overlord

how do you tell if your thrust bearing has gone?
When i start my engine from cold i get a loud tapping noise at 2-3000+rpm and when you press the clutch pedal down it seams to stop the noise or at least change the pitch. I have had 2 different clutches on the car and the noise was the same with both. Also i have low oil pressure and the rear crank oil seal keeps leaking even though i have replaced it twice now.
I rebuilt the engine about 500 miles ago and it has made the noise since the beginning.

any ideas

merlin24

iTrader: (1)

Excessive end float on the crankshaft ?? Might tie in with the rear main oil seal failure - can you see the front crank pulley moving backwards and forwards(with the engine running) when the clutch is operated by someone ??

Mick

overlord

just had a look and i cant see any movement on the crank also the noise seams to go away when it warms up

rapid.STI

iTrader: (5)

piston slap?????

STI_Baly

iTrader: (23)

I would say the same if the engine is utilising some forged pistons???

overlord

nah its all standard parts the oil pressure seams low to for some reason i dont get it though as all the parts like crank and bearings were new. I ordered a oil pressure tester to see if the gauge is out because the one in the car reads 1 bar at tickover when at 70 degrees c and below 1 bar at 80 degrees

merlin24

iTrader: (1)

If the oil pressure gauge is not faulty - the pressure relief valve in the oil pump may be partially jammed open giving a low pressure - did you strip and inspect the oil pump/replace it when you built the engine ??

overlord

I have fitted a new rcm oil pump but it made no difference. If the new pressure gauge says pressure is still low i think i might pull the engine back out strip it down and have a look. On the main journals i didn't put any sealer im wondering if this could have something to do with it

Slowboy Racing

Sealer wont be anything to so with it unless it’s floating around the oil ways causing a problem. You can check the end thrust better with someone in the car and you at the front other wise it will be hard to determine.

Loose tolerances will also affect oil pressure.

First thing to do is replace the gauge and hope it’s just that.

STI_Baly

iTrader: (23)

If possible test the gauge with a regulated air supply - i.e. 1 bar of pressure into the main feed. This will tell you whats what....and save you paying for a new one. (this is only if you have access to air supply, and does not mean the air pump at the local petrol station)

Hope that helps and saves you a few quid.

STI_Baly

iTrader: (23)

You said you built the engine 500 miles ago - how did you check your bearing clearances? (i'm assuming you built it yourself here?).

overlord

Yeah i built it myself and checked the bigends clearance with plastigauge and the thrust bearing with feeler gauges.
I got my oil pressure tester today and it is close to the in car gauge .
Also i can now hear a sort of grumbling noise when i rev the engine so i think the mains must have gone for some reason.