Strange sound from the passenger footwell

[71tuscan]

Since i've replaced my radiator and valley gasket, I have a new, strange sound coming out of the passenger footwell.
It sounds like fast circulating water with a lot of air in it, although i took great care in getting all the air out of the cooling system when refilling it.
The sound is relative to the engine speed, and I'm almost 100% sure it is caused by captured air in the heater matrix.
Does anyone know a way to get it out? My Chimaera is a 1999 450. I've been searching for a purge valve, but i can't find anything.
Coolant temperature has dropped 5-20 degrees, depending on circumstances, so the cooling system works absolutely perfect.

[Goaty Bill 2]

See the Goat's Patented Funnel Design:


And follow the instructions below.
Please note that I do not sell the actual funnel arrangement, but I do sell the plans for £5.00 each set.


Reposting ChimpOnGas aka ChimpofDarkness aka ChimpaFrolic (and too many other aka's) without any permissions whatsoever ( Original post Wednesday 14th November 2012);

ChimpOnGas aka ChimpofDarkness aka ChimpaFrolic said:

First off the heater in these cars is extremely effective, there is nothing wrong with the design of the system at all.

If your heater is not performing well, then there is most definitely something wrong.

When I first bought my Chimaera the heater wasn't very effective, especially at speed on a very cold day where things could get uncomfortably chilly.

A rad blind helped, but it was always a bit of a compromise between being warm on the move & running the engine too hot when city driving.

I assumed they were all like that

I was wrong

After bleeding the cooling system properly the heater proved itself to be a proper little furnace even on the coldest day.

I now only ever use the full hot setting on the very coldest day when on the motorway for sustained periods, as soon as I slow to pass though a town it's essential to turn it down or you absolutely cook.

I don't use that rad blind any more, the heater works perfectly without it and the car runs a maximum 85* on the TVR temperature gauge idling in traffic.

It does seem these cars can run perfectly well with air still trapped in the cooling system, and the place that air sits is the heater matrix.

There is definitely a drop in cabin temperatures as speed increases, but if your heater fails to keep you warm on a cold day at speed you need to bleed the air out of the matrix.

If your car has recently has a top end rebuild, it's extremely likely they didn't bleed the cooling system properly, there is a proven process that if not followed will almost certainly leave air trapped in the heater matrix.

Follow these steps, then tell me your heater is still ineffective.


Jack & support at the front so the nose of the car is as high as possible (this helps encourage a good flow around the heater and force the trapped air out)
Remove the brass plug from the swirl pot & insert a large funnel
Open the heater valve fully by putting the heater control to it's hottest setting (it may be worth checking it's truly fully open at the valve itself)
Fill your large funnel you the brim with coolant and start the car
Increase engine revs and wait for the thermostat to open (you can feel the hoses to establish the thermostat has opened)
Keep filling your funnel (IMPORTANT: Don't let the coolant in the funnel drop to the level of the swirl pot)
Rev the engine to get the water pump spinning, this will aid circulation & help burp the air out
Keep adding coolant to your big funnel as the level falls and the trapped air gets burped out
Go back inside the car & check the heater performance, if all the air has burped out you should have a continuous column of water circulating around the heater matrix and an extremely effective heater
Switch off, remove the funnel, replace the brass swirl pot plug, then drop the car back on it's wheels
Go for a drive to test the heater performance at speed
After following this process I would put money on you having a fantastic heater again

[Hedgehopper]

I've had similar problems. You could try one of these to bleed the air out......

http://www.carbuildersolutions.com/uk/black-nylon-...

Or you could just loosen the top heater hose at the back of the engine.

[jojackson4]

Or just remove the 6 mm bolt that blanks off a redundant hose at the front of the
Inlet manifold once it's bled there jobs a good one

Hth

[Goaty Bill 2]

All well and good, but by the time you are hearing it gurgling through the heater pipes/matrix, you probably have air elsewhere in the system as well.

I just noticed that Dave's post doesn't seem to mention bleeding the air from the radiator via the bleed screw (and tightening it back up again of course) prior to starting the engine.

[pbaker43]

When the water is hot it will heat the air, the hot air will always rise, so if there are pockets in the system eventually they will burp out, can take some time for all the air to escape.
71 tuscan I had your issue.. did as the thread suggests, removed the brass screw, got the engine hot, jack the front up and just keep an eye on the temp reading and water level.. At one point I thought the engine was purged, after 5 minutes of running and revving there was a huge burp of air like a geyser, I filled the funnel quickly and checked all was ok.. since that day no issues even in 43°C climbing the mountain passes the engine never passed 92°C, in winter the heater was ‘like the girl of your dreams’ red hot…