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4.2L Oil cooler o-ring replacement

 
Old 06-17-2019, 06:42 PM
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Default 4.2L Oil cooler o-ring replacement

just finished the oil filter housing o-ring replacement on my '08 4.2....138k. mucho oil everywhere. Of course, now I am needing to do the same on the oil cooler (its pissing oil commensurate with rpm) yep, literally! and could use a tip or two on the preferred method of removing the generator. The belt tensioner sits directly below the generator and I'm seeing that as needing to come down for starters. Its 2 bolts holding the generator on and a drop down once they're off, so my question is can I get them off without taking pieces off the front end..Its quite tight in there. Thinking its smarter to get some expert advice before I attack the problem. The oil cooler mounts to the engine easily enough but you can't get at it without removing the alternator..........seeing how this is one of the several or so chronic oil leak issues with this variant, I'm thinking there's some folks here who have experienced the process and lived to cuss about the engineering design. Any tips would be appreciated.

Jim
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Old 06-17-2019, 10:57 PM
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Yes it can be a pain, and if you do not want to pull the nose to service position, some fines-ing can be done. The real question is will it be done on a lift or a creeper, that will make all the difference. I will try to keep this short as it will be easy to get lost in details. But if your are mechanically inclined you will be just fine with some pointers and shortcuts.

disconnect battery
remove belt from tension-er from the bottom, leave the rest of it in place.jack/ support
remove 2 bolts for alt and slide forward, don't remember if the top or bottom come out, one ill not. leave for later
support oil pan and from the top remove the top bolt for the snub mount mount
support front section of sub frame and remove front sub frame to body bolts. Reinstall the bigger bolts 1 on each side a few turns in.
lower sub frame and let it hang on bolts or drop a bit and leave support under
lower oil pan jack/ support slowly. you will know when to stop more or less when the alternator bolt you couldn't remove will be able to be pulled out further and into one of the fan blade openings in the fan shroud allowing another 1-2 inches of it to be removed. You will have to push and pull and tweak to get it out and into the opening. Now using a pry bar, and as a leverage point, and a small piece of 2 x 4. Place the wood on the front side of the motor against it and behind the a.c line, kinda in front of the alternator. Use the pry bar and rest a spot closer to the handle on the wood and the tip (flat end/ back side) up against the fan motor, like right in the middle. Pull backwards using the wood as a fulcrum and apply (carefully) pressure to the fan shroud) This will push it out ever so slightly and at this point you'll be able to remove the other alternator bolt the rest of the way.
Using a pry bar wiggle the alternator from the engine till it is almost if not just about out.
Remove the allen on the top back of the alternator holding the 2 coolant lines to it. Also remove the connector and 13 mm nut.
Right around the shock area on the block you fill find a 10 mm bolt holding the coolant line to the engine or engine mount, remove that to give you more wiggle in the one coolant line
Remove alternator.
There may or may not be another 10 mm bolt holding the coolant line around the engine mount, I don't remember
With the engine still lowered, and a mirror you should be able to locate the engine mount bracket bolts. I think 6? There are different lengths i believe.
You will be able to tell if you will need to completely remove the 2 sub frame bolts you put back in to further lower the engine or not, but be careful not to over do it and break any coolant hoses.
8 mm allen i'm pretty sure are the bolts. It will be good to have all these just in case a super stubby 1/4 inch 8 mm allen socket and 1/4 swivel socket. stubby 3/8th 8 mm socket , reg 3/8 8 mm socket and a 3/8th reg 8 mm ball allen socket. And a 8 mm allen key for safe measure as sometimes the bolts are crazy tight from age.
Once the bolts are removed (and remember always tap them in all the way with a hammer before you go to loosen them. If you strip any, definitely the top ones, my condolences. It will take some pulling because the one alt coolant line will be in the way wherever you put it.

Be sure to have all the oil cooler o-rings and a new coolant adapt-er pipe/fitting. Little 1 inch long plastic coolant pipe. A metal replacement is available

Lube the 2 o-rings on the adapter before installing, be very gentle going back in to not pinch a o ring.
Install the rest in reverse order.

Think i covered it all, may have missed a thing or two but with what i wrote you will deffinitly be able to take car of the rest


-Cheers
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Old 06-17-2019, 10:59 PM
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Sorry that what written in relation to a A8. So i believe just disreguard the part with the pry bar against the fan should, I think you will have more room.

