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Odd engine noise when started from cold


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Hi Stan,

don't mind air trapped in the engine, this is never the case.

In my poor opinion this is the hope of the desperates.

Desperates, sorry for that.

Ciao, Marco

Edited by Z320
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BTW, you look great, very  enthusiastic!

What I would do next - if you want my advice - is to run the engine without fan belt.

Edited by Z320
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I heard a similar noise on a 4 recently, the source was slightly loose fan blades, all blades could be moved by hand, worth checking.

Paul

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  • 2 weeks later...

I still have not tracked down the funny noise but I have a few more data points.

  • The noise does not start when the engine is started, it lags by a few seconds.
  • The noise does not change with engine rpm
  • Operating the clutch does not have any affect on the noise
  • The noise goes away after a short time but the engine is not yet up to full operating temperature. It has a bellows style thermostat that opens around 180 degrees.
Edited by foster461
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1 hour ago, Ian Vincent said:

I agree with all of that Stan. 

Rgds Ian

I wished we lived closer Ian, I'd like to put these cars next to each other and compare noises.. I have been all over the engine and underneath with a stethoscope as well as some tubing in the ear just trying to figure out the general location but I have yet to find it. If I had to commit today I would say it is coming from the rear of the engine or somewhere in the middle of the car, not especially at the front where all the whirring things live. Nothing (fan, generator, water pump etc) are loose. Car drives and runs like a new TR3a other than this noise when started from cold (cold is relative given the New England summer where it is likely to be 90 degrees for the rest of July).

 

Stan

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Might I suggest you bypass the car's heater (..easy enough done with a closed loop of rubber hose) and then try it.   If nothing else it will eliminate the possibiity of an air-lock in that part of the system (i'm thinking old household radiators and pipes which bang if they have air in them) as being the cause. 

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  • 1 year later...

Hi all,

I am late to this issue but believe I know the answer.

Some years ago we fitted a sump to a mates TR, he is an experienced motor mechanic, and in the absence of a gasket we used a tube of gasket sealant.

When we started the engine it made a racket just like that. Oil pressure was good, no leaks but a clanking sound that almost disappeared when the engine was hot. In this case it didn't totally disappear.

Investigation revealed that the crankshaft was just touching one of the baffles in the sump. Put a gasket on the sump and problem solved.

The clearance between the crank and the baffles is measured in low thousands of an inch.

I'm 60% this is the problem.

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My TR3 also has exactly the same noise on cold start-up, it has had it since I bought the car in 2012. I thought it was piston slap, that and the high oil consumption led me to rebuild the engine during lockdown 1. New pistons, liners and head refurbish. The noise was still there. I initially used a standard thin sump gasket but it dripped oil. I then fitted a thick cork gasket to the sump, oil leak cured but the noise remains just the same.

Mick

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Hi all,

Having just dropped the sump, found that the oil pump filter flange had indeed been rubbing on the sump in the past. I've now run the engine with the the sump removed and temporary oil reservoir, oil splashing everywhere, the rattle is still there, but even louder! Stethoscope pinpoints sound source to rear main bearing cap. 

I've replaced oil filter and Purgulator head, Oil pump drive, distributor, pedestal, fuel pump. checked the new oil pump still good as new.

Engine is coming out, again!

Regards

Vince

 

TR4A Engine Rattle.m4a

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30 minutes ago, minnisotafats said:

 Stethoscope pinpoints sound source to rear main bearing cap. 

I've replaced oil filter and Purgulator head, Oil pump drive, distributor, pedestal, fuel pump. checked the new oil pump still good as new.

Engine is coming out, again!

Regards

Vince

 

TR4A Engine Rattle.m4a 728.48 kB · 7 downloads

Anything back there might be more easily accessed by removing the gearbox and flywheel, but I cannot think of anything there that could cause the noise you have, especially if it does not alter with engine speed.

Ralph

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If it's any consolation and at the risk of speaking too soon, my noise disappeared of its own accord eventually.  Because it was a noise that disappeared once the engine had warmed up, I ignored it and then suddenly noticed that it wasn't there any more.

It definitely sounds mechanical but as you have observed it isn't linked to engine speed.  I would have gone with some sort of oscillation of the oil pump pick up when the oil is cold if it weren't for the fact that you have now run the engine with the sump removed and the noise is louder than ever.  I have (and had prior to my recent rebuild) the same type of rear oil seal as you and when I dismantled that, there was nothing loose inside there, it was an absolute bugger to remove the rear cap.

As a final thought, could it be something like the camshaft oscillating back and forth as a result of oil pressure when the oil is cold?

Rgds Ian

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40 minutes ago, Ian Vincent said:

If it's any consolation and at the risk of speaking too soon, my noise disappeared of its own accord eventually.  Because it was a noise that disappeared once the engine had warmed up, I ignored it and then suddenly noticed that it wasn't there any more.

It definitely sounds mechanical but as you have observed it isn't linked to engine speed.  I would have gone with some sort of oscillation of the oil pump pick up when the oil is cold if it weren't for the fact that you have now run the engine with the sump removed and the noise is louder than ever.  I have (and had prior to my recent rebuild) the same type of rear oil seal as you and when I dismantled that, there was nothing loose inside there, it was an absolute bugger to remove the rear cap.

Simple - 2 tapped plates attached to the cap by 5/16 unc screws.  Evenly tighten the hex head screws in the tapped plate and out the cap comes.  Leave the main cap bolts in loose so the cap comes out squarely.

Peter W

IMG_1816.thumb.JPG.985a599d1572967ef14702c9ab786cc4.JPG

 

40 minutes ago, Ian Vincent said:

As a final thought, could it be something like the camshaft oscillating back and forth as a result of oil pressure when the oil is cold?

Rgds Ian

 

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Vince,

Just like Ian, my noise stopped after a shot while  (a dozen or so start-ups) and never came back

Like you say:

 “Stethoscope pinpoints sound source to rear main bearing cap. “

That is the area that I heard it the most. Lower rear part of the block.

 

Charlie.

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1 hour ago, BlueTR3A-5EKT said:

Simple - 2 tapped plates attached to the cap by 5/16 unc screws.  Evenly tighten the hex head screws in the tapped plate and out the cap comes.  Leave the main cap bolts in loose so the cap comes out squarely.

Peter W

IMG_1816.thumb.JPG.985a599d1572967ef14702c9ab786cc4.JPG

 

 

Funnily enough I ended up doing something very similar. I bolted a short length of angle iron to the bearing cap and put two set screws with nuts  upside down in holes at each end so that as I unwound the nuts from the set screws they lifted the angle section and bearing cap. 

Rgds Ian

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