i think you need to flush the whole cooling system, it helped on my car

 

Rust? You have rust in your radiator? Are you using the pink or purple coolants? If not, you need to switch to them post-haste.

Also, I'd be interested to get opinions on the idea of running vinegar + distilled water through the radiator for about a week, to break up deposits like in a coffeemaker. It worked on my old Mazda, but I don't know how a Passat would respond.

 

Yes, rust. Not a ton, but a few flakes. I'm running whatever antifreeze was in the car. The previous two owners (they knew each other) always had it serviced at the dealer.

I would likely refill with Prestone one-fill extended life coolant (Yellow). That's what I run in everything else. There's lots of everything else, so I've tried to standardize on fluids.

Vinegar is simply a weak acid - acetic acid actually. I would acid flush now, but I need the freeze protection. The shop doen the road uses some kind of acid to flush cooling systems and they do it on the spot, no running the car for a few days. Maybe I'll find out what they use and hit it with acid now.

It took tons of crud out of my truck - I was amazed. It had 230k at the time. It ran 4 years cooler also. It might take a minute for that to make sense.

 

I would likely refill with Prestone one-fill extended life coolant (Yellow). That's what I run in everything else.

No you will not. I will find you and slap you until you change your mind.

EDIT: YOU PUT GREEN COOLANT IN??? Are you effing stupid or what? You don't know a damn thing about this car, do you? The radiator is aluminum, the block is aluminum and iron, and the coolant pump turbine is PLASTIC. You cannot use orange coolant because it will damage the plastic, and you DEFINITELY can't use green coolant because it will damage the plastic AND the aluminum.

Change that shit out, like right now. No wonder you have rust.

 

Do your Volkswagen a huge favor and don't dump the coolant crap in that you do to your Domestics.

Unlike your Chevy (or Ford, really does it matter?), there's a bit more engineering in your VW. Introducing your Prestone to the VW's cooling system is going to create a nasty chemical reaction which will cause more gunk and plugging-up problems than you have already. And you will also kiss your cooling system corrosion protection goodbye.

Toyotas are the same way. I never use the green/yellow shit in my Toyotas.

Not bashing your domestics, I've had my share (and I don't miss them ). But the VW uses special coolant for a reason, and if you don't want to become another VW statistic, you really should keep her that way.

edit: I have the same problem too, btw. I just flushed mine a few weeks ago and the core is now plugged again. But I don't have rust, I have brown sludge contamination from someone adding the improper coolant somewhere down the line... Keeps filling up in the expansion tank, too.

 

Well I flushed the heater core again and got just as much crud out. mainly black flakes and brown flakes.

I talked to the shop down the road, they don't use acid, they use basically boiling water and compressed air.

I ended up dumping the coolant into buckets, then flushing with hot water, engine on, engine off, back flushing, etc. for about 1 1/2 hours. At the end, I would still get a flake or two every ten minutes. If this keeps up I'm going to put a Y-strainer inline with the heater core. Since basically the heater core is acting as a filter for the coolant.

Against your advice, I put Prestone back in. It is green. It was all I had on hand and I'm going to get freezing weather tonight. I figured after 1 1/2 hours of hot water running through the engine it was probably pretty well purged of the old coolant.

Going to run to the city this afternoon to test the heat!

 

Against your advice, I put Prestone back in. It is green. It was all I had on hand and I'm going to get freezing weather tonight. I figured after 1 1/2 hours of hot water running through the engine it was probably pretty well purged of the old coolant.

Yea, you should be fine as far as contamination goes. Just keep in mind that Prestone doesn't offer the same corrosion protection as the VW/Pentosin.

But I'm not saying your radiator will rust out by tomorrow.

Good to hear you got good heat again. I'm planning on a complete flush this month as well. Hope to acheive the same results.

 

Wow, some of you guys get testy. Should I let it freeze?

BTW - Heat ouput still not good. Better than yesterday, but Apparently we will need to do something different.

The rust was with the stock coolant.

