I have a very noticeable knock and vibration when the engine is cold and taking off in first gear. It quites down shifting through the gears or when I raise rpm's. The car runs... (almost) perfectly when warmed up. The oil pressure stays around 4.5-5 bar while driving (VR120-50) at Idle 2-2.5 bar and sounds quite after it's been ran for a bit. Any ideas has to why I'm getting this knocking at start up? and more importantly what can I do to resolve it!
Thanks guys, appreciate it!!

 

Check motor mounts.
http://www.clarks-garage.com/shop-manual/eng-11.htm

When you spun the rod bearing oil pressure drops below normal or there is no oil pressure. It feels like engine is loosing power.

 

Thanks joonas, good to know...hopefully that means my bottom end is fine. Why am I getting this knocking though? Is it a timing issue. What can I do to resolve?

 

Did you check the motor mounts?
Is it knocking when the car is not moving? What happens if you rev the engine? Try also push down cluch pedal and listen then.

 

are you sure it is knocking? I know i have bad motor mounts, and below about 1100 rpm, especially cold, something up front vibrates and really kind of sounds like its knocking. I think its something up by my passenger side headlight, because when i put it up you can visibly see it shake. Maybe its the same for you?

 

Definitely support checking the motor mounts.....also check your exhaust.

I had a noticeable knocking and buzzing.

Turned out my exhaust was cracked.

 

Could be a lifter going bad as well

 

Installed new motor mounts when engine was out for a rebuild. It starts right up great, though it does have more lifter noise than I'd like, it quites down after driving 10-15 minutes. The knocking only happens when I take off in first gear. Then it seems fine. Once the engine hits 1500+ rpm's it stops.
How do you determine if it's the exhaust?
If it were a rod bearing wouldn't the noise get progressively louder as you increase rpm's?

 

Yes it would get louder and more frequent. Unplug each spark plug individually and listen while idling. If the noise goes away when you unplug a certain cylinder then it is probably a rod bearing.

 

How would disconnecting a plug effect the knocking of a rod bearing? Wouldn't the crank still be rotating?

 

Fluidplay, i have been experiencing a cold motor "knock" for a long time now. and just RECENTLY i started hearing it below 1500rpm while taking off in first gear... so i started getting worried.

how long has it been happening to you? can you sometimes feel it through the gas pedal?

 

yea but the piston wouldn't be compressing so there's pretty much no pressure on the rod.

 

Don't worry about the rod bearings. If they are knocking you lose oil pressure soon. Damadge is done allready if this problem is rod bearing related.

If it only happens on first gear only it is strange. Check motor mounts and balance shaft alignment.
Is the knocking coming form engine or gearbox?

 

well were never in low rpm in any other gear

 

You need some mechanic's smoke (I prefer Marlboro Lights)

Move the smoke around the exhaust while running. If it blows....it leaks