If removing bottom hose doesn't work then try jacking the back of the car. Removing the heater feed bottom hose might help also by venting any lock since your car doesn't appear to have a heater flow control valve in keeping with the later 3.7.
Richard?
I am confused. Can you help me?
Isn't the normal goal when flushing (different from draining) to do so with the entire coolant system rather than merely a bit of it? Only draining the radiator
does not achieve much.
That can be done be merely removing the top and bottom hose and using them with a hose to flush the rad. Even if only that
I prefer it to using the top cap (if one's rad still has one) and its bottom drain cock for the obvious reason.
One cannot flush a cooling system by merely draining the radiator..or even flushing it. Unwanted debris is as likely to remain in the engine, approximately
1/3 of the old coolant (and possible debris) remains in the engine. And of course, the engine cannot be properly flushed without removing, at least, the
thermostat. I pull the engine drain plugs as well. Is there some reason to flush only part of the system? The Ford Duratec 3.0 and method and all others go
much farther than that.
That being said, the right engine coolants now last as much as 100,000 miles depending on ambient conditions. Their technology has vastly improved in
the last 20 years. And digital coolant testers are very cheap (under 10 quid) and easy to use.
L.
P.S. Sadly, access to the Roadster thermostat is a PIA.
