My Gti6 Plumbing

[Garry 1]

 

Please see above a sketch of how my cars coolant system is plumbed in.

 

It is a little different to Spikys diagram as I don't have a 'T' on the line that goes from the header tank to the engine connecting the heater matrix, although it does get there in a round about way.

 

The reason i have posted this is because after a run the coolant gets spat out of the header tank over flow, even when it has been bled and filled correctly, although the coolant pipes don't have bleed screws.

 

For example, even after driving over to Germany for 3 hours or so, i stopped for fuel and it spat the coolant out. I have always struggled to keep the thing cool, it is ok during normal driving, but when on track or sat in traffic it gets really hot.

 

Anyone have any suggestions?

[All Praise The GTI 3]

mine randomly spits out coolant occasionly for some reason also???

[BuD 0]

My gti6 (in 306) has always run hot (altho never into the red) but fans are never far off coming on. I think this is pretty much how they are, from reading the gti6 forum - and means that there is a lot of pressure (no pun intended!) on the cooling system.

 

Your diagram looks ok, to me, its different to how I have done mine but I have retained the standard 'water' oil cooler which from your pic looks like you dont use.

 

If you arent running an oil cooler what are oil temps like?

 

Also it looks from your pic like you have an extra outlet on the water distro block on the back of the block (eg like a plastic 8v one not an alloy gti6 one - obviously not an 8v one tho because they dont fit.) If this is the case you could try connecting the matrix to the metal pipe on the back of the engine and run the expansion tank down to the distro block using an 8v pipe. I dont know why this may make a difference but it would be marginally more similar to the original fitting so may have some unseen benefit?!? It is also what I am doing and my temps seem very good on normal road driving and it happily idles on the spot for hours if needed with the fan coming on and going off. Havent given it the beans yet tho and its off road again atm.

[Spiky 37]

mine is setup as below

 

i have a new rad and it normal driving it runs at 4th line on the gauges, unless i'm on track and it goes vertical

 

many people have set it up this way, with no issues

 

 

EDIT to add

as i now run a 16 mocal oil cooler, the oil cooler on mine has now gone

 

 

 

Edited May 22, 2008 by Spiky

[Alastairh 47]

Are you sure your running the correct expansion tank cap for the engine?

 

Al

[Spiky 37]

ok after actually reading your whole post, (sorry, sped read it )

 

and looking at your picture,

 

i have a feeling that with only the small pipe from the rad being fed tio the expansion , that this may be your problem,

 

why have you not done the "t" peice like i have????

[BuD 0]

i have a feeling that with only the small pipe from the rad being fed tio the expansion , that this may be your problem,

 

eh? the small pipe on the top of the rad always goes to the expansion tank - this what you have in yours too.

 

why have you not done the "t" peice like i have????

 

It looks from his diagram he has a different water distro block so doesnt need to, see above.

[Spiky 37]

hi bud,

 

sorry what i meant to say was he "only" has the small pipe, and hasn't got the expansion bottle in normal circulation, like mine

 

i think he should add the T peice back in

[gti-si 0]

I'm sure he must have the bottom expansion outlet piped in Spiky...I can't even see he'd be able to fill it otherwise?

 

I think it's a little hard to see on the diagram as it's unclear where the metal pipe is connected, maybe add some flow arrows on the pipe to show where/how the network is filled?

[Spiky 37]

I'm sure he must have the bottom expansion outlet piped in Spiky...I can't even see he'd be able to fill it otherwise?

 

I think it's a little hard to see on the diagram as it's unclear where the metal pipe is connected, maybe add some flow arrows on the pipe to show where/how the network is filled?

 

 

well according to he ARROW FLOWS he dont, so i think thats the problem

[Garry 1]

Thanks for your responces.

 

The header tank feeds the heater matrix, not the engine, which may well be the problem (the line blocking off the solid pipe below the arrow going into the matrix shouldn't be there ).

The heater matrix goes to the engine.

 

Why is it like that? Thats how Pug Performance did it.

 

I will have a go at putting a 't' in like spiky has suggested to link the header tank direct to the engine.

Edited May 22, 2008 by Garry

[Miles 331 1 Cars]

On a old iron block engine I had it would spit water out when hot, this was due to a very small Headgasket problem but when running around on the road it was fine and never lost a drop,

when these engine's are in the 6 the water never really get's hot at all even when pushed hard to my surprize, compare that to my 406 and it's a different storey.

Not being a flow expert the only differance between the old 8v and these is the lack of the pipe from the stat housing to the expansion tank, I know a turbo I had in didn;t have this to start with and the owner said about it running hot but it's now back on and the temp is back to normal but it's yet to be pushed hard to find out for sure

[Spiky 37]

Thanks for your responces.

 

The header tank feeds the heater matrix, not the engine, which may well be the problem.

The heater matrix goes to the engine.

 

Why is it like that? Thats how Pug Performance did it.

 

I will have a go at putting a 't' in like spiky has suggested to link the header tank direct to the engine.

 

 

just to check, your expansion bottle only has one pipe? and goes to top of rad?

