Volkswagen Passat Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I read comments recommending to search previously answered questions & I have tried, I really have. I saw many replies about bleeding but I have almost no flow to the heater. There is simply not enough coolant to allow bleeding. I used garden hose at low pressure both ways on heater connections and flow out was same as flow in both directions ; seemed very clear. topped everything up and gently eased off the return hose from the heater to see only an occasional little bubble emerge from the bleed hole. After a while removed it completely and only drips & occasionally a tiny trickle coming from the heater outlet. Removed the supply or 'in' to the heater and the same result less than a trickle ; put my finger over it and no pressure. I see mention of other bleed poiunts in the V6 threads but mine is petrol 4 1.8 so don't know what to do thanks for any help
topendtrev
 

·
2004 B5.5 Variant 1.8T
Joined
·
23,570 Posts
If it's the 1.8T (I think the non-turbo is the same) you can squeeze the upper radiator hose connected to that hard coolant pipe over the intake manifold repeatedly to create a siphon effect which will push out the air pockets and pull coolant into those places.

Take the little hose off the top of the coolant reservoir. Squeeze the upper radiator hose flat, then plug the little hose (like holding your finger on the end of a straw). When you release the big hose, it should pull coolant up to the top and the coolant in the reservoir should go down a little. Do that a few times before pulling back the hose ont he heater core to help the filling go by quicker. Once you hear less gurgling and more of a sloshing liquid sound, you should be able to pull back the heater core hose to purge the remaining air. Close everything back up and run the engine and circulate the coolant which will force out any remaining air.

The A4 1.8T AMB motor had a bleed screw in place of that little hose from the hard coolant pipe over the intake manifold. That made it easier.
 

·
Registered
Joined
·
1,601 Posts
How many miles and when was your last timing belt installed? Assume you are doing this static,you need to unscrew,disconnect reservoir level sensor and raise reservoir as high as possible, and as suggested I would also try (when cold) with engine running.
 

·
Registered
Joined
·
5,256 Posts
...you should be able to run the engine and do the bleed procedure at the heater core hose..
...and as suggested I would also try (when cold) with engine running.
No, no, no, don't have the engine running. The return pipe from the heater core (where you purge the air) will never completely fill because of the spinning impeller. With the pump stopped, the coolant level can equalize throughout the system, while the higher pressure from the lifted coolant reservoir fills the circuit and forces the air out.
 

·
2004 B5.5 Variant 1.8T
Joined
·
23,570 Posts
No, no, no, don't have the engine running. The return pipe from the heater core (where you purge the air) will never completely fill because of the spinning impeller. With the pump stopped, the coolant level can equalize throughout the system, while the higher pressure from the lifted coolant reservoir fills the circuit and forces the air out.
Maybe I forgot my own method, or maybe my coffee hadn't kicked in yet. No harm done when I did it but I agree the air should be purged by gravity fed coolant first. To avoid confusion, I edited my response. (y)
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
How many miles and when was your last timing belt installed? Assume you are doing this static,you need to unscrew,disconnect reservoir level sensor and raise reservoir as high as possible, and as suggested I would also try (when cold) with engine running.
Hi she had/ still has 125,000 miles on her. I have replaced the heater blower motor as it was dead and the temperature sensor so they working now. No way of knowing about the timing belt I had a quick and belts seemed ok but I need to look better. I am assuming the timing belt is external and I can spot it.
I saw also recceomendations about bleeding oil give those a try,
thaknyou,
Trev
 

·
Registered
Joined
·
8 Posts
Discussion Starter #8
If it's the 1.8T (I think the non-turbo is the same) you can squeeze the upper radiator hose connected to that hard coolant pipe over the intake manifold repeatedly to create a siphon effect which will push out the air pockets and pull coolant into those places.

Take the little hose off the top of the coolant reservoir. Squeeze the upper radiator hose flat, then plug the little hose (like holding your finger on the end of a straw). When you release the big hose, it should pull coolant up to the top and the coolant in the reservoir should go down a little. Do that a few times before pulling back the hose ont he heater core to help the filling go by quicker. Once you hear less gurgling and more of a sloshing liquid sound, you should be able to pull back the heater core hose to purge the remaining air. Close everything back up and run the engine and circulate the coolant which will force out any remaining air.

The A4 1.8T AMB motor had a bleed screw in place of that little hose from the hard coolant pipe over the intake manifold. That made it easier.
thanks muchly oil give that a go tomorrow
Trev
 

·
Registered
Joined
·
8 Posts
Discussion Starter #9
How many miles and when was your last timing belt installed? Assume you are doing this static,you need to unscrew,disconnect reservoir level sensor and raise reservoir as high as possible, and as suggested I would also try (when cold) with engine running.
thanks muchly oil give that a go tomorrow
Trev
 

·
Registered
Joined
·
1,003 Posts
I'm not sure which engine you have but on the 1.8t engines available in the US, the timing belt is not visible without removing some covers, etc. And even if it is visible, I wouldn't try to appraise it based on how it looks. How many miles were on the car when you bought it? I think the OEM spec for the first timing belt change is 105k miles so if it had less than that when purchased, I would assume it has not been done. If it breaks, it will bend valves and cause all sorts of expensive trouble.
 

·
Registered
Joined
·
5,256 Posts
That's right, and the belt could be in perfect condition and still jump/tear/break if a roller's bearing seized. You can't judge the condition of those rollers by visual inspection either.
 
1 - 11 of 11 Posts
Top