Tinkling sound

johnsimister

Active Member
I will shortly be overhauling the cylinder head of my recently-acquired 1972 2000 TC. The compressions are low (150-160psi against the minimum of 190 stated in the manual), the fuel consumption is high and the hillclimbing ability is feeble. A set of NOS genuine Rover exhaust valves is on its way, which I saw on eBay and seemed too good to miss.

While the engine is apart I thought I would see to the metallic tinkling noise that occurs around 1200rpm and goes away as the revs increase. I have read about this sound before and it's clearly from the timing chain area, but is there a particular well-known cause for this particular sound? A faulty upper or lower tensioner, a problem with the rubber-faced plates on the opposite side, or one or both chains worn? The engine has done 66,000 miles and oil pressure seems very good according to the gauge, but it sometimes takes a couple of seconds longer than I'd like for the oil light to go out on start-up. I might replace the big-end shells so, with the head and the sump both removed, it would be a good time to attend to the tinkle.

Another quick question: what is the diameter of the tappet shims? I have a good range of Hillman Imp shims whose thicknesses match those of the Rover's thin shims, so if the diameter is right I could use those when reassembling the cylinder head.

Many thanks for any wisdom anyone can offer.

John
 
carb intake heat shield??
had on cracked before,only rattled at a particular revs,
oh and look at dynamo brackets - had one of those cracked too...
same scenario- only vibrates/rattles at one particular harmonics/revs
neil
 
Thanks for the suggestions. Have checked and all good with heat shield and alternatior brackets. Definitely timing chain-related. Have now discovered this thread:

Chain rattle I think?

...so I guess it will have to wait until I investigate it properly. Something amiss with the bottom tensioner sounds favourite. Could that be causing the slightly slow oil pressure build-up?
 
Could be the metal insert to the heat shield between the carbs and the manifold that's come adrift and is rolling round in the inlet manifold.
 
Tinkling chain is normally the top chain. Have you checked the guaze filter under the banjo bolt on the timing chain oil feed. Could also be stuck top chain tensioner or broken top chain guide. Chain can make this noise on start up but stops after a few seconds when oil pressure builds.
 
The diameter of the shims is 1/2 inch. There are 13 mm shims for Kawasaki motorcycles and also for some 80’s and 90’s Mercedes that would work.
 
Could be the metal insert to the heat shield between the carbs and the manifold that's come adrift and is rolling round in the inlet manifold.
That's only on the single carb cars Pete. The TC's don't them.

As for the noise I would say its the timing chains. The tensioners are hydraulic on the four cylinder engines, working off of oil pressure (hence the high pressure line going from the oil pump directly to the top tensioner. If the noise is going away at higher revs I'd be inclined to drop the sump and look at the main bearings. They tend to wear in about 45-50k miles, lowering oil pressure. You can replace the shells with just the sump removed and the engine in situ. However, its getting a tougher to find standard main and big end bearings these days. This is a good thread to read before diving in Changing Main Bearings

Modern Rolon tensioners seems to have quality issues. I've had the rubber foot part company from the aluminium plate on the bottom tensioner in the past, the noise sounded like a bad alternator bearing. I've also come across a 'rebuilt' engine where the mechanic had failed to fit the small plug in the back of the tensioner, that stopped any pressure building up and the tensioner working.

Just a few thoughts...
 
I've also come across a 'rebuilt' engine where the mechanic had failed to fit the small plug in the back of the tensioner, that stopped any pressure building up and the tensioner working.

Those plugs can fall out in normal use as well.
 
Those plugs can fall out in normal use as well.
True enough. Although in this particular case it was the one of many issues including recut valve seats 2mm below the cylinder head face, valve guides with no seal O rings and god knows what else.
 
True enough. Although in this particular case it was the one of many issues including recut valve seats 2mm below the cylinder head face, valve guides with no seal O rings and god knows what else.

How disappointing. He wasn't an Australian was he? I worked with an australian who left the valve guide seals out on a land rover diesel engine he rebuilt. When quizzed about why it smoked so much he just said "Valve guide seals????" Mind you he did a Dolomite sprint head gasket by removing the thermostat, and when that came back and he finally took the head off, he did that by hammering a chisel in between the head and the block. Amongst other misdemeanors...*

* I should point out that I'm sure that not all Australians are like that...
 
This would have been an American guy From New Jersey in the 80’s I think. Blimey! I know Sprint heads are a pig to remove, but that’s some serious violence to kill an engine.
 
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