noob... please help!

[Demo19]

hey guys im new here and to the wonders of mk3 7m's.
just to give a insite of car before i plead for help on current problem, i bought the car a few months ago as non runner with bhg, i read up on it all and undertook the replacement, had head and block deck checked they where ok, so i rebuilt and it was perfect.. well so i thought.. i took it for mot which it failed on emmisions i suspected it would as it'd been sat for years, on the way home the turbo shat itself so i ordered new cat + turbo kit again all seemed well till it took it for a pre mot drive and thats where the lastest problem developed, i have a distinct knock, sounds like tappit buh im aware main bearings sound this way to, only occurs between 2000ish and 3500rpm not on idle and quietens down on high revving so i started investigating went over obvious things like metal vibrating in engine bay, put stethoscope over engine top to bottom back to front over and over again, i am pretty convinced its coming from cylinder1 exhaust side (heard of valve lifter oilway block cause it) but this is where i become clueless... Is there anything else i can check before i start stripping? or any experience on the matter as to what it may be

any input really appreciated
im a noob and totally clueless really dont be to mean :icon_bigg
dan

 

[customs]

There are a few things you can do.
1: Take a video of the car making the noise and post it here. Someone is bound to see it and hopefully help you out. If you go that route, please use a good quality camera.
2: Take it to a local shop and have them take a listen. Any qualified automotive tech should be able to pin point the location and reason for the engine noise.

 

[veedubin]

If you have replaced the HG and know how to use a stethoscope for diagnosis, I'm going to assume that you are mechanically inclined at the least.

I would start by removing the exh valve cover and check your valve clearances. If the noise is indeed coming from that area, start there. Get something non-marring to push on the lifter (cam lobe up, valve closed) verify it doesn't have any side to side play. Look for wear marks indicating oil starvation etc...

If that yields no results then go over again with the stethoscope.

FWIW my last 7m with rod knock would only knock @ those RPMs and on decel.

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[veedubin]

Also, quick test; pull your dipstick and wipe it on a sheet of white paper ... look for any glitter.

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[Demo19]

Thanks for response one thing i forgot to mention is i drained the oil and there was no sign of metal particals in the oil. I also re-timed and checked with strobe and it was spot on, i will check valve clearance and for signs of exsessive wear, if i cant find anything i will post a video maybe that will help

 

[Demo19]

Update.. Finally had time to remove cams and check for wear, dryness ect, The cam and bearing cap on cylinder 6 where extremly worn and it apears that the oilway on then intake side is partly blocked as the white metal is roughly worn and scored so on finding this i starting getting wound up forgetting i infact had a spare head complete with valve assembly and cams sat on my dinningrooom table, so i have ordered another metal head gasket and the new head shall be put on the second i get new gasket and half day to spare, fingers crossed will be ok when i rebuild, im getting very desperate to put it back on the road. Failing that i will be ripping the sump off to inspect the main bearings.. Will post picture of cam/bearings for you guys to give your opinion on at the moment i feel this will be the cause as theres enough movement to allow the cam to slap, (a friend who builds alot of rb26's is saying theres prob around 20thou of movement and its a deffinate cause)