I have a rattle coming from under the passenger side of my valve cover it seems. It's most pronounced at idle and full throttle. It goes away around 3000 rpm but will be audible again under load. It almost sounds like a rocker arm is loose or a valve is stuck.

If anyone has any information about what this could be, please help. Thanks in advance.

Chad

 

I forgot it's an overhead cam so there's no rocker arms. Could I have a stuck valve?

 

Possibly a valve but a rattle sounds more like a timing chain. Maybe you tensioner has given out. Stuck valves normally are a loud ticking and the car will run differently.

 

Yes, I think it may be the timing chain tensioner from everything I've read on here. I haven't seen this problem posted for a Gen. 1 Mini though, only Gen. 2. Is there a timing chain or belt on my 04 MCS? Has anyone worked on these before? I read that it's only an hour of labor to replace it. Will I be able to access it and change it with the removal of the valve cover?

 

All the Gen 1's had a timing chain. The timing chain tensioner is on the backside of the block look for a camshaft install. It shows how to remove it. Not too hard but you have to be creative with the socket extensions

 

Thanks a lot for that information. I have followed a link and have seen the tensioner bolt location. I'm assuming the tensioner is located inside, in front of that bolt and that's what needs to be replaced. Is that correct? Will I be able to access it with the valve cover removed?

 

Yeah you are actually removing the cover when you remove the bolt head. The tensioner should just slide out. Having the valve cover off shouldn't have any effect.

 

So are you saying I can do this job without removing the valve cover? From what I've read, I need to remove the engine mount to access the tensioner bolt. Does this sound correct? Then just remove the tensioner bolt completly and as you say the tensioner should slide out, right?

 

You just need to raise the car, remove the front wheel, and unscrew it. Nothing to check under the valve cover unless you have something else to do.

 

Thank you very much for all of your help!! I just need to make a trip into Orlando in the morning to the Mini dealership for the new tensioner. I'm not going to drive my car obviously. I'll let you know how the job goes. Thanks again!!!

 

Sounds like the same issue I have.

 

It's pretty simple to swap out the plunger. Like previously mentioned, just jack up and remove the liner. I would suggest using one of those swivel socket elbow things and a long extension. It's pretty tight in there and I found it difficult to use just a ratchet and socket.

 

I just pulled it out. I just did it from the top and reaching in. It was a bit tight but after I broke it loose I was able to unscrew it with my fingers and pull out the tensioner. After pulling the tensioner out I noticed it felt like there was a spring inside. When I read the instructions on installing a new tensioner they mentioned putting constant pressure on the tensioner to compress it. replace the cap and reinstall. So with that said my tensioner must be my problem because when I compress it, it just bounces right back up just like a dry spring. I'm assuming it's supposed to stay compressed and slowly decompress. Mine doesn't seem to be filled with any fluid at all to make it work correctly. It is a hydraulic tensioner, right?

 

"It is a hydraulic tensioner, right?" Yes it is...

It will be hard to compress & slow to decompress - much like a 90 - 10 shock only harder. If the tensioner is easy to depress - it has seen better days.....

 

Well it seems I have found the problem then. Now I just have to hope that the Mini dealer will have a new one for me. Thanks for everyones help!!!

 

Not that we have a ton of Minis here - the local forign auto parts - always stocks 1... really, just 1. the good is, that 1 is not even a mile away.... the dealer is 50.

 

I installed the new tensioner and the rattle is gone at idle. When I put it in gear and start to move it ratttles when I take off but then goes away. I'm wondering if I need to install a new timing chain. I have a feeling it has a bit of slack in it. Currently I have 72000 miles on it.

Any thoughts?

 

It might need a chain... I'd give it a little more time. 72k isn't that much.
911s had a similar tensioner, long story, the short is, the cahin, when the tensioner is first installed, is not tight. It doesn't take long for the tensioner to react, time wise but it be a couple of starts & stops before the chain is snug....

 

Thanks Stevecars60. That makes sense and would explain the partial cure of my problem. The one thing I was concerned about was that the new tensioner seemed to have the same resistance as the old one. I discussed this with the mechanics at Orlando Mini whe I was over there today. They just said that they would have started with replacing the tensioner as well and go from there.

As far as the tensioner coming back out slowly after being depressed is incorrect according to those mechanics. They said that they all pop out quickly. They told me to depress the tensioner until it stays, install it and then turn the motor over by hand a few times and this will pop the tensioner out. I told them I could install it in the extended position with a little pressure. They told me that was because the slack of the timing chain was in the correct place allowing me some extra room and that it was ok. I just figured I may have a bit more slack from wear thus allowing me to insert it in the extended position.

I will give it a while and see if the rattle goes away. Your explanation makes sense and makes me feel a bit better.

Thanks,

Chad

 

Chad with a little luck...... might check the install hardware for tight
Have a grand weekend,
Steve

 

Steve, I torqued the tensioner bolt/plug to spec. Hopefully it will tighten up from here.

Thanks

 

I just went for a drive and after a warm up the rattle is back! Now what? Is it timing chain time or something els?

Please help!!!

 

Its hard to troubleshoot more with limited info. If it is not correlating to RPM (not a rattle at a certain RPM) then it is not a valve. I have doubt your timing chain would be worn out but it could happen. Does it do it with the clutch depressed? It could be worn springs in the dual mass fly wheel; granted thats on the drivers side.

 

Is the AC on?
Take a long screw driver put it to your ear, to the blower, "P" side cylinder head & locate exactly where the noise iscomming from - You may have already tried this..... next thing would be the chain... with the VC off, how does the chain & tension feel? A good visual may help
Feeling bad the tensioner wasn't the issue............. I have a friend that has +120k, OE tensioner & chain.

 

Also check your supercharger pulley to make sure all the allen bolts are tight. Just an idea