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cooling system help

1949 Views 4 Replies 4 Participants Last post by  Fluid, 
T
i have just purchased a golf mk3 1.9tdi, occasionally i have smelled coolant when driving, i have also noticed a small amount of coolant around the bottom of where the header tank sits, after doing a little more investigating, i have noticed a lot of very tiny air bubbles in the pipe that goes into the header tank, is this normal, are header tank/pressure caps prone to fail? are headgaskets known to fail? the engine is ahu (i think) the car does not overheat.
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T
lots of tiny air bubbles are not normal, you smell coolant because it's leaking somewhere , try this: on a cold engine, start the car.

Let it run for a few seconds and then open the header tank, if it's pressurized then you know you have a bad headgasket. This is because it's leaking into the coolant system. That could be the small bubbles but if the coolant is clean then maybe not the headgasket.

It oculd just be a bad coolant tank that's leaking coolant.
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chittychittybangbang
The best thing to do is to get a pressure tester. This pressurizes the coolant tank and if there are leaks than it will show. If it's a bad headgasket then the test tokendog mentions will detect it. There isn't always coolant and oil mixing with a bad headgasket.

There is also the EGR cooler. This is a heat exchanger between the exhaust and coolant system. If it's leaking into the exhaust you should smell it in the exhaust and notice a slow loss of coolant.
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T
carried out dye test (turned green =bad) took head off and it was more bent than a banana, one question regards the re-build though, after removing the head i found only one dowel on number 2 headbolt is this right? i would have thought that there would be 2 dowels? any thoughts would be very welcome, many thanks
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F
Bentley should show but if the head came off. Sucks that it was damaged, remember to loosen the headbolts gradually so that the head comes off level. When you tighten them, tighten them each little by little so that the head is level while the bolts are tightenied.
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