Dried coolant found on oil pan

needshelp said:

There is a screw on the front of the engine below the vacuum bottle location. You have to look under the line to see it.

There is another bolt that requires a 8mm hex bit located below the location of the engine coolant temperature sensor

What is the VACUUM BOTTLE

What is the LINE

What is the ENGINE COOLANT TEMPERATURE SENSOR

Please help..any one have pics or a diagram?

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Vaccum bottle is the black round sphere hanging on the right front of the engine as you look at it.

The coolant temp sensor is located on the back right of the engine. Identify the back coolant hoses on the engine. they are 1-1.5 inches in diameter. Familiarize yourself with how they run around the engine and you'll begin to understand. Temp sensor is wired on the back of the engine on the back-right.

Do a google search and you'll find it. ("temp sensor VW MKIV replace") Hey, there's a youtube video

The electrical connector for the coolant temp sensor (and all other vw electrical connectors for that matter) can be a pain to get off. Look at any other more visible one to understand, but to remove, push the connector on deeper or "tighter" and while doing so, use a finger to pull back on the retention tab, the. While pulling back on the tab, pull entire connector off.

OK..so seems nothing is attached to the pipe anymore anymore..except it inside the block...now all i have to do is get it out of the block.

i am so sorry guys, i am lost here.

is there a site..or a manual where i can see this?

Thanks for all the write ups and comments on this thread. I just completed this, and I think if given the choice, I'd rather do two timing belts back to back. It's not that hard, but pushing and prying on that pipe to wrestle it into position is not fun. I ended up removing more coolant lines than are listed, just to free up some space. Easier typed than done is an understatement for sure.

o-ring replacement on rigid coolant line to block

Guys and gals,
Yesterday was my time for this lovely job. And, indeed, lovely it was! Being a 100% shadetree mechanic who has been relegated to doing 100% curbside repair in front of my townhouse, I must say it was an absolute joy to behold - once I finally came in from the 30-mph wind gusts and had it all sewn back together!
If I had the heated garage my brother, dad, and sisters enjoy at their respective homesteads, I would have knocked this out in a much more pleasant fashion - but it would still be a PITA!
Looking back on things, there are several instances in my motorhead life that I can think of that were less wretched to tackle in terms of both final result (it's just a dang o-ring seal!) and volume of components to remove in order to actually do the job.
Repair jobs I've done that I'd rather do again than this one:

1. remove and replace the automatic transmission on any of my older trucks
2. remove and replace all 4 rotors and install new pads (any car like this profile will suffice)
3. replace front axles and new CV joints
4. struts/shocks replacement
5. VW 99 NB headliner replacement
6. I will just stop now. There are MANY repairs other than this one that come to mind. Mainly, because for such a trivial part, when it eventually stops doing its job (which it will!) there is so much tedium involved - and I was so disappointed that when it was all over, I didn't have any 100-horsepower increase, 25+mpg increase, nor the ability for my car to be 100% invisible to radar as a final result!

Kudos to every one of us who has been here & done it.

Kudos to all of youse who added you insights and experiences to this thread - as well as the OP - back in 2007, I think - seven years ago!
All the nonsense aside, I still love my little 1.9 TDI but NOT my '99 Beetle's shoehorned engine bay.

Guess all my old work trucks - especially the old IH trucks - spoiled my future with modern engine bays!

Happy motoring, all!

heidelberger AKA Adam

So, I have coolant leaking in this same area. I have a 99.5 with 199xxx miles, stock.

The coolant is in the middle of the block(behind the dipstick) all around where the hard line goes into the housing. There is no wetness/leaking under the housing or to the passenger side of the housing. My understanding is that there is an o-ring that goes on the end of the hard line where it connects to the housing.

My question is, this is the same O ring everyone in this thread is talking about replacing that is causing the leak? How does the hardline come out of the housing, I don't see any bolts?

Estergard87 said:

So, I have coolant leaking in this same area. I have a 99.5 with 199xxx miles, stock.

The coolant is in the middle of the block(behind the dipstick) all around where the hard line goes into the housing. There is no wetness/leaking under the housing or to the passenger side of the housing. My understanding is that there is an o-ring that goes on the end of the hard line where it connects to the housing.

My question is, this is the same O ring everyone in this thread is talking about replacing that is causing the leak? How does the hardline come out of the housing, I don't see any bolts?

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Are you referring to where the hard (steel) coolant line enters the engine block? It enters the block almost next to the thermostat, right in the eye of the water pump impeller.