BTW Attofarad, eventually every radiator leaks. My 1996 Dodge has always had the regular old fashioned green stuff. 257,000 miles later, still no leaks on the aluminum radiator.

I'm getting the right stuff from VW tomorrow. I can dump the passat into buckets and use to fill the motorhome. I have that apart right now, and it will take 8 gallons or so to fill.

So the loaded question to you guys. Pink, Red, Purple?

FYI - In regular antifreeze color doesn't matter anymore. It has to do with chemistry. I had found a neat article about antifreeze "colors" in a auto repair trade publication a few years back. I've got it bookmarked somewhere.

Quote from Prestone on the horrific, VW hating stuff I did put in:

Prestone® Extended Life Antifreeze/Coolant is compatible with ANY antifreeze/ coolant – regardless of color – for use in ALL makes and models of cars and light duty trucks. This patented formula provides a high degree of performance durability and carefully balanced protection against temperature extremes and rust corrosion of all cooling system metals, including aluminum.

 

Prestone® Extended Life Antifreeze/Coolant is compatible with ANY antifreeze/ coolant – regardless of color – for use in ALL makes and models of cars and light duty trucks. This patented formula provides a high degree of performance durability and carefully balanced protection against temperature extremes and rust corrosion of all cooling system metals, including aluminum.

1. It doesn't say anything about being plastic-friendly, does it?

2. Of course they're going to tell you it'll work in all cars and trucks; it's not like they're on the hook if you screw up your engine by putting in the wrong stuff anyway. I hate this phrase because it's so overused, but "caveat emptor" nonetheless.

 

Prestone antifreeze is still a blend of ethylene glycol which is not compatible with our cooling systems. Prestone wants you to buy their product, of course they tell you it's compatible.

Then again, you can say the same thing about VW's coolant. But I've seen the damage first hand from using ethylene glycol in my Toyota (blown head gasket) and don't plan on cheaping out again.

 

So the heat was not good last night, and got cooler as the drive went. So I decided to fill the system with some prestone flush today before I head out.

BTW - The Prestone extended life I put in everything is yellow. I have 4 bottles of Petrosin Purple waiting for me at local parts store.

First I unhook the heater, hook up hoses and blow it out I stick the compressed air nozzle through a thick rubber washer and hols that against the hose. You should see the stuff coming out! - amazing the amount of carp I get out. Post pics later. I alternate filling with water, and blowing.

So I don't have the right allen wrench to pull the drain out of the block, so I alternate hooking up various hoses, putting bolts in others, and blowing with compressed air. By the time I'm done I have a gallon of coolant in the bucket that looks like chicken soup, there's so much stuff floating around! Keep in mind this has been in the system for less than 24 hours, with 2 1/2 hours drive time!

I then flushed with the garden hose again, filled 4 buckets with more chicken soup, run it clear for an hour, poured in the flush and I'm off.

I'm going to add a strainer to the heater hose circuit, that looks to be the only viable way to keep it from plugging.

 

no no no... stop what you're doing dude... the reason deus was so "mouthy" (more than normal) as well as the other few people warning you is a good indication of what you're doing is wrong. i will tell you FOR FACT as a mechanic in training (we actually test shit to destroy it in order to learn what it takes) that what you're doing is a terrible idea....

drain that shit out of your car, fill it with water, let thermostat open
drain it again
put more water in, let thermostat open again
and drain it once more....

as stated above these "universal" coolants out there are a TERRIBLE idea. you have NO idea how many customers i've dealt with in my current job bitching at us because of what the bottle said, and HOW BADLY it fucked their system.
from gel to leaks emptying their system to the point of new head gasket!

seriously, avoid the purple stuff, and get the vw pentosin pink/red G12 or G12+.
the reason deus said "pink/purple" was because back in 98 or so and previous, vw/audi had a previous concoction of G12 that was purple.
it's specified for the vehicle for more than just getting them money...
you think the chicken soup you have now is bad? wait down the road and dont come back complaining how the reliability of your car sucks balls.

 

seriously, avoid the purple stuff, and get the vw pentosin pink/red G12 or G12+.
the reason deus said "pink/purple" was because back in 98 or so and previous, vw/audi had a previous concoction of G12 that was purple.

