Blown Head Gasket?

DieterLange

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Jul 19, 2020
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Brisbane, Australia
TDI
2004 Mk5 Golf 2.0 TDI (BKD)
I have discovered that my passanger carpets are soked (right hand drive no sunroof) I took at the carpet and the insulation and underlay was soked. So after spending about an hour with a hairdryer drying the insulation, underlay and carpets I did some research on what could lead to my carpets becoming wet and I have so far eliminated the following:

- A/C drain hose clogged/broken
-Scuttle and windscreen drains
-Fresh air inlet letting in water

I started thinking that my heater core might be leaking or the hoses leading to it might be leaking. This is supported by the fact that I have a unsolved coolant leak. But the carpets dont smell like coolant but there is no standing water to see if its coolant or not as all if it got absorbed by the insulation and underlay.

So what are some ways to check if it is the heating core. And if it is can I just bypass the coolant pipes from entering into the cabin through the firewall and into the heating core becuase I have never had the need for heating considering I live in Australia.
 

Mach1

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Sep 27, 2005
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Spicewood, Tx.
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05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
How about your coolant level going low?

Or try and get a bit together and see if it has color, or old school taste(not recomended).

You could bypass the heater core with a loop in the hoses, and even pressure test the coolant system.

Hope this helps.
 

DieterLange

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Jul 19, 2020
Location
Brisbane, Australia
TDI
2004 Mk5 Golf 2.0 TDI (BKD)
How about your coolant level going low?

Or try and get a bit together and see if it has color, or old school taste(not recomended).

You could bypass the heater core with a loop in the hoses, and even pressure test the coolant system.

Hope this helps.
My coolant level does go down, I have to top it up about every week (normally to midway between the 2 lines). From what I can see when I squeeze the insulation the water seems to be clear. I'll probably just get the carpet completely dry and go for a drive with the heater cranked all the way on and see if the carpets get wet again. Or better yet get some UV coolant dye incase its a very small leak
 

vwappathy

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May 3, 2018
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Huntsville, AL
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2014 Passat SE TDI MT 2006 Jetta TDI MT
I agree with turbodieseldyke. Unless you were running straight water in your cooling system, you definitely would smell anti-freeze inside the car. Take the cap off the coolant reservoir and compare the smell. You might want to borrow someone with a good nose, haha.

To find your unsolved coolant leak, I would use a cooling system pressure tester. Pull your carpets back first just in case it is a heater core.
 

Problypropylene

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Sep 6, 2017
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Colorado
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'03 Jetta Wagon TDI 5-speed manual, '03 Jetta Wagon TDI auto
It's not the heater core. We had a small leak in one of ours and you will smell it before it gets bad enough to soak carpet (ours was contained inside the hvac system, no wet carpet, very strong smell and light residue on the windshield from the defrost vents.)

Do you have a sunroof? the tubes running in the A-pillar shrink with age and can come disconnected which will leak water into the floorboards.

I've had various door leaks in my mk4 cars. I think the seals just shrink a bit with over 200k miles and nearly 20 years old. You can fix the leaks by adjusting the door alignment inwards with the hinges and latch. The doors have drain holes at the bottom that get clogged with dirt and wax and will then leak into the floorboards if they fill up. You'll have to remove the door panels and window regulators to clean that up.

I would take the carpet and under layment out (it's actually not that hard if you are mechanically inclined) very easy to clean with soap and dry once it's out of the car. If it smells like mildew/mold vinegar and baking soda works well.

While the carpet is out you'll be able to see where the leaks are coming from. Have someone spray a hose around the doors, windsheild, sunroof, etc until you see water coming in, then track it down.

Kind of a PITA, but I hate having a soggy nasty smelling interior. If you're going to keep the car it's worth the trouble to have it dry and clean inside.
 
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DieterLange

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Jul 19, 2020
Location
Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
It's not the heater core. We had a small leak in one of ours and you will smell it before it gets bad enough to soak carpet (ours was contained inside the hvac system, no wet carpet, very strong smell and light residue on the windshield from the defrost vents.)

Do you have a sunroof? the tubes running in the A-pillar shrink with age and can come disconnected which will leak water into the floorboards.

I've had various door leaks in my mk4 cars. I think the seals just shrink a bit with over 200k miles and nearly 20 years old. You can fix the leaks by adjusting the door alignment inwards with the hinges and latch. The doors have drain holes at the bottom that get clogged with dirt and wax and will then leak into the floorboards if they fill up. You'll have to remove the door panels and window regulators to clean that up.

I would take the carpet and under layment out (it's actually not that hard if you are mechanically inclined) very easy to clean with soap and dry once it's out of the car. If it smells like mildew/mold vinegar and baking soda works well.

While the carpet is out you'll be able to see where the leaks are coming from. Have someone spray a hose around the doors, windsheild, sunroof, etc until you see water coming in, then track it down.

