Morning everyone .. Apologies for this being my first post, I have used the forum alot over the years for information. Now i require your help please?! This is on a b18c4, very similar to the C1/C6

Will try and keep this short, vids below, first is stone cold, started up first thing this morning. Second is after a 15 minute drive to work. What I can tell you;

>It only happens when cold. Once hot it disappears.

>As you can here, doesnt happen straight away, takes 4-5 seconds to come in
>Seems to eminate from the dizzy area, however I KNOW its not the dizzy as I bought a new one and it didnt affect the noise
>It doesnt seem to raise up and down with revs.

>Once driving it seems to have a sweet spot at 1500 rpm where you can here it. It doesnt get worse under load.

>The car runs sweet, no idling issues or running issues, which leans me to think its not head related? Ive thought, a loose valve, but surely this would make her run like a dog? Thought LMA, but its not consistant?

>Other thoughts are maybe the recess in the inlet Cam where the dizzy enters is worn? Or something in the end bearing of the cam?



Any imput would be greatly appreciated! And valve clearances are being done next weekend... .

 

Anyone even hazard a guess?

 

ive heard this the same on a b16a2. its maybe a lma. he have changed the dizzy too. but the same noise. replace the lma and look at the cam cap and cam

 

hmm... is it coming from the distrib or manifold or engine itself..? try and narrow it down. remove intake tubing and take a listen, put ur hand over it to see if u feel any air pushing out the tb. check the cap/rotor, perhaps something broke off and is rattling...

just gotta start narrowing down the search

 

Thanks for the comments guys ..

So to try and narrow it down for you, ive done the old, screwdriver trick and the place at which it is at its loudest is on the column between the distibutor and the cam cover..

Pic attached (i think)

Im pretty certian that its not coming from the intake side.. Once your ear passes over the intake and intake manifold, the sound becomes faint.

It does indeed sound like something has broken off and is rattling :-(

 

Is there some sort of bearing in this column that could go ?

 

no bearing. u can hear the exakt noise on the screws from the valve cover

 

sounds like a bearing possibly distributor bearing ...and its def still there in the second vid its just not as loud

id look at dizzy then move to the timing side but perhaps its even the input shaft bearing ... see if it goes away couple seconds after you push the clutch in

 

the distrib only has 3 bolts. just mark where the bolts were at so u can match it up when reinstalling. and spin the distrib by hand and check the o rings/shaft etc. should be obvious if its the bad part

 

Thanks for the input guys.

I've tried the distributor side, I bought a brand new one and it was still the same.

Re clutch, also thought it could be that, took the cover off the fork and wiggled it around and it doesn't affect the noise. Depressing the clutch also doesn't have an impact.

I'm at a bit of a loss :-(

 

You need to rev the engine and see if the sound is rpm related. It could be a bearing somewhere on the timing belt side...possibly power steering bearing, alternator bearing, ac bearing, even tensioner bearing. If the pressing of the clutch pedal doesn't have any bearing on the sound it's likely not the tranmission or clutch bearings. I suppose it could just be something rattling underneath, you could jack it up and get underneath and listen.

 

Hello, i have exact the same problem with my B16a2.

1# Video:
http://www.maxrev.de/b16a2-stark-mah...or-t331064.htm

Sound comes from the same location and i have replace the dizzy too, but nothing changes. My next step will be change the LMA's, but it will takes a few time. What u think about it? and did anyone else know what it could be?

 

take the cap off the end of the fuel rail and see if the screw backed out.

 

The rattle comes definitely from BAD LMA's ..I had the same problems and it is now after changing alright

https://vimeo.com/118824132