Hmm. I thought G12 was pink and G12+ was purple. Have they gone back to pink again?

 

Sounds to me like he intended(and then did do) more work on the coolant system and didn't want his car to freeze. I'd rather throw in 10 bucks worth of prestone which will be completely flushed out then 40 dollars worth of pentosin that I'm just going to throw away in less then a week...its not going to cause any harm over night.

Anyway OP - you need G12 coolant for the certain model your of the passat, just make sure its the right one regardless of purple pink yellow plaid poka-dot before you put it in or it will destroy your water pump, at the least.

 

Sounds to me like he intended(and then did do) more work on the coolant system and didn't want his car to freeze. I'd rather throw in 10 bucks worth of prestone which will be completely flushed out then 40 dollars worth of pentosin that I'm just going to throw away in less then a week...its not going to cause any harm over night.

Or he could leave it empty. It can't freeze if it's empty, can it?

Anyway, I'm done bitching now.

 

I flushed my core as well as the rest of the cooling system last night and upon driving today I've nasty liquid-suction/pumping sound upon light acceleration in 1st and 2nd gear. Any ideas?

 

the problem you're having is you perhaps didn't fully burp the system, and the waterpump hit an air pocket. is your coolant level lower than normal? give it a check asap.

Hmm. I thought G12 was pink and G12+ was purple. Have they gone back to pink again?

oh, you're correct in what you were saying, i was talking 100% OEM fluids used. back in the past vw supposedly used a g12 that was purple. personally, i have never seen the g12plus outside of the bottle, so you've got more info on me there, if it is, or isn't purple now.

Being an engineer and skeptic by nature I do have to ask how is VW's aluminum, cast iron, and plastic different from everyone elses?

Also, I just took about 40 gallons of old antifreeze to the truck repair shop for recycling. I had a bucket out back for several years that had a mix of both red extended from something I forget now, and some old green. Well it was full of waxy goo, and the bucket interior was coated with wax. It smelled like rancid fruit juice.

FYI - At the truck shop they have two waste coolant streams. Regular green - gets filtered, tested, and chemically enhanced as needed right on site with two machines.

All other long-life coolants get collected in barrels and sent off-site for processing. This product is then offered back for sale as recycled "extended life" coolant to these shops, fleets, etc. He was unsure of what specs it's meant for as they do not use it. Though he grinned as I was pouring the VW stuff in and said your making that barrel worth more huh?

well, let me just say this, and i mean no offense. you are an engineer, not a mechanic. those guys at the recycling plants may sell that stuff back off, but that's only because antifreze has a high price right now. it's a business they can make a quick buck in, while still acting as a "recycling and disposal" facility getting bonuses from the state.

it may be clean crap, but it's still crap.

lets see the condition of your seals and gaskets after you use that junk.

 

mjs361 - There's still air trapped in your heater core. It will work it's way out.

FYI All - Breathe easier. I have (4) 1.75 bottles of Pink Pentosin in hand. At $23 a bottle. And I didn't even get kissed!

I'll purge and flush again tomorrow. Same routine. Only I'll use the Pentosin to fill back up.

Being an engineer and skeptic by nature I do have to ask how is VW's aluminum, cast iron, and plastic different from everyone elses?

Also, I just took about 40 gallons of old antifreeze to the truck repair shop for recycling. I had a bucket out back for several years that had a mix of both red extended from something I forget now, and some old green. Well it was full of waxy goo, and the bucket interior was coated with wax. It smelled like rancid fruit juice.

FYI - At the truck shop they have two waste coolant streams. Regular green - gets filtered, tested, and chemically enhanced as needed right on site with two machines.

All other long-life coolants get collected in barrels and sent off-site for processing. This product is then offered back for sale as recycled "extended life" coolant to these shops, fleets, etc. He was unsure of what specs it's meant for as they do not use it. Though he grinned as I was pouring the VW stuff in and said your making that barrel worth more huh?

