deposits in oil lines

[willbrown]

hello,

i am having the top end of my motor rebuilt at present. my mechanic has started reasembly of the new cams, lobes, rockers etc. however he found some black flakey plastic type deposits in the cam oil feed lines. on further inspection he took off the sump plate and has found some of the same deposit there.

has anyone come across this before? any ideas what the deposits might be and what the best fix might be?

any pointers much appreciated.

will

[roblav]

That may be residue from timing chain rails. Five out of six of them are black plastic, and if a timing chain tensioner ever let go, the chain would bounce up against them and wear them out quickly. Hopefully, the metal screen at the oil pickup tube at the sump did it's job (along with the oil filter) and those plastic shavings are not inside the crank. Make sure the cam tower oil spray orifices are clear too.

[willbrown]

thanks, roblav

i will have that investigated. the car had carrera tensioners installed in '96 so i guess it could have hapenned before that.

best,
will

[nick-moss]

I'm the mechanic in question here.

The cam oil feed lines were partly blocked and the cams and rockers were trashed. There was quite a lot of the same flakes in the sump strainer

I have just spoken to another engine specialist this morning (Steve at JZMachtech) and he has a Carrera 3.2 in his workshop at the moment with a similar problem. They found what looks like bits of an "O" ring or oil seal that someone must have dropped in the oil tank. The oil pump has macerated the rubber and the bits had blocked the cam feed and the cam and rockers are knackered. They are stripping the motor entirely to clean out all the oil ways and cleaning the oil tank and lines too. He recommended that we do the same.

[neilk]

I'm the mechanic in question here.

They are stripping the motor entirely to clean out all the oil ways and cleaning the oil tank and lines too. He recommended that we do the same.

Ouch!!! Sorry to hear that Will. I guess it's upgrade time if the budget allows.