Hey Guys and Welcome back to the SimpleCarGuy channel. In this video, we will have some fun installing the oil pump, oil pick up tube, the timing chain and timing the engine. I liked doing the timing chains so much that I did it twice. More on that later!
If you are new here, well, I have been rebuilding my BMW N55 engine for the past few weeks and it’s been a great learning experience. I have replaced the main bearings, crankshaft, sealed the bed plate, installed new rod bearings and a new head gasket. The last huge item on the list is the timing chain, which is today’s video.
While I’m doing this with the engine out, it is possible to do a timing chain job without having to remove the engine from the car. As in previous videos, I won’t be showing those steps, but I’ll do a quick overview on how to get where we are. I recommend you watch my previous videos where I show a lot more detail on disassembly.
HOW TO GET TO THIS POINT:
So, the quick overview. Here we go.
Step 1: Unplug the battery and drain the oil from the engine. Remove air filter housing or clean air pipe running over the valve cover depending on the car and undo the gas pressure lines.
Step 2: Remove the underbody protection, intake silencer housing, fan cowl and the serpentine belt that runs the accessories. With that access, you can now remove the vibration damper and the front crankshaft seal. If the belt tensioner is in the way, you may need to remove it as well.
Step 3: Remove the valve or also known as the cylinder head cover by unplugging the vacuum lines, wiring from the injectors and anything else that’s in the way. If you will be reusing the valve cover, make sure you undo the bolts in the correct order (show here) and remove it from the cylinder head.
If you aren’t replacing the oil pump or oil pump chain and sprocket, no further disassembly is required. Otherwise, you will have to remove the front axle differential, remove the power steering pump and remove the bearing support to be able to remove the oil sump and have access to those parts.
Before you can remove the timing chain or the oil pump components, you have to rotate the engine into the TDC (Top Dead Center) position using the main bolt. You know it’s in the correct position when cylinder number 1 is at the very top. Now we can install the timing tool onto the camshaft to make sure they do not move while we remove the central bolts on the intake and exhaust camshaft adjusters. You should have no issues unbolting these. Then remove the chain tensioner as well which will give your chain some slack and allow you to remove the camshaft adjusters by hand.
Next, the main bolt must be loosened and taken out. This is a tough one. With the engine out, it took an 8 foot pipe to get it done, but I have also done it in with the engine in the car on my N20 timing chain job and it was a little easier. Whichever way you go about this, make sure the socket is very secure on the bolt and doesn’t slip and spray some WD-40 or whatever else you have if it’s a bit rusty.
With the main bolt out, there are only a few things holding the timing chain and timing chain guide in place. The 2 bearing journals that are hiding behind the screw plugs, the crankshaft hub, two little screws at the top by the camshaft adjusters and of course the camshaft adjusters themselves. With those removed, hold the timing chain and guides with one hand and remove the hub with the other making sure not to drop the sprocket. I recommend keeping the chain tight to avoid this and just pull it up as soon as the hub has cleared it.
Now that everything out of the way, we can finally get to fun parts! Since I’m rebuilding the engine, I’m reinstalling the oil pump using new bolts. The install is very simple, but to be safe I do a mock up with old bolts while I’m working on getting the chain assembly in. Just in case I have to move it or something isn’t lining up properly. If I used new bolts and have to loosen them, I’d have to get new bolts again. The 3 bolts at the top are torqued to 10 Nm and then 180 degrees angle of rotation for the longer bolt and 90 degrees for the shorter bolts.
We are almost done with this job and as you can see it does take some time and effort to get there, no wonder a shop would charge you a couple thousand bucks for this! Anyway, to install the new chain and tensioner, make sure it’s all assembled correctly and the sprocket pointing the right way. Then it can all be lowered into the engine, lining up the sprocket with the crankshaft hub and locking it in place with a new main bolt. You don’t want to tighten it to spec just yet. First, reinstall the 2 bearing journals and the 2 little screws at the top to hold everything in place. Torquing all to spec, of course. Now the main bolt can be torqued to 100 Nm and additional 270-degree rotation. I recommend having someone help you out with this one, it felt a little sketchy as I was doing it.
With the main bolt locking everything in place, it’s time to install the intake and exhaust camshaft adjusters back in with the chain around them. Should be pretty easy since the chain tensioner is not yet installed. Of course, you have to make sure that the intake adjuster goes on the right side and the exhaust on the left, you cannot mix these up! While you are pulling the chain over the exhaust adjuster, make sure it is sitting on the guide rail and not anywhere else. With everything looking good, we can install the pretensioning tool instead of the chain tensioner and torque it to 0.6 Nm and torque the central bolts to 20 Nm with 180-degree rotation after. The very last step before testing is installing the chain tensioner and torquing it to 55 Nm.
Once everything looks good, we can remove all special tool and rotate the engine a couple of times making sure everything sounds good and recheck the timing. If everything still lines up and the timing tool fits as it did before the engine is timed and ready for its new crankshaft seal and re-assembly. A video on front crankshaft seal is coming out soon!
Now, remember how I said I had to do this job twice? Well, after I rotated the engine a few times, it made this clicking sound from the camshaft adjuster which I wasn’t very sure about. So, I posted a short clip to check with others and see if it’s normal. I learned that indeed, it is normal and it will go away as soon as oil pressure is built up and circulating, but I also learned that I was making a mistake. Initially when I looked at the timing components, they looked fine to me so I reused them.. but after many, many convincing arguments from strangers, I have decided to replace it all with brand new stuff, including the chain tensioner. Anyway, thanks for watching, check out the links in the description for parts needed, leave a comment down below and I’ll see you in the next one.