Help what’s gonna by on in this pic. And why.

Chris_TDI_98

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Joined
Jul 19, 2012
Location
Hartford, CT
TDI
1998 Jetta TDI 1.9L mk3 1Z AHU
Anyone ever see something like this before.
How did you fix it.
Also, apparently the coolant temp sensor is dead or disconnected/broken wire because the glow plugs run full cycle (10 sec) above 45 degrees F when they should run and immediately shut off after 2 sec.

 

ToddA1

Top Post Dawg
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Aug 3, 2011
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NJ 08002
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'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
I’d spend money on routine maintenance, rather than leds and other wants. Rather than the car getting stolen, you’re slowing killing it.

-Todd
 

Chris_TDI_98

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Jul 19, 2012
Location
Hartford, CT
TDI
1998 Jetta TDI 1.9L mk3 1Z AHU
I’d spend money on routine maintenance, rather than leds and other wants. Rather than the car getting stolen, you’re slowing killing it.
For real. I’ll do coolant flush and refill next.
What’s the best spot along the coolant pathway to unhook a hose and put a garden hose in and blast it with water til it’s clear and clean??
 

RoseBud68

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Dec 16, 2016
Location
PSL FL
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'99 mk3 Jetta 1.9
I’d spend money on routine maintenance, rather than leds and other wants. Rather than the car getting stolen, you’re slowing killing it.

-Todd
Could not agree more with this ^^^^. But hey, these kids today are only thinking about one thing.
 

My_name_is_Rob

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Apr 27, 2012
Location
Mexico 🇲🇽
TDI
2013 A4 Quattro
Any tip on which spray it with so it gets off the gunk and not hurt the wires hoses and sensors ??
I sometimes use an engine degreaser on mine, but it should be a cold engine, and it should be rinsed off with water before running the engine. Most wand car washes have an engine and tire degreaser as well, and a good soak does wonders.
 

ketchupshirt88

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Joined
Oct 31, 2012
Location
waupaca, WI
TDI
2005 Passat daily, a bunch of others in the graveyard out back...
For real. I’ll do coolant flush and refill next.
What’s the best spot along the coolant pathway to unhook a hose and put a garden hose in and blast it with water til it’s clear and clean??
All of them... seriously, it’s the only way to even get a majority of the old stuff out. You want to flush the heater core, radiator, head, block, everything. You also may find that the “quick connections” with the clips and orings at the lower radiator and thermostat don’t want to seal anymore once opened. I used “right stuff” to remedy that and just open it at the hose clamp instead of the clip thing.

Some consider it bad to use green coolant in a VW... but it’s a 20 year old car in rough shape anyway, as long as you don’t mix coolant types it doesn’t really matter.

That housing is a pretty common issue with cracks, but at least it’s easy to get to and fairly cheap to replace.
 

Vince Waldon

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Apr 25, 2009
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Edmonton AB Canada
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2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
What’s the best spot along the coolant pathway to unhook a hose and put a garden hose in and blast it with water til it’s clear and clean??
There isn't, because there are multiple paths, some of which are only open when the engine warms up. You also don't want to blast a system built for 15 psi with a 40 psi garden hose... or your next post will be about replacing a heater core. :) :)

You'll need to drain it as best you can, fill it with water, run it up to temperature, let it cool, drain it, re-fill with water... etc etc etc... until what you drain is clear. 2-3 times generally does it.

Some people pull the t-stat so that they don't have to run the engine all the way up to temperature.

All of this is in the service manual, BTW, which would probably be a great investment, given how much work you have ahead of you with this car, per all the threads... and you'll probably discover more stuff as you dig in that you'll want to research.
 

turbodieseldyke

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Jun 6, 2010
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Free Mustache Rides
TDI
98 jetta
You also don't want to blast a system built for 15 psi with a 40 psi garden hose... or your next post will be about replacing a heater core. :) :)
Assuming the lower hose (or something) will be disconnected, the system will never even reach 4psi.

