940 Turbo Head Gasket replacement
 

I recently purchased a 92 940 Turbo which has a few issues. Upon purchasing, I knew of all the cosmetic issues, as well as some brake work needing to be done. The main issue is a possible Head gasket leak.
The symptoms i have seen is a milky substance on the underside of my oil cap and small stains underneath the engine on the surface it has been parked on

I would like to know of any possible problems when replacing the gasket, as well as any tips to help it go as smoothly as possible. Thanks

the foaming may be due to condensation and some blowby. before you rip into the engine you should test for a clogged PCV (flame trap) and inspect for leaks including cam seals/main seals/oil pan. There are some other tests for head gasket problems - wet/dry compression and HCs in the coolant are two which are easy enough to do. Have you taken the car for a good long drive to heat it up fully and get any latent moisture out of the system? Any smoke coming out of the dipstick when you pull it with the engine running? Any signs of weeping between the head and block? Any loss of coolant or oil consumption? If you are going to pull the head then you should send to a machine shop to have it checked for flatness and consider freshening all the bits in the head (valve seals, check the guides etc). New parts for the timing belt and PCV plumbing too.

Thank you!
I will do all those tests and report my results back here after

Just some milky stuff on the cap is not 100% indicative of bad HG, neither are oil spots. Take a compression or leak down test to make sure.

Good News!
After letting it run for a while, I can confirm the milky substance was caused by condensation, Thqnk you all for the tips!