boiling sound

[coopsa4 0]

Help please. VR6

 

I have changed the heater matrix, dash out, took me a full day. Connected the heater pipes up and slowly filled with new coolent, no problems. Been out today and oil temp got up to 108, water temp 100.

 

You can hear a boiling noise coming from the thermostat area, thinking I have a airlock I have taken the water pipes off the top of the rad and the heater matrix, refilled, been back out and still the same. The top water pipes seem very hot, the bottom radiator pipe is a lot cooler. The cap on the expansion tank is black and looks old, is this a good place to start? There is plenty of pressure in the system.

 

Any ideas

 

Thanks

[Critical_Mass 10]

It would well be an airlock. Did you put the heater and fan on full whilst the engine warmed up and did you massage the pipes? Also did you leave the expansion cap off whilst it heated up also?

[coopsa4 0]

Yes, tried all that, been out about 4-5 miles car running perfect, heater getting hot, still boiling noice at thermostat, forgot to say car has aircon, does this make any difference? Is there a place to bleed the rad? :confused4:

[Critical_Mass 10]

sorry dont know if aircon would make a different, cant see how if it does. The boiling sound is probably just water running. I occasionally get it when ive been for a run and i turn the engine off, its sounds like boiling water but its just the water circulating into the reservoir.

 

Sorri i cant be more help. As long as temps are ok and the heater works. not sure it will be a problem