overheating engine

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janieh
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Re: overheating engine

Post by janieh »

New Kentish Campers wrote:It's not a bad idea to test your new Dalek cap before you fit it.

Just blow hard though the pipe outlet and you should hear a quacking noise, like a Duck :) If you can blow straight through with no noise, then it's a duff cap [I happened to me on a brand new one recently :roll:]

Thanks, we've done that and it does quack, but the old one doesn't. So hopefully it's ok.
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janieh
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Re: overheating engine

Post by janieh »

OK, so we now have a new cap on the tank. Having looked at the coolant, it's right up to the top in the header tank. Is this right? I don't know if I'm being stupid, but I can't see a maximum line.

So from looking at the wiki, it looks as if I have to start the van, and raise the revs to about 2K and top up the expansion tank. Then drive a bit, topping up with water if temp goes up. Then, with the engine still running I need to open the radiator bleed valve. To get to this do I have to pull off the front grill and it'll be on the right side?

Then raising the revs again I wait until air stops coming out the radiator. Then turn it all off and top up the header tank again.

Does that sound right? I'm planning to do this tomorrow morning.
Cheers
Jane
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mark
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Re: overheating engine

Post by mark »

the link is the way................follow it to the letter and you cant go wrong, print it and have it to hand

mark

http://www.brick-yard.co.uk/forum/bleed ... 29710.html" onclick="window.open(this.href);return false;
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Oldiebut goodie
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Re: overheating engine

Post by Oldiebut goodie »

janieh wrote:OK, so we now have a new cap on the tank. Having looked at the coolant, it's right up to the top in the header tank. Is this right? I don't know if I'm being stupid, but I can't see a maximum line.

Jane
Marks on the right:-

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marlinowner
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Re: overheating engine

Post by marlinowner »

My understanding is that the header tank is the pressurised tank, with the dalek cap, it should be completely full. The tank behind the numberplate is the expansion tank, should be filled to between the Max and min lines.
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janieh
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Re: overheating engine

Post by janieh »

marlinowner wrote:My understanding is that the header tank is the pressurised tank, with the dalek cap, it should be completely full. The tank behind the numberplate is the expansion tank, should be filled to between the Max and min lines.

Yes thanks, that's what I thought. I was just confused by the fact there was a minimum line on the header tank. The picture above is the other one, and I can see the marks on that one.

cheers
Jane
1998 Westfalia Club Joker, 1.6l TD

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janieh
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Re: overheating engine

Post by janieh »

mark richards wrote:the link is the way................follow it to the letter and you cant go wrong, print it and have it to hand

mark

http://www.brick-yard.co.uk/forum/bleed ... 29710.html" onclick="window.open(this.href);return false;

Thanks, I'll give that a go.
1998 Westfalia Club Joker, 1.6l TD

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Re: overheating engine

Post by ghost123uk »

Re the rad bleed screw, when you have removed the grill it is actually on the left side of the rad, but the right as you are looking at it, if you get my meaning. Be careful not to undo it too much or it will come right out and if you have pressure in there you will get a fountain of very hot water !!

Tip = After you have done the initial bleeding, as you describe, then, once the van is roughly up to temperature, you should have some pressure in the cooling system. At this point, if you undo that rad bleed screw half a turn you will get either air or coolant being forced out by the pressure. If coolant comes out all is good, if air comes out keep bleeding / topping up until no more air does come out. Obviously with a hot engine you cannot just take off the Dalek cap safely, but let it all cool and check levels topping up as required. After a few "cycles" of cracking the bleed screw when hot, eventually you will get no more air coming out and the job is done.

Note = when the engine is up to temperature it is normal for the top up tank (behind the flap) to be higher than when it is cold. During the cooling down phase it sucks coolant from that top up tank back into the header tank, thus ensuring the header tank is completely full to the very brim. Make sure the thin pipe from the Dalek to the top up tank is in good nick and well secured or during the cooling down phase it will suck in air, not coolant.
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Re: overheating engine

Post by ghost123uk »

janieh wrote: So from looking at the wiki, it looks as if I have to start the van, and raise the revs to about 2K and top up the expansion tank

I have not checked with the wiki, but just to sure things are clear here. The topping up at ~2,000 rpm is into the tank on the left, the one with the Dalek cap on it, not the tank behind the flap.

