How to listen for crank bearing noise

[daverclasper]

Hi.  Using a screwdriver/stethoscope, What's the best engine area to try and locate any possible noise please. I was thinking bottom of block for Mains maybe?, though what about Big Ends?.

Maybe noise is more general anyway, if you see what I mean and experience helps?.

Also, any other tips?.

Cheers, Dave

Edited January 8, 2021 by daverclasper

[johny]

Also I think your oil pressure is a good indicator of bearing condition as although it could just be down to a poor oil pump either way it needs the sump off to have a look. You dont have to have a dash gauge just screw an industrial type one directly in place of the block oil pressure switch connection once in a while to see what reading youve got...

[DanMi]

easiest way is while driving as that is when they are under stress. Big ends will give a knocking when accelerating and mains more of a rumble. Listening at idle will probably not help as if they are making a noise then there really is a problem, that really should have been noted whilst driving. If you think there maybe a problem also check crank endfloat, pull the crank pully back and forward it should move a few thou if much more it may have dropped the thrust washers

 

[Pete Lewis]

using any form of sound  device will only give a geographical zone and let you know if its a knocking or a whirring racket 

whilst  a listen to the alternator or water pump is easy  zones on the crankcase is much wider and less defined as the heavy casting will mask much 

but will determine its front or rear 

as said mains will give a good rumble under load  and big ends can end up as a big ball bearing in a tin can you dont need a stethoscope 

certainly a good dull knock on load 

why do you think you have a  problem  or are you trying  to find one ??  

Pete

pete

 

[dougbgt6]

And little ends! There’s something else to worry about, a distinctive tinny rattle. 

The prime directive says  “If it ain’t broke, don’t fix it.”

What are you going to do if you detect something? Wait and see! 😆

This is the first amendment  “If it ain’t broke yet, don’t fix it”

Doug

 

[daverclasper]

On 08/01/2021 at 18:21, Pete Lewis said:

certainly a good dull knock on load 

It's more of a quieter dull knock (I think) under light acceleration and doesn't appear to get worse at faster acceleration/higher revs (though more general exhaust noise then, so not sure?), or when, say mauling it a bit in higher gears.

Can't hear it, revving up up in neutral.

It's being doing it for about the past 1000+ miles (quite gentle use) and I don't think?, has got much worse.

Oil pressure has stayed the same (although did drop about 10 psi at 2000 rpm and a little bit at idle, almost over night, after an oil change and a longish run, and has a few oil changes, since then with different, though good 20/50 oils and still the same and not got worse.

This was fair while/good few 1000 miles, before the noise started.

Worth trying to drop sump do you think, and have a look at bearings, or keep taking the paranoia pills?.

I don't want to make the crank journals worse if pos, by keep running it?.  No facilities for engine out (no garage and have to work at side of road).

I realise this is a sort of "how long is a piece of string" scenario, though any thoughts much appreciated please.

Thanks, Dave

 

Edited March 14, 2021 by daverclasper

[Pete Lewis]

Dave you can take the sump off on a 6cyl vitesse in the car   its not easy , the stg rack needs to be released and the engine raised a good bit 

then 

fight the sump to a standstill and once cleared the oil pump it pops off 

one trick is undo the oil pump thro the sump /block gap and let it fall in the sump (  cant do that to put it back) 

to do that on road side would be a certain challenge  but rack/ pump and Xmember are all there to hinder 

may be advised to release hoses to avoid stretch when lifting the lump

 a can of moly or STP  may solve your knock  but i hate addatives  

eg   https://www.stp.eu/en

 

[johny]

I recently heard my mains rumbling when revving the engine at stationary and I think the big ends were even more so. Isnt the engine more 'loosened up' and likely to rattle like that and anyway its going to be much easier to hear than when driving...

Dont suppose you know the mileage the engine has done? 

[daverclasper]

Thanks. Car has done about 120,000 miles and has original engine. No idea if it's had rebuilds?.

I know the sump to steering rack clearance is tight on Vitesse, though mine is 1mm at nearside edge of sump (I imagine the rubber engine mounts can compress over time?).

Clutching at straws here I reckon, but any chance this could be causing the noise when driving?.

Cheers, Dave

[Pete Lewis]

4 minutes ago, daverclasper said:

1mm at nearside edge of sump

far too close    have a look at the mounts and get some height in the engine  at 1mm that will contact quite hard with torque moving the engine on its mounts

there is a minimal shift in all the mount bolt holes may improve but you seem to need new rubbers 

Pete

[daverclasper]

Cheers Pete. I stashed some NOS ones a while back. Worth fitting I reckon?.

 

[Pete Lewis]

definitely

 

Pete

[Dick Twitchen]

On 14/03/2021 at 19:20, daverclasper said:

Can't hear it, revving up up in neutral.

Could be that knackered engine mounts mean that once in gear, when you hear it, that the sump is connecting with the steering rack at least.  Worth cjhecking the gearbox mounts as well given nothing there in neutral.

Dick

[Pete Lewis]

 Dave  whilst ts not good practice to drive with the bonnet UP  just open it and look at where the engine moves to when you engage a gear and get some bite on the clutch 

with the handbrake on 

it will move a good bit more than you think

at 1mm   something is bu**ered  , but the fix is cheap and easy .

youve just solved your main /big eng worries 

Pete

 

[daverclasper]

Cheers.  Been away for a few days and still in a rush so no time tonight, though sprayed the engine mount fastenings with penetration oil for changing them soon.

Did notice some 2 shims on each side (look the same as the suspension to chassis ones, for camber altering, though no time for a good look) I think between the mounts and the suspension turrets, though can't check now.

Is this common for fettling, or suggests a problem?.

Thanks, Dave

 

 

 

 

[poppyman]

On 21/03/2021 at 15:14, Pete Lewis said:

 Dave  whilst ts not good practice to drive with the bonnet UP  just open it and look at where the engine moves to when you engage a gear and get some bite on the clutch 

with the handbrake on 

it will move a good bit more than you think

at 1mm   something is bu**ered  , but the fix is cheap and easy .

youve just solved your main /big eng worries 

Pete

 

Good point that Pete, Dolomite 1850's are known for that.

Tony.

[Gully]

19 hours ago, daverclasper said:

Did notice some 2 shims on each side (look the same as the suspension to chassis ones, for camber altering, though no time for a good look) I think between the mounts and the suspension turrets, though can't check now.

Is this common for fettling, or suggests a problem?.

Thanks, Dave

The shims are normal.

Gully

[Pete Lewis]

not uncommon as the mounts sit in a Vee formation adding  shims between the mounts  raises the engine 

so you need new mounts and  maybe more ....shims 

Pete

[daverclasper]

Cheers for that, have some spare chassis/turret shims.

What sort of approx gap would I aim for between the pressed channel in sump and rack?.

Also, I assume the gear box mount doesn,t need loosening for this amount of engine raising?.

Thanks, Dave

Edited March 26, 2021 by daverclasper

[Pete Lewis]

the snag of the front mounts is they sort of form a Vee  and the mount plate will jam on the flange of the turret so to lift you best remove the 4 bolts to the block then it ( bracket and mount )  all falls off easy ...dont have to touch the gearbox mounts , assuming they are OK 

 sorry its long time since i did mine 

Pete

 

[daverclasper]

Cheers

Only got a short window for this fix.

Assume do one side at a time?

Use a scissor jack under sump for more accurate lining up of mounting to turret fastenings?

I guess it's only vertical movement to line up engine to fastenings doing this?

Fasten mount to bracket, then bracket to block and last, mount to turret? If that makes sense?

Thanks, Dave

Edited March 29, 2021 by daverclasper