2003 Jetta Coolant Leak

[davidm2232]

I recently purchased a 2003 jetta, my first TDI. i really like the car but i am starting to hate it. i have a leak on the coolant outlet flange. i settled for an automatic as i had a deal on in, but i would much rather have a 5 spd. so, i am stuck with the plastic flange i have heard problems about. i was pleasantly surprised to find a new flange with o-ring for $15 including shipping. the part should be here today or tomorrow. sadly, this is not my only problem. my coolant system is getting pressurized. i can open the resivor and it will hiss after sitting all night. i can also run the car for less than a minute and it will be pressurized. i have come to the conclusion that it is most likely the EGR cooler and not the head gasket. how would i test this before i go through all the work to swap it out? my buddy did the egr delete, so i can get a working cooler from a 2000 jetta. are they the same part? will the exhaust over-pressurize my system, causing more leaks? thanks so much.

 

[davidm2232]

Update: I pulled the EGR cooler (a lot of fun) and i put pressure and heat to it, no leaks. I am still getting pressure in the tank even after 30 seconds of running cold, or in the morning after sitting. there does seem to be soot in the tank. I really don't want to pull the head as i just got the car and the PO recently replaced the timing belt and water pump. I installed the flange earlier this evening and took it for a short test drive. i didn't see a drop in coolant level but time will tell. Any ideas would be greatly appreciated.

 

[djamwolfe]

When you get ready to start your car in the morning, relieve the pressure from the coolant tank, put the cap back on, and start the car. If the coolant lines get pressurized right away, you most likely have a head gasket leak.
From what I understand, you can reuse the timing belt if it has been done recently. But maybe someone with more experience can chime in about that.

Devon

 

[djamwolfe]

Sorry I just re-read your last post and you already did that... Im going to call a headgasket -- just did mine, wasnt too bad.

Devon

 

[dieselfuel]

Install a set of ARP TDI head studs.

Search "tothemax ARP". There, you should find info on how to install them without removing the head.

I plan on installing a set this spring, or summer.

Good luck,

 

[jokila]

Should original head bolts be reused or updating to this a better way for a stock engine?

 

[dieselfuel]

The ARP's are much stronger than stock. That's the point of using them. The ARP's provide more clamping power. You torque the studs to 125 ft/lbs.

I believe the stock bolts you torque to, like, 75 or so.

The ARP studs you want are part # 204-4706 for the ALH engine.

 

[davidm2232]

but would the extra force really help? would it damage the block? i really don't want to throw money at this. different bolts seem to simple. am i just over-thinking it?

 

[zukvw]

the arp bolts are most benifical when you plan on doing future hp upgrades, they will not hurt anything, and could benifit clamping force on your new head gasket, but are not neccesary... make sure when you take your head off, you check to make sure its not warped....goodluck

 

[davidm2232]

So the car has started to overheat on highway drives. Bar's head gasket fix did not work. I am going to replace the head gasket but fear the head is warped. the guy i am having do the job has a new complete head he is willing to sell for $400. I am going to replace the head rather than repairing it to minimize downtime. If it is warped, how much could i sell it for? When i am putting the new head on, how do i know what gasket thickness to use? do i need to worry about the block being warped? The previous owner may have overheated the engine, but i am not sure. how much would you pay to have a friend do a head gasket job if you helped? i would do it myself, but he has all the tools and knowledge that will make the job go much smoother and quicker. thanks so much.

 

[zukvw]

dont but the head unless you need it... just check yours first, the easiest way to check it is with a sraight edge ruler and a flashlight... just put the ruler ont the head and hit with the flashlight on one side if any light passes through to the other side, its warped, then use the other one....the best way to check it is with a micrometer.....as far as how much to pay him, just ask him what would be a fair price, i would say a couple hundred wouldnt be unreasonable.....good luck

 

[Dimitri16V]

make sure it's a quality head from a quality country

 

[mam0032]

I'm having the same problem. I havn't done my head gasket yet, but I'd like to keep up with how yours is going, keep us posted!

One thing I wish I'd known about 70 thousand miles ago is that these MK4's have trouble with the cooling fans. If you put the key in the on position, turn the AC on, with the fan on it's lowest setting, you should see both the AC Fan and the Main Cooling fan start up. When I performed this test on my car two days ago, the main fan wasn't working. Pulled one from the junk yard, plugged it in, and it fired right up. I suspect that's the reason my head gasket is gone, and it probably means the head is warped.

