Stee1e

1994 1.8 Eunos

Just finished rebuilding after some work to my head. All starts fine but this hose is irritating me. In my photos I took it appears to run underneath the intake manifold and around the back of the block. But now I can't figure out where it goes. I did an a/c delete during the rebuild.

Concencus on a local UK group is that is the coolant overflow, this could be right but the oem is still attached (not in photo) so maybe the previous owner used it for something else. Any ideas?

AlwaysBroken

If it went around the back of the block and under the intake manifold, it's the coolant line that goes from the back of the head to the oil cooler/heater (behind the oil filter) and then on to the throttle body and then on to the cooler neck and then on to the water pump manifold.

It looks a bit thick to me, but it seems that someone wrapped something around it to protect it from being abraded.

Anyway, that line takes hot water from the back of the head and uses it to:
-warm the oil on startup
-keep the throttle from icing
-keep coolant flowing past the thermostat in non-reroute setups (like yours) to prevent the thermostat from staying cold and never opening.

Annoyingly, your picture has a crossover tube blocking my view of the thermostat neck.

Stee1e

Thanks mate, when it runs I get no leaks so this is also confusing. It makes me think it has something to do with the A/C delete. I shouldn't worry about it, with no coolant leaks it can't be a problem.

Cheers