D3 A8 Coolant leak
10-23-2013, 05:00 PM
#11
AudiWorld Member
Thread Starter
I believe the source to be the o rings behind the water pump unit itself. # 8, 11. I would probably order all new gaskets (if thats possible to just get the gaskets. Ill call audi monday.
If anyone can help me understand the challenges related to a coolant flush, that is what I am most concerned about with this job.
12-08-2013, 07:58 PM
#12
I have a 07 audi a8L with 57k on the odometer. I have noticed a slow coolant leak since I have had to refill once or twice over the past year. WHen I changed my oil yesterday I dug around a bit to try and find the culprit. Sure enough...
I found a drip leak from this part on the bottom right of the front of the engine. The radiator lower radiator pipe goes into it. Its located in front of the oil pan and bolts to the engine. Im guessing its a water pump or something? Can anyone ID this part?
The leak is coming from the back of it. I assume there is a gasket that needs to be replaced but identifying the part is the first part.
Then ill need to research how to fix it...
I found a drip leak from this part on the bottom right of the front of the engine. The radiator lower radiator pipe goes into it. Its located in front of the oil pan and bolts to the engine. Im guessing its a water pump or something? Can anyone ID this part?
The leak is coming from the back of it. I assume there is a gasket that needs to be replaced but identifying the part is the first part.
Then ill need to research how to fix it...
07-20-2014, 05:55 PM
#13
AudiWorld Member
Thread Starter
So an update! I decided to proceed with this job. The front end of the car is off and im waiting on one more part to finish the job. Ill be reassembling next saturday!
the final part will involve bleeding the system. I understand i need to turn the heat on high and fans on low. I also understand i need to fill the coolant resevoir and basically let the car cycle several times in order to ensure the coolant level is correct.
So my questions are:
1) are there bleeder valves on the D3 A8 and where can i find them?
2) I do not see a filler cap on the radiator, so aside from filling the resevoir, how do i ensure there is enough fluid in the key areas of the system that are now going to be completely empty? How do I fill those pieces/areas before I start the car for the first time?
I know there will be air that i need to get out, but the last thing i want to do is have the water pump completely void of any fluid whatsoever. Or is that ok for a little?
What makes me nervous is that I have the car apart the the water pump off. There is no more fluid draining from the system, but my resevoir still has about the minimum amount in it. So The lower areas (radiator/ front coolant pipes/water pump, are going to be bone dry.
Any help on filling/bleeding as I reassemble to finish this job would be great.
Ill be happy to post some pics after i wrap it up.
the final part will involve bleeding the system. I understand i need to turn the heat on high and fans on low. I also understand i need to fill the coolant resevoir and basically let the car cycle several times in order to ensure the coolant level is correct.
So my questions are:
1) are there bleeder valves on the D3 A8 and where can i find them?
2) I do not see a filler cap on the radiator, so aside from filling the resevoir, how do i ensure there is enough fluid in the key areas of the system that are now going to be completely empty? How do I fill those pieces/areas before I start the car for the first time?
I know there will be air that i need to get out, but the last thing i want to do is have the water pump completely void of any fluid whatsoever. Or is that ok for a little?
What makes me nervous is that I have the car apart the the water pump off. There is no more fluid draining from the system, but my resevoir still has about the minimum amount in it. So The lower areas (radiator/ front coolant pipes/water pump, are going to be bone dry.
Any help on filling/bleeding as I reassemble to finish this job would be great.
Ill be happy to post some pics after i wrap it up.
07-20-2014, 07:11 PM
#14
AudiWorld Super User
The area that dripped coolant was the oil cooler pipe
and I replaced the Water Pump by mistake. The seals of the water pump and thermostat were intact. Hopefully you don't bark up the wrong tree like me. On the safe side, when everything is out, look at the oil cooler also.
When engine is off.
- Leaks when hot - leave it a few days without running, no more leaks
- Leaks stop when the engine is cold or cooler.
- Leaks small amount, then larger amount after a while.
That's oil cooler pipe problem.
When engine is off.
- Leaks when hot - leave it a few days without running, no more leaks
- Leaks stop when the engine is cold or cooler.
- Leaks small amount, then larger amount after a while.
That's oil cooler pipe problem.
Last edited by ltooz_a6_a8_q7; 07-20-2014 at 07:16 PM.
07-25-2014, 04:15 PM
#15
AudiWorld Member
Thread Starter
the final part will involve bleeding the system. I understand i need to turn the heat on high and fans on low. I also understand i need to fill the coolant resevoir and basically let the car cycle several times in order to ensure the coolant level is correct.
So my questions are:
1) are there bleeder valves on the D3 A8 and where can i find them?
