VR6 - Loud rattle on startup

[zman240uk 0]

Just changed my timing chains & tensioners as part of a head overhaul. When starting the engine it make an awful rattling for the first couple of secs then it disappears. Sounds like its coming from the chains or the head. Does this sound like a problem with the top chain tensioner piston or the cam followers? It goes away as oil pressure builds, but certainly sounds very unpleasant.

Followers and tensioners are all brand new.

Anyone else experienced this?

[Supercharged 2]

Does it do it every time? - may have just been 'dry' when you started initially...

[zman240uk 0]

Does it most times. Up to 3 or 4 times a day depending on use.

Very occasionally it will start with little or no rattle.

Weird huh.

[jetta16v 0]

i havent got a clue about v6s, but general knowledge, can i throw hydraulic tappets into the mix? common for them to clatter on startup. i have no idea if the engine in questions comes with hydraulic tappets or not so apologies if it doesnt.

[dr_mat 0]

Sounds to me like the tensioner piston isn't holding pressure. It's suppose to stay pressurised when you remove the oil flow, but if it leaks then you get that "cold start rattle" every time.

It's a simple job to replace it, or at least remove it, bleed it and replace it.

[CrazyDave 0]

I had this problem with my VR. See here.

 

http://the-corrado.net/.archive/forum/viewtopic.php?t=48571&highlight=tensioner

 

Hope this helps :)

[Jonny_L 0]

I get this on mine, though usually only when it's cold and the car's not been run for a couple of days. The engine's supposed to have done 47k, but The noises it's making suggests they lied. I reckon the chains need doing.

 

As you say, it's only til it builds up pressure. I never really thought much of it, but if it's a leak in the tensioner piston, I reckon I should try and sort it out.

[zman240uk 0]

Spot on with the diagnosis. The seal in the tensioner piston had a hole. Have now replaced it and startup is a much less noisy affair.

Cheers...

[CrazyDave 0]

Great news! :)

[diggerbucket 0]

Interesting.... Where is this piston located? Easy to get to?

[CorradoVR6-Turbo 0]

Its on the back of the head,32mm socket nut head,unscrew it to reveal the tensioner

 

[Jonny_L 0]

Have a goose in the knowledge base, there's a very comprehensive guide in there on how to do the chains, should help you out.

I'll be starting on mine soon, though I've gotta replace the chains as well.