Quick assessment of my car please! M20B25

[Jboss12]

Alright so is this a blown head gasket?

I have a 1992 BMW 325ic and just did the timing belt, water pump and thermostat. The temp gauge never went past the 1/4 mark. I opened up the thermostat housing only to find it empty. So I put my new Tstat in and the engine temp reads just below the halfway mark.

Here are the symptoms:
-coolant looks brown and this is even after I somewhat flushed it out
-the coolant will sometimes be boiling after a drive (I notice it gargling away once I turn the engine off)
-sometimes the coolant will come directly out of the expansion tank relief hose and onto the ground

Other things to note:
-Car doesn't seem to overheat. It will sort of creep up the halfway when I'm sitting still for a while but never overheats
-the coolant to water mix is like 20% coolant to 80% water (it's temporary)


Sound blown? It seems to me like its leaking between the cylinder walls and into the coolant in the engine block. This might be a redundant question but I just figured I'd ask

Thanks PNW

[e30austin]

I'd say the brown you see is just rust/corrosion from some numb nuts using just water with no coolant mix. I wouldn't be too concerned. With that said, I would go ahead and run a compression test, if you are that concerned.

[boostless]

I'd put my money on the cooling system isn't holding pressure or you have air in your system somewhere

[2mAn]

boiling makes me think there is air in the system. hopefully its something simple

[Jboss12]

Thanks for the responses, I appreciate it. Yeah I'm hoping it isn't the head gasket but if it is I guys I can just dive into doing that. I'm becoming familiar with the m20b25 quicker than I thought

[kylelauffer]

check the oil and see if its milky color. if so your getting coolant in the oil and thats a blown head gasket. also how does your exhaust smell and look or can you see any kind of smoke. even a little bit. sounds like cooling system needs some attention first though before making assumptions.

[Jboss12]

check the oil and see if its milky color. if so your getting coolant in the oil and thats a blown head gasket. also how does your exhaust smell and look or can you see any kind of smoke. even a little bit. sounds like cooling system needs some attention first though before making assumptions.

The oil looks great, no signs of coolant or yellow rings on the oil cap. The exhaust doesn't produce any visible smoke whatsoever, it does smell a little sweet I guess but it's not anything that noticeable. I'll definitely take care of the cooling system first before I go into anything else