chain rattle? Vanos Noise??? Help

chandler · #1 (**permalink**) 06-18-2007, 10:39 AM

I think I mentioned this before but here is the deal:

95' M3
Car has 77k on the clock

Car pulls fine, runs strong, no oil burning, no funny smells, etc.

I have noticed two different things going on

1: when I let off the throttle and the engine brakes itself, I notice a very rapid rattle come from the timing chains / vanos area. It is like rattling a box of tic tacs as fast as possible. it does not do this under accel or at idle.

2: My motor is knocking / pinging when I give it full throttle at low RPM's in too high of a gear. I am using only the highest octane available and have even tried octane booster to get rid of the problem. Can anyone else clue me in as to what is happening? It is not bad and won't knock/ping unless I try to do it.

All help is appreciated.

chandler · #2 (**permalink**) 06-18-2007, 03:08 PM

Stumped you guys huh?? LOL BTW, I am not looking for a diagnosis. I am looking for a similar problem or a history of this problem. Thanks!

TYE · #3 (**permalink**) 06-18-2007, 04:54 PM

Whens the last time the timing chain tensioner was replaced

chandler · #4 (**permalink**) 06-18-2007, 07:52 PM

I have no idea. Probably never. I am going to tear into it this weekend armed with some shiny new parts

I have just googled 'vanos noise' and there seems to be a history of this problem...

chandler · #5 (**permalink**) 06-19-2007, 09:15 AM

Tye, remember the days when this post of mine would have had 30 responses by now? I miss those days. There are no true gearheads around here anymore. There are no responses because most don't even know what a VANOS is or maybe even how to open their hood! How embaressing for dtmpower. I feel really bad about that but it is true!

philsans5 · #6 (**permalink**) 06-19-2007, 10:38 AM

Don't knock us all, we may not be OG but I've forgotten more than most people will learn. Vanos is noisy, just the way it is. It's a gear on gear driven mechanical item. Yes, TYE is right, replace your tensioner. You may even want to replace you secondary tensioner inside the valve cover. It's the one in between the 2 cam sprockets. Push down on it, if it's strong and snaps back into place, you're good. You can try to purge your tensioner too, hold the idle at 3k rpm for 3 minutes. This builds pressure to force more oil into the tensioner.
And now the bad news. Lifters tick when they get worn. Lash caps, updated retainers should be installed from an S52. (Not sure if the replacements from the factory come milled down or not, but they are different sizes) Your mileage is right for this, sorry. It ain't fatal, mine raced for a season and a half with some crazy ticking. Or run thicker motor oil, 20/ 50 ftw...

philsans5 · #7 (**permalink**) 06-19-2007, 10:42 AM

And the pinging... Don't you guys get stuck with crap gas out there?? I'd keep running the booster every 3rd tank, have your injectors cleaned and maybe replace your knock sensors. They shouldn't let it ping, that's their job to retard timing.

chandler · #8 (**permalink**) 06-19-2007, 02:15 PM

I don't think it is the valve retainers and neither do any of the places I have brought it to. The reason they don't think it is the valve retainers is because itwould tick at all times and idle and such and it is not doing this. Only under decel while engine braking. Not down a hill mind you but picture a flat surface and give it gas in 1st and then just let off the gas and coast in gear. That is where i hear the noise. once i reapply the throttle (tension to the chain so no slack on the other side I am thinking) the sound goes away. the local dealerships and some of the most renowned BMW shops in the area tell me that it is not something to worry about and that it is not a case of a bad chain. Actually most of their replies were the same...'we don't sell timing chains because they never break'. So It could either be the vanos unit or the tensioner. I guess I'll just buy both to see and see what happens. ugh...

As for the knocking, i am trying not to give it too much gas in too high of a gear and this seems to alleviate problem. I am running octane booster but I should prob have the fuel filter, injectors, knock sensors and o2 sensors replaced anyways. I just wanted to see if what I was describing came back with a reply like:

"oh yeah that is a totally easy fix, it is just the VANOS unit. Really cheap and easy and can cause pinging under load because of the timing issues. really not a big deal!!!"

That is what I was looking for.

TYE · #9 (**permalink**) 06-19-2007, 10:49 PM

I still say definitely do the timing chain tensioner, and check the secondary one as well.