 

[Diesel Mania_26]

check:
- compression
- pull glow plugs check GPs for coolant leaks
- check oil for coolant
- check coolant for oil...

if you pull the head check it with a straight edge - unless your cylinder head is severly damaged it is still repairable $400 for a new rebuiilt one is a decent price - as long as it is done right... valves and such SHOULD be OK but all can be checked... and new gasket new bolts as they are stretch to yield bolts (I hate em - but thats what they are) new gaskets all around...
while you have you rturbo out - its not a bad idea to clean the VNT vanes so that they dont start sticking and causing an 'overboost' condition minutes after you have evreything running again... you can do this in a weekend.

 

[mam0032]

Question for york77777 and rhader,

Is there anything else exhaust coming from the coolant reservoir could be? If the EGR cooler has been ruled out.

 

[Diesel Mania_26]

if I read your question right you are asking:

- is there any other way for exhaust to get into the coolant other than the exhaust and the cylinder head / gasket?

not unless the block is cracked and getting pressure into the coolant - hence the compression checak as well as the oil and coolant check for oil or coolant respectively ...

you can remove the EGR cooler all together easy enough to plumb a return coolant line (you can purcahes one for about $30 at diesel geek :
http://www.dieselgeek.com/servlet/Detail?no=413
and block the ports on the EGR itself and turn off the EGR via Vag Com.... in order to completely rule out the EGR cooler.

if you are getting coolant into a cylinder you should be able to tell by the shiny Glow Plug tell tale signs. it will look cleaner than all the rest. and a slight leak should be noticeable via a compression test. not to mention you should see something out the exhaust if that is the case as well. also are you losing coolant at all??

 

[Diesel Mania_26]

what York said - do a compression test first....

 

[mam0032]

if I read your question right you are asking:

- is there any other way for exhaust to get into the coolant other than the exhaust and the cylinder head / gasket?

not unless the block is cracked and getting pressure into the coolant - hence the compression checak as well as the oil and coolant check for oil or coolant respectively ...

you can remove the EGR cooler all together easy enough to plumb a return coolant line (you can purcahes one for about $30 at diesel geek :
http://www.dieselgeek.com/servlet/Detail?no=413
and block the ports on the EGR itself and turn off the EGR via Vag Com.... in order to completely rule out the EGR cooler.

if you are getting coolant into a cylinder you should be able to tell by the shiny Glow Plug tell tale signs. it will look cleaner than all the rest. and a slight leak should be noticeable via a compression test. not to mention you should see something out the exhaust if that is the case as well. also are you losing coolant at all??

Yes, I'm not trying to be argumentative, I just don't know.

I'm not loosing coolant as far as I can tell, but then, I don't know how long this has been going on. I just dumped a ton of money into this car over the past month, and wasn't sure I should go and get a compression tester. Seeing as how I've got two of these cars, it wouldn't be a bad investment, I'm just hurting in the pocket book.

I guess I'll go get one tonight. Is this a good go by for the procedure?

http://www.myturbodiesel.com/1000q/multi/compression-test-VW-TDI.htm

 

[Diesel Mania_26]

yes - thaths a great resource for almost anything to do with a TDI.

make sure you clean around the Glow plugs prior to removing them so yo udont get any dirt into the cylinders.... if you have compressed air - blowing around the glow plugs prior to removing any of them usually works well to remove all of the dirt around teh Glow plugs so it doesnt fall in as soon as you remove them.... and then do this one at a time... most testers you can run the car to check the compression or ths starter turning can give you the read outs... sometimes a helping hand is beneficial here....

 

[dieselfuel]

Those are good numbers. Your compression is fine.

 

[Powder Hound]

... I am going to replace the head gasket but fear the head is warped. the guy i am having do the job has a new complete head he is willing to sell for $400. ...

A complete new head for $400 is either hot (as in stolen) or is CRAP (Chinese Replacement Auto Parts) probably sourced from our favorite dealer of useless junk, Prothe.
.
.

DON'T BUY IT!!! ​

.
.
Send your head to Franko6 for repair if needed, after checking for flatness.

 

[davidm2232]

just wanted to update. I was messing around looking at my A?C and found my main cooling fan is not spinning. i'm in the process of diagnosing that now. the head my buddy has was from a guy he bought a whole bunch of parts from at a low price since he was selling all his tdi stuff. As for the HG, i have started to overheat on the highway, so a new gasket and required parts are scheduled to arrive Friday. looks like a i should get it fixed this weekend. I'll post if anything new comes up. These constant problems are really starting to annoy me. Thanks to all the posters at helping with the endless problems.

 

[mam0032]

Yes, the fan is a big deal. For what it's worth, my fan was the culprit. I simply plugged a new one in and it immediately started working. I was thinking about wiring some sort of light in-line with the fan, so you can see if it's coming on or not, haven't put too much thought into it just yet.

