One way valve in coolant pipe going to throttle housing

[jekel 10]

Hello, as title, my valve seized, had spare, cut out and replaced, in fact old one cleared straight away when off, little plastic ball thing, got bit sticky, but...what's it for? Meant to help prevent air locks or something, can just remove and run straight pipe instead? Spare was'nt new, could seize again I'm thinking.

What's whole coolant to throttle housing for, meant to cool intake air at housing or something?

 

Mines got a strut brace and had to lower expansion tank slightly to accommodate, so throttle housing highest point of coolant system, so mine might be more prone to air locking if removed? New engine, water pump etc., not had any air locking probs so far.

[Jim 1]

Coincidentally, we've had a few discussions on this recently. Everything works fine without it BUT you may find (as me and a few others have) that when you put the ignition on after the car has been sat for a day and the auxiliary water pump fires up, you'll hear the sound of water gurgling and sloshing behind the dashboard through the heater matrix for a second or two.

 

As a replacement, I bought one of these (different vendor but similar thing):

 

http://www.ebay.co.uk/itm/ONE-WAY-FUEL-NON-RETURN-CHECK-VALVE-PETROL-AND-DIESEL-BIO-FUEL-6-8-10-12mm-Size-/302173921974?var=&hash=item465af822b6:m:m_1PVP19zubFukBMP0wwfuQ

 

Need an 8mm one for the Corrado. Spliced it in line on the coolant hose into the throttle body and secured with a couple of jubilee clips. That solved the problem of the water noises from behind the dash nicely :)

[Wesleyvr6 10]

Coincidentally, we've had a few discussions on this recently. Everything works fine without it BUT you may find (as me and a few others have) that when you put the ignition on after the car has been sat for a day and the auxiliary water pump fires up, you'll hear the sound of water gurgling and sloshing behind the dashboard through the heater matrix for a second or two.

 

As a replacement, I bought one of these (different vendor but similar thing):

 

http://www.ebay.co.uk/itm/ONE-WAY-FUEL-NON-RETURN-CHECK-VALVE-PETROL-AND-DIESEL-BIO-FUEL-6-8-10-12mm-Size-/302173921974?var=&hash=item465af822b6:m:m_1PVP19zubFukBMP0wwfuQ

 

Need an 8mm one for the Corrado. Spliced it in line on the coolant hose into the throttle body and secured with a couple of jubilee clips. That solved the problem of the water noises from behind the dash nicely :)

 

strange you say this as i replaced mine for a genuine pipe and still get the gurgling! Any ideas?

[Jim 1]

Are you sure the non return valve was actually present in the pipe?

[Wesleyvr6 10]

yes defintely there.

[g0ldf1ng3r 13]

coincidence indeed - my valve arrived mid last week.....then my VR popped its matrix on friday before i had chance to either fit it or give it the mechanic (as it was in his shop for work anyway)

 

i believe these valves were to stop the matrix blowing IF the system overpressurised, as detailed here http://www.cars.com/recalls/volkswagen-corrado-1992/

[jekel 10]

coincidence indeed - my valve arrived mid last week.....then my VR popped its matrix on friday before i had chance to either fit it or give it the mechanic (as it was in his shop for work anyway)

 

i believe these valves were to stop the matrix blowing IF the system overpressurised, as detailed here http://www.cars.com/recalls/volkswagen-corrado-1992/

 

Having had good look at old one and spare can't see that been the case, there's no spring, or pop off mech. etc., just straight one way valve, ball in sort of little cage affair, takes no pressure to blow one way, closes other way.

When mine was seized, expansion tank started to back up and fill too high, and signs leaking out overflow, and yes heard the gurgling, as described, on aux. pump run, though wasn't overheating or anything. Now fixed, running perfect levels. Most of air came out running without cap when cool, after a run, with cap fitted obviously, level dropped inch or so, rest of air out nicely, which tends to suggest it helps the bleeding process, or stops air locks in operation, those pipes are highest part of coolant system of mine (with slightly lowered expansion tank due to strut brace, but probs on standard car too?

 

P.S. old one unseized with blast from jet washer but wasn't dirty or anything, no gunge anywhere in pipe or anywhere else (new engine) so not sure why seized in first place, and therefore used the spare rather than old one.

[g0ldf1ng3r 13]

i have been looking into this & found the recall number & details of the recall - http://www.cars.com/recalls/volkswagen-corrado-1992/

 

it reads as though a one way valve is not the correct item, nor should it go in the hose to the throttle housing, i qoute:

 

DEALERS WILL INSTALL IN THE COOLANT INLET HOSE TO THE HEATER CORE, A PRESSURE REDUCER WITH A 5MM DIAMETER SECURED BY A SPRING TENSIONED HOSE CLAMP.

 

ALSO A NEW RELAY THAT WILL CHANGE THE OPERATION OF THE SECONDARY ELECTRICAL COOLANT PUMP WILL BE INSTALLED.

 

clearly saying it goes in the matrix inlet hose

 

but now ive read the OP first post again maybe we are on about different things

[jekel 10]

i have been looking into this & found the recall number & details of the recall - http://www.cars.com/recalls/volkswagen-corrado-1992/

 

it reads as though a one way valve is not the correct item, nor should it go in the hose to the throttle housing, i qoute:

 

DEALERS WILL INSTALL IN THE COOLANT INLET HOSE TO THE HEATER CORE, A PRESSURE REDUCER WITH A 5MM DIAMETER SECURED BY A SPRING TENSIONED HOSE CLAMP.

 

ALSO A NEW RELAY THAT WILL CHANGE THE OPERATION OF THE SECONDARY ELECTRICAL COOLANT PUMP WILL BE INSTALLED.

