Possible BHG?

[frontierguy25]

My Koyo Race Radiator started leaking the other day really bad, it got hot twice but not fully to the red line... As soon as I saw it start to creep up I pulled over and put some more water in it... I temp fixed the radiator with some of the liquid aluminum puddy... it's not leaking anymore and the car didn't leak on a trip.. it did blow a little water out of the resivoir though, I did fill it up to the top... I did a couple of 2nd gear 19psi pulls too... still holding water and making a ton of power... Now the thing is I changed my oil yesterday and the oil looked fine and the water looked fine, just the cap has some weird white gunk underneath it, my first thought was bhg... I checked the plugs and they are all fine and the pistons look normal not super clean like a bhg would do.. going to do a compression test in a little bit and see if it is ok as well..

My catch can pipe did pop off the other day and I ran like that for 2 days before I changed my oil... Could that have caused the residue? Also with the temps fluctuating here with the snow and everything I was also told that might cause it too..

Thanks guys in advance for the input...

BTW I have a Titan MHG w/arps at 85lbs... only 15k miles on the rebuild...

Now my turbo is smoking pretty bad too.. it is going to get rebuilt next week along with getting a new mishimoto radiator...

 

[ben1984j]

Koyo radiators seem to have a pretty good reputation from what I've heard, I wouldn't think one of them would leak unless there was excessive pressure in the cooling system (I'm surprised that the radiator was the "weakest link" and not something else though). It's possible that your radiator cap isn't releasing pressure as it should, that would be something to check. Not to say the radiator couldn't just be defective, I guess.

Also, did you resurface the head and block when you put on the MHG? And re-torque the ARPs (studs I'm guessing based on the torque spec you posted)? I don't know if not re-torquing (by itself) would cause HG failure, but machining the head and block is pretty much crucial with an MHG...

 

[frontierguy25]

I've heard of a couple of the koyos doing this acutally.. It seems to be a flaw with a couple of them that were sold at the same time... but I'll try the cap... but it seems to be releasing the pressure because I get some in my overflow... Or its not keeping enough pressure in there?

I've done a couple of these MHG's now... everything was prepped correctly...

I just need to rebuild my turbo and see what's going on... The sludge isnt brownish like a bhg, its like pure white and very little layer...

Going to do a compression test today and report back later... But man it feels powerful!