Engine ticking noise - stupid question?

[colin3511]

I have rebuilt a CP PI engine. It all fired up with excellent oil pressure. However, after a few minutes I could hear a ticking noise related to RPM. It is a very annoying ticking noise that can also be heard when driving.

 

So this is what I have done:

 

Reset valve clearances 4 times.

Checked the MU float twice.

Swapped the MU drive gear.

Replaced cam followers with another new set.

Swapped rocker assembly.

Swapped the MU.

Swapped the distributor.

Dropped the sump and removed pistons. These were checked for little end fit and were all OK.

Swapped the head for a rebuilt unit (currently for sale on BST).

 

Noise still persisted so in the end I rebuilt a CR engine and swapped the engine over and all is OK now. The problem is that it is a matching numbers car with a known mileage of 81K. Therefore I want to put the original engine back in.

 

I have stripped the engine to investigate. Most likely cause would be cam. This is the original cam reprofiled for fast road by Newman. It looks perfect as you would expect for 300 miles use. When taking the crank out I am 80% sure that number 2 bearing had one slightly lose bolt.

 

Could this be the cause or would the bolt undo itself completely over those 300 miles.

 

Hopefully someone may have experienced a similar issue and any thoughts welcome.

 

Thanks

 

Colin

[DRD]

I always get a ticking noise but once the oil has warmed up it goes away. I've always thought it's the tappets sticking a bit.

 

Daz

[DaveN]

One ‘slightly’ loose bolt....maybe? I doubt it very much Colin. They are face to face joints, so there will still be contact between the cap faces. However what is the condition of the shells?

Did you try running it without the drive belt? That would discount water pump and alternator!

[Drewmotty]

A slight exhaust manifold leak can sound like a tap.

[Peter Cobbold]

Tacho drive can tick, depending upon the angle it is forced to take off the disy.

[RogerH]

Hi Colin,

I had something similar on my 4A and lived with it for two years - continually adjusting/checking tappets etc -

In the end I pulled the cam which was seriously duff on #1 & 2 lobes.

 

My problem was in using a standard cam with marginal hardening and uprated valve springs (fitted to new Moss head).

 

Roger

[Z320]

Rev counter cable

[iani]

I have two alloy rocker covers, with one of them, a rocker just picks up on the inside, gives a ticking noise, I now use the other cover.

 

Ian

[harlequin]

The tick in my engine turned out to be a cam follower, the face was breaking up after only a few hundred miles. Rubbish parts again!

 

George

[colin3511]

Thanks for all your replies.

 

Fan belt was removed to rule out alternator and water pump. Even removed pulley in desperation.

 

Cam followers are all perfect and I swapped them for another new set anyway.

 

Tacho cable removed, so it wasn't that.

 

Swapped between standard and alloy cover.

 

If no-one thinks it is the loose bolt I guess it must be the cam. When I checked with Newman they were surprised it was reprofiled by them. They did check and confirmed they had done it.

 

I think I'll get it bored out and the crank re-ground and fit another cam. Original engine with original pistons. Only needed a hone and the crank polished, so it didn't seem to be necessary to do anymore. This will eliminate every possible cause - I Hope!

 

Thanks,

 

Colin

[colin3511]

Should say loose bolt was only finger tight!

[Nick Jones]

Should say loose bolt was only finger tight!

 

Then it may well have been the cause of the tick and worth taking the engine apart for all it's own...... as would soon have a caused a catastrophic failure, they don't stay finger-tight long! Can't have been done up right in the first place - these never come loose if properly torqued.

 

Nick

[DaveN]

If the crank and bores are good why go to the expense of rebore and regrind?

[Waldi]

As part of your work:

Replace the con rod bolts (but I guess you would).

Waldi

[astontr6]

Thanks for all your replies.

 

Fan belt was removed to rule out alternator and water pump. Even removed pulley in desperation.

 

Cam followers are all perfect and I swapped them for another new set anyway.

 

Tacho cable removed, so it wasn't that.

 

Swapped between standard and alloy cover.

 

If no-one thinks it is the loose bolt I guess it must be the cam. When I checked with Newman they were surprised it was reprofiled by them. They did check and confirmed they had done it.

 

I think I'll get it bored out and the crank re-ground and fit another cam. Original engine with original pistons. Only needed a hone and the crank polished, so it didn't seem to be necessary to do anymore. This will eliminate every possible cause - I Hope!

 

Thanks,

 

Colin

I would still be looking at the cam? If it came from Moss who until recently only seem to use reprofiled cams! They had a dreadful reputation for early failure. As I understand they now only sell cams which are made from new blanks! Check old threads on this forum and you will see what I mean. Our American cousins called their cams some very nasty names!

 

 

Bruce

[littlejim]

Sorry about this!

If it was a Rolls Royce it would be the dashboard clock!

 

[John L]

Might be worth checking to see if any of the pushrods have been touching the cylinder head, you might see a polish mark on the stem.

I noticed when I did my cam change recently that the pushrods are very close to the casting marks in the cylinder head where the pushrods go thru.

Having just changed the cam on mine the engine does have a different tappety noise than before, even though I have checked the tappets several times, I think also the rule of 13 doesn't always seem to work, I tend to them now on compression per cylinder.

John

[PandO]

This 'Ticking' could well be the MU shuttle. Easily checked if it can be heard with the engine idling - stick a long screwdriver (or similar) between it and your ear. (If you have no stethoscope).

Edited August 2, 2018 by PandO

[Casar66]

Well, it sounds stupid, but when the noise is there get the chokecable knob, pull it a little and hold it. You will know it imidetely if that is the cause for your noise. I had the same and nearly got MAD about that. But indeed the ticking noise came from the choke cable.

Carsten

[Casar66]

any news?

I am curious

[colin3511]

Hi carsten,

 

It will be a little while until I know. Currently running a CR engine until I rebuild the CP one again. I'll fit a new cam and get the crank ground and hope it's all OK when I exchange engines in the Autumn.

 

Hoping to get a buyer for the CR engine before exchange, so they can hear and even test drive it before it comes out. It's one thing saying it's been rebuilt but if you can hear and drive it, along with knowing the oil pressure is excellent even when oil is very hot is much, much better.

 

Colin