Where is my coolant going?
Discussion
OK apologies if this has come up before... losing coolant, about half a litre per 100 miles... no obvious leaks, no steam from the exhaust, no visible mayo in coolant or through oil filler (oil is clean and clear on the dipstick too), not overheating, fan kicking in on queue... just keeps needing top-up!
So, two questions...
1. possible causes?
2. what nice easy systematic steps can I try to pinpoint the cause?
If the head gasket(s) needs changing...anyone know what the cost would be at a specialist? Could do it myself but too many other commitments (can't be arsed)!
So, two questions...
1. possible causes?
2. what nice easy systematic steps can I try to pinpoint the cause?
If the head gasket(s) needs changing...anyone know what the cost would be at a specialist? Could do it myself but too many other commitments (can't be arsed)!
Edited by Wedgii on Tuesday 3rd August 23:55
Edited by Wedgii on Tuesday 3rd August 23:56
A coolant system pressure tester would let you pump the system up to full pressure (or ideally a bit more) with the engine cold, makes finding leaks a bit more pleasant. Basically a bicycle pump with a pressure guage and a one-way valve, attached to a radiator cap. I made my own 'cos I didn't fancy paying Sykes-Pickavant money 
Leaks wot I 'ave 'ad over the years include...
Radiator top hose
Rad itself
Heater valve
Expansion tank (three times
)
And the ever-popular... steel pipe under the inlet manifold. See if you get a pool of water collecting on the top of the valley gasket, at the rear of the engine, when the car has been stood for a while. There are two steel pipes that take the coolant back to the heater, they have a habit of corroding through from the inside, causing pin-prick holes. Of course when the engine's hot it evaporates so quickly you can't see it, but if it drips when the car's cold you can soon find it.
Leaks wot I 'ave 'ad over the years include...
Radiator top hose
Rad itself
Heater valve
Expansion tank (three times
)And the ever-popular... steel pipe under the inlet manifold. See if you get a pool of water collecting on the top of the valley gasket, at the rear of the engine, when the car has been stood for a while. There are two steel pipes that take the coolant back to the heater, they have a habit of corroding through from the inside, causing pin-prick holes. Of course when the engine's hot it evaporates so quickly you can't see it, but if it drips when the car's cold you can soon find it.
Wedg1e said:
A coolant system pressure tester would let you pump the system up to full pressure (or ideally a bit more) with the engine cold, makes finding leaks a bit more pleasant. Basically a bicycle pump with a pressure guage and a one-way valve, attached to a radiator cap. I made my own 'cos I didn't fancy paying Sykes-Pickavant money
Leaks wot I 'ave 'ad over the years include...
Radiator top hose
Rad itself
Heater valve
Expansion tank (three times)
And the ever-popular... steel pipe under the inlet manifold. See if you get a pool of water collecting on the top of the valley gasket, at the rear of the engine, when the car has been stood for a while. There are two steel pipes that take the coolant back to the heater, they have a habit of corroding through from the inside, causing pin-prick holes. Of course when the engine's hot it evaporates so quickly you can't see it, but if it drips when the car's cold you can soon find it.
Wedg1e, didn't mean to tread on the toes with the name, mine was just a play on the Wii thing ... Anyhoo, thanks for the info...great idea to pressurise the system cold, I'll get on it next weekend!Leaks wot I 'ave 'ad over the years include...
Radiator top hose
Rad itself
Heater valve
Expansion tank (three times
)And the ever-popular... steel pipe under the inlet manifold. See if you get a pool of water collecting on the top of the valley gasket, at the rear of the engine, when the car has been stood for a while. There are two steel pipes that take the coolant back to the heater, they have a habit of corroding through from the inside, causing pin-prick holes. Of course when the engine's hot it evaporates so quickly you can't see it, but if it drips when the car's cold you can soon find it.
grumbledoak said:
Is it continuous, or could you be going through an overfill/boil off cycle? That one has a very cheap fix...
Otherwise, I'd be looking at a pressure test.
Unfortunately it's continuous, although there was one instance where I overfilled it and some water blew past the pressure cap aftre a short run, 'though this hasn't happened since, even for longer runs! The water losses seem to be persistent and undetectable so far! Aah the mystique of a TVR never ceases to bemuse! Otherwise, I'd be looking at a pressure test.
Wedgii said:
Wedg1e, didn't mean to tread on the toes with the name, mine was just a play on the Wii thing ... Anyhoo, thanks for the info...great idea to pressurise the system cold, I'll get on it next weekend!
No worries, it's not like you can copyright a username.... 
I think there's also a 'wedgie' - though he doesn't drive a Wedge, his name is Mike Wedge!
Mine's supposed to be 'wedgy one' as in, I am the wedgy one...
Got a sketch for my coolant tester somewhere, I'll see if I can find it...
I seem to have the same thing aswell.
Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
have you checked the water pump is not leaking a tiny bit of fluid from the 'tell tale' at the front?
Stu
Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
have you checked the water pump is not leaking a tiny bit of fluid from the 'tell tale' at the front?
Stu
hallsie said:
I seem to have the same thing aswell.
Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
Stu
Look out for the cast alloy rocker covers from the XR4i engine, they look a whole lot more modern than the pressed tin ones. I ground the Ford logos off mine and had them powder-coated (red, funnily enough, but that was the car's colour) - looked stacks better.Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
Stu
Better still, find a complete XR41 engine, it'll run on unleaded. I got my engine for £50 before 4-star disappeared, a year later they were fetching much more
I seem to have the same thing aswell.
Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
have you checked the water pump is not leaking a tiny bit of fluid from the 'tell tale' at the front?
Stu
Ive put it down to the inlet manifold gasket and I have a plan to have the top end off during the winter to clean up the rocker covers that were painted crapilly with red paint, and send the heads off for an unleaded conversion ( no paperwork to confirm this has been done, although the engine is supposed to only be 12 years old) so Ill do the gaskets during this period.
have you checked the water pump is not leaking a tiny bit of fluid from the 'tell tale' at the front?
Stu
hallsie said:
send the heads off for an unleaded conversion
Send them to me and I'll "convert" them to unleaded for 50 quid! ;^)
Apart from airlock issues and leaks that evaporate, are you running a waste pipe to the ground from the pressure cap, or a catch tank?
If the former then any occasional burps just end up on the road. Mine has a catch tank and a siphon back in, and "tops itself up" from that, which tends to eliminate airlocks at the same time.
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