Kind of a PITA, but I hate having a soggy nasty smelling interior. If you're going to keep the car it's worth the trouble to have it dry and clean inside.
Mk5 with no sunroof and right hand drive, I have checked the door drain holes and there not clogged. Luckly after drying the carpet, underlay and insulation they no longer have a damp/moldy smell. Probaly get someone to point a hose at the car with the carpets out and see were the water is getting in. For the coolant leak has anyone used a UV dye with a UV flashlight before to see were the water is leaking?
 

Mach1

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05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
On the coolant leak, you could use the dye and light method, there isnt too many leaks I havent spotted just by pressure testing the system and looking under the car with
a dry floor, it will show, have to remove the belly pan though. I would still suspect the heater core.

Have you been topping off the coolant with antifreeze or just H2O?
 

DieterLange

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Jul 19, 2020
Location
Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
On the coolant leak, you could use the dye and light method, there isnt too many leaks I havent spotted just by pressure testing the system and looking under the car with
a dry floor, it will show, have to remove the belly pan though. I would still suspect the heater core.

Have you been topping off the coolant with antifreeze or just H2O?
I've been driving with the skid tray off for about 2 weeks and left a piece of cardboard underneath but I haven't spotted any wet spots. My coolant has dropped again but the carpets are still dry. Ive been topping off with just some distilled water because its not that much water
 

Mach1

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Spicewood, Tx.
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05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
Does the system build up pressure on it? The pressure tester puts a bunch of pressure to spot those hard to find leaks. I have seen leaks large enough for the coolant system to not pressurize.

Does your car have very much antifreeze left in it? I was thinking it was getting fairly watered down and that was why you couldnt smell coolant?

If you are not seeing coolant leaks underneath the vehicle...
 

DieterLange

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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
Does the system build up pressure on it? The pressure tester puts a bunch of pressure to spot those hard to find leaks. I have seen leaks large enough for the coolant system to not pressurize.

Does your car have very much antifreeze left in it? I was thinking it was getting fairly watered down and that was why you couldnt smell coolant?

If you are not seeing coolant leaks underneath the vehicle...
Carpets haven't got wet again but I haven't been running the heater ever (not cold enough to need it), the coolant system does build up pressure when hot. When I open the lid of the expansion tank when at operating temp, air whooses out and the coolant level rises, so I'm assuming the cooling system is pressurising. I don't know how watered down the coolant is, still looks like it has a fair bit of color to it, and if it has a distinct smell if you have the expansion tank lid of when hot. I probably haven't added more than 100-200ml, then again I've only had it for just over a month so dont how much previous owner added if at all, or if it was even leaking before I bought it.

When I was driving the other day I distincicly smelt a hot coolant smell coming into the cabin but after about 30 seconds or so it went away. Checked the carpets when I stopped and the morning after and they were dry, very slightly damp in one point but probaly just some left over moisture from when it got wet the first time.

Ive just washed the car and from first look carpets are still dry I will check tomorrow morning if they are still dry. I'm starting to think the wet carpets were either the previous owner fault or from me spraying the underside of the car the first time I washed it (I didn't do it this time just in case). Still doesn't explain why I have a slow coolant leak that and cant see any evidence of it underneath the car.
 

DieterLange

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2004 Mk5 Golf 2.0 TDI (BKD)
Carpets are still dry after the wash, so that pretty much rules out a rain water leak causing the wet carpets. Its not an A/C drain hose blokage becuase thats the first thing i checked. Ill have to run the car with the heater on for a long drive and see if the carpets get wet.

Im really lost on where to even start looking for the leak becuase I havnt found evedince of a leak. Could this mean a water pump leak or coolant flang faliure? Whats the best way to find a leak if a physical inspection has found nothing?
 
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Mach1

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I would find a convenient day to run the heater and do so, I would pressure test the coolant system, I would pull back the carpet and leave it back just for diagnostic reasons,
The heater core leaks are pesky sometimes to diagnose and you dont want to do one unless absolutely sure its leaking. Somewhere in there I would exercise the heater/ac doors. Sometimes the vapor/liquid can get caught in the doors and plenums.

A light shined up into the doors and unit might be a good thing to do as well.

They are a pain to troubleshoot however nothing like replacing a heater core.
 

DieterLange

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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
I would find a convenient day to run the heater and do so, I would pressure test the coolant system, I would pull back the carpet and leave it back just for diagnostic reasons,
The heater core leaks are pesky sometimes to diagnose and you dont want to do one unless absolutely sure its leaking. Somewhere in there I would exercise the heater/ac doors. Sometimes the vapor/liquid can get caught in the doors and plenums.

A light shined up into the doors and unit might be a good thing to do as well.

