E30 Zone

got a bit of a problem i think with the pre tensioner or timing chain on my m42

I got a mate (mechanic) to fit the pre tensioner, when he did he said the car made an awful noise as if say the timing was way out. He immediately turned the engine off and and replaced the old one, and its back to normal...tappy

Any one have any idea why this could be?

What is included in a timing chain changeover? is it worth doind?

thanks for any info in advance

Ross.

The tensioner has to build up the pressure first so upon the first time you start the engine, it can be noisey.

But, from one or two cases I've seen where there was a timing chain failure about 3K after a new tensioner was put in to an engine without replacing the rest of the timing gear which ended up in completely ruining the engine so...
Definitely worth doing the whole job even though it's costly...

You'll need the
chain,
Two cam sprockets,
Crank sprocket,
All the guide rails,
Possibly the idler gear (sometimes it's still in pretty good shape)
Tensioner,
Upper and lower timing cover gaskets and also the rubber gasket that goes between the two
Crank pulley seal,

Also worth doing the thermostat while doing the job too while your there

Apotentially very costly job if you're not able to do it yourself. The parts alone can be a few hundred!

As Dave said, when you put a new tensioner in it will "diesel" for a few seconds until the tensioner fills with oil and extends fully thus tensioning the chain.

When I replaced mine, I extended the tensioner manually by hand before putting it in. It still "dieseled" when it was first started but only for a couple of seconds. Stick it back in and let it sort itself out - it will sound terrible for a few seconds but will be ok.

You say the problem you have is that the engine is 'tappy'. This doesn't sound like a timing chain related issue to me. Are you sure it's not the injectors or the exhaust manifold?

I thought the procedure is to fit the new tensioner and upon starting the engine hold the revs at 3000rpm for 10 seconds to get the tensioner filled with oil.

Follow the link.

http://www.esatclear.ie/~bpurcell/318is ... ntensioner

Regards

Gareth

that's one way

ive read that before, i might ask my mate to do it ( hes a mechanic).

would you guys recommend doing the whole job or just the pre tensioner?

aj_mckay- Can i ask why you say that? i got my exhaust done a few months ago, the guy who fitted it said it was a decent manifold (didnt need replacing) with new exhaust??

its the tappy noise that comes through the steering wheel if that makes it any clearer?
it seems to be worse on a cold morning untill it warms up, but still tappy when warm.

rossd wrote:aj_mckay- Can i ask why you say that? i got my exhaust done a few months ago, the guy who fitted it said it was a decent manifold (didnt need replacing) with new exhaust??

its the tappy noise that comes through the steering wheel if that makes it any clearer?
it seems to be worse on a cold morning untill it warms up, but still tappy when warm.

Where are you based? It would be useful for you to get someone who knows E30s to have a look/listen before you start asking your mechanic to start doing expensive things like replacing the timing gear on a suspicion it may be that.

The fact the noise eases when the engine warms up makes me question whether it's the timing gear even more.

Without hearing it myself it's almost impossible to make an accurate judgement on what the problem may be...

By the way, if you're going to replace the chain tensioner, don't pay someone to do it, it's really really easy - just a case of undoing the old one from the driver's side of the engine block and replacing it with the new one. Just like changing a lightbulb! I did mine a few months back in the hope it would quieten the timing gear a bit - I'm not sure it did to be honest.

Sounds like it's hydraulic lifters to be honest...
These or the injectors give a tappy noise especially on cold mornings.

Timing gear problems will be accompanied by a distinct hissing from 3-4k rpm rather than tapping

cheers dave il try listen out for that

the mechanic was doing it as a favour when he was checking out my brake's

Im from Leeds by the way, one of my mates is on here, he knows a guy whose into his e30's called steve (not sure if hes on here) dont think he lives too far away might try get in contact

cheers for the advice guys

Ross.