Picking up Block Test Today
 

I ordered my Block Test from NAPA and it comes in this afternoon. Will this tell me DEFINITIVELY if I have a BHG? The only symptom I have is coolant spitting out the overflow bottle after a long drive. No other symptoms such as oil/water mix, white smoke out of tailpipe, or overheating. So I'm hoping I can count on this as proof positive. Also, I heard the test requires comparing colors in the fluid. I am somewhat color blind. I can tell red from blue, but if it comes to telling different shades of yellow or green I'm up shitcreek. Is it easy to see the difference? If anybody has done this before maybe you can give me some advice. One more thing. Does anyone have a link to a site that covers BHG's ?

Thanks

Scruffboy

Lots of info by IHateHakes in this post, http://www.toyota-supra.info/forums/showthread.php?t=7128&page=17&pp=10

Good luck! your problem could be many things, rad cap, water pump, or even a blocked radiator. The symptoms of a BHG are similar to having worn impellors on a water pump. By the way don’t rely on the temperature gauge to tell you anything, its not until you nearly run out of coolant that it will start to increase.

Is your block tester kit similar to this one? http://cgi.ebay.co.uk/USA-UNIVERSAL-ENGINE-CYLINDER-HEAD-BLOCK-TESTER-KIT_W0QQitemZ160121367108QQihZ006QQcategoryZ30922Q QtcZphotoQQcmdZViewItem

Just checked out the instruction for the one on ebay When Fluid Turns From Blue to Yellow Combustion Leak is Present. Hopefully your one may be the same in which case you will be able to tell the difference.

Hey BillUK
 

You listed a lot of causes but I performed the test with a NAPA kit and the fluid definitely turned yellow so I'm assuming BHG. This symptom (water out of overflow) has started slowly, but now on long drives (which I don't do often) it is definitely more noticeable. I only drive the car 2 or 3 times a week, usually under 10 miles. The symptom showed up a couple of months ago. Can a lot of damage happened since then? What I want to know is should I sell the car. I'd rather keep it. Even now it drives nice. But this is an expensive fix. I tell ya, when the shit hit's the fan, it really hits it. One more question. This kit was expensive, is it re-usable?

Scruff

Yes the block tester is reuseable. Just rinse out the testing tube and discard the "used" fluid. You should have a 16oz bottle of that blue test fluid which will last you literally dozens of block tests.

Just make sure you rinse out the testing tube really good.