with the revs. A picture as requested.
Post by Phil Nottingham on Oct 6, 2019 9:07:12 GMT
Best to remove top and side rocker covers and check tappet clearances to see if any one is looser than the others. At this stage it can be done with engine cold but the inlet valves must ultimately be set HOT ie engine fully warmed up after driving.
Inspect all the cam rollers to see if any flats are present.
If they seem OK start the engine and see if you can pinpoint one tappet - note that rocker pads (inlet especially) can become concave when worn so the correct gap can only be set with a Click adjuster - not feelers. Rocker shafts can also wear but I would be surprsed if they are at this low mileage unless the oil feed is restricted. Again this can be readily checked with the rocker covers off.
It useful to see if the knock is at engine speed, half of it or just 1 cylinder or random
You will need new cork gaskets.
There are other more serious causes eg camshaft, small ends, piston slap! It may even be an anciliary such as dizzy, water pump or dynamo.
Years ago I had a mk1 Morris Oxford 1952 model side valve I had the ticking noise which increased with engine revs turned out it was head casket, I never lost any water while the noise was present, when head casket had been replaced ticking noise was gone, it was on less than 70,000 miles. Also I seem to remember someone replacing dizzy cap to stop a ticking noise which it did as Phil mentioned.
Does this apply to the V8 engine also? I have similar experiences (see previous thread) like a stone in a tyre. Taking all steps like copper grease, shims and even replacing front bearings has not effected any improvement.
As you have stated that the noise seems to come from under the rocker cover this will not apply, but as an ex-mechanic I can tell you about a bottom-end knock that turned out to be a hard lump on the fan belt. I have also seen a v8 truck engine missfiring on one cylinder that turned out to be worn points. The lobe for the misfiring cylinder must have been fractionally lower than the rest!
Years ago I had a neighbour whose hobby was rebuilding 1930s MGs. If he had a noise that was difficult to locate he would use a stick as a sort of stethascope (sp !) It seemed to work
George, my Dad taught me the same technique, but he used a large screwdriver. A long shaft and a handle big enough in diameter so you could hold it against your ear-hole without any risk of it going in if bumped.