2) I do not see a filler cap on the radiator, so aside from filling the resevoir, how do i ensure there is enough fluid in the key areas of the system that are now going to be completely empty? How do I fill those pieces/areas before I start the car for the first time?
3) there is no filler cap on the radiator, do i just fill it before connecting the top inlet hose? Otherwise, it will be bone dry and could cause the water pump to suck air for too long.
I know there will be air that i need to get out, but the last thing i want to do is have the water pump completely void of any fluid whatsoever. Or is that ok for a little?
What makes me nervous is that I have the car apart the the water pump off. There is no more fluid draining from the system, but my resevoir still has about the minimum amount in it. So The lower areas (radiator/ front coolant pipes/water pump, are going to be bone dry.
Any help on filling/bleeding as I reassemble to finish this job would be great.
Ill be happy to post some pics after i wrap it up.
So my questions are:
1) are there bleeder valves on the D3 A8 and where can i find them?
2) I do not see a filler cap on the radiator, so aside from filling the resevoir, how do i ensure there is enough fluid in the key areas of the system that are now going to be completely empty? How do I fill those pieces/areas before I start the car for the first time?
3) there is no filler cap on the radiator, do i just fill it before connecting the top inlet hose? Otherwise, it will be bone dry and could cause the water pump to suck air for too long.
I know there will be air that i need to get out, but the last thing i want to do is have the water pump completely void of any fluid whatsoever. Or is that ok for a little?
What makes me nervous is that I have the car apart the the water pump off. There is no more fluid draining from the system, but my resevoir still has about the minimum amount in it. So The lower areas (radiator/ front coolant pipes/water pump, are going to be bone dry.
Any help on filling/bleeding as I reassemble to finish this job would be great.
Ill be happy to post some pics after i wrap it up.
07-25-2014, 09:17 PM
#16
AudiWorld Super User
Audi has a special vacuum procedure for filling coolant, but it is not necessary at all. In my opinion it is just another over complicated procedure.
1. Bleeding valves are under the plenum close to the windshield. Red arrow showing one. The other one looks exactly the same and as far as I remember it is nearby. Be very careful with those valves. They are plastic garbage. Use really large screwdriver. May be even some wider tool that can fit in those slots.
2. Just fill the expansion reservoir and keep adding until it stops going down. Coolant will slowly fill the engine. Opening bleeding valves will make this faster. Start the engine and turn heating to high. Keep the bleeding valves opened until they leak just coolant, no air. Keep adding coolant to the reservoir. Basically just like any newer car.
3. No need for that.
1. Bleeding valves are under the plenum close to the windshield. Red arrow showing one. The other one looks exactly the same and as far as I remember it is nearby. Be very careful with those valves. They are plastic garbage. Use really large screwdriver. May be even some wider tool that can fit in those slots.
2. Just fill the expansion reservoir and keep adding until it stops going down. Coolant will slowly fill the engine. Opening bleeding valves will make this faster. Start the engine and turn heating to high. Keep the bleeding valves opened until they leak just coolant, no air. Keep adding coolant to the reservoir. Basically just like any newer car.
3. No need for that.
07-25-2014, 09:40 PM
#17
AudiWorld Super User
+1 What Mishar said, plus some more...
After following what he outlines, once you have the bottle filled up all the way, as the vehicle coolant gets hot, close it up with the cap and leave it closed. Then let car completely cool off--overnight preferably, but at least 6-8 hours. At that point system will likely again be down a bit as the air gets worked out. Fill it one more time to its final level per the bottle markings. That should do it. Has worked on my W12 twice that I have done it, and several times on my 2000 A6 4.2.
I assume you are using either G13 from Audi or G12++ (no longer available from Audi, but widely available from others and indy sellers), and distilled water to make up the mix. I usually use this as a chance to change coolant fully. Thus beyond the usual lower radiator hose pull, I will open a far bottom hose like at the tranny cooler; on a 4.2 I think you have the block drain too that I haven't found on a W12; maybe the oil cooler on a 4.2 is effectively down that low already though. If you don't drain it fully, do not assume you can just put half the total capacity in as coolant first, and then just add the water. Better to pre- mix it to start.
I assume you are using either G13 from Audi or G12++ (no longer available from Audi, but widely available from others and indy sellers), and distilled water to make up the mix. I usually use this as a chance to change coolant fully. Thus beyond the usual lower radiator hose pull, I will open a far bottom hose like at the tranny cooler; on a 4.2 I think you have the block drain too that I haven't found on a W12; maybe the oil cooler on a 4.2 is effectively down that low already though. If you don't drain it fully, do not assume you can just put half the total capacity in as coolant first, and then just add the water. Better to pre- mix it to start.
08-10-2014, 01:35 PM
#20
AudiWorld Member
Thread Starter
I completed the job this past friday. Everything is back to normal!