So it seems the blast with compressed air/water did it to the core. I drove for about 2 hours today. Outside air temp was 48, air delivery temp at the dash, fan on 1, was 130 to 150 degrees. All day, drove with the sunroof open. It was baking my wife in the car this evening, in the 30's outside. She was officially too hot!

FYI - I think I am still going to add a strainer. I picked up a Grainger part number 4yd29. I have used these for other inline strainer needs in the past. The manufacturer will tell you they are only for water, but I can tell you from experience they tolerate coolant and diesel fuel just fine.

Thanks all.

 

Being an engineer and skeptic by nature I do have to ask how is VW's aluminum, cast iron, and plastic different from everyone elses?

I put all sorts of shit into my wife's chevy corsica V6 before I knew any better. Mixed different types and grades of fluids, went quadruple service times before flushing etc etc, just unbelievable stuff. I'm selling it now with 160K and its running like a champ, lol. Thing is we can't stand it anymore because the drive, fit and finish, styling, quality and everything about the VW's make the sale for us. They have personality, and along with charming quirks they have strange ones too.


Point is that with regards to the quote, after owning just 3 different VW's for 9 years I NEVER doubt the ability for them to be phsychotically finicky about the strangest things.

PS
1 pascal (Pa) ≡ 1 N/m2 ≡ 1 J/m3 ≡ 1 kg/(m·s2)...? I can't figure out what you are referring to with 50PA. Maybe nothing and I'm just over thinking things.

 

formoeshin - 50 Pascals is the standard test pressure for measuring air leakage rates in buildings in the US. If I lived in Canada, I would be 75 Pascals.

I do Building Science consulting, testing and research. I decided awhile back to change my online identity to something anonymous.

 

I'd never own an air cooled VW. Sorry. Though I'm a fan of Deutz engines.

 

I am running the Yellow coolant too. I don't know if it is Prestone or some other kind. (and I don't care,it was on sale and had a rebate!) Flushed all of the brown crud out last year when I had the heads off.

Update, I am using Peak 150K coolant. It was free when I got it.

 

Chemically, the Yellow Prestone and the Pink Pentosin look identical. I spent the $100 on the Pink, so don't flame me!

But, I must comment. I just flushed the cooling system on our motorhome. I know for a fact the green coolant has been in there for 10 years. I ran everything through filter cloth - and found NOTHING.

I got almost 1/4 cup of crud out of the passat. It will be interesting to see what the strainer catches!

 

OK all here's an update.

Since last posting I flushed the whole block again. I couldn't get the right wrench to get the drain plug out of the bottom of the block. So instead I ran the engine, and flushed with straight hot water right out of the water heater. I did this for nearly the entire day. Setting the throttle up to 2000 and 3000 rpms. I switched where I put the water in, where I let the water run out, etc. I blew out with compressed air, alternating in and out ports, etc.

I had a small lake forming on my property.

What's one thing that NEVER happened? The flakes and bits of crud never stopped coming. After hours and hours and hours they only slowed down.

So I put the strainer in the supply line, and filled up with pink pentosin. Well today the wife had enough. At 7 degrees outside temp. The delivery air temp inside was 67 degrees. Only a 60 degree temperature rise. When I put this all back together a while back I had 100 degree temperature rise.

BTW - This is my standard. Engine warmed up, cruising at 60 mph, air delivery set to panel, a stick thermometer stuck in the vent grill. Then compare outside temp on your guage panel to air delivery temp. Initially I had 100 degrees rise, now I have 60.

So I pulled the strainer and guess what - screen is better than 60% clogged with more flakes and bits of rubber. So in two months time enough crud circulated through my strainer to drop flow too low.

I pulled the strainer, scrubbed the screen, rinsed the housing out, put it all back in and now get 100 degree rise again. Which still isn't as good as any other car on my property, but is apparently as good as it gets for this car!

Also, FYI - I had 150 degree coolant going into the core and 100 degree coolant coming out. The engine is up to temp, but the hoses loose that much heat before getting to the core - which I think is part of the problem.

