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The following is not meant to be a complete step-by-step on how to do the job. I intend it to be informational with things that I learned along the way that might help others. I would not attempt this without some kind of service manual. I have omitted many important details that are covered in a service manual (like torque procedures). If nothing else, after reading this you should get a good sense for the amount of work involved and why a mechanic is going to charge you north of $500 in labor to do the job.
Tools that you absolutely must have that might not be in the average tool box:
- 12 mm allen wrench
- 3/8" breaker bar -- for cam shaft positioning. DO NOT use a socket ratchet!
- 3-jaw puller
- Set of Torx bits (for the coil-over-plug removal)
- Torque wrench (duh!)
Recommend, but, I managed without them:
- Chain style locking "pliers" to hold crankshaft pulley when removing/installing crankshaft pulley bolt.
- Crankshaft pulley installer
- Remove the intake Plenum -- Disconnect all wires and hoses to the plenum, including the EGR tube. Disconnect the throttle cable(s). Unbolt and remove the plenum with the throttle body attached. Stuff rags into the intake ports to prevent anything from getting dropped in. Use a couple of zip ties to hold the wire bundles over the center of the engine
- Remove the valve covers -- Remove the coil-over-plug assemblies. I used a sharpened putty knife to carefully slip between the head and the cover to loosen it enough to pop it free without damaging the cover gasket. The cover gaskets are rubberized and reusable if care is taken.
- Remove the cross-member above the radiator.
- Drain the cooling system and remove the upper radiator hose.
- Remove the fan assembly.
- Remove the drive belts.
- Remove the power steering pump -- There's no need to disconnect any hoses or drain the system. It simply has to be pulled aside. Take note that there are only 3 bolts holding the pump in place and ALL of them are accessible with a socket wrench through the holes in the pump pulley. If you are struggling to get at one of the bolts, most likely the bolt is holding only the bracket and not the pump. The farthest inside bolt has a spacer that is pressed through the bracket and against the pump. This spacer needs to be pried away from the pump in order to free the pump enough to remove it from the bracket.
- Now that the pump is out of the way, all the power steering pump idler bracket bolts are a cinch to get at. Remove the bracket.
- Remove the bolt in the crankshaft holding the main pulley in place. If you don't have a proper tool to hold the pulley, you can manage by using the tab at the bottom of the timing chain cover as a prop for a screwdriver through the pulley spoke.
- Remove the crankshaft pulley using a 3-jaw puller.
- Remove the timing chain cover.
- Remove the spark plugs to ease rotating the crankshaft.
- Rotate the crankshaft around until "colored" links of the timing chain are oriented with the respective sprockets as shown in the photo's below. Additionally, align the crankshaft position with the arrow on oil pump (right side, when looking from the font). I found the "dark colored" links to be very difficult to see. Also note that from the factory, the timing chain marks on this engine were NOT lined up with the chain -- they were all off by 6 teeth in every location (the photos below show the correct line-up used during assembly).
Note that the crank position does not look correct in this picture -- partly due to the camera angle, and partly because it really is off by a little bit...
- With everything in alignment, remove the timing chain tensioner. Take note of the extension of the timing chain tensioner before removing it. This will be useful for gauging the wear of the cam chain later.
- Remove all the timing chain guides. Note that this requires removing the large plugs in the front of the heads using a 12mm allen key. I did not have one and my local hardware store was conveniently out of stock when I needed it, so, I made one from a long coupling nut as shown on the right. The coupling nut was 1/2" wrench size with a little work on the grinder reduce it down to make it ~12MM. No sir, I'm not too proud to admit any of this!
- Remove the cam shaft sprockets. Be warned: I had a problem with the cams not staying in the exact location once freed of the chain. Use caution when removing the bolts since the cams may spring violently once the sprocket bolts are removed (ask me why I know about this)! Use a 3/8" 'breaker bar' that has a non-ratchet head so you can ease the spring pressure in either direction after removing the cam sprocket bolts. Do NOT hold the cam shaft with a standard 3/8" ratchet since it can only apply torque in one direction!
