Volkswagen Passat Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
26,616 Posts
Discussion Starter #1
V6 coolant pipe seals replacement.

This was done on a B5.5 with the later style PCV but should be similar to the earlier styles.

Reason for replacement: Coolant leak seen under the intake manifold.

Difficulty level: Moderate, but Painful. Your hamstrings and back will be killing you.

Time: Varies greatly, but this took me just under 6 hours with stopping for pics and I work at a casual pace (and double check everything). Plan on much longer for enough breaks to keep from getting sore. I’ve done this several times, so it is not hard to me (but it is still painful).

Parts needed from ETKA, Page 59 : http://xyrotr1.com/etka/B5.5/1 engine, clutch.pdf
5 Seals:
2: N-909-125-01 List: $2.90 each.
1: N-905-607-01 List: $2.00
1: N-903-800-02 List: $2.00
1: N-903-653-02 List: $2.00
From Page 89
2 Intake manifold gaskets:
2: 078-129-717P List: $30.18 each!

Special tools needed: 5mm ball head allen socket.

If the vacuum hoses, plug wires or PCV hoses are original and/or old/fragile, they should also be replaced.

To save my back, I always raise the car on jack stands to just below waist height.

Remove the engine covers and loosen/unplug the coolant tank, no need to remove the hoses. Tip the tank forward and towards the passenger fender, zip tie if needed to keep it out of the way.

Remove the flexible intake hose and snorkel from the throttle body (5mm ball head)

Remove the PCV system from the valve covers, intake manifold and throttle body.

Remove the 4 bolts holding the coils, it’s wiring harness (and ground) and the passenger side plug wires (easier to pull them from the plugs than the coils). Slide the coils and wires over the driver’s side inner fender.

Start to unplug the wiring harnesses:
The passenger side injectors.


The throttle body and vacuum plate plugs (color coded).


The driver’s side injectors. The driver’s side CCT.


Pull the whole harness over behind the hood strut out of the way.

Remove the vacuum lines to the combi valves from the plastic T to the left of the vacuum plate. Remove both hoses here or at the Combi valve.


Remove the vacuum line running along the driver’s side of the intake from the plastic T on the to right of the vacuum plate.

Unbolt the 3 bolts holding down the vacuum hose plate, leave it there.

This is what it should look like:


Remove the throttle body from the intake manifold (3 5mm bolts, 1 8mm bolt), leave it there.

Loosen the 6 hex head bolts on each side of the intake manifold (5mm). Use needle nose pliers to lift them out.

Lift the intake manifold slowly, starting with the driver’s side and then up over the passenger side valve cover and lay it upside down on top of the cowl cover (by the a/c). The fuel lines are left attached as is the vacuum plate.



Now you can see where the coolant is leaking, but you have a lot more work to do.



Look for the 2 plastic guides used for assembly. One might be in the block, the other might be here:



Remove and throw them away. You can also vacuum the dirt from the block and intake ports.
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #2
Part 2:

Remove the rest of the PCV hoses.

Remove the 2 vacuum lines from the throttle body. Remove the 2 coolant lines from the metal pipe and set the throttle body out of the way (now is a great time to clean it!).



Remove the plugs from the firewall behind the coolant tank and the passenger side knock sensor plug. Push them out of the way of the coolant pipes and combi pipe.

Unbolt the wiring harness from the back of the metal cross pipe.

Remove:
The 2 bolts holding the combi pipe to each of the combi valves. Do no drop the gaskets!

The 5mm allen bolt on the back of the driver’s side head holding the combi pipe in place.

The 6mm allen bolt from the inner side of the passenger side head and then the 10mm bolt up front.

The 10mm bolt holding the P/S hose to the head.

The 13mm nut holding the P/S hose to the metal coolant cross pipe.

Loosen the large bolt (just enough to allow the hose to rotate) holding the P/S hose to the pump. Rotate the hose up as far as possible and tighten the bolt again.

Lift the combi pipe up and out (rotate slightly as needed).
This is what it should look like now:


Remove the 2 outer bolts on the driver’s side combi valve. Loosen the inner bolt and rotate the combi out of the way.