 

clearly saying it goes in the matrix inlet hose

 

but now ive read the OP first post again maybe we are on about different things

 

Think we're talking about different pipes. My dad had an Audi UR quattro in the 80's and mother had a Golf, both from new and I'm sure they both got recalled to do a modification to heater hose or hoses good few years later, maybe it's a widespread VW thing.

Only problem ever encountered mind, Golf ran faultlessly for 15 years or so, until sold, and the quattro my dad finally parted with after bout 15 years again and was pretty much in condition it was in showroom, never resprayed, resto'd or any work needed other than servicing, and a rear silencer, wish he'd never parted with it. When they came out probably the best car in the world bar none, and prob. still the best built.

[Wullie 1]

The recall was for a pressure relief valve to be fitted in the heater plumbing just before the matrix. If the pressure in the system got too high it diverted the flow from the matrix inlet to the outlet to reduce the pressure to the matrix. It is a completely different thing to the non-return valve initially mentioned. It was fitted to my 1.8 KR engine.

[g0ldf1ng3r 13]

Think we're talking about different pipes. My dad had an Audi UR quattro in the 80's and mother had a Golf, both from new and I'm sure they both got recalled to do a modification to heater hose or hoses good few years later, maybe it's a widespread VW thing.

Only problem ever encountered mind, Golf ran faultlessly for 15 years or so, until sold, and the quattro my dad finally parted with after bout 15 years again and was pretty much in condition it was in showroom, never resprayed, resto'd or any work needed other than servicing, and a rear silencer, wish he'd never parted with it. When they came out probably the best car in the world bar none, and prob. still the best built.

 

i think we are too m8

 

though now i am unsure as to what this part is actually for in the hose to the throttle body lol

[g0ldf1ng3r 13]

The recall was for a pressure relief valve to be fitted in the heater plumbing just before the matrix. If the pressure in the system got too high it diverted the flow from the matrix inlet to the outlet to reduce the pressure to the matrix. It is a completely different thing to the non-return valve initially mentioned. It was fitted to my 1.8 KR engine.

 

thanks Wullie

 

it is that exact pressure relief valve for the matrix inlet hose that i am trying to find but struggling majorly - several frustrating calls to VW today & none the wiser

[g0ldf1ng3r 13]

so - can anyone tell me what this one way valve to the throttle body is for?

 

thanks

[Jim Bowen 1]

I assumed it was because the matrix was quite high up in the system, so it stopped the coolant draining back out of it, but i'm kinda guessing.

[g0ldf1ng3r 13]

I assumed it was because the matrix was quite high up in the system, so it stopped the coolant draining back out of it, but i'm kinda guessing.

 

im not sure as i have gotten confused along the way.

 

i know Jim brought one to stop the gurgling behind the dash but i am unsure why or how

 

i do now know they are not the part to reduce pressure to the matrix lol

[Jim Bowen 1]

I fitted the same as Jim to mine a few years back, i just noticed someone mention it on the forum and thought i'd better fit something, Did seem to stop the running water sound behind dash.

[g0ldf1ng3r 13]

I fitted the same as Jim to mine a few years back, i just noticed someone mention it on the forum and thought i'd better fit something, Did seem to stop the running water sound behind dash.

 

thanks m8

 

i have one so may as well fit it if it actually does something - be nice to know exactly what though

[jekel 10]

so - can anyone tell me what this one way valve to the throttle body is for?

 

thanks

 

That was my original question, lol. M

[jekel 10]

That was my original question, lol. M

 

My theory is it's to stop airlocks, it's about the highest part of collant system, is on mine, as expansion tank lowered a bit to accommodate strut brace.

 

I think my VR6, probs. all later ones, mines a 94, may already have the pressure reducer thing. I renewed coolant pipes and kept and cannibalised old ones. The one that goes from engine to heater, and branches of to throttle, is all metal inside at the t-piece, incorporating a chamber, with about a 5mm entrance, like a thimble with a 5mm hole at one end, that's all I can see, not sure what's after that but it's not just a t piece, so maybe that's the pressure reducer? C; 5like a

[jekel 10]

P.S. It's that bit of the pip[e that gurgles on the auxiliary pump run if got any air in system, gurgling because it's an ideal air trap presumably, but sure VW must have reasons for fitting it.

[g0ldf1ng3r 13]

My theory is it's to stop airlocks, it's about the highest part of collant system, is on mine, as expansion tank lowered a bit to accommodate strut brace.

 

I think my VR6, probs. all later ones, mines a 94, may already have the pressure reducer thing. I renewed coolant pipes and kept and cannibalised old ones. The one that goes from engine to heater, and branches of to throttle, is all metal inside at the t-piece, incorporating a chamber, with about a 5mm entrance, like a thimble with a 5mm hole at one end, that's all I can see, not sure what's after that but it's not just a t piece, so maybe that's the pressure reducer? C; 5like a

 

lol i too was hoping someone would know

 

the recall for the pressure reducer was not until 1998 so no VR's left factory with it. the reducer is as you say is in the matrix feed hose & is a 5mm diameter insert. i have since found that mk3 golf matrix was revised to incorporate a pressure reducer

 

but that means i was still wondering why this valve is needed in the hose to throttle body - maybe it is to help prevent air locks like you say

[jekel 10]

lol i too was hoping someone would know

 

the recall for the pressure reducer was not until 1998 so no VR's left factory with it. the reducer is as you say is in the matrix feed hose & is a 5mm diameter insert. i have since found that mk3 golf matrix was revised to incorporate a pressure reducer

 

but that means i was still wondering why this valve is needed in the hose to throttle body - maybe it is to help prevent air locks like you say

 

That's my theory scuppered then, lol. The plot thickens!