They are a pain to troubleshoot however nothing like replacing a heater core.
If it is leaking ill just bypass it, can't be bothered to replace it plus I don't ever use it anyway. Would a heatcore be bypass be reversable becuase if so I might consider doing one and seeing if my coolant level still drops. The coolant doesnt drop consistently, it will stay the same for 3 mornings straight and then on the 4th morning the coolant will be below minumum on the expansion tank with no water underneath the car (skid tray removed at the moment).
 
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Mach1

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Yeah you could bypass, just take note on how you bypass it so thats its easily reversable.

That would be some good diagnostic as well, it might be a little while however you could tell if thats the leak or not, good call.

My other recommendation would be to seal all the openings that are exposed from the bypass, here in Texas we get alot of criters that like to burrow into openings.

Good thoughts..I see Brisbane, yeah you dont need any heater..like here in Texas..
 

DieterLange

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Jul 19, 2020
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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
I'm not really sure that its the heater core, because my coolant level is dropping much faster now (have to top up every morning) but carpets are still dry.
 

DieterLange

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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
After running some errands this morning (~40km) and the car standing for ~4-5 hours I checked the coolant to see that it had dropped by about 5cm or so. I opened the oil cap and to my surprise saw this but the dipstick was clean no sludge just pure oil but the crankcase breather had some sludge build-up around the sides. After doing some research I found that it could just be condensation in the engine and not a blown head gasket but then again I don't do any short trips and the car always get up to operating temp. So far my car has leaked just over 2L of coolant so I find it odd that I've only found sludge now. What do you guys think, blown hg or condensation or something else?

Edit: Started the car just now and it almost sounded like the pistons were hitting something or knocking as if they were facing some resistance when cranking like it was hesitating to crank, I stopped cranking immediately when it happened and then cranked again and it started almost immediately without hesitation.
 
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DieterLange

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Jul 19, 2020
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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
Any thoughts? I've been doing lots of reading and I'm scared that it might be a cracked cylinder head seeing as the early BKD engines were prone to crack. I don't know what to do, to be honest, seems like the only way to sort this out would be to take off the head which I don't have time to do at the moment. Don't know if it would be worthwhile keeping if its got a cracked cylinder head.
 

Tdijarhead

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Nov 10, 2013
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Lawrenceville PA
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
An oil cooler leak could cause water in the oil. If you have no other external signs of a leak it might be worth putting a new cooler in.

Is there any sign of dampness on top of your transmission? I had a small leak at my coolant temperature sensor that pooled a bit on top of the transmission.

If your car is a PD how about the little coolant hose that comes into the back of the head behind the tandem pump?

How about the tandem pump if you have a PD?
 

DieterLange

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Jul 19, 2020
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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
An oil cooler leak could cause water in the oil. If you have no other external signs of a leak it might be worth putting a new cooler in.

Is there any sign of dampness on top of your transmission? I had a small leak at my coolant temperature sensor that pooled a bit on top of the transmission.

If your car is a PD how about the little coolant hose that comes into the back of the head behind the tandem pump?

How about the tandem pump if you have a PD?
I've checked for water/dampness on the top of the gearbox and found nothing and checked the coolant flange but that seems fine.

Is there any way to check if the oil cooler is the cause of the leak? Don't really want to replace it if I have to seeing as its just over $400 (AUD) for a new one.

For the past 3 days, I've been taking the cap of the expansion tank after driving to release pressure and so far I haven't lost any coolant. I'll continue to do it for a more conclusive result will post results after another week. When I get around to it ill also do a compression test and post results but I don't really have time to do one at the moment.

How is the tandem pump related to the cooling system? I thought it was just a secondary fuel pump.
 

Tdijarhead

Top Post Dawg
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Nov 10, 2013
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Lawrenceville PA
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
I misspoke about the tandem pump. Internal leaking there mixes oil and diesel not oil and coolant.

I’m not sure how you would check an oil cooler idparts here in the states has them for less than $100.

I have 2 or 3 used but serviceable ones laying around in my garage, so I’d just swap one out to test it. That won’t help you though.
 

DieterLange

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Jul 19, 2020
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Brisbane, Australia
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2004 Mk5 Golf 2.0 TDI (BKD)
couldn't I take off the two coolant hoses block of one of the outlets/inlets and pressure test it? (blowing out the water before pressure testing so I don't force more water into the oil)

Or I could do something like this
 
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Tdijarhead

Top Post Dawg
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Nov 10, 2013
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Lawrenceville PA
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
If you’re going to try that, just remove the cooler, it’s held on by just one bolt. You might want to get the two new gaskets though. Here in the states they are about $4 each. An upper and a lower gasket they are different.
 

VWDal

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May 29, 2019
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DFW
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05 Passat TDI
Hi everyone, I am doing this job right now. How is everyone removing the oil cooler? Do you need to take off the turbo oil lines beneath it first? I can get the 32mm socket on, but not the wrench - anyone else having this issue?
 
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