Blocking or Bypass of Heater Core lines, which one's better?

[JohnM]

Bypass.

Jury rig a pipe with flexible extensions on both ends for it.

I have old cars too, all are bypass.

Is bypass better than capping off the inlet and outlet? My old car was factory bypassed (got clogged and had very hard to detect pinholes) and my friend's car of similar make was capped (leaked too but kinda easier to check).

[lowslowbenz]

^

I'd like to think so. My bypass tubes are all outside already (engine bay) where its easy to check should they leak. The system holds a bit more coolant too (as compared to a plugged one), so I think that's one benefit there.

[JohnM]

I think most Japanese FWD engine designs route the bypass under the intake manifolds between the block and the firewall.

[jvnj]

^

I'd like to think so. My bypass tubes are all outside already (engine bay) where its easy to check should they leak. The system holds a bit more coolant too (as compared to a plugged one), so I think that's one benefit there.

Ah yes, a bit more coolant. Thanks for your comments, Sir LSB!