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strange metal noise coming from area around dizzy cap area

Posted: Sat Sep 15, 2012 9:18 am
by e30cheeseman
Right when it's cold and I rev there's a noise like a loose bracket coming from that AREA I have taken the cap off to see if anything in there was broken but nothing. It's a 325i engine. It does it for roughly a minute when cold then goes

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 9:49 am
by Grrrmachine
Get a long screwdriver and put the blade on the rocker cover, then press your ear to the handle. Does the rattle sound like it's coming from inside the engine?

If so, the noise you have might be the tappets. They need to be manually adjusted when cold, so if this noise is a cold-only issue it makes me think this is valve-train noise rather than a worn cam belt tensioner. Might also just be old oil that's too thick at cold, making your engine a lot noisier than it should be. Could also be a snapped exhaust stud that's making a weird noise, and as the engine warms up the gap closes so that the noise goes away.

It's also worth getting under the engine and grabbing the pulleys and seeing if you can wiggle them; looseness may mean a water pump with a failing bearing.

So lots of things for you to check. If it is your tappets there's an adjustment guide in the Wiki:

http://www.e30zone.net/e30zonewiki/inde ... M20_engine

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 9:52 am
by e30cheeseman
The tappets are bit loud . If I take the cap off the rocker cover my engine dies lol I'm assuming it's not meant too . Right so it may not be a cam belt tensioner

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 9:58 am
by Grrrmachine
The crank case is pressurised, so if you open the oil filler cap you make an air leak and kill then engine. That's normal.

It MIGHT not be the belt tensioner, you just have to make sure. Hope the best and plan for the worst, and all that.

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 10:31 am
by Brianmoooore
It's probably not the belt tensioner, but if it is, and it fails, your engine is total scrap, so it's important that it is quickly confirmed as the culprit, or eliminated from enquiries.
Your should be able to see top section of the belt where it goes around the cam pulley with the distributor cap and rotor off, and be able to get some idea of its condition.

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 10:56 am
by e30cheeseman
I'll have a look in a min, my local garages are all booked up for weeks :/

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 12:24 pm
by DanThe
Good chance its the water pump on its way out if its a scraping sound?

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 2:35 pm
by e30cheeseman
It's not a scrapping. It just sounds like a typical loose bracket. Took the dizzy cap off and the arm the belt doesn't look bad. I think it's this black plate that's behind the dizzy cap that's where the noise I have heard is coming from and moving it around it's making the same noise

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 5:01 pm
by e30cheeseman
It's the cam belt slapping the cam belt cover so yeah great :(

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 8:09 pm
by Brianmoooore
So it needs a cam belt kit. That's just a normal service item that you should be changing anyway on a fresh car, unless you have proof of when it was last done. Include a new water pump in your shopping list as well.
Get them both from carparts4less, and choose the more expensive options.
I wouldn't drive the car in the meantime, especially if the noise has recently started.

Re: strange metal noise coming from area around dizzy cap ar

Posted: Sat Sep 15, 2012 8:24 pm
by e30cheeseman
I know but I didn't want to be doing it now as I don't have the money. I have a mechanic friend that can do it so I'll use whatever he gets