[Garry 1]

No, 3 outlets.

 

One is blanked off

One is the small breather pipe going to the top of the rad (O/S)

and the third is from the bottom of the tank that goes to the solid pipe on the back of the block.

[Alastairh 47]

I think i understand what you mean Garry.

 

Basically the bottom heater matrix hose isn't turned towards the expansion tank as per how myself, Spiky, Maxi, Dan T etc done ours. So its running down like a 8 valve does. But the thing thats got me confused (it has been 2 months since i last looked at a GTI6 engine) but doesn't the bottom water distribution block only have 2 outputs on ( To the radiator, and the metal back pipe) or has this been swapped, or have i missed something?

 

As i said, check your expansion tank cap. I had the same problem, and a proper 306 item fixed it.

 

Al

[welshpug 1,626]

all pug expansion tank caps are the same, i.e every system runs at 1bar, and all caps are interchangeable until fairly recently where they have moved to a screw fitting, still the same pressure though.

[Spiky 37]

i dont think the water is circulating right then,

 

as alastairh says, you've change the block at the back haven't you? any reason for this?

 

i think i'd block off the extra pipe and t peice like we have and see how you get on, as we know this way works.

 

no point reinventing the wheel

[Garry 1]

Ok I have found some pics which should help explain:

 

 

Back of the block

 

 

 

If you look below the blue sensor and to the right of the swirl pot you can just make out the inlet that the heater matrix connects to.

[Matt Holley 11]

My header tank in teed into the heater matrix hose that goes on the black metal pipe, in my mind thats the bast way as when you fill up the water goes down the metal pipe to the plastic block at the bottom and fills the engine up from the bottom, as the old 8v did.

 

This is practicaly the same as garrys but instead of needing a tee peice he has an extra outlet on the plastic block, I would be interested to know what engine that came off.

 

I have replaced my header tank cap with a new one as the old one didnt hold pressure very well after 16 years and I could here it hissing and some times let a bit of coolent out when sat still when hot, its been fine since.

[taylorspug 7]

The expansion tank cap is a key item, ive got a 20lb one (i think?) on mine and no expansion tank at all, and i have no overheating or water fountain type problems whatsoever. Temp runs about 85 deg for normal driving and heats up to around 90 when im pushing on. Maxi had similar probs with his 6 converted 205, and the higher lb cap im sure sorted it straight away.

[maxi 36 1 Cars]

The XU10J4RS seems to be a very fussy engine when it comes to cooling. They all suffer with head gaskett failure and they all run extremely warm, something I dont like at all. My 306 is regularly right up near the red on the gague, something I dont like at all.

 

One thing many people miss when doing this conversion is that the 306 coolant system runs at a much higher pressure and if your header tank cap is very slightly weak, it will be highlighted straight away. I discovered this quite a while ago and always run the higher pressure caps which are readily avaliableat my local factors.

 

Another factor is that these engines are a nightmare to bleed, especially when in a 205. You think all the air is out but there is still a bit lurking in there.

 

Your solution is in upgrading the coolant system to suit the new engine.

 

1. Lower temp stat

2. Make sure its well bled with as many bleed points as poss

3. Uprated cap to cope with the higher pressure

4. I run twin fans with the speed restriction capacitor cut out (when the fans come on, they are on flat out)

5. Have a slightly lower fan switch

6. Make sure you run anti freeze. Not only does it stop the coolant freezing up in winter, prevent corrosion internally but also quite a high concentrate will keep the engine running cooler.

 

 

I really believe that the higher running temp has lot to answer for with the regular failure of head gasketts on these engines. I believe if the temp can be kept down slightly you wont have this ejaculation problem and your gaskett will last longer. I am going to re-plumb both my 205's slightly differently as I think things arent being helped with this T piece malarkee.

 

Maxi

Edited May 23, 2008 by maxi

[Spiky 37]

one major people seem to over look is the OE gauges are rubbish, and unless you run a accurate guage, you wont know the actually temperture,

 

mine runs low(4th notch(, and only half on track on a summers day.

 

now is this safe?????

 

i dont know yet as i dont run new accurate gauges, untill then, i will "ASSUME" it's running ok.

 

 

and assumption can be the major of all Fook ups

[maxi 36 1 Cars]

one major people seem to over look is the OE gauges are rubbish, and unless you run a accurate guage, you wont know the actually temperture,

 

mine runs low(4th notch(, and only half on track on a summers day.

 

now is this safe?????

 

i dont know yet as i dont run new accurate gauges, untill then, i will "ASSUME" it's running ok.

and assumption can be the major of all Fook ups

 

 

Quite true, although since they are the only thing most people can go by, they cant be ignored. Just take precautions and then accidents cant happen

 

Maxi

[Spiky 37]

BUT and it's a big BUT

 

people take them as gospel

[maxi 36 1 Cars]

BUT and it's a big BUT

 

people take them as gospel

 

 

Im not disputing that at all but if the gague is hanging off the end of the scale and you have warnings such as the fan going ten to the dozen it cant be ignored.

 

Maxi