Head Gasket or EGR system???

miningman

Veteran Member
Joined
Sep 3, 2007
Location
alberta
TDI
2003 Golf
I'm having to top my coolant level on my 2003 tdi more frequently than previously. No evidence of leakage so I guess I'm starting to burn it. Its no where near bad enough yet to start pulling it to pieces yet, but I'd like to figure out where to start the process. How do I determine the likely source of the problem??
 

Carlos_TJ

Veteran Member
Joined
Aug 3, 2014
Location
Tijuana Mexico
TDI
2009 Bora (BXE PD)
- pressure test the system
- safely get under the car and look for traces of coolant. If using G12 it leaves crystalized red traces. It is also visible under black light. Also carefully inspect hose matrix from the top.
- Confirm expansion tank. Look for cracks. When was the last time the cap was replaced?

If after all this there are no traces of coolant leak, then should start headkgasket leak checklist
 
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Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Water pump, water flange on left side of head, hoses, radiator, exhaust. Of all the problems, the overflow tank ranks low, but easy enough to find. Just don't replace it 'because'.

A common leak Water flange cracks; water on the transmission... or the water pump is leaking/ not installed correctly. Rust from previous wp has to be cleaned out or the new gasket will ride up on the rust and if not immediately, it will leak sooner than it should. We do see some early failures on certain wp's.

We just lost a whole car to overheat... not my timing belt install... and the end result was a $4000 bill to recover. She opted to junk it. All because the mechanic installed without cleaning rust in the block bore for the pump.

Most common: The cylinder head water flange, water pump, cut or damaged water hose.
Visual inspection usually finds all of these. Take harmonic balancer and lower timing belt cover off to view bottom of water pump.

Troublesome: Head gasket blown from overheat.
Check for exhaust gasses in overflow tank. Bubbles in water return line are a bad sign.

Stranger places for leaks: EGR cooler, oil cooler.
Check with vacuum for leaks.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
put a UV die into the coolant, 1 week later, use black light to see where its going, it will show up in the exhaust pipe if your burning it, Highly unlikely, on a turbo diesel though. HG failure usually shows up as boost or compression making its way into the coolant, not the other way around.


Best thing to do is a leak down test (150PSI) and compression test on each cylinder, and a pressure test on the coolant (15-20PSI) Check of air bubbles in the coolant res.

ill bet you its one of 2 things if its not the pump or a HG
the Tee for the oil cooler and the head flange is leaking, or the head flange is leaking.
thats assuming you have a good healthy system, those 2 parts are prone to leaks right out of the box.
 

eddieleephd

Top Post Dawg
Joined
May 27, 2012
Location
Battle Ground, Wa
TDI
2002 jetta Wagon
I highly suggest you inspect, and replace, the hose coming off the back of the head over to the thermal T that connects to the return line to the reservoir.
I just replaced mine, it was fat and swollen. Common one to miss leaks at because it's well hidden.
Mongler is pointing out the same thing I see.
Sent from my Armor_2 using Tapatalk
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Eddie is right. That hose to the water nipple is hard to see. It will cause water on top of the transmission, same as the water flange. I wouldn't rule out anything.

I gave all of the reasons and in order of how common they are. Head gasket is surely not the least common, but certainly is the most troublesome.

It doesn't take a week for HG test. We have a fluid tester or you can use a 'sniffer' The fluid one is a cheap tool and easy to check. Blue fluid turns green to yellow if exhaust gas is detected. https://www.youtube.com/watch?v=QjUkh7SZu5c
Here is a relatively cheap version of the fluid tester:
https://www.ebay.com/itm/BT-1-COMBU...h=item3f7e9350a5:g:vA8AAOSw4DJYi63f:rk:2:pf:0
But that is after checking the more common things like flanges and water pumps.
 
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eddieleephd

Top Post Dawg
Joined
May 27, 2012
Location
Battle Ground, Wa
TDI
2002 jetta Wagon
But that is after checking the more common things like flanges and water pumps.
Return nipple on the coolant ball and level connector, hoses, thermostat o-ring and housing, o-rings in connectors at the radiator and heater core, heater core itself. radiator petcock drain.
Anything coolant related whatsoever.
The flange, the nipple out of it, and the hose connected to it on the back corner of the head are the easiest to miss and that hose should just be changed either way.
 

k_pt

Veteran Member
Joined
Oct 13, 2017
Location
pt
TDI
VW MKIV TDI
HG are almost bullet proof on these engines.

Just pressure test it to 1bar, if you didn't find the leak, check the egr for coolant.
 

gmenounos

Vendor
Joined
Jun 26, 2003
Location
Watertown, MA, USA
TDI
'99.5 Golf GLS, '01 Jetta GLX Wagon (TDI conversion)
If you have a FrostHeater, tighten the clamps if they're not factory self-tightening ones. I've had a couple of coolant leaks caused by FrostHeater connections becoming loose over time.

Sent from my PH-1 using Tapatalk
 
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