Remove the 4 bolts (5mm allen) holding the metal coolant cross pipe to the heads. Pry the pipe back until it pulls out of the block. (it will spill a bit of coolant). Lift it up and remove the heater hose. Then remove it from the car.




Remove the other heater hose.

Remove the engine lift tab on the inner front of the driver’s side head. Push the large coolant pipe to the side and remove the 5mm allen bolt holding the small coolant pipe underneath of it. Remove the pipe by tapping it to the back (hit it on the tab where the bolt was).

You are almost halfway done. Time for some more Advil.


Sop up all of the coolant from the top of the engine.

Clean the 2 holes in the front of the engine block with some sand paper and cloth to remove any rust and rubber seal left over.

Clean the back of the heads.

Remove the seal on the metal pipe left in the V. Clean the groove where the gasket was.

With the other 2 pipes on the work bench (or floor), remove the seals and clean all of the gooves. Also clean the inside of the large pipe that connects to the pipe inside the V. Make sure everything is clean. You don’t want to do this job again! Yes, the CTS leak was fixed already.


Install all of the seals into/onto the metal pipes. Use new coolant to lubricate them to ease installation (and prevent tearing). Installation almost as much fun. Take your time, do it in the reverse order and watch the wires that weave through the pipes (install them before the combi pipe!).

Once the throttle body coolant lines are connected, you can fill the system and check for leaks.

After everything is done, be sure to adapt the throttle body!

Fill the coolant and bleed the system.

Enjoy,

Paul.

Special thanks to my wife Ofelia for taking the pictures!
 

·
Registered
Joined
·
320 Posts
Excellent writeup and documentation. I have had to replace similar coolant pipe seals on other VW engines recently, so I guess not too surprised to see these starting to fail. How much coolant did you observe leaking? Having to refill the reservoir often? How many miles on the engine? Thanks again!
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #4
It was not my car, but I replaced mine 18 months ago. On my car it was a slow drip. On this car, it was leaking pretty fast and left a puddle overnight.
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #6
Mine was an 01 B5, but it started leaking after the trans was dropped due to the lift tab being moved. The heads had been rebuilt previously, so the seals had less than 20K on them.

The car in the writeup was probably an 03. Both engines were ATQ, but the earlier AHA should be similar. I would guess the mileage was around 100K or more.
 

·
Fore!
Joined
·
1,564 Posts
When I replaced the smaller pipe, I tapped it in but the flange at the back next to the bolt hole was slightly above the block, and the pipe went way farther into the block, maybe 1/2 to 1 inch. I had to tap it back out. There is no surface in the block which stops it from going in too far. The flange at the back seems to hold it in the right place, but is this normal?
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #8
Here are the pics in order since PB died:
98034


98035


98036


98037


98038


98039
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #9
And the next 6 pics:
98040


98041


98042


98043


98044


98045
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #10
And the last of them:
98046


98047


98048


98049


98050
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #11
A few pics of the back of the engine with the trans removed for a better idea of how the heater hoses connect and where the pipes and combi valve are.
Back with heater hoses and cross-over pipe:
98078


Passenger side:
98079


Driver's side:
98080
 

·
Registered
Joined
·
313 Posts
So I have marked where I think my leak or leaks are. Either way, gonna have to follow your writeup and see what it is.
I am pretty sure it is the connection under the intake manifold that the arrow is pointing at.
98090
 

·
Registered
Joined
·
26,616 Posts
Discussion Starter #14
I had training as teen, but I have always been mechanically inclined. It's not a terrible job, just time consuming. I dread removing the trans or dual cats on a V6 Tip car.
I've had people drive 250-350 miles to have me work on their cars, but Wi is a bit far :)
 

·
Registered
Joined
·
313 Posts
I followed your post but never ended up having to touch the kombi valves
Perhaps this helped:
98282


I ended up making the ball-head Allen wrench shorter and then glued it back into the 5mm socket. made it easier for the screws that face the firewall.
The socket was donated from a random set of mixed metric sockets I had for years.
98284
 
1 - 15 of 15 Posts
Top