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Roman, Technician
Category: Audi
Satisfied Customers: 556
Experience:  over 20 years vw audi and porsche technical repair
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audi A6 Quattro: rear coolant drain plug question

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rear coolant drain plug question- how can I be sure system is flushed?

Roman : Hello ,Here to answer automotive questions and make you feel comfortable and become familiar with your product. Are you talking about the one in the block between the trans and
The engine?Sorry I had to switch to this mode. Some reason I could not type into the space any longer.The plug will have a rubber o ring on it and will not look like a bolt. If this is the drain I think you are asking about.??Let me know so I can answer your question correctly.
Customer: replied 4 years ago.

yes back just short of the transmission...appears to be 2 6 mm side by side..removed the one the instructions tell me to remove and no coolant...why is there 2 of these (neither look like a drain plug just a 6mm allen screw

Then you removed the wrong one. It's not easy to see it. You will need to use a long hex bit with a ball end to get to it easier. Once you pull it out the block will drain.all over the place.

Make sure the engine is hot when you pull the plug this ensures the thermostat is open. Or if you replace the water pump and thermostat temp won't matter. But make sure the engine is cold when you fill it.

Open the breeder on the top metal hose while filling till a solid stream comes out. Then stArt the engine,leave the bleeder open make sure its a solid stream again.

Let me know What happens
The plug is harder to see it is not exactly lined up straight for removal.

Put those back that you removed they are for the oil pan. You don't want to leak oil.
The drain plug is a different color, slightly. And has a bigger head. A goldish color. Not blue or green with a small head like you removed.
Customer: replied 4 years ago.

Yep, its not.breaking free yet.afraid ball allen will round it I have radiator off and most all coolant removed

You can pull the thermostat and water pump only. To flush the block after its all together fill the with using a water hosp through the expansion tank. Leave the prefer open and run the engine. Let it get hot till the t t stat opens so you know water us flowing through the block. Turn on the heat, high but low fan. Once its flushed drain the radiator, pull the bottom hose. Then refill with straight coolant. You will be good after that.
Customer: replied 4 years ago.

ok great, I can skip the plug in the back. thanks much!! attempting to replace cam and crank seals now... any tricks to assure success? have the correct audi tools...

Just double check there is 16 links between the cam marks before you put it all back together

There's not much else. Except to double check the work
Customer: replied 4 years ago.

Not certain I understand



Are you removing the cams to replace the seal?
If not don't worry about that. I thought you were taking out the cams.

As long as you have seal installer you should be ok.
Customer: replied 4 years ago.

nope, just the cam seals and yes I have the seal puller tool

Then you really should have no problem. You don't need to remove that block plug. You can flush the system the way I have described. I have come across the same situation at the dealer a number if times and this is how all the techs went about to flush the system.

Filling the radiator with coolant and block full of water will make a 50/50 mixture.
Customer: replied 4 years ago.

new themostat is in, waterpump is out...surprise how clean the water was...I am thinking the new pump and gasket dont require any sealant?? is that a correct assumption???

No sealer if its a metal gasket
Customer: replied 4 years ago.

Its paper material gasket...doesnt say anything about sealant and looks like old one didnt have any either...what do you think I should do??


You can use gaskets sealant on paper gaskets. The brown that does not dry and remains sticky is best. Made by permeate. Airplane sealant I think its called.
Customer: replied 4 years ago.

any trick to get the seal pulley to dig into seal??

Pulley? Or puller? To remove the seal?
Pry it out.
How is it going?
Customer: replied 4 years ago.

Finished all three seals without issue...all seems to be good with timing as I have cam pulley s back on etc and new timing belt is under tension

Great, you did a did big job. Is there anything else I can help with don't hesitate to ass.
Did my answer help?
Customer: replied 4 years ago.

had to leave out of town for work this week and wont get back to this until Friday so I hope to hell I dont forget anything! also hoping my timing wont be an issue as I followed instructions to a "t" and after manual 2X crank rotation the cams appear to return to correct alignment so...

If you have any further questions for me just ask?
Roman and 2 other Audi Specialists are ready to help you
Customer: replied 4 years ago.

The transmission occasionally has a slight shift delay at or around 30mph...any thoughts? Car did sit for a few months prior to use

are there any leaks?
Is the fluid full?

This is the first thing to check, then any logged faults.

Let me know?
Customer: replied 4 years ago.

no leaks, I will check fluid level again as I dont recall for certain and I can hook up my Ross-Tech software and run a scan this weekend when I get back home

ok let me know if you find something we will continue
Customer: replied 4 years ago.

no problems so far?
Customer: replied 4 years ago.

she started up and runs smooth, no leaks to be found... was amazed the old coolant had no corrosion at all. need to add coolant after I determine system is empty...

Great. The coolant breaks down over time. You will not see any contamination unless its full of oil.
Customer: replied 4 years ago.

Thanks again Roman, just finishing up some headlight issues with mount tabs and hope to address the transmission this weekend if not before

ok let me know if you have any questions?