coolant diagram

[98A4TurboAWD]

Having a hell of a time tracking down a cooling leak. It's a phantom I tell you. I am about to pull the front of the car apart so I can get in and get a better look but a diagram will help me before I get to that point.

I have tried searching and have come up short. I seem to find every vw, tdi, and audi engine aside from the one I need.

Any help is appreciated.

[bakedziti]

http://workshop-manuals.com/audi/a4_..._coolant_pipe/

This is the only free manual I have access to; it can be a pain with the popups, but use the left hand toolbar to navigate within the cooling section.

[Crucible35]

When you first start the car do you hear any water rushing through your dash when you move the car from parked? I had a coolant leak that went directly from the water jacket into Cylinder 3. The belief was that it was caused when I had the stage two oil consumption fix (pistons and rings) where they created some scoring on the cylinder wall that eventually made it into the water jacket.
Prior to that, I did need to have my water pump replaced (as did many B8 A4s) since there were flaws with the old plastic water pump. They leaked quite a bit.

[MacFady]

Happy hunting

[98A4TurboAWD]

awesome! thanks fellas. i am suspecting it is the return line on the turbo.

[98A4TurboAWD]

Actually appears to be the supply pipe.


If I'm seeing this right, I need this pipe: https://www.ecstuning.com/b-genuine-...ly/06h121497b/

[estrov]

Actually appears to be the supply pipe.


If I'm seeing this right, I need this pipe: https://www.ecstuning.com/b-genuine-...ly/06h121497b/

I replaced that line and had to remove the turbo to do so.

[98A4TurboAWD]

I replaced that line and had to remove the turbo to do so.

Damn, really? What makes it necessary to remove the turbo? I got eyes on both banjo bolts, I was hoping I could get it off without removing the turbo.

Any tips?

[bakedziti]

Damn, really? What makes it necessary to remove the turbo? I got eyes on both banjo bolts, I was hoping I could get it off without removing the turbo.

Any tips?

I learned the hard way that you can remove those banjo bolts without removing the turbo again. Long story short; I neglected a crush washer for the return line. If you still have the original T55 in there, or even one of ECS' Hex replacements, you can use a drive bit and a box wrench to remove the banjo bolt. Just tap the bit out of the 3/8 socket in a vice and you'll get more clearance. Small hands and a long set of needle-nose pliers let me finish it from above.

http://m.homedepot.com/p/Husky-T55-T...w&gclsrc=aw.ds

[estrov]

I didn't see a way to get at that behind the turbo. I too, had a crush washer problem with a non-oem turbo and purchased that coolant line thinking it was the problem. It wasn't - it was the crush washer on the turbo leaking. Long story short, I removed the turbo to get at that banjo connection to the block.

Here is how I determined the leak location and this may help you, OP as well. I used pressurized air forced into pipe #25 after removing pipe #18 at clamp #52. This created a leak at my bad banjo connection. It may work for you.

[98A4TurboAWD]

I didn't see a way to get at that behind the turbo. I too, had a crush washer problem with a non-oem turbo and purchased that coolant line thinking it was the problem. It wasn't - it was the crush washer on the turbo leaking. Long story short, I removed the turbo to get at that banjo connection to the block.

Here is how I determined the leak location and this may help you, OP as well. I used pressurized air forced into pipe #25 after removing pipe #18 at clamp #52. This created a leak at my bad banjo connection. It may work for you.

It's definitely the line right where the metal meets the rubber. I did order 4 crush washers for the job though as I would definitely never reuse them.

[98A4TurboAWD]

Just wanted to follow up, in case anybody has this problem. Nothing sucks more than finding an old thread describing your problem then you never find out what it was or how the fix went.

After getting under the car I saw the leak coming from the line in the picture above. Turned out that indeed that was the cause of the leak, and the part from ECS was the right part.


I am making this to let you know that if you attempt this fix without putting your car in service position, you are doing yourself a great disservice. Had I put it into service position, it would have been a couple hour job. Instead I worked on it for 5 hours yesterday. After 4.5, I threw in the towel and put it into service position then left it until this morning. I went out this morning around 11:30am and was done by 12:30. I'm not kidding. Somebody mentioned that pulling the turbo is necessary. That is not true. If I did this again and put it into service position, I'd be done within a couple hours start to finish including cleanup.

Service position > Remove N75 > Remove other thing bolted on turbo by N75 held in by 3 screws > Air box. This is all just removed for room.

I tried so hard to get this in from the bottom but the problem is keeping the crush washer on the banjo that sits at the block from falling off while you try to get it lined up. I know people use a drop of superglue in some cases, but honestly I don't think it would have held with how tough this is to do from the bottom. Doesn't help that I have had a valve cover leaking for the last 3 years so everything is a disaster over here.

You'll need your new line (above).

4 new washers:


If you don't have a set, this was like $25 prime on Amazon. You'll need the 14mm and 6mm if memory serves.


Remove airbox to have easy access to the first banjo bolt:


Put the star head into the banjo. This particular bit has a 5/8" head on it so that's the wrench I used.


An extension with a swivel makes removing the fastener holding the line to the block a breeze:


Once you're in service position, this is the view that you will have - this makes the job a breeze. Once you have access to the area between the wastegate and the block, you can easily put the new line in and bolt it down.


Good luck.

My car is fixed. Good experience, as now I know what is down there. If anything else should go wrong, I will know what requires service position and what does not.