 

[davidm2232]

update after head replacement

So my parts came in and i changed the headgasket and put on a new head with the help of my local expert. we took it down the highway for a test drive with four people in it and i ran it pretty hard. there were no issues and it ran great. That was last night. this morning, i went out and started it in about 30 degree temps. it started the best i have seen without the coolant heater plugged in. i took it for a run on a fairly hilly road and ran it hard. no issues. i filled it up with fuel and decided to drive up to my grandmother's house to visit, about 5o miles away. i got about 1/4 of the way there when the car began to overheat on uphills and during hard acceleration. i noticed that when it got hot, the cabin heater would only blow lukewarm air but would get hot again in relation to the temperature gauge dropping back to 190. the temp stays solid at 190 for miles on flat road at constant speed. i was told that a new water pump and thermostat were put in. what could be the issue? this car is very discouraging. i would appreciate any ideas. if it was the water pump, could having the thermostat heat up and open make too many paths and cause a poor flow situation in the block and the heater core? how would i test the pump or thermostat? and i will post back after the car cools down to see if the tank is still pressurized. how much can i sell that head for, we could not see any warping or damage but... anyone interested? should i PM frank06, does he buy damaged heads?

 

[dieselfuel]

Did you re-use the head bolts? I believe they are one time use. ( I highly recommend the ARP head studs. They are worth the money, imo).

Also, remove the t-stat. Reach inside and try to spin the propeller on the water pump. If the propeller moves, you've got a faulty water pump.
Replace it with a water pump that has a brass propeller. Also, replace the t-stat, regardless, with a Genuine VW t-stat.

Keep us informed.

 

[davidm2232]

I do plan on replacing the t-stat and checking the water pump. i just went out to inspect the car after it cooled down and found some good news and bad news. the good news was that the coolant was down, so the overheat/no heat may have been caused by air in the system (i have my fingers crossed). I refilled the reservoir with Walmart's "universal" coolant for "all makes and models". i have been doing some reading and found that using non-G12 coolant can cause problems. is this the case or is that the G12 manufacturers saying that you need their product. I am going to do a coolant flush when i change the thermostat as i also have Bar's Head Gasket Fix in my system and i feel that may be part of my problem, anyone else think so? should i order the right coolant for the car or is universal fine?
the bad news was that the tank was pressurized almost instantly after start up, so replacing the head, gasket, and bolts didn't help in that respect. i did notice a smoother cold start, but that may have been fine tuning the timing after the head was replaced as much as anything since the water-pump was replaced by a non-vw mechanic according to the PO.
i swear this car will put me in an early grave.
Anyone have an install procedure for the ARP studs? thanks so much.

 

[dieselfuel]

Here's the thread: http://forums.tdiclub.com/showthread.php?t=291940&highlight=arp

BTW, I'm planning on installing my set of ARP head studs tomorrow (along with a set of stabilizer links :>)

 

[davidm2232]

I just did a pretty hard run and had it sustain a temp of like 210. I stopped a d found that the lower radiator hose was stone cold. This would indicate a bad thermostat, right? Would this cause a failure of the cooling fans to turn on despite the hot temp since the rad is not getting hot? Thanks so much.

 

[davidm2232]

i got a thermostat and plan to put it in on wednesday. i'll update if i find anything new out.

 

[Franko6]

Lots of mistakes... a possible Chinese head? Mixing G-12? ARP's 'just because'? Thermostat? Not likely.

I can't sell and head for $400. For that price, you'd have to go to Prothe or Clearwater for their CRAP.

Mixing G-12 with anything else will cause the calcium carbonate in the G-12 to drop out of suspension. That clogs your heater core, as very least.

ARP's are an expensive fix that doesn't work for for a warped head. Sure, you can get 125ft lbs torque in an ARP stud, but for you don't need them for a stock engine. The fastest diesel engine to go up Pike's Peak used stock head bolts. And it was NOT a stock engine. ARP's in this case are a waste of money. Stock head bolts, if you bother to check torque to about 120ft lbs. That is plenty. I'd check them to see how tight they are right now. I've had more than one head put on using gasoline engine specs; preload of 44 ft lbs and ONE 1/4 turn instead of two 1/4 turns as needed in the diesel.

If you have checked the EGR cooler for leaks, and it's ok, the problem is your head gasket or you have a cracked block. I've seen one cracked block, but the crack emanated from a rod that went through the block. I doubt your block is cracked.

If you replaced the head and never checked the replacement head for flatness, that sure could be your problem .004" warp is hard to spot and that is enough to cause a blown head gasket.