There is a rubber seal on the end of that line. I suppose you could use an O-ring, but the proper VW part is not exactly an o-ring...it has more of a square cross section. The hard steel line is bolted to the engine in at least two places (maybe three). I can't remember 100% right now, but I've changed this line on two 2003 ALH engines. It's not all that difficult, but it is time consuming. Even when all the bolts are removed, it can really stick in the block and be hard to remove.

There's one or two bolts on the front of the engine, and one is back around the corner below the vacuum pump area.

HTH,
Rem

Rembrant said:

Are you referring to where the hard (steel) coolant line enters the engine block? It enters the block almost next to the thermostat, right in the eye of the water pump impeller.

There is a rubber seal on the end of that line. I suppose you could use an O-ring, but the proper VW part is not exactly an o-ring...it has more of a square cross section. The hard steel line is bolted to the engine in at least two places (maybe three). I can't remember 100% right now, but I've changed this line on two 2003 ALH engines. It's not all that difficult, but it is time consuming. Even when all the bolts are removed, it can really stick in the block and be hard to remove.

There's one or two bolts on the front of the engine, and one is back around the corner below the vacuum pump area.

HTH,
Rem

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I read through most of this thread and I am confused now because the way I understood was that there is an o-ring on the end of this hard line that tends to leak.

I think am talking about where the hard steel line goes into the block, under the injection pump and behind the thermostat. For some reason, it is leaking coolant around where it goes into the block. It's wet behind the oil dipstick tube and under the injection pump. What you're saying is I can unbolt it from the block then, and wiggle/gently pry and pull it out?

I have a manual, so I think I can just change the o-ring on the end of it.

http://www.idparts.com/hard-coolant-pipe-ring-early-a4-p-3400.html

I'm going to call them in the morning and see what they say.

Estergard87 said:

What you're saying is I can unbolt it from the block then, and wiggle/gently pry and pull it out?
http://

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Yes. I've replaced this hard coolant line on two 2003 ALH TDI's, and I'll be doing it again shortly on a 2000 ALH. This line rusts all to pieces here.

You have to remove a bunch of stuff...vacuum reservoir ball, all the coolant return hoses, the turbo oil feed line, the plugs/connectors for the IP and the 3rd injector, dipstick tube, etc, etc.

Unbolt the line from the block, and then simply pull it out of the block so that you can replace the o-ring.

Don't know if this was mentioned elsewhere but, when ever I have discovered that the o ring is leaking it is almost always because there is a leak in the injection pump drizzling fuel on the connection. It can deform the thermostat o ring as well. Might want to take care of this one, too. Taking the pump out to fix it's leak makes it easier to remove the coolant pipe and clean the rust out of the bore in the block. I take a 1/2" copper pipe fitting cleaning brush and bend the handle to accommodate getting it squeaky clean before putting the coolant pipe back in.

JETaah said:

Don't know if this was mentioned elsewhere but, when ever I have discovered that the o ring is leaking it is almost always because there is a leak in the injection pump drizzling fuel on the connection.

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Checked my records and I replaced my leaky IP seals on 12/27/2009 and then had to fix the cooling pipe o-ring on 8/24/2011 (It leaked for a while before I found these threads on the forum). Makes sense!

And I just discovered this weekend during oil change that this lovely oring in my Jetta is leaking, now I'm kinda tempted to relegate this one to a shop, but I fear that they might break half of the sensors and destroy some hard line, I have replaced this once in an engine that was out of the car and even then it was remove everything, with the engine in the car this will be for sure a pain in the rear.

Now, does anyone have the part number for the oring?
I found two in this topic, but my parts supplier says those dont exist -.-

Did you try http://www.idparts.com ??
If its a fun o-ring to change I would not want a China made one.

wonneber said:

Did you try http://www.idparts.com ??
If its a fun o-ring to change I would not want a China made one.

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Senso is in Portugal...must be somewhere closer like a VW dealer.

A4's have a choice of two styles...double wide and single narrow.
Get one of each and you got it covered...maybe two of each

I will send an email to VW and go to another parts shop in the weekend, hope that the oring will hold in one piece for a couple more weeks, I wont for sure use a cheap/aftermarket part after seeing the work it takes for sure.

Just a curiosity, given that its just a plain oring, does anyone know the dimensions?
Because I can get pretty cheap/free viton orings, NBR90 is also a cheap candidate, but given that the cooling system runs at 90ºC I wont risk it, but NBR as no problem sealing combustion chambers in my tuned two stroke engines, they run alot cooler(50-60ºC full load), and there is just a 2mm lip of alu between the NBR and the heads/liners, so viton will for sure hold it.

