Replaced chain tensioner. Fixed cold rattle. Now rattles when warm.

[M42Power]

So, i replaced my tensioner.

I did it because i was getting some cold engine rattle.

Now i am getting a rattle down the drivers side guide ONLY when it's fully warmed up.

lelque. Are my timing components completely shot?

[M42Power]

No input?

I'm going to take the valve cover off to see what's going on.

[bmwman91]

Sorry man, that's pretty odd. I am trying to think of how the chain might still rattle when the oil warms up and thins out. If the tensioner is new then that shouldn't be the issue. Is the sound DEFINITELY chain rattle, or does it just sound sort of similar and come from somewhere in the front of the engine?

[bmwm42]

Thin oil a worn out slide rail a broken guide as a result of the new tension

[kwill22]

I'll second the rail and oil. What weight are you using?

[M42Power]

I just went trough the other tensioner thread and i found out that my old tensioner was in the locked-up-super-extended position. Maybe the new one doesn't go that far out.

Anyways, i took the valve cover off and ,no surprise, the teeth are sharp. The chain seems good. Both the adjustable gears were off a few degrees, maybe they weren't properly tightened last time round? (sorry for shitty pics)








My oil is fresh castrol gtx 10w40.

So i am at least looking for a timing rebuild... Head is clean tho.

[bmwman91]

Hmmm, yeah if the old one was stuck in the past-max position then there is probably a lot of wear on all the guides. Your old tensioner...was it the original one / old design? If so, then I bet all of your guides are original too, and in need of replacement at some point.

[M42Power]

Just took a look at my old tensioner and it was indeed the old style. Kinda makes sense, my car has around 130k miles. The old tensioner's spring is pretty stiff still.

So i should replace at least the guides and the gears. At 130k the chain is still probably good i guess.

Now regarding driving the car. Can i stick the old tensioner back in so i can drive it around without it rattling when warm or should i just park it and wait for me to get the money to overhaul the timing?

[bmwm42]

Just took a look at my old tensioner and it was indeed the old style. Kinda makes sense, my car has around 130k miles. The old tensioner's spring is pretty stiff still.

So i should replace at least the guides and the gears. At 130k the chain is still probably good i guess.

Now regarding driving the car. Can i stick the old tensioner back in so i can drive it around without it rattling when warm or should i just park it and wait for me to get the money to overhaul the timing?

Id replace everything timing related before driving unless your looking at changing your engine

[kwill22]

Yep chain too. It's cheap and you're in there so might as well do it.

[bmwman91]

Hey, one thing to consider is swapping in a later-model M42 timing case, or even an M44 timing case. As far as I know, the later M42 case is a direct swap, and for the M44 one you would need the M44 oil pump gears and an adapter bracket to hold the crank position sensor. The benefit of those is that they do not have the little idler sprocket that is super prone to failure, but instead have a small plastic deflector rail there. Keep in mind that taking the timing case off and putting it back makes the job considerably harder than just a rebuild, so a basic overhaul of the guides and chain might be all you want to sign up for!

[M42Power]

Hey, one thing to consider is swapping in a later-model M42 timing case, or even an M44 timing case. As far as I know, the later M42 case is a direct swap, and for the M44 one you would need the M44 oil pump gears and an adapter bracket to hold the crank position sensor. The benefit of those is that they do not have the little idler sprocket that is super prone to failure, but instead have a small plastic deflector rail there. Keep in mind that taking the timing case off and putting it back makes the job considerably harder than just a rebuild, so a basic overhaul of the guides and chain might be all you want to sign up for!

For a timing case swap i think i would just buy a late m42 from an e36.

For now i will do sprockets (if i can find good used ones, otherwise i will just buy new), guides and chain.

And gaskets since it's been leaking.

[bmwman91]

Sounds good. That should have you covered.

[M42Power]

Not looking foward to the crank bolt tough

[bmwman91]

Getting it off is no problem, just remove the air filter box and put a block of wood there. Stick a breaker bar with socket on the crank bolt and leave it vertical...and run the starter. SMACK! Right into the wood, sometimes it takes 3-4 tries. Don't hold the starter motor on for more than 1-2 seconds. Anyway, it'll almost always work to break it loose.

As for putting the bolt back in, I am not sure of the best way to do it without some sort of crank lockign tool. I got a big steel plate and used a drill press to put matching holes in it so it would bolt to the crank and rest against the passenger side frame. Maybe someone here will have a suggestion for that if you can't make a lock tool. There is the 8mm lock port in the flywheel, but that seems like sort of a scary place to try to lock things up with all that torque.