 

wow that is alot of crap.. I am fixen to flush mine sounds like I might have fun.. thanks for the updates..
helps me know what to expect..

 

Some Pictures for you

Again, wanted to point out this is the screen after being in car for 2 months. It was installed after flushing and blowing engine out for 2 days!

The strainer setup before going back into the car

What rinsed out of the filter housing

The dirty screen

What came out of the screen

 

Neat idea for the in-line heater core filter.
(if I'm ever at your house, I know which bowls not to eat out of)

 

geeeeeeeeeeeeeeeeeeeeeeez

What are the condition of your hoses? Thats the only thing I can imagine that would continue to degrade and fall apart...besides maybe the water pump. I'm pretty sure that when I flushed my system out that the third round or so omitted any flakes or crud.

My particulates kind of resembled yours without the black chunks.

 

The light brown flakes are on the inside of the hoses. I've seen the insides of many of them. The hoses seem solid, and look good , other than the brown stuff lining them.

I have a theory that at some point someone put the wrong coolant in - which would react with the film of coolant still on the hoses. And maybe after making the brown goo and a good flushing - this is what you get.

The black chunks are definitely rubber.

The bowls - come on, is it that big a deal? Seriously though - they are porcelain with a hard glaze. After a trip through the dishwasher they'll be fine. Probably safer than the well water I drank when I was growing up! Uhh, maybe THAT explains some things.....

 

50pascals...where did you get the parts for your heater core strainer?

 

He mentioned 'Grainger' in an earlier post.

 

50pascals, did you notice any animals mysteriously dying in your neighborhood over the last year oke:

 

Strainer is Grainger # 4yd29

http://www.grainger.com/Grainger/items/4YD29?Pid=search

@yetanother20v No, nothing dying. I set up appropriate pans, etc. to gather everything until water runs clear. The trace chemicals left are probably pale in comparison to what naturally leaks out of all the other equipment on the property. Not to mention what the surrounding farms spray on their fields!

BTW - I've looked into this coolant chemistry thing more and had discussions with the rep from BG and a friend who is a chemist. The resultant sludge, coating, flakes, etc. Are a result of a polymerization reaction between the different coolant packages. The polymer is apparently a short chain - basically wax. This was evidenced by the waxy goo present in the bucket I sent for recycling.

Citric acid works well because the acid removes corrosion, and is a mild acid. And also because it has some mild solvent properties as well to dissolve wax. I suspect that flushing with some added alcohol (or other mild solvent) would imrpove the results. I don't plan to try alcohol right now. But the thought of a non-foaming degreaser doesn't scare me. Hand cleaner or purple power might find their way into the mix.

The first ingredient in the BG cooling system flush is citric acid - go figure.

For now I've got the box of citric acid powder from ebay. And I just realized I have a few gallons of purple power on the shelf....

I will be doing the whole works on the car tonight!

Interesting to see what will come out.

 

Strainer is Grainger # 4yd29

http://www.grainger.com/Grainger/items/4YD29?Pid=search

I'm so putting that inline filter on my car! Do you have a pic of the install?

I pulled the passenger side heater hose back to see if anything would come out, and I got nothing...no air or coolant out the bleeder hole. Both heater hoses were hot, though.

Am I losing coolant, or what? Seems like there is a large amount of air trapped somewhere. Engine temp stayed at 190 the whole trip.

I figured out a trick today bleeding air from the system. I went to PepBoys and picked up a small vacuum 'T' and 3' of wiper fluid hose. I pressed the 'T' into the bleeder hole (with a small screw sealing the open end) in the hose and attached the wiper hose to it. The other end went into a small container of distilled water.

I held the overflow reservoir up high and at an angle so the hose off the top pipe over the engine rose up without any downward dips, held the other hose in the distilled water container, and had my wife rev the engine to 3k, then back to idle. Every time the engine returned to idle, bubbles came out of the system. We did this until it looked like we got them all.

There are only a few small gurgling sounds now and I hope they work themselves out. Heat is great (for now). Just as long as it works for the next 800 miles (to Mammoth and back:driving I'm good.

-greg