Mad_Max
Veteran Member
Couple of weeks ago my Jetta pinged me with low coolant warning. I have added about 4 oz of G12 and moved on. When I got the same message couple of days later, I new that there is a leak that needs to be addressed.
Search on this forum pointed me to couple of main culprits: heater hoses or a small hose that goes around the tandem pump. Small hose checked out OK, but one of the heater hoses, as reported buy multiple people, was covered in oil residue and really squishy and looked like it was as suspect.
I have replaced hose assembly - part# 1K0-122-157-HP ($50) and turbo inlet green seal ring - part# 3C0-129-646 ($8.50). For the seal part number I had to get Brian's help because my local parts department "specialists" were absolutely clueless.
Unfortunately replacement of the heater hoses did not fix the problem. After driving for couple of days I checked the level of coolant and noticed it drop again. Checking underneath the car showed a little residue on the back of the engine block close to bell housing, but it was nearly impossible to see where it was coming from due to all the piping around the motor.
Suggestion from Brian to check the flange underneath the tandem pump saved me a lot of the headache. I would not thought it would leak there and get to all the way to the back.
For the debug with engine OFF I made a small pressure rig out of some hoses and T-connector that I got from local parts store.
Once I gave it ~15-20 psi it started to leak right from the place that Brian suggested. Here is the trouble maker:
For some reason the orange gasket became really dry and fragile, almost plastic like and got pushed out buy the coolant pressure.
Here is a new flange with gasket - part# 03G-121-132-B ($33). Or if you are really cheap you can get gasket only - part# 038-121-688-D ($11). The little ring is the temp sensor seal ring - part #N-903-168-02 ($3.50)
Brian suggested, I quote "You never replace just the seal on the plastic flanges anyways, always get a new flange." so I replaced the whole thing. $22 bucks is a cheap insurance.
Here is the location on the engine where it is situated. It is really hard to see it leaking because it is located between the tandem pump and charge pipe going to the intercooler.
So far it been a week since I have done the repairs, no leak so far
.
While Air box and the battery was out of the car and I was waiting to the parts and I'm @~65K miles.,I also flushed brake fluid with 2X0.5L bottles of DOT4 B-000-750-M2 ($15). Bleed the brakes with aid of VCDS and bled clutch also.
And also since I had it all apart I decided to change trans fluid - almost 2 liters of the G-070-726-A2 ($28). I followed DIY posted on myturbodiesel:
http://www.myturbodiesel.com/1000q/a5/manual-gear-Oil-Volkswagen-Jetta-TDI.htm
I know that some people say trans frout does not to be changed at all or at least up to ~100K, I decided to do it anyway. In my case it seem to improve getting in the first gear, where lately it was requiring either a decent push or getting into second gear first and the first one to make it a smooth shift. Or maybe a clutch bleed that fixed it. I do not know which one, but combination of both seem to work for me.
Again props to Brian for the help to solve the coolant puzzle.
Max
Search on this forum pointed me to couple of main culprits: heater hoses or a small hose that goes around the tandem pump. Small hose checked out OK, but one of the heater hoses, as reported buy multiple people, was covered in oil residue and really squishy and looked like it was as suspect.
I have replaced hose assembly - part# 1K0-122-157-HP ($50) and turbo inlet green seal ring - part# 3C0-129-646 ($8.50). For the seal part number I had to get Brian's help because my local parts department "specialists" were absolutely clueless.
Unfortunately replacement of the heater hoses did not fix the problem. After driving for couple of days I checked the level of coolant and noticed it drop again. Checking underneath the car showed a little residue on the back of the engine block close to bell housing, but it was nearly impossible to see where it was coming from due to all the piping around the motor.
Suggestion from Brian to check the flange underneath the tandem pump saved me a lot of the headache. I would not thought it would leak there and get to all the way to the back.
For the debug with engine OFF I made a small pressure rig out of some hoses and T-connector that I got from local parts store.
Once I gave it ~15-20 psi it started to leak right from the place that Brian suggested. Here is the trouble maker:
For some reason the orange gasket became really dry and fragile, almost plastic like and got pushed out buy the coolant pressure.
Here is a new flange with gasket - part# 03G-121-132-B ($33). Or if you are really cheap you can get gasket only - part# 038-121-688-D ($11). The little ring is the temp sensor seal ring - part #N-903-168-02 ($3.50)
Brian suggested, I quote "You never replace just the seal on the plastic flanges anyways, always get a new flange." so I replaced the whole thing. $22 bucks is a cheap insurance.
Here is the location on the engine where it is situated. It is really hard to see it leaking because it is located between the tandem pump and charge pipe going to the intercooler.
So far it been a week since I have done the repairs, no leak so far
.While Air box and the battery was out of the car and I was waiting to the parts and I'm @~65K miles.,I also flushed brake fluid with 2X0.5L bottles of DOT4 B-000-750-M2 ($15). Bleed the brakes with aid of VCDS and bled clutch also.
And also since I had it all apart I decided to change trans fluid - almost 2 liters of the G-070-726-A2 ($28). I followed DIY posted on myturbodiesel:
http://www.myturbodiesel.com/1000q/a5/manual-gear-Oil-Volkswagen-Jetta-TDI.htm
I know that some people say trans frout does not to be changed at all or at least up to ~100K, I decided to do it anyway. In my case it seem to improve getting in the first gear, where lately it was requiring either a decent push or getting into second gear first and the first one to make it a smooth shift. Or maybe a clutch bleed that fixed it. I do not know which one, but combination of both seem to work for me
.Again props to Brian for the help to solve the coolant puzzle.
Max