water sound behind dash

[kotu100]

maybe the head is cracked, causing constant BHG's
i did the HG the exact same way i did mine, and im running 400whp for the last couple months, daily with no problems.

 

[lewis15498]

This is very possible.

 

[suprarx7nut]

this would be the fourth time for me

4th bhg on the same motor probably means it hasn't been fixed properly. You may have a warped head/block.

 

[kotu100]

i wouldn't doubt it, the car had some type of half metal half composite HG on it before.

i did check the head and block surfaces for warpage, but there only so much a straight edge and feeler gauges can do.

 

[radiod]

I had a cracked head...blew through an HKS 2.0mm bead MHG 35,000km (22,000mi) after the rebuild. It's definitely not impossible to have cracked heads, especially if it's been overheated (EVER!) in it's life. Alluminum is relatively soft in comparison to steel and will anneal if subjected to high temperatures (kind of like when you overheat your car with a BHG). After it starts annealing, things just go downhill from there.

 

[supradjza80]

I would have to agree that lifting the front of the car may help some but really isnt necessary if the car has a proper thermostat with the Jiggle valve (most will cut this valve out which is fine to) which allows air to escape to the Rad. If you have a continued issue with this I would recommend checking the other symptoms of the head gasket (exhaust in coolant, oil in coolant, coolant in oil, low compression in 2 cylinders etc.)

I have drained my coolant probably 15 times when I flushed the coolant system, I would just fill the rad and drive it with the heat on and there has never been any water fall sounds and I never burped it.