It would be pretty sweet if someone could find the dimensions, I passed by a parts store and they dont have the dimensions, they just sell the new tubes that come with orings, sadly none in stock to measure one

I'm about to undertake the replacement of this o-ring now that it has finally failed at 205k miles.

Are there any tricks to reaching and removing the oil feed line bracket on the exhaust manifold? Can this be removed from the top side?

Thanks

You need only to remove the M6 (10mm head) bolt that holds the clamp to the exhaust manifold bracket. Move the intake tube just past the air box and get at it from the top side.

Make sure you track down the reason the o-ring failed...usually means that the IP or an injector return hose is leaking diesel fuel on that area.

MOGolf said:

[*]Move the pipe out of the engine towards the car's battery. Watch the part of the pipe sticking out towards the front of the engine. It will come up against the dipstick tube. (This is why dieselgeek needs to come up with a shorter replacement.) You'll need to move they pipe above the dipstick tube.

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Would pulling the metal dipstick tube out of the block make this job easier as it would no longer be blocking the coolant pipe? It looks like that metal tube is just inserted into the block and seals with an o-ring. Or is removing the lower dipstick tube just asking for trouble?

You can rotate the metal tube in the block's hole to maneuver the 'tee' part over the lower dipstick tube once the bolts that attach the tube to the block are removed. The plastic dipstick tube needs to be removed.

And it's my turn for this leak, but I may have another issue. I started this thread, which has lead me here. My water pump just blew out, and I had a shop replace my water pump. They then found this leak. Should this be leaking if they did it right?

If I'm understanding correctly, and this plugs directly into the water pump, I would assume this should be able to be corrected during the water pump job.

Am I correct in that assumption?

RustyNuggets said:

And it's my turn for this leak, but I may have another issue. I started this thread, which has lead me here. My water pump just blew out, and I had a shop replace my water pump. They then found this leak. Should this be leaking if they did it right?

If I'm understanding correctly, and this plugs directly into the water pump, I would assume this should be able to be corrected during the water pump job.

Am I correct in that assumption?

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I've read your thread.
The hard pipe o ring replacement and water pump don't need to be done in parallel. I had a water pump fail, which turned into a TB job because it's damn near the same amount of work.

You have not given the forum any photos, vids, or anything that any of us can work with to help you, since in your other thread, the shop is incompetent with this engine. They have not pinpointed the leak. It's time to take it to a specialty shop for these vehicles. Or, take it home, steam or degrease the engine, run it, watch for where leaks are, take DETAILED photos, and post up again.

I'm not trying to be salty. But the quality of help you receive is going to be directly related to the quality of information you provide.

Anyway, if it's the hard coolant pipe to block interface leaking, I did this repair:

https://forums.tdiclub.com/showthread.php?t=491854

My car is in pretty good shape, and this o ring was hammered if you go look at the thread.

We're all here to help, but internet guessing it's the worst case scenario because you'll start throwing money and time to everything but the issue.

Point of interest, some people remove the o-ring from their coolant ball cap.
I actually never had one on my cars for some reason...stuck one on the '01 and
noticed pink all around the rim of the ball. Even pushed up into the sensor wires :-(
This is even after I did the saw-cut into the white part of the sensor "socket" to drain
any potential leaks.
O-ring has been since removed.

This seems like a bad idea... the coolant system can't pressurelize so it will boil at a lower temprature if the cap doesn't seal.

A stock motor will not have a problem without the o-ring. My Golf was that way for over 200k miles and was fine UNTIL I turned up the power then I had a problem. Now replaced head gasket turned power back to stock then noticed the radiator was weeping so again removed o-ring, no more leak all good for the last 8k miles.

My O ring started leaking im going to tackle this job, it looks like a Pita ,it seems the more you take apart, in the front of the block the easier to to do the job, but I see like 2 different seals #s here.

MAXRPM said:

My O ring started leaking im going to tackle this job, it looks like a Pita ,it seems the more you take apart, in the front of the block the easier to to do the job, but I see like 2 different seals #s here.

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Yeah, if you don't know which, get both. Read Jetah's post on the first page again.

With the age getting up in these cars I have found it best to replace these seals along with the thermostat and housing if you never have, as required maintenance. Even if they are not leaking now they get hardened and wear and one bump will knock something loose. As a side note - never seal these seals with silicone sealant. You are only asking for trouble. They must be able to move around as designed.