As for gas, Seattle gets 92 octane, unlike the crap 91 here in Cali.

chandler · #10 (**permalink**) 06-20-2007, 09:38 AM

Quote:

Originally Posted by philsans5

Don't knock us all, we may not be OG but I've forgotten more than most people will learn. Vanos is noisy, just the way it is. It's a gear on gear driven mechanical item. Yes, TYE is right, replace your tensioner. You may even want to replace you secondary tensioner inside the valve cover. It's the one in between the 2 cam sprockets. Push down on it, if it's strong and snaps back into place, you're good. You can try to purge your tensioner too, hold the idle at 3k rpm for 3 minutes. This builds pressure to force more oil into the tensioner.
And now the bad news. Lifters tick when they get worn. Lash caps, updated retainers should be installed from an S52. (Not sure if the replacements from the factory come milled down or not, but they are different sizes) Your mileage is right for this, sorry. It ain't fatal, mine raced for a season and a half with some crazy ticking. Or run thicker motor oil, 20/ 50 ftw...

Isn't that what I do when I am driving?

philsans5 · #11 (**permalink**) 06-20-2007, 10:25 AM

pretty much, but that's bmw's procedure. Beats me what they're going for! Do you have an oil pressure gauge? Mine did the valve lash noise thing when I came in from a session, usually at or lower than 10 lbs of pressure. Still, run it, it's fine.

BadGTho · #12 (**permalink**) 06-20-2007, 12:55 PM

Quote:

Originally Posted by chandler

Stumped you guys huh?? LOL BTW, I am not looking for a diagnosis. I am looking for a similar problem or a history of this problem. Thanks!

didn;t stump me.. sorry to let you down.

that has all the signs of a timing chain that is seriously loose. is it Orig>? and lets talk about oil.. what kind, how much, and how much pressure.. oh.. and the pingin could just as easily be a lack of tune up as it could vanos.

a bad vanos will sound like a dense rattle at 3,000 rom or so.

chandler · #13 (**permalink**) 06-20-2007, 02:24 PM

Quote:

Originally Posted by BadGTho

didn;t stump me.. sorry to let you down.

that has all the signs of a timing chain that is seriously loose. is it Orig>? and lets talk about oil.. what kind, how much, and how much pressure.. oh.. and the pingin could just as easily be a lack of tune up as it could vanos.

a bad vanos will sound like a dense rattle at 3,000 rom or so.

Thanks for the feedback. I really appreciate it.

It is definetly not a DENSE DEEP rattle with like a few marbles rattling around. It is i think the chain slack. makes sense right under decel with no tension on it right? I am leaning towards a chain tensioner. but which one? the main timing chain one or is there one that keeps the tension between the camshafts as well?

As for oil, I am running dinosaur goop castrol 20w/50 Pretty thick shit. Never had a oil psi light come on. don't have trouble cold start. Other than the knocking and the rattle on decel there is nothing really going on with the car performance wise. I even try to get it to spew smoke and it won't do that. I am running a Jim C chip and using premium gas. Sometimes after hard running I do smell rotten eggs which quickly subsides. Cat converter.

BadGTho · #14 (**permalink**) 06-20-2007, 02:31 PM

Quote:

Originally Posted by chandler

Thanks for the feedback. I really appreciate it.

It is definetly not a DENSE DEEP rattle with like a few marbles rattling around. It is i think the chain slack. makes sense right under decel with no tension on it right? I am leaning towards a chain tensioner. but which one? the main timing chain one or is there one that keeps the tension between the camshafts as well?

As for oil, I am running dinosaur goop castrol 20w/50 Pretty thick shit. Never had a oil psi light come on. don't have trouble cold start. Other than the knocking and the rattle on decel there is nothing really going on with the car performance wise. I even try to get it to spew smoke and it won't do that. I am running a Jim C chip and using premium gas. Sometimes after hard running I do smell rotten eggs which quickly subsides. Cat converter.

it does sound like the chain/tensioner. as far as which specific component... if i was your mechanic, i would tell you to replace the entire timing set for good measure while you are in there. i think the only exception to that advice would be if a certain component was visibly damaged (IE the chain totally stretched) better safe than sorry.

that oil is pretty darn thick IMO.. but better thick than thin with these cars... it might not hurt to get a mechanical reading of oil pressure.. but i'm sure you are OK.

the eggs would be a CAT.. but thats unrelated.

chandler · #15 (**permalink**) 06-20-2007, 03:24 PM

Yeah eggs don't bother me.

BMW Bellevue has 1 chain tensioner left. (the little screw thingy) $200.00 effing dollars... I really don't think it is the chain stretching. That is pretty unlikely. So here is my dilema: Go on the annual drive to leavenworth or stay home on staurday and rip apart my timing system.....