-Cheers
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Old 06-18-2019, 06:54 AM
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Many thanks........its good to have a sense of the process in your mind before you start taking parts off. One thing I am at an impasse with is the mention of replacing the one " inch "cooler pipe" because I can't find an indication for it after 2007. I know there's an aftermarket metal one but all listings indicate up to 2007. Also, what are your thoughts on disconnecting and capping the coolant lines on the alt rather than removing the bracket on the back of the alt. Is it a six of one/half dozen of other or is it easier/harder with them still hanging there. I'm familiar with having to run out an alt bolt through a fan blade to clear it. always something. Sure appreciated your taking the time to reconstruct this painfully laborious repair. Thank-you
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Old 06-18-2019, 09:55 AM
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Now that you mention it I believe Iíve done some where it didnít use the coolant pipe either. Its been a while so I canít really remember which car did it didnít have it. In my opinion I would get it just to have it so just Incase you need it itís there, I believe there cheap either way. As for the bolts for the bracket, thereís 6 total I think and I think it was the bottom 3 are shorter, and top 3 longer. Or top left corner, bottom left corner and other 2 bottom bolts are short and the other 2 long. But nothing to worry about .

-Cheers
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Old 06-18-2019, 09:58 AM
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Oh and the coolant lines, I may have done it the way youíre saying one time. But itís tight to get the clamps off. Also the rubber lines arenít that long to where once you start to pull the alternator off the lines wonít let it be pulled out. You can try to just loosen the 5mm Allen on the alt so that the lines swivel a bit and then with the alt pulled away some youíll be able to access the 2 clamps for the hoses better. At that point you wonít have to worry about the o rings on the metal pipes to alternator.

-Cheers
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Old 06-18-2019, 12:20 PM
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Originally Posted by Sam Zubel View Post
Oh and the coolant lines, I may have done it the way youíre saying one time. But itís tight to get the clamps off. Also the rubber lines arenít that long to where once you start to pull the alternator off the lines wonít let it be pulled out. You can try to just loosen the 5mm Allen on the alt so that the lines swivel a bit and then with the alt pulled away some youíll be able to access the 2 clamps for the hoses better. At that point you wonít have to worry about the o rings on the metal pipes to alternator.

-Cheers
We'll have to see what the best option is at the time but I'm thankful for your input all the same.........not looking fwd to this by any means but it'll be on a lift, which will allow for more access.
Thanks again...
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Old 06-18-2019, 03:14 PM
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My pleasure. If i was in your spot i would have loved to get some pointers as well. Good news is that you'll be doing it on a lift. The first time i had to do one it definitely sucked but was not as bad as i thought. Once you do a few it really isn't that bad of a job. The main thing is to learn to tricks and shortcuts which i tried my best to point out, and remember all of them more or less for this job. I think the part about this job that is the biggest pain is the bolts for the engine mount bracket/ oil cooler assembly to engine block. Some were easy and others were on the verge of completely rounding out, but thank god they didn't, that where the allen key came in, with a deep 1/2 inch socket, 14 mm or something, slipped onto the long part of the allen key and with a long 1/2 inch extension onto the socket for leverage (great make shift allen breaker bar). One of the bolts i had to use that because things were in the way and a socket and ratchet wouldn't be straight on. Really comes down to the top 3, more so the top middle and top right, since their counter sunk deep. Only use the ball allen after you cracked them clearly. Get creative with stubby and swivel combo.

Another tip, i believe it will be the top middle bolt, you'll notice taking it out it'll get hung up and or to take it out all the way it'll be easier to leave it for last and finish unscrewing it while pulling the bracket away from the block together. Before putting it back it, run a nut down on it and with a cut-off wheel shorten it 1/8-1/4 inch and take the nut off to fix/ clean the threads nice. Just that little bit wont do any harm and it'll make everything so much better. I think it gets hung up on the metal coolant pipe to alt. Its a little fuzzy but when you get there, if its a different bolt or the same you'll know exactly what i'm taking about, and you'll tell yourself "why wouldnt they just make this bolt 1/4 inch shorter, it'd make everything so much easier" Ha . Good luck and like to hear back after you get it done.

-Cheers
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Old 06-18-2019, 03:34 PM
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I've done it without putting the car in service position only because I have thin hands: https://www.audiworld.com/forums/4-2...cment-2964525/
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Old 06-18-2019, 03:42 PM
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I've done this job on C5/A6. D2/A8. D3/A8. I've never put it in service position on any of them. But C6 A6 i actually haven't done one on one of those yet. Probably why my input might seem a bit hectic, trying to puzzle any shortcuts from all the above so my apologies for that. However i do need to do this job on my own vehicle. C6 S6. Once i get around to doing it ill add in anything here for others to see for future reference.

-Cheers
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