Hi all,
I have Mk 4 Sr 2 Escort RS Turbo sitting in my garage. I have noticed when turning it over and running it for a while that the header tank cap hisses when the engine is hot.
I dont think it's a knackered head gasket as the engine runs like a dream. No mayonaise in the oil etc, etc. CVH's have a bad history of cooling problems.
I am thinking of buying a swirl pot. Bailey do one for £94. I have googled this issue but am still not sure if a swirl pot would cure the pressurisation issue I have.
If so, or not, what exactly does a swirl pot do, and would it stop my header tank from blowing???
MTIA AdyBee..
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Try buying a new cap first. About £5, I'd guess, a lot cheaper than a swirl pot (whatever that does in the cooling system). I thought a swirl pot was a device inside the petrol tank, where the pick-up pipe takes in petrol. Like a baffle to prevent surging in the petrol tank when braking, accelerating and cornering, I could be wrong.
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I would do the same, faulty filler caps are not unknown.
A swirl pot is a device to remove air from coolant, oil etc. From memory, Cosworth had to fit them to the Lotus 49 F1 cars on the dry sump oil return pipes, the oil return pumps were removing oil from the crankcase mixed with large volumes of air which had to be removed before the oil was recirculated The oil/coolant is fed into the pot at a tangent, follows a circular path through the pot, the action of which causes any air to be expelled from the oil/coolant. The air-free oil/coolant then flows out of the bottom of the pot. Sorry, a bit of a long answer, but I am trying to explain.
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I would also advise you to get to the bottom of the problem rather than fit something else in order to cure it. As far as I am aware there are no common problems with this kind of thing on a Series 2 RST and I would be tempted to try a new header tank cap first. If this doesn't cure it and the header tank rim is in good condition then I am afraid you may have some early signs of head gasket failure as there is obviously still a large pressure build up that isn't normal.
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I would be concerned about a new header tank cap. This is because the header tank itself has "stretch marks" around the side of it. Looks like it's on the verge of blowing already.
I notice that the swirl pot for this engine has a small outlet on the top of it. Is the air from the coolant restricted with a pressure valve, or just allowed to escape to atmos?
If it is the head gasket leaking from compression to the water jacket would the tank not have blow up long ago, considering the pressure developed in the cylinders? The car has a turbo the size of my shed on it.
AdyBee...
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At this point I think you need to get the cooling system pressure tested properly. Most garages should have the equipment to do this. It makes no difference whether you have a turbo or not. the person doing the testing should have the data to hand to check if the system pressure is correct. The radiator/header tank cap has a pressure relief valve in it, and this will stop overpressure in the system. This cap needs checking out as well. I have seen several faulty caps which have released at too low a pressure, causing coolant to be blown out, or hissing from escaping air which is drawn in to replace the missing fluid.
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I didn't realize that the cap itself acts as a pressure relief valve. I will call TC Harrisons to order one in. I dought they will have a 1988 model on the shelf.
Just out of curiosity, how much should you tighten these caps? I take it a pair of Stilsons aren't required.
Many thanks for your help..
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You might find they will have one on the shelf. The cap won't be unique to that model, it will be the same as ones used across a proportion of the ford range. You don't have to get one from the main dealer though, I think you might stand a rearonable chance of buying one from an independant motor factors or maybe even halfords.
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Tighten firmly like a slightly worn tap, but not murder-tight.
--
groups.msn.com/honestjohn - Pictures say a thousand words.....
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