starting to get a bit of knocking when it firsts starts up in the morning but goes after a few seconds, I suspect crank bearings are on their way out, whats the going rate to have these replaced before anything else starts to go.

it's a MY99 with 98k on the clock

TD05 18G
FMIC
Apexi power FC
straight through 2.5" exhaust

 

U sure its not piston slap, a big end knock would be there all the time.

 

If it goes after literally a few seconds it could just be the followers, Piston slap tends to hang around for a while until engine is warm, Does your oil pressure light go out as soon as it's started?

 

Big end knock might go away once the oil has warmed up and been pumped fully along the crank to all bearings. Depends how bad it is.

 

it lasts about 10 - 15 seconds depending on how warm a morning it is (If it's freezing or not)

It's more of knocking than a tapping

oil light goes out as it's cranking, It is still there I think but very faint.


Just want a price range so I can get an idea how big a whole I'm gonna have in my pocket

 

IF the engine is knocking it wont be long before it goes bang, if were you i wouldn't use it and get it taken to a reputable garage to get it looked at before it goes bang as the price for a refresh as opposed to complete rebuild will be different ends of the scale.

 

Sounds like piston slap to me,if you have bigends going i would have thought they would knock under load whether hot or cold.

 

definatley not there underload (well from what I can hear over my exhaust! lol)

 

I know as said above bigends sound can go when the oil pumps through them,but when the oil gets warm it usually comes back and you cant mistake it.when pulling hard like up a hill or on boost they will knock like hell.From what ive heard a lot of classics can suffer from piston slap on start up and its not a real problem as long as it goes,i would search piston slap on here if i were you and see what it says.

 

cheers mate

one or 2 have mentioned piston slap which seems to be the flavour

I know internet diagnosis can be a minefield, just wanted some idea's on pricing just in case

 

Piston slap does NOT disappear after 10 seconds of running.

In fact you will NOT hear piston slap on immediate start up, it usually appears after 5-10 seconds of running and then remains for 5mins to 15 mins (depending on how cold the weather is).

A 10 second knock that appears immediately on start up to me suggest a bottom end knock caused by the oil draining down overnight, possibly caused by an oil pump seal, loose backplate screws or a pick up pipe seal problem, which over time has caused an excessive wear issue to the point that the big end bearings are now starting to knock during the initial absense of oil pressure (such as a start-up).

But to be sure, the engine needs to be heard by someone with trained ears

IIRC MY99 cars have solid valve lifters, so it won't be those

 

As above its probably best to get a garage to listen to it,but i would have thought if it lasts 10 to 15 seconds that would say the shells are pretty bad and unlikely to go quiet as i wouldnt have thought it take anything like that time to pump oil through them,you never know it could be something cheap hopefully