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Greetings all.

Following a complete engine rebuild on a 65 TR4A there is a rattle coming out of the breather tube which is relative to oil pressure, it is Irregular and not relative to engine speed. Sounds a bit like a loose piece of metal randomly clanking around against sheet metal.

Lasts for no more than five minutes when starting from cold then disappears.

Noise disappears when end of breather tube covered or when pressure relief valve on filter head is wound out to reduce pressure down to 30 psi.

New: Pistons & liners, camshaft, valve gear, oil pump rotors, all shell bearings, timing chain & tensioner

Machining: Head unleaded conversion and skimmed, crank reground and machined to accept upgraded oil seal housing

Checks completed:

  • Oil pump drive fully engaged.
  • Oil filter & purgulator head replaced
  • Starter bendix not contacting flywheel ring gear while engine running

Has anyone experience similar, before I remove and strip?

Vince

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I should have read your post more carefully. The noise disappears if you cover the breather. It sounds to me a bit like a glugging sound so I wonder if it’s an oil circulation thing. Engine cold noisy, warm the noise disappears.  That also fits with reducing the oil pressure. 
 

What’s the pressure at start up and when fully warm?  Oil level high?  

Edited by peejay4A
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Rambling thought, but your description appears to link it to internal compression and temperature both of which affect the little ends in the con rods even though you say the noise is not consistent and disappears when the temp increases (typical little end play), were they replaced ? 

Or as plan B if the crank was machined and an improved rear oil seal fitted whose was it ? Was the oil scroll machined off and a Land Rover type seal fitted or is it a Marx seal behind the existing oil scroll ? If a Marx seal the seal can be contacted by the crank to flywheel securing bolts if not exactly to length causing a noise.

Or as a plan C is it a dropped valve seat (unleaded conversion) that the valve is luckily lifting back into it's head machined socket (I've had that) until it's nipped in place by an increasing head temperature (I should try a compression test before stripping to see what it shows). 

Mick Richards

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I’d suggest maybe it’s in the oil pump drive somewhere, either the shaft, gears or pump itself. When you reduce the pressure to 30psi the pump is not having to work so hard so the oscillations of the pump pulling and pushing are less pronounced, and hence the noise goes away.

While the oil is cold, again the pump is having to work harder causing chatter.

Maybe blocking the breather has a similar effect by causing back pressure in the system and restricts some movement in the pump components. 

Kevin

Edited by boxofbits
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3 hours ago, Lebro said:

+1 I was thinking the same, but still hard to say what is actualy making the noise.

Bob.

 Very difficult Bob I’d imagine without stripping it unfortunately. The fact the noise can be manually controlled with the pressure relief valve does point in that direction, but hopefully not too much trouble to correct.

Kevin

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Thanks for your replies, responses to some of your questions:

  • Oil pressure constantly hits the Pressure relief valve limit setting of 75 psi regardless of engine temperature.
  • Dipstick registers half way.
  • Small ends replaced and reamed professionally.
  • Crank scroll machined off and Rimmer 60862RCT rear crankshaft seal fitted. See photos.

Vince.

SAM_2075b.JPG

SAM_2079b.JPG

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Do I take it that you 75PSI even at Tick over? If so I would suspect a blockage somewhere, & the relief valve is working overtime. Oil filter holes to block not blocked by the gasket ?

Bob

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  • 2 weeks later...

You say the dipstick registers half? Both my TRs make a similar noise if they're a couple of pints short on oil - always have done. As soon as they're filled the noise disappears immediately.

Cheers,

JeffR

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  • 1 month later...

HI Jim,

After a lot of investigation I found it to be either the crank shaft pully bolt torque or the fact that the oil level was less than 3/4 up the dipstick. Having retorqued the crank shaft pully bolt to 120 ft-lbs (163 Nm) and filled the oil up to max, the noise stopped. So I need to reduce the oil level back down to less than 3/4 to eliminate that as cause.

I cannot reconcile the symptoms' I had to the crank shaft pully bolt. I pinpointed the noise to originate from the rear main bearing cap. The noise was relative to high oil pressure viscosity/temperature at start up, disappeared after 5 minutes warm up, could be made to disappear during this time by reducing pressure to 30 psi at he oil filter adaptor.

I did do the the bolt up to 150 ft-lbs initially then read that this was at the limit the thread could take so reduced it back to 120 ft-lbs.

If it was the crank shaft pully bolt not being tight enough, why was the noise origin at the rear main bearing cap and why did the noise disappear when reducing the oil pressure relief down to 30psi.... strange.

Vince

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Hi Vince,

having re-read this thread a thought comes to mind.

The front crank bolt being loose (ish)  can cause the pulley to rattle on its woodruff key.  But this gives a humungos racket at the front end.

A max oil level should have no effect on the noise except perhaps use more oil !!.

My thought is - could it actually be the Oil filter relief valve ball bearing rattling about.  Clearly it must move in order to relieve the pressure. 

When it warms up it may have grown such that rattling can't happen.

A mystery indeed.

 

Roger

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May be nothing, but

When I had almost come to the end of my engine rebuild, it was all together except flywheel, water pump & distributor (& drive gear)

I put a gallon of running in oil into the engine, & with a pressure gauge connected to the gauge pipe, I spun the oil pump round using an electric drill.

At low speed (& pressure) all was fine, when I cranked up the speed I got a noise similar to yours. I suspected it was the pump running out of oil, & sucking air through. the dipstick had been showing around half way between min & max. I added a couple more pints (of Duckhams) to raise the level to just below max, repeated the pumping, & there was no noise.

So, I recon you simply did not have enough oil in.

Bob.

Edited by Lebro
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Just now, Lebro said:

May be nothing, but - when I had almost come to the end of my engine rebuild, it was all together except flywheel, water pump & distributor (& drive gear)

I put a gallon of running in oil into the engine, & with a pressure gauge connected to the gauge pipe, I spun the oil pump round using an electric drill.

At low speed (& pressure) all was fine, when I cranked up the speed I got a noise similar to yours. I suspected it was the pump running out of oil, & sucking air through. the dipstick had been showing around half way between min & max. I added a couple more pints (of Duckhams) to raise the level to just below max, repeated the pumping, & there was no noise.

So, I recon you simply did not have enough oil in.

Bob.

Funny how a lot of TR4cylinder engines prefer to run with the oil level at half way between full and empty then, if you fill them to full they burn it off to half way.

Stuart.

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I know, but that's what happened.  I normally run mine a tad below max & don't experience oil loss.

May be dipstick length is not that well controled ?

Bob.

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This sound was discussed back in 2019 in a thread entitled:

"Odd engine noise when started from cold"


I mentioned:

Here is an idea.

(Yes, please tell me it’s a load of bowlex if you think so, because it is a bit way out…)

When the engine is cold and not been used for a while, ALL the oil will have drained into the sump.

When the pump starts up, oil is dispersed all around the engine. Being cold it does not flow so well, so it takes a while to make it back to the sump.

Could it be that the oil level in the sump goes down just below the inlet pipe, and so sucks air in as well (Although I have said the oil pressure remains constant…).

Once the oil is hot it drops back into the sump faster and so does not cause starvation.

(I suppose you could run the engine for five seconds, switch off, and check the dip stick to see the state of affairs.)

 

What did Sherlock Holmes say?

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

 

Some people thought it was a reasonable idea, so I've mentioned it again.


Charlie.

Edited by Charlie D
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