To answer Chris: when I flushed mine, my nozzle fit perfectly into the reservoir cap hole, so that's where I stuck the hose. YNMV (Your Nozzle May Vary)
 

Vince Waldon

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Edmonton AB Canada
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2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Assuming the lower hose (or something) will be disconnected, the system will never even reach 4psi.
If there's any restriction, at all, which there could well be if different coolants have been mixed or the system has gunk in it... the system pressure can reach garden hose pressure... and it can be the last straw for an aging heater core.

Been there, seen it with my own eyes (luckily not my car... I was running towards my friend's car screaming "STOPPPPPP!!!!" at the time.) :)

To answer Chris: when I flushed mine, my nozzle fit perfectly into the reservoir cap hole, so that's where I stuck the hose. YNMV (Your Nozzle May Vary)
With the t-stat closed a large segment of the cooling system circuit will not be flushed simply forcing water down the reservoir... 'cause the t-stat's exact job is to isolate that segment from normal flow.
 

burn_your_money

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Oct 16, 2012
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Missouri
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99 Beetle, 96 B4V, 05 Passat wagon
Since you're going to have the cooling system apart anyways, you may as well replace the lower rad hose and any other hoses below the injection pump since it looks like it's leaking and diesel loves to eat coolant hoses.



If you can find somewhere with a hot pressure washer it will have your engine looking great in minutes. Whenever I'm washing my engine I just avoid the alternator with direct spray. I figure if I wreck anything with the pressure washer it was about to go anyways and I'd rather it go at home then on the road. So far I haven't wrecked anything with it. The key of course is to keep the pressure low enough to not blow brittle plastic apart. I find it easiest to adjust by moving the wand further away from the engine.
 

Chris_TDI_98

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Jul 19, 2012
Location
Hartford, CT
TDI
1998 Jetta TDI 1.9L mk3 1Z AHU
Sorry.
Can we get a name and/or part number for the “cracked housing” in the photo?
Just to be totally sure.
Murphy’s Law has been tending to strike whenever and wherever possible here recently.
 

Steve Addy

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Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Sorry.
Can we get a name and/or part number for the “cracked housing” in the photo?
Just to be totally sure.
Murphy’s Law has been tending to strike whenever and wherever possible here recently.

028121132A is the most common part number given for it, but that's VW and not the part number used by some manufacturers.


Steve
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
It's the Cylinder Head Coolant Flange. If you plan on keeping the car for a long time, Choochlyman makes an aluminum replacement. It's the last one you'll ever have to buy. I've replaced OEM due to flattened o-rings, and aftermarket due to just plain poor quality and warping (including the longitudinal cracks like you have).




On this picture you can see the manufacturing defects on the aftermarket on the right vs the OEM one on the left. The one on the right cracked lengthwise and the end that attached to the head was egg shaped from the heat, in addition to being no longer flat.





 
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Chris_TDI_98

Veteran Member
Joined
Jul 19, 2012
Location
Hartford, CT
TDI
1998 Jetta TDI 1.9L mk3 1Z AHU
Got the part at eEuroparts. Love being located nearby their warehouse!
Any tips or tricks on removing the cracked one and installing this new one?
Is it just a simple
1. unbolt the two bolts holding on the old cracked one,
2. pull off the hoses,
3. push the hoses on the new one,
4. and bolt it in?
 

Steve Addy

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Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I don't like that brand but if the casting looks clean I would use it.

Check to be sure the small steel inserts do not protrude beyond either side. If they do you will need to grind the excess off before installing. I've seen it before where the steel protrudes on the backside by about 1mm and the flange won't seal flush with the cylinder head until the extra is removed.

Steve
 

Chris_TDI_98

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Jul 19, 2012
Location
Hartford, CT
TDI
1998 Jetta TDI 1.9L mk3 1Z AHU
Good point, Steve. I checked the ends of those metal sleeves, here’s what they look like:








Looks good, and feels smooth to the touch!
 
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