VW Audi 1.8T Engine Bleeding the coolant system in a B5.5 Passat

Step-by-Step tutorial showing VW-Audi 1.8T 20V engine coolant system bleeding.
If you have funny coolant readings on your temperature sensor and you recently had the system open then you may have air in your coolant system.
I highly recommend following this coolant bleeding system procedure every time the coolant system has been opened.

[@Blaydrnnnr]

I had looked for a bleeder valve for this system, but didnt find one. I just had to replace the alternator on my sons Passat 1.8, (exactly the same as your Audi ) and to do that job, you have to remove the radiator hose. Now he has no heat. I'm guessing that just refilling the coolant expansion tank wont bleed out all the air and I think it may be the reason the heat stopped working, since the system probably has air in it now. I'll give this a try and see if his heat comes back. Cant think of any other reason it would suddenly stop working after replacing the alternator. Thanks for the vid.

[@kyledpiper]

I have an 03' 1.8T AWM. Coolant steamed the car up bad today. Began to overheat so I did the neutral ride, heat on, and limped home for about 1mi. No visible hose leak. The battery bay is filled with fluid, so I was thinking maybe the heater core, before the water pump, thermostat, etc. I topped off with distilled water just to check. Once running, I cracked the reservoir and it backfilled. It took about 5min of running for it to drop maybe from the MAX level to the LOW level. I cracked it again and it filled. The only thing I noticed at the reservoir was that the return was coming in, but the top inch was foamy. Maybe not a head gasket as I did pour in an additive (I know). Interestingly, after the single top-off - there are no more lights or overheating issues whatsoever, at idle OR operating temp at any speed range up to 60mph. Was there something clogged perhaps? A "passed stone". Really odd. I plan to flush and replace the system. The vehicle has 238K and I just replace the oil pressure sensor - runs great.

[@ViikatemiesFIN]

Good vid. I just finished changing my V5 Passats serpentine belt, pulleys and water pump. I had to drain coolant (obviously). After rebuilding the front there was no heat to the cabin. I didn't want to use your method because mine hoses (where the bleeder hole is) have some kind of plastic pipe around them. So I just used the old trick. Park your car steep uphill, remove the coolant cap and it should bleed itself. At least mine did.

[@a-wale6376]

Where u hearing a gurgling sound at the rear from your muffler??..

[@zoubirbelaribi77]

Great video, thanks so much!

[@tomryan7260]

very usefully video thank you....

[@deejamesdaboss]

How do u bleed it cold how will the coolant come out ... I'm. Not mech sorry ???

[@PlaceboAddress]

I replaced the rear coolant flange & need to burp the system. From your video you say do the process after the engine warms, but I'm supposed to let it cool?? I really need to burp my system.

[@DaOneEnOnly]

@placebo addy If I said to warm the system I do not recall the context. You should bleed the coolant system cold. Does that make more sense?

[@n9wox]

Looks like a brand new coolant reservoir. Did yours start to crack or leak?

[@DaOneEnOnly]

Mine was OEM and didn't crack. However it was severely discolored to the point it was hard to see the coolant level.

[@changk4499]

Step 1 after you fill the coolant tank and wait for the anti freeze to come out of the coolant heater hose is the car surpose to be running or off?

[@DaOneEnOnly]

Car should be off the entire time.

[@CJFX_]

what's the grey thing at 1:38 next to the power steering fluid /green thing?

[@DaOneEnOnly]

I assume you are asking about the grey cylinder to the left of the power steering. That is the vacuum pump for the brake booster. It is only fitted on automatics.

[@JohnPooley-te9ei]

Nice1..DaOne & thank u

[@2121heatherh]

Are you supposed to bleed it everyone you add coolant? I didn't and now I'm told my water pump might be bad. Coolent leaks at bottom of engine, not in hoses or radiator. However, since I over filled it with water, it's not leaking. Could it because it pushed out the air that I didn't bleed out the bottom? Is there anything I can do to fix my mistake?

[@DaOneEnOnly]

You could bleed the system now. You only need to bleed it if there is a leak, you drained all the coolant, or if you open the system -as in remove a hose. Sadly I need to know more about the symptoms to understand if it could be the water pump.

[@ndailorw5079]

@@DaOneEnOnly I’ve never used nor have I ever heard or been told to use a 50/50 coolant mix for my 2003 Audi A4 1.8t Quattro. I’ve always used straight coolant, never a 50/50 mix. Are you suggesting or saying that my car should also use a 50/50 coolant mix, that I’ve been doing it wrong all along? Or are you simply saying that the 50/50 mix you do here pertains to this Passat and not to the Audi?

[@andrewszekely6547]

​​@@ndailorw5079 Every car must use 50/50 coolant!!! That translates to -35 degrees Celsius.

[@garypreston6300]

Hello do I bleed it when it's cold then as been on my audi all day trying the get the air out

[@DaOneEnOnly]

Yes bleed cold. Burns are not fun.

[@adesh6953]

Do you have to start the car while bleeding ?

[@DaOneEnOnly]

No, Car should be off. It can be on if required for beginners.

[@classichk2559]

my audi 1.8t start overheat after 10 minute and it have a new waterpump. i dont know what the problem can be. and it working fine on a normal temperature in this 10 minutes

[@DaOneEnOnly]

Unfortunately that could be many things. Impeller failure, coolant leak, air in the system, blockage, head gasket, etc. I'm sorry I can't be of more help. I wish you the best of luck!

[@n9wox]

That happened to me. Temp gauge is usually at 190F. Above that is overheating. I turned the car off and let it cool a bit. Then started to squeeze various coolant hoses to work the air out.

[@fredlivingston46]

Same procedure on a 99 passat ?

[@DaOneEnOnly]

Yes. Should be identical on 99 Passat

[@abbas674]

I used peaks purple cooler for Audi 2006 and up IS that bad?

[@DaOneEnOnly]

The service manual is specific about G12 or newer coolant. I'm not sure if pikes is compliant with those vw standards. I recommend checking the bottle to see if they are listed. If they are not listed then your guess is as good as mine if it is okay or not.

[@luisrew12345]

Depends on year of the audi

[@ftgjoejoe420]

Do u leav the car running

[@DaOneEnOnly]

No

[@DaOneEnOnly]

You do not need to. You should be able to do it without it running by lifting up the bottle. If you're having trouble then you can have it run.

[@n9wox]

You're missing the cover for your cabin filter.

[@bmamalis]

It doesn't have one. It's covered by the large plastic cover that goes over that whole area below the windshield.

[@n9wox]

@@bmamalis That must be the difference between B5.5 & B5. I have a B5 and there is a separate cabin filter cover, and there is no cover over the battery/cowl area.

[@qqwrdthjjj]

there is no cover for the cabin filter

[@stevephillips4333]

Stop bouncing around

[@aaronwillden8067]

"umm"

[@mraolaguez]

Uhh**

[@TheSloganOfficial]

This is the most PROBLEMATIC FUCKIN PIECE OF SHIT OF A EUROPEAN CAR!!!! NEVER AGAIN BUYING EURO CARS!!!!!!