Hi so I have a 2003 MCS and recently I did a major service including the timing chain tensioner. Ever since then on cold starts it will make a rattle. I found out it is coming from the side with the timing chain and felt behind the engine and it was wet near the timing chain tensioner bolt. Is the timing chain tensioner bolt leaking does that make any sense would that cause the rattle on cold start. Appreciate any feedback.

 

Very well could be, if you have a rattle on cold start it is VERY likely its the chain tensioner and I'd replace it yesterday.

The leak could also be the valve cover gasket or the oil filter housing gasket. Less likely but also possible is the timing chain guide bolt access plug o-ring leaking. Everything on mine was leaking so replaced everything. ZERO leaks now. Its lovely. I'd check the guides and make sure they don't have excessive wear. Its not too terrible to get the valve cover off....and while the valve cover is off, you can replace the valve cover gasket and the chain guide bolt access plug o-rings as well as the camshaft position sensor o-ring AND the oil filter housing seal.

 

So just real quick could it maybe be the bolt is not right enough just before I spend more money on a new tensioner since I put in the other one less than 1000 miles ago

 

Probably the oil filter housing gasket. They get hard an leak. It is right above the timing chain tensioner.

 

If it isn't tight, it absolutely could be the problem. Also, if you didn't tighten it down, it could be backing out further. That thing is a pain in the *** to get a wrench on. Trying to remember, but I think I had to loosen something that was right next to it in order to fit my ratchet in there...oil filter housing maybe? Tried a couple different ratchets and sockets and gave up and just moved whatever was in the way.

 

You didn't accidentally forget the crush washer for the timing chain tensioner?

 

I didn't see any crush washer on the bolt or anything never heard of that for the tensioner

 

They come with a crush washer that has to be installed with it. The crush washer is a one time use item. Has to be replaced everytime just like the one on the Oil drain plug. If you are missing the crush washer there is the reason you have a leak.

Sorry just read back and realized this is on a 2003. My comments are more for the N15-N18 engines. I forgot the older ones were different.
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Edit#3
Ok so after doing a couple minutes research there is still a crush washer sealing ring on the Tensioner retention bolt on the 2003 Mini.

 

You can see it in this screen shot

 

Hm very weird on my car it does not seem to have one it's just the bolt and I'm not 100% sure if the tensioner was replaced before I replaced it but very well could be.

 

UPDATE: The oil I felt was simply the valve cover gasket thankfully and I replaced the tensioner with a oem tensioner and it still does a rattle on cold starts. Coult this be as simple as a tappet on cyl 1 is making that or do i need a timing set any ideas.

 

Hi all was just wondering if that plug leaking from a bad crush washer would that cause the tensioner to lose tension and cause a rattle on start? I know it is via oil pressure but i also thought it was spring loaded, was just wondering before I buy a new plug to see if I can fix my issue. Thanks!

 

If anything, I'd think it would allow for more tension since it would push the tensioner further in. It is spring loaded and has notches inside and the oil pressure keep it from retracting somewhow (a guy on youtube cut one open after he replaced it). Not to frighten you, but I replaced my chain tensioner twice and still had the rattle. I took the valve cover off and the guides looked OK. So, I replaced the belt tensioner again thinking it must be the culprit. Nope. Ended up being the front guide was broken half way down. I came to this conclusion by looking to the super charger and eventually leading me back to the timing chain.

So, look at your belt tensioner too. If it appears be dancing up and down, the little shock absorber on it may be done. Mine wasn't really dancing, but I was like frick it, and replaced it anyway.

Which lead me to my super charger bearings possibly going bad.

One way I could think to check if its your super charger is to remove the belt, then start it. Just let it run long enough to listen and then turn it off. You'll know right away if the rattle is gone. If it is, then your super charger or belt tensioner are to blame. I'd replace the belt tensioner at that point and pray its not the super charger.

If the rattle is still there, its your timing chain, chain guide, or timing chain tensioner. I replaced the timing chain, chain guides, cam and crank sprocket and called it good for another 100K miles. No more rattles, leaks, new belt, and new belt tensioner. FYI, chains don't stretch. The little holes in the links wear out over time causing the overall length to increase.

 

Hmmm didn't even think of that but that does make sense I did already get a new plug with a crush washer to see if it somehow fixes it if and most likely not I will check the belt tensioner which I do know is bouncing around and such. I have a new one just don't have the time to install it. That k you so much for the input!

 

Check the washer

https://www.northamericanmotoring.co...-180miles.html

 

Oh that could definitely work I did see that they never posted the specifics of the washer would you happen to have any guess to the size thickness anything of that sort. Because if the new plug does not work might resort to that.