Just a quick update. We have been driving this a lot more and have about 500-600 miles on it without further issues. I did find an exhaust manifold at the salvage yard for about $25. I will just hold onto it until it is needed, but so far so good. I have also replaced the front struts, rear shocks, front/rear links, tires, and I have treated the entire underbody since there was only surface rust currently.

 

Long term update.

Leak is still there but is minor. Multiple pressure tests indicate a very small/minor leak. I checked along the top of the exhaust manifold and was not seeing any new buildup after cleaning that entire area with a hose. Leak only occurs under full temp and high pressure so i do suspect an oring at this point. The most interesting behavior is that the leak will create a vacuum in the upper radiator hose after the car has been left to sit. This means the system retains pressure and the leak must be related to expansion/contraction of materials.

Lack of buildup on the top of the exhaust manifold is steering me to the oring. My potato brain keeps forgetting my boroscope in another location so i want to scope the area again and see if there is a residue buildup at the coolant water bypass. If there is then ill factor that into the replacement steps.

Car overall is a bit rusty in parts but strong elsewhere. Got to get some fiberglass bondo for the rear fender, and my rocker corners are starting to go. Rest of the car is still strong, the rust proofing seems to have made a difference.

It seems we are keeping this car for slightly longer than expected so im replacing 3 calipers and pads and rear rotors coming up. Rear right was seized, front left has a broken bleeder and is a pain to bleed. Fluid barely comes out with the vacuum extraction system. Will just replace them and keep the old ones for rebuild if needed.

Might have a minor oil leak at this point but am unsure. Car will need summers next year but the rest of it looks good.

 

changed front and back brake pads, rear rotors, and front calipers and the braking is markedly improved.

A random knock sensor code showed up, cleared it and it has not come back yet.

Confirmed that the leak was at the oring. No leaks around manifold but i can see it coming out of the oring.

Will plan on doing that one day.

 

I recently stumbled upon this thread having the same issue of a leak on top of my turbo manifold. I had a shop replace the turbo manifold with new gaskets and o ring but it's still leaking. The guy at the shop said it's leaking from on top of the manifold somewhere but not from the manifold where the new gasket was installed. Does this make sense? Is there another place above the turbo manifold besides the gasket that could be leaking coolant? It's a very slow leak that barely shows up but you can smell it and see it in the passenger side corner of the turbo manifold. When I look at the old manifold removed there were leaks from the curved metal outlet nipple and from the o-ring on the driver side. But there is also a large build up of dried old coolant in the center of it possibly from above somewhere? Any thoughts would help. Thank you.

 

clean the manifold with a hose or some sort of pressured water and then watch for coolant evaporative buildup. That should help you narrow down the issue.

Had buildup on the center but i cleaned it out with a hose and i no longer see any buildup. I did see some dampness on the oring side with a boroscope and that led me to guess that is where my leak is coming from.

If i understand you correctly, both the o ring and the entire rear manifold were removed and re-gasketed?

Does your leak only happen when hot or also when cool. This leak of ours is an only hot leak and the system will reseal (upper coolant hose holds a vacuum by radiator). Does this happen on your car as well?