Here is the parts list for the coolant system (ignore the tie rod related stuff as I am doing that job soon too).
The job I would say was medium in difficulty. I first attempted to do the job without removing the front end. Its tight, but there was seemingly enough room to do the job. I got all the way down to one hose clamp that couldnt be undone without the front end off due to the angle and limited room. Save yourself the extra time fidgeting and trying to do it without the front end off. Trust me i tried for way too long.
CHALLENGING AREAS TO PAY ATTENTION TOO!
The front end actually isnt bad at all. The difficult areas were the 3 bolts holding on the drivers side front bumper cover, the passenger side front bumper bar bolt, the radiator clamps, and the water pump driver rod.
The 3 bolts holding the drivers side front bumper cover were more inaccessable than the passenger side due to the air compressor and tanks. To make this easier, take the front drivers wheel off (and the liner). I did the passenger side 3 bolts from underneath the car without problem.
The passenger side bumper bar bolt needs the passenger headlight removed to get it off. Bolt itself is easy and accessible once headlight is out. (the drivers side is reversed and bolt goes in from bottom so no need for that headlight to come out). Passenger side headlight comes out with 4 bolts, so not too bad. I did it without taking the airbox out using a long extension.
The radiator clamps have a U shaped metal piece that needs to be lifted off with a flathead before the major arteries feeding the radiator can come off. There are 2 big ones and a small one. you can pull the radiator forward just enough to get a screwdriver in to pry the clamp up and out. (i drained system first so didnt need to worry about the massive outflow when you do this.
Finally, the driver rod behind the water pump unit. Make sure to pull the old pump off carefully and out straight. Any angle or pressure and you will break the female end of the water pump where the rod inserts into. If you do that, you will have to replace the 150 dollar water pump. If you dont, and that part looks OK, you may be able to refurb the rest of the unit without that part having to be replaced (replace thermostat and gaskets, etc.).
Job was a lot of work and about 10 hours total. I filled the radiator about half way before reconnecting the top hose so that the burping time would be reduced.
I had to warm her up and cool her down with bleeders open about 4 times to get it level.
Happy to talk on phone, just PM me anytime. I also have the audi tech manuals and can email pics of the details if you need or you can just buy them off ebay for like 20 bucks like i did.
SAVINGS OF ABOUT 1 G!!!!!
Here is the parts list for the coolant system (ignore the tie rod related stuff as I am doing that job soon too).
The job I would say was medium in difficulty. I first attempted to do the job without removing the front end. Its tight, but there was seemingly enough room to do the job. I got all the way down to one hose clamp that couldnt be undone without the front end off due to the angle and limited room. Save yourself the extra time fidgeting and trying to do it without the front end off. Trust me i tried for way too long.
CHALLENGING AREAS TO PAY ATTENTION TOO!
The front end actually isnt bad at all. The difficult areas were the 3 bolts holding on the drivers side front bumper cover, the passenger side front bumper bar bolt, the radiator clamps, and the water pump driver rod.
The 3 bolts holding the drivers side front bumper cover were more inaccessable than the passenger side due to the air compressor and tanks. To make this easier, take the front drivers wheel off (and the liner). I did the passenger side 3 bolts from underneath the car without problem.
The passenger side bumper bar bolt needs the passenger headlight removed to get it off. Bolt itself is easy and accessible once headlight is out. (the drivers side is reversed and bolt goes in from bottom so no need for that headlight to come out). Passenger side headlight comes out with 4 bolts, so not too bad. I did it without taking the airbox out using a long extension.
The radiator clamps have a U shaped metal piece that needs to be lifted off with a flathead before the major arteries feeding the radiator can come off. There are 2 big ones and a small one. you can pull the radiator forward just enough to get a screwdriver in to pry the clamp up and out. (i drained system first so didnt need to worry about the massive outflow when you do this.
Finally, the driver rod behind the water pump unit. Make sure to pull the old pump off carefully and out straight. Any angle or pressure and you will break the female end of the water pump where the rod inserts into. If you do that, you will have to replace the 150 dollar water pump. If you dont, and that part looks OK, you may be able to refurb the rest of the unit without that part having to be replaced (replace thermostat and gaskets, etc.).
Job was a lot of work and about 10 hours total. I filled the radiator about half way before reconnecting the top hose so that the burping time would be reduced.
I had to warm her up and cool her down with bleeders open about 4 times to get it level.
Happy to talk on phone, just PM me anytime. I also have the audi tech manuals and can email pics of the details if you need or you can just buy them off ebay for like 20 bucks like i did.
SAVINGS OF ABOUT 1 G!!!!!
Last edited by dripppps; 08-10-2014 at 01:42 PM.
