thicker oil with HG maybe going down ( CO² in coolant )

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thicker oil with HG maybe going down ( CO² in coolant )

Postby benTSH » Fri Apr 21, 2017 12:26 am


I use my beloved Legacy just for "town" use and just a few highway ride each weekend; it is a second vehicule so I won't going to restor the engine.

since many mounthes I have air bubble in the coolant and there is for the moment a little quantity of CO² as the chemical test was not clear but not bad : the color was at a scale of 2 over a 5 levels scale :wink: so I suspect head gasket but maybe it would be a leak on the cabin heater pipes as I heard a lot of air bubble when I activate the heater and I get no warm.

But with 275000 km I'm aware the HG is not young but the oil level is stable and with no coolant so my problem is when I ride more than 45min there is too much air in the coolant and the engine temp is a little less cooled and a little more hot than an usual "good health " engine so I'm wondering if I should better use 10W-50 instead of 5W-40 as I use now ?

Thanks by advance
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Re: thicker oil with HG maybe going down ( CO² in coolant )

Postby Surge » Fri Apr 21, 2017 6:29 am

Changing the oil is not going to help.

The head gasket in these cars leaks combustion gasses into the coolant jacket, but doesn't normally mix with the oil or have any effect on it.

What you could try is a bypass of the heater core, if you want to rule that out.

But if you've already tested for CO2 in the coolant, I think you should just get the head gaskets done.
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