98 S70 Missing Cyl Head Bolt Massize Coolant Leak

[sven]

I pulled a head recently and that hole did not have a bolt in it. Was the head new?

Nope, head was original. I just had it redone at a local machine shop. I think I was the one who removed the bolt and misplaced it

BTW, Love your youtube videos...I watched your head gasket series and that helped out.

[cn90]

This setup in a 1998 model maybe a prelude to 99+ years where the Volvo engineers run a coolant line (via a Banjo bolt) to heat the PCV system, I may be wrong but it is what I learned from the link below:

http://www.justanswer.com/volvo/6b0ji-s ... -side.html

[cn90]

I am not sure when that bolt was introduced by Volvo engineers. But in 1998, the Volvo engineers messed around with the PCV design by incorporating the coolant flow alongside the PCV tube (which I think is a convoluted design that turns out to be worthless)...

So while the engine was built for 1998 (and possibly earlier models), they already drilled a hole in the 1998 engine and experimented with this modified design (coolant running alongside the PCV tube).
In fact, engineers do this all the time, they take an existing engine and mess with it, then mass-prpduce it later. So during the experimentation stage, the hole is drilled but plugged with a bolt/washer.

For the curious mind, I took photos from another thread:
2001 C70 PCV system explanation
https://www.matthewsvolvosite.com/forums ... =1&t=60728

[rspi]

BTW, Love your youtube videos...I watched your head gasket series and that helped out.

Thanks for watching and glad they helped.

I guess the engineers try all kinds of things to try to make things work better (and creates more work).

[sven]

So happy to report her S70 is back in service. Runs reeeealy nice actually. Started right up in 10F cold at the first try. This was my first volvo head-job and was actually a pretty fun project. Saved it from ending up in the junkyard!

[abscate]

This setup in a 1998 model maybe a prelude to 99+ years where the Volvo engineers run a coolant line (via a Banjo bolt) to heat the PCV system, I may be wrong but it is what I learned from the link below:

http://www.justanswer.com/volvo/6b0ji-s ... -side.html

Ive speculated that the heated PVC system on the late 1998- on cars is one reason it plugs less than the earlier models - My 1999 was first cleaned at 150k TTBOMK - and it had no debris worth mentioning.