Vacuum gauge usages and interpretation

[Steve Webb]

Hi Eric,

I’m currently learning how to use a vacuum gauge in college. I see you have two vids on this already (exhaust restrictions and how to find TDC). I can’t believe we weren’t shown this tool earlier on in College because it can diagnose almost anything…..IF you can interpret the results.

An example. I put this on my car which is 14 years old. It held steady vacuum at 15inHG at idle. According to those results the engine is doing good but is a little worn…exactly what I’d expect for a car of those years.

I was actually trying to diagnose a head gasket failure (well, checking the new one I’ve fitted wasn’t failing) and I’d be looking for a drop of around 10inHG and back up every time the compression was lost on the cylinder that was closest to the HG leak.

Anyway I’ve rambled on…

I appreciate you need the cars to do the work but even a discussion on interpreting the results would be brilliant… especially as these gauges only cost a few pounds.

Thanks

Steve

🙂

Topic

[EricTheCarGuy]

Thank you for the suggestion. It is a good one but to be honest I’d have to ‘stage’ all of the problems that I show in the video in the same way I did in the exhaust restriction video. That may not be so easy with things like weak valve springs or a compression loss. I’ll consider what I would be able to do however if the opportunity should arise.

Thanks again for the suggestion.

[Author]

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