DIY: Coolant Exchange Pipe / Valley Pan Replacement. e70 n62 4.8L

[Repete]

Well I completed this job yesterday, with much thanks to Gregg's write up. So I'd like to add a few points from my experience for those taking this on. In addition to the valley pan (which was obviously the problem) and coolant pipe (URO) I also replaced the water pump/thermostat, both belts, various seals and the simple cabin air filters.

I deduced I had the valley pan leak as I found the coolant leaking down onto the bell housing and leaving traces of blue coolant down the sides. There was no coolant out of the front weep hole of the timing cover. Also when I removed the rubber 'drain plugs' on the bottom of the bell housing it was dry. If there had been signs of coolant coming out here, the problem would be the much more involved gasket inside the trans/engine connection.

While the write up was very helpful, an Ipad on the workbench was great. I found the water-pump and belts replacement much more difficult and time consuming than the simple instructions above might have suggested.

My first unexpected problem was the tensioner pulley for the accessory belt, very difficult to get to the upside-down torx bolt (T45 I believe). So I drove a mis-sized nut onto the treads on the tip of the bolt from the top that allowed me to simply loosen and tighten the bolt from the top side (righty-loosely, lefty-tighty). Needless to say I left this cross-threaded nut in place for any future jobs. I did still need to break it free initially using the torx head from with an upside-down ratchet from the topside.

Second speed bump was getting the harmonic balancer off but this is probably due to the Canadian corrosion. With enough penetrating spray, tapping and prying I finally got it off and put some anti-seize on during reassembly. Considering how difficult it was to remove, I thought maybe the large center bolt had to come off too, but I read it does not. For reassembly there is a small key pin that needs to be lined up.

Third, to replace the serpentine belt you need to remove the guard/cover over the power-steering pump, 3x10mm nuts to be removed. Not too bad, but I found it was easiest to get the bottom nut off from under the car with a wrench. The torx head bolts don't need to come out.

The DIY didn't mention when to drain the coolant (using the blue drain on the rad) but I did it right before taking off the water pump. There was still a lot of fluid that spilled out, I'm sure there is a better way but I just used a lot of towels and buckets to limit my environmental damage.

I had disconnected the oil sensor as suggested but wasted a lot of time trying to 'rout' the wire out but could not figure how to get it out, let alone back in place. I had considered cutting the wire but found I could work around it. In fact I think you could probably leave most if not all of the 5 passenger side electrical wires (that pass under the fuel crossover pipe) in place. The manifold comes out forward and I rotated it to the left out of the way but still in the engine bay to complete the rest of the job. So no need to remove the oil sensor wire in my experience.

The coolant pipe job was straight forward though I didn't need to drill the hole to get the front pipe out. I put a section of paperboard (cereal box) under the pipe to catch all the debris. I did find that one of the tips on the plastic "Y-connector" was broken and could have also been a contributing factor to the leak. I glued and wired it back to together as best as possible and will have to order a new one asap.

Also you might try removing the 3 rear wires after lifting the manifold up and forward some. I did this on reassembly and there was enough length in the wires for a couple inches of additional working space.

I thought it would take me about 8 hours, told my wife it was going to take about 12 hrs and in the end it was a 15 hr marathon to complete the jobs. But there were a number of items that were time thieves for me, not including bouts of parenting my 3 young children.

Tools I found most useful:
- work/trouble light
- flex extensions for sockets
- magnet to place nuts into place
- sharp pics for seal removals
- large selection of torx sockets and drivers

Thanks gregg3gs for the DIY pics. Good luck!

[Repete]

Originally Posted by Repete

Well I completed this job yesterday, with much thanks to Gregg's write up. So I'd like to add a few points from my experience for those taking this on. In addition to the valley pan (which was obviously the problem) and coolant pipe (URO) I also replaced the water pump/thermostat, both belts, various seals and the simple cabin air filters.

I deduced I had the valley pan leak as I found the coolant leaking down onto the bell housing and leaving traces of blue coolant down the sides. There was no coolant out of the front weep hole of the timing cover. Also when I removed the rubber 'drain plugs' on the bottom of the bell housing it was dry. If there had been signs of coolant coming out here, the problem would be the much more involved gasket inside the trans/engine connection.

While the write up was very helpful, an Ipad on the workbench was great. I found the water-pump and belts replacement much more difficult and time consuming than the simple instructions above might have suggested.

My first unexpected problem was the tensioner pulley for the accessory belt, very difficult to get to the upside-down torx bolt (T45 I believe). So I drove a mis-sized nut onto the treads on the tip of the bolt from the top that allowed me to simply loosen and tighten the bolt from the top side (righty-loosely, lefty-tighty). Needless to say I left this cross-threaded nut in place for any future jobs. I did still need to break it free initially using the torx head from with an upside-down ratchet from the topside......


Thanks gregg3gs for the DIY pics. Good luck!

Ok hopefully someone will find this funny. The other night I replaced the A/C tensioner pulley because I thought it was the source of my squeaking problem (couldn't be the water pump because I replaced it last year). Completely forgetting what I had done and written about before, I struggled with the tensioner pulley bolt again - the worst part is that I spent a good 30 mins trying to tighten down the nut that would just not go back on. Yep... the mis-sized one I put on last time to save me time in the future. I guess it helps to reread your own posts every once in awhile. It also turns out that saving $30 on the water pump was a bad idea because the URO pump I installed last year has failed after 20,000km and now I have to replace it standing in a foot of snow.

Oh yeah another pitfall to be avoided... do not pull up gripping the top of the fan shroud, I pulled too hard on this and broke a piece of the fan blade. Of course you can't buy only the blade and the whole unit is around $500. So far I have glued it back into place but I don't think this is going to work unless I can balance the fan blade perfectly which will be tricky. Any tips?