The one behind the flap can be called the expansion tank (hence my typing this) or the "top up tank" by some. I call it the "top up tank" to help avoid any confusion with the other tank (which is usually referred to as the header tank).
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Re: overheating engine

Post by janieh »

ghost123uk wrote:
I have not checked with the wiki, but just to sure things are clear here. The topping up at ~2,000 rpm is into the tank on the left, the one with the Dalek cap on it, not the tank behind the flap.

The one behind the flap can be called the expansion tank (hence my typing this) or the "top up tank" by some. I call it the "top up tank" to help avoid any confusion with the other tank (which is usually referred to as the header tank).

Thanks for the clarification. That is what I understood, but yes the wiki is a bit confusing as the bottom post re diesel engines calls both tanks expansion tanks!
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Re: overheating engine

Post by ghost123uk »

I just went to the wiki to E D I T that to make it correct, but on reading it, it is correct :?

Bleeding the system on a diesel or GTI engined van is much easier. Fill the system as much as possible, then start the van, raise the revs to about 2K and top up the expansion tank while you have the revs elevated. Put the cap on and gently drive about half a mile. If the temp starts to climb over the mid-point on the gauge stop and re-fill with water. The half mile drive should open the thermostat. Now with the engine running crack off the radiator bleed at the front. Raise the revs to about 2K and allow it to bleed until no further air bubbles come out. Now switch off and top up as necessary on the main expansion tank. If you're suspicious repeat this bleed process again, but it shouldn't be necessary. Wait for everything to cool down and top up the tank behind the number plate.
(Bold by me)

Also, I had not before noticed, the author of that last bit ("TC") mentions the bleeding technique I use and mentioned above ^^^ :)
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Re: overheating engine

Post by janieh »

Hi Everyone.
Just thought I'd post an update on our van. It's still not sorted but hopefully getting there as we go on holiday to France soon!

Our previous garage annoyed me by constantly saying that it wasn't a real problem and it was just the lights, and they pretty much refused to do the sniff test when I mentioned it. They were a bit patronising to be honest. Even though I've used them loads before. So then following all your helpful instructions we got a new dalek cap and worked out how to do the bleeding ourselves. We managed to get quite a bit of air out and topped it up until the red light went out (briefly!).

Then the van needed it's MOT anyway, so I took it to Oliver at T25 Direct in Dulwich. The light was back on so we asked him to look at the coolant system and see if he could spot any problems. He found that the header tank was leaking and replaced it. Topped it all up and said that I need to take it for a proper drive to see if it was ok now. So I took it for a long drive down the A3 and it was ok up to a point, then once I got some speed up it started to overheat again, and then got really got when I was in 5th gear. Afterwards there was over 1 litre of coolant missing, and also even though cool it was still pressurised and there was lots of water in the tank behind the reg plate.

So now after discussing with Oliver, he thinks the dalek cap has been overcome by pressure and that the engine is pressurising the system. He's going to do the sniff test and see if the head gasket has been breeched. Sounds expensive! But as long as he fixes it I don't care. It's driving me nuts!

ta everyone. Jane.
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Re: overheating engine

Post by ghost123uk »

Umm,
janieh wrote:So now after discussing with Oliver, he thinks the dalek cap has been overcome by pressure and that the engine is pressurising the system

This is now starting to sound like yet another case of a blockage somewhere in the bleed ring and / or the associated thin pipes and "T" pieces coming off it.

Like this example =

Image

This can cause a lack of coolant flow around the left hand head and causes the coolant in there to boil, overcoming the dalek caps ability to work correctly. I have had this, and quite a few others have too. Needs to be fixed though before you actually use the van much, on mine, before I had figured it out, it cost me an engine :(

Could still be a gasket failure though too, a sniff test will tell.

Hope you get it sorted in time !
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Re: overheating engine

Post by janieh »

ghost123uk wrote:
Could still be a gasket failure though too, a sniff test will tell.

Hope you get it sorted in time !

Well he's done the sniff test and says it is the gasket. So he's working on it and we should get it back next week. Pretty expensive job though! oh well.
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