2000 2.7l 986 Coolant & Exhaust Gas Intermix
 

Hi everyone, looking for some advice.

I bought a beautiful year 2000 986 with the 2.7 engine.

Recently i had a mechanic diagnose that my coolant is mixing with exhaust gasses.

Now they said it's most likely a crack in one of the cylinder heads.

Could there be any other way that exhaust gases are getting in the coolant and if so how would I diagnose this without tearing the engine apart.

Just looking for the most financially sustainable way to keep this car running as I really do love it.

Can I just buy a a replacement head and slap it on there and hope it works? Or does it have to be the exact same part number and year?

Mechanic recommended to just drop a 3.2lt "S" engine into it as apparently they don't have this issue as much. But they are quite dear tbh and I don't know if it's a straight swap either?

What's everyone's advice here?

For the conversion check https://www.pelicanparts.com/techarticles/Boxster_Tech/11-ENGINE-911_Engine_Swap/11-ENGINE-911_Engine_Swap.htm

For the coolant: it may be useful to use an endoscope to look into the cylinders via the spark plug holes in order to be able to narrow down the fault, otherwise you will not be able to avoid disassembly with such a fault pattern imho.

Do you do your own mechanical work? If you do, I would suggest removing the engine and removing the heads to see what is up, and make your decision on what you find.
If you are paying someone to do all the work it would likely be less costly to just switch in a replacement engine.
On swapping a 3.2 for a 2.7... it is pretty straight forward if the new engine is a 2000 or 2001. If it is a 2001 there may be a problem with the temperature sensor which isn't complicated to work around. I know because I swapped a 2.7 for a 3.2 in my 2000S (temporarily) then installed a used 2001 3.2.

Long before even thinking about pulling the heads or the engine, I would be pressure testing the cooling system to see if it is really leaking coolant.........................

How did the mechanic come to this determination?
What was the clue that led him to say what he did?
What was he doing that even caused him to look for the symptom? and thus the cause?
Had you been adding or losing coolant?
Did he pull the spark plugs and show them to you?