Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) T16 Plus 4 tapping noise

Hi All,
I have just started up and moved the plus 4 after a few months of sitting.
I was immediately struck by a tapping noise coming from the engine. Sounds like something to do with Valves to me.
After 5 or 10 mins of running, it seemed to subside to where it cannot be heard.
It was very cold today, but I haven't heard this before.
Is it something to be concerned about?
Should i get it looked at? Or just try and fire her up tomorrow to see if it is doing it again?

Sounds like top end was devoid of oil until you pumped some more round

As said, sounds like the cams were dry.a bit unusual on modern engines.check the oil level and keep an eye on it. Also don't rev the engine from cold.

This particular Rover engine was quite prone to this if left over a period, their getting a bit older now I would be tempted to run a deterdent oil through and flush the system this will give the internals bait of clean before a re fill. Only because its in your pride and joy.

Hydraulic tappets pumping up

They can sound like a bag of nails for a while if they've leaked down during a lay up.

Yep hydraulic tappets. They are known for it

I am NO expert and have next to no hands on experience with digitally controlled engine management systems. My thinking is old school, and these days my memory is suspect..!

Average car engines are not initially designed to be laid up for months at a time, though many of us baby boomers have vehicles which we may rarely use, and thus operate them outside their ideal design envelope..?

It seems logical that the top of the engine is where the most heat will be generated, and retained the longest after shut down.

Consider when the engine was last used, thus up to normal running temps or higher when initially shut down.

In such a situation the oil will be hot and thin (runny), add to that the effects of gravity, and the oil will have a tendency to drain back down to the lowest point in the engine, this process can take a shorter time when the oil is hot, however, even cold oil will follow the effects of gravity over time...

As best I can remember around the time that overhead cam (OHC) engines began appearing in mundanemobiles such as the Ford Cortina, there were all sorts of problems related to excessive camshaft wear, some of which may have been down to oil drain down and thus the lack of lube on initial start up..?

I think around the same time new oils may have been formulated to avoid this type of issue, and one I can remember was Castrol Magnatec,

The term magnitec suggesting that the oil could help avoid drain down by holding on using seemingly magnetlike properties, in areas where drain down might otherwise leave surfaces without lube on initial start up..?

The oil pump generally lives in the sump where all the oil gathers. If you consider that the majority of the oil may well have drained back into the sump over time, and that in general on initial start up the galleries are configured in such a way that the oil pump output will likely feed the main bearings and big ends first, and in time the oil pressurised by the pump will begin to travel through the other galleries to eventually end up at the very top of the engine last.

Thus it seems logical that on initial start up there is zero oil pressure, until all the galleries fill, and the TIME it might take to achieve oil pressure will depend on a number of factors, the majority of which would seem to be related to the amount of drain down that has occurred since the engine was last run..?

In a worn engine there tends to be more space to be filled with oil due to the wear that has taken place, which can take longer to fill to the extent that the oil can then pass on through the engine to build pressure. The other side of that coin is that with a wider space to exit, the oil can drain down quicker when the engine is shut down... Also a worn engine will generally display lower oil than normal oil pressure at idle when at operating temperature.

TIME being all important.... if an engine is started and run regularly then the it is unlikely to rattle at start up unless worn. An engine that is laid up for months on end will be more prone to rattle in the same circumstances...

I have read where some folk take a lot of care to avoid the metal to metal contact causing rattling, by ensuring that the engine does not fire up, either by ensuring there is no fuel present or in some cases sparks. In such cases the engine can then be spun over using the starter motor until oil pressure begins to register on the gauge, or if no gauge the oil warning light extinguishes, after which the sparks or fuel can be re-applied in the knowledge that the oil has circulated round the engine`s most vulnerable areas..

Of course using high quality oils and the correct oil (if still available) for your engine would seem to be the best insurance..?

As ever more than happy to be corrected if my thinking is incorrect in any way.