Header tank pipes

Header tank pipes

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njhucker

Original Poster:

377 posts

259 months

Monday 15th September 2014
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I am presently touring France and Spain in the 400se. Had a problem where I lost a load of coolant in san Sebastian where it was 33 degrees. Just wondering if I have the coolant pipes on the side of the header tank the correct way round. Can someone have a look and let me know if the small pipe from the top of the Swan neck connects to the tank connection nearest the windscreen or nearest the bonnet.

mrzigazaga

18,534 posts

164 months

Monday 15th September 2014
quotequote all
Hi mate...Mine goes from the swan neck into a reducer and then into the bonnet side inlet of the expansion bottle...Cheers...Ziga


Number 7

4,101 posts

261 months

Monday 15th September 2014
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On my 400 the swan neck small pipe goes to the header tank connection by the windscreen, and the other upper header tank connection (not the overflow) goes to the connection near the thermostat which also feeds the metal pipe which goes under the inlet manifold. Check the fan comes on? If not, connect the otter switch pins together. Good luck.

njhucker

Original Poster:

377 posts

259 months

Monday 15th September 2014
quotequote all
Thanks for your replies guys. So basically one is the same as mine and the other is the other way around. Guess therefore it doesn't make any difference. My fan is coming on at 90 degrees. Have driven over the Pyrenees today and it has been fine. Maybe I need to look at a more powerful fan. I had the rad recored last year and have new caps. When it boiled over the other day I had been in a traffic jam for miles crawling into San Sebastian and it was blistering hot weather. We will get to the Costa Brava in 2 days and wanted to minimise the risk of it dumping the coolant again.


KKson

3,395 posts

124 months

Monday 15th September 2014
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Hi, I was loosing a load of water on mine- turned out that the brand new header tank cap was lifting prematurely. I fitted a new one and not lost a drop since. Just because something is new doesn't mean it cannot be suspect. Cheers.

mrzigazaga

18,534 posts

164 months

Monday 15th September 2014
quotequote all
KKson said:
Hi, I was loosing a load of water on mine- turned out that the brand new header tank cap was lifting prematurely. I fitted a new one and not lost a drop since. Just because something is new doesn't mean it cannot be suspect. Cheers.
Very true...I had that happen with the blanking cap on the swan neck...The cooling system on a Wedge doesn't make any sense...There are a few variations to how it is plumbed in and i think it was trial and error...When mine is up to temp and the cap is off there is no visible movement of water...No flow whatsoever!...Give it a little rev and then a small swirl appears for a second or so...On the 280i it used to flow a lot more at idle.

I have an alloy rad with twin kenlowes to fit and the rad has no top overflow..Just an in and out so i will have to re-think it a little..I guess it won't matter if i blank off the swan neck...People have tried all sorts of ways but with hardly any improvement....I think Martin...(The Hatter) found a good way of routing it but I'm not sure how...Hopefully he will pass it on....smile

If your fan is bringing the temperature down and switching on and off then its efficient enough...If its staying on until you switch the ignition off then its not...Check for any leaks, Even small ones as this will contribute to the water not pressurising and will cause it to boil over...Cheers...Ziga

V8 Fettler

7,019 posts

131 months

Tuesday 16th September 2014
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njhucker said:
When it boiled over the other day I had been in a traffic jam for miles crawling into San Sebastian and it was blistering hot weather. We will get to the Costa Brava in 2 days and wanted to minimise the risk of it dumping the coolant again.
It didn't do too badly then, sounds like a marginal issue. Do you lift the bonnet to get some of the hot air out of the engine bay in slow traffic?

njhucker

Original Poster:

377 posts

259 months

Wednesday 17th September 2014
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I had the problem reoccur in Andorra today. Basically when the system pressurises all the coolant is pushed to the very top of the header tank leaving the top hose and swan neck full of air. It then stays that way even when it has cooled down, and the level can only be returned to normal by squeezing the top hose several times.

mrzigazaga

18,534 posts

164 months

Wednesday 17th September 2014
quotequote all
Hi mate...It sounds like you are getting air into the system from somewhere, If there are no visible leaks then maybe it needs a bleed...When it has cooled down find some level ground and check the level, Then remove the swan neck cap...I believe the swan neck should be full of water if not then thats where you top it up...Not the expansion tank...When you initially warm the car up does the temperature gauge reach the last marker before the red and then drop to just over halfway...This would indicate that the thermostat is opening, If not then that could be the problem....Ziga