- Remove the cam chain enough to clear the water pump.
- Finally, the water pump can be removed. Once I got it free, I found that the gasket was disintegrating. The rubber material was literally crumbling into pieces upon removal. My sister-in-law was very lucky that the gasket had not started leaking coolant into the crankcase.
- I urge you to drain the oil at this point since, undoubtedly, coolant dribbled down into the oil pan upon removing the water pump.
Take a close look at the wear on the cam chain guides. My sister-in-law's engine had been replaced and we don't know how many miles it has on it. The deepest wear on the worst cam chain guide was only ~0.020" deep. We decided not to replace the guides.
Next came the cam chain itself. The tensioner was roughly 3/4" extended with tension on the chain. The tensioner extends ~1.5" at the wear limit indicator, and a bit further past that as shown in the picture to the right. Since it had over half of the travel remaining, we decided to keep the old cam chain in service as well.
- Even after reading the procedure in the manual, one of the most confusing things to do was to "reset" the cam chain tensioner before installing it. There's a special tool that might help you with this, but it is not really required. The trick is to release the check valve ball while compressing the tensioner so that the trapped oil can escape. I used a tiny allen wrench to apply a small amount of pressure on the ball while firmly applying compression to the tensioner body. It's easier than it sounds and you are not done until the tensioner wants to spring back on its own after being released from compression. If it does not do this, the problem is most assuredly because it has yet to be compressed enough to fully reset it. It's very messy and the oils squirts all over -- wear eye protection!
- Install the water pump. Follow the torque procedure in the manual.
- Install the cam chain and cam shaft sprockets. Get the chain alignment with in a tooth or two, but, don't sweat it just yet.
- Now the really fun part -- aligning the cam chain to the sprockets while installing the guides. Start installing the cam chain guides one at a time. For better or worse, I started with the one on the right side of the engine (i.e. the side with the tensioner), then the two around the water pump, and finally the one on the left of the engine. I knew the crankshaft was very close to the correct position, so, I correctly aligned the right-side cam to the chain and found a spot that it would rest at without constantly holding the cam. Next, after installing the guides around the water pump, it took a bit of cam positioning to get the chain aligned with the left-side cam shaft. This one did not want to stay in position on its own and I had to use the 3/8" breaker bar (as mentioned above, do NOT use a normal 3/8" ratchet for this!) to hold the cam in the correct position while also positioning the chain around the crank shaft sprocket and also installing the final guide on the left of the engine. It really helped to have an extra set of hands for this operation.
- Once the chains are all aligned, install the cam chain tensioner. Once installed, compress it with a small pry bar and it should extend out against the guide.
- I then took the opportunity to spin the crankshaft around by hand for several revolutions to make sure nothing clanged.
- Install the timing chain cover and torque appropriately.
- Install the crankshaft pulley. The correct way to do this is with a special tool that threads into the crankshaft and then pushes the pulley onto the shaft. I tried getting one from the local auto parts store, but, they didn't have one with the correct threads for the crankshaft. Naturally, the bolt that holds the pulley on the crank is too short to be of any help for the task. I wound up heating the pulley in the oven to ~250 degrees and then tapped it onto the shaft using baby sledge hammer. Not exactly elegant, but I was out of options on a Sunday afternoon and had to proceed. Before you scream at me, remember that this is done in very cramped space and I could only get about a 3 inch swing of the hammer, so, there was no heavy pounding involved -- even though it was a 3 lb hammer. I used a backing board against the radiator to prevent damaging it during the backward swing.
- The rest of the installation is the reverse of the the tear down.
- Don't forget to connect the hood latch release cable when installing the radiator cross member -- yeah, that was an "ohh sh!t" for me (managed to connect it in place, but, twas a pain).
- Also, don't forget to refill all the fluids -- engine oil (you did drain it, didn't you!?!) and coolant.
When it's time to start the engine the first time, be prepared for quite a racket until the oil pressure comes up -- the cam chain tensioner needs to be "pumped up" with oil before it will hold the correct slack on the chain.
If you found this helpful, please leave a comment on my blog . Enjoy!
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