VicTrawler
Senior Member
- Joined
- Mar 19, 2015
- Messages
- 234
- Location
- Canada
- Vessel Name
- Halcyon I
- Vessel Make
- 1984 36' Universal Europa Sedan
I just replaced the cooling hoses (freshwater side) on my Lehman and I want to ensure I'm completely purging all air from the system.
I followed the instructions in the manual, which are:
- Fill the system and purge the exhaust manifold while doing so.
- Top up the expansion tank.
- Run the engine at 900 RPM and wait for the thermostat to open, then keep the expansion tank topped up.
Now, when does the thermostat open? I kept the radiator cap (expansion tank cap) off the entire time, all the way up to just about 180F. I did notice more turbulence when it got closer to 180F, so I'm assuming that was the thermostat opening. That being said, I had bubbles almost the entire time, but they did seem to subside to almost nothing UNLESS I throttled up to 1500+ RPM, in neutral, then I got more air.
What was also weird is that after I throttled back down to 700-800 RPM, I'd get an arcing spray of coolant out of the radiator cap. What the heck is that? Is that a tonne of air trying to escape? It also seemed to be random if/when it would do it. I would throttle back up to 1500 RPM and back down to 700 or so and it would only have an arcing spray about half the time.
And yes I will bleed the system from the exhaust manifold bleed valve once everything cools down.
I also didn't have anything in the overflow (plastic) tank during this process as I had not yet re-filled it.
Did I do any of this wrong?
One more thing, I was getting steam (I hope) from the radiator cap opening. It didn't smell like exhaust. I'm assuming that's normal. I think if it was exhaust, the bubbling would've been far more significant... unless that's what the arcing spray was... hope not, because that would be a head gasket.
Pardon the rambling. Any suggestions/input would be much appreciated! All of this effort is to try to tackle an overheating situation.
I followed the instructions in the manual, which are:
- Fill the system and purge the exhaust manifold while doing so.
- Top up the expansion tank.
- Run the engine at 900 RPM and wait for the thermostat to open, then keep the expansion tank topped up.
Now, when does the thermostat open? I kept the radiator cap (expansion tank cap) off the entire time, all the way up to just about 180F. I did notice more turbulence when it got closer to 180F, so I'm assuming that was the thermostat opening. That being said, I had bubbles almost the entire time, but they did seem to subside to almost nothing UNLESS I throttled up to 1500+ RPM, in neutral, then I got more air.
What was also weird is that after I throttled back down to 700-800 RPM, I'd get an arcing spray of coolant out of the radiator cap. What the heck is that? Is that a tonne of air trying to escape? It also seemed to be random if/when it would do it. I would throttle back up to 1500 RPM and back down to 700 or so and it would only have an arcing spray about half the time.
And yes I will bleed the system from the exhaust manifold bleed valve once everything cools down.
I also didn't have anything in the overflow (plastic) tank during this process as I had not yet re-filled it.
Did I do any of this wrong?
One more thing, I was getting steam (I hope) from the radiator cap opening. It didn't smell like exhaust. I'm assuming that's normal. I think if it was exhaust, the bubbling would've been far more significant... unless that's what the arcing spray was... hope not, because that would be a head gasket.
Pardon the rambling. Any suggestions/input would be much appreciated! All of this effort is to try to tackle an overheating situation.