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Discussion Starter · #1 ·
As my previose strings have shown I may or may not have HGF or reading other strings just sludge in me pipes. The final test is a pressure and sniff test but what is it and what do they do
 

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A sniff test shows if there are any traces of gasses in the coolant that shouldn't be there posibly indicating HGF.

A pressure tests shows up any leaks, indicating the same thing, and if there are any leaks in general.
 

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The pressure test will pressurise the coolant system without the engine running, this see if there is a leak.

The sniff test checks for combustion gases coming out of the coolant with the engine running.

Dam James C's fast fingers.
 

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Discussion Starter · #4 ·
Okay if I get it , a pressure test can be done by a meter on the cylinders by removing the spark plugs and a halfords hand held tester Or according to strings ,bubbles in the coolant resevoir when cold as the gas escapes from the pots. I had a Nissan which would build pressure and release through the leak witha sound like air brakes.
The sniff test done by a hot wire detector in the water bottle which would detect the solvents in the petrol.
I am going to get a garage to do a test but keen to understand what they do
 

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Think the coolant pressure test involves pressurising the coolant, then locking it off and watching for any drop in pressure indicating a leak.
A compression test done with the plugs out is something quite different.
 

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Okay if I get it , a pressure test can be done by a meter on the cylinders by removing the spark plugs and a halfords hand held tester Or according to strings ,bubbles in the coolant resevoir when cold as the gas escapes from the pots. I had a Nissan which would build pressure and release through the leak witha sound like air brakes.
The sniff test done by a hot wire detector in the water bottle which would detect the solvents in the petrol.
I am going to get a garage to do a test but keen to understand what they do
AFAIK a cylinder pressure test and a coolant one are two different things.
 

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AFAIK a cylinder pressure test and a coolant one are two different things.
A compression test (plug removal) would not always show a possible HGF, more so in the more common failure of the gasket betwen the oil and coolant ways.

A simple sniff test using an exhaust emissions MOT tester in the top on the coolant tank would detect the presence of hyrocarbons giving a much better idea if the HG has failed.
 
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