986 2.5 startup rattle!

[mike121]

hi there

my car has an almost machine gun like rattle when starting from cold. i thought it was the starter motor not disengaging properly so i had it reconditioned, but that didnt solve it.
i now think it might be timing chain rattling from low oil pressure in the chain tensioners. if this is the case, what do i have to do to the tensioners? recondition them or buy new ones?

any advice anyone?

Mike

 

[AndyW1973]

Or possibly a hydraulic lifter?

 

[Motorhead]

Mike,

I guess that yours is a high mileage car so it's probable that the tensioners will be worn and need replacing, if indeed that's the problem.

I don't know what oil you're using but you could try a higher viscosity oil to see if that helps, otherwise I suspect that probably it's an engine out job.

Jeff

 

[Motorhead]

Mike,

Just an update re tensioner replacement. Here's a useful link:

http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner.htm

Cars with the intermediate shaft (IMS) engine have a very complicated chain and tensioner arrangement and although it appears that it's possible to do the work with the engine in-situ, I'd imagine that it would be much easier with it out of the car.

As Alan says, the hydraulic tappets also are a common source of rattling on start-up, so you need to convince yourself that it's one or the other before embarking an extensive work programme.

Finally, if you've only just noticed the rattling you should be aware that a loud rattling noise when you start the engine or accelerate is a typical symptom of IMS bearing failure.

Jeff

 

[CLIFFWILKINS]

I would get it checked out Asap before damage is done.

 

[richardjjs1]

Ive got a noise when it starts up but its pretty obviously a baffle in the silencer that goes of within 2 mins of starting

(Says he hoping!)

 

[strobeme]

I know this is an old thread...... but I get a one second chain rattle at start-up every time I leave the car for a few days. I don’t get any rattles any other time.

Everything I have read on other forums suggests this is just the time it takes for oil to be pumped back up through the system after it has drained off when static.

If it is a continuous rattle....... then understandably that might be a problem!

 

[Motorhead]

I think that’s right Jonathan. Probably it’s just taking a few seconds for the oil to fill the chain tensioners.

Maybe the oil pump’s getting a bit tired in its old age..!

Jeff