Coolant Foaming Up

[SkyHi_33]

Hi guys, just did a turbo conversion on my rb25.

Now the car was running tops before the conversion, chucked a new manifold, turbo, braded lines etc on to it and started it up. No tune, no driving, just idling and the coolant started foaming up out of the radiator. It is quite a thick white/browny foam.

Now when the turbo was done, the coolant drained out of the turbo water line and would have been fairly low. I topped it up with water before starting but the thermostat wouldnt have opened. Have not topped it up and bled it since.

I checked the engine oil, inside rocker covers etc. and am pretty sure (well, from what i can tell) the head gasket is ok. Remember, the car hasnt been driven at all, just idling and a quick rev or two when it warmed up.

Reckon it would have just been the low coolant? Flush it out a couple times then fill it up and bleed properly?

Edited November 8, 2010 by SkyHi_33

[TiTAN]

you hooked the oil/coolant lines up correctly?

[SkyHi_33]

you hooked the oil/coolant lines up correctly?

yeah double checked that... oil feed is mid way through the block, return on the bottom? water line off the intake manifold, return towards the back of the block?

[TiTAN]

yep.

oil feed is close to inline with the return half way up the block, return is just above the sump. water is from the intake side of the block on the rear heater hose fitting, and on the exhaust side near the back of the block.

do you have any pictures of the foam?

[Luke_ENR34]

Alloy rad? Would not earthing that cause it?

[SkyHi_33]

nah just a standard 33 radiator... no pictures of the foam unfortunately. was running around making sure there werent any leaks etc and didnt get a chance to take a pic.

ive had a quick search and smeone mentioned that it can happen when the coolant is very low, the water pump pumps air through it and foams it up :S

[snozzle]

some cars with slightly dirty coolant systems do that, dont worry about it, just make sure all the air locks are bled out and the coolant isnt leaking from anywhere that u worked on

[ClutchBurndout-:(]

head gasket?

[Rolls]

Could it be a leak in the turbo seal causing air to get into the system? check the exhaust doesn't have coolant and isn't steaming.

Other option could be air has got into the system during installation, leave it idling for a few minutes until the thermostat opens up and see what happens, you won't kill anything at idle.

This is assuming the foam is just air and not the coolant mixing with oil or something else.

Edited November 8, 2010 by Rolls

[SkyHi_33]

had it idiling for about 15min before, exhaust is clean, no smoke (bit of condensation at start as its been sitting around) the coolant is greeny brown and started foaming up before but seems like its slowly clearing up.

have not had the chance to bleed the coolant system yet as its in the garage blocked off by other cars (dont wanna make a huge mess) but will try do it during the week. i did let the thermostat open and topped it up some more tho.

checked the engine oil after i shut it off, seems clean/normal. all lines seem fine, no leaks that i can see. turbo spools up fine just revving it and can hear it smoothly slowing down after its shut off (ball bearing) so i think its all hooked up fine.

Edited November 9, 2010 by SkyHi_33