Fuji Fellow Posted July 14, 2005 Share Posted July 14, 2005 In these forums I've heard of a test for Hydrocarbons in the coolant. Is this a test that can be done easily at home, or does it require going to a radiator shop? What equipment is involved... something special? I'm suspecting my 88 EA82 wagon is beginning to have HG troubles. It shows the classic signs of slowly overheating and puking coolant after a time on the freeway, but it will sit and idle indefinatly with no temperature problems. I guess if it tested positive for HC in the coolant, that'd be a sure sign of of the head gaskets leaking. I'm wondering... has anyone ever just retorqued the head bolts and had that be enough to fix small HG problems? I know it's kind of a moot point because by the time you've done all the work to disassemble down to the heads, you might as well take them off and replace the gaskets. BUT, just curious if maybe "aluminum creep" in the heads was allowing the HG to leak a little, that retorquing the head bolts might fix that. Anyone? Quote Link to comment Share on other sites More sharing options...
jeffroid Posted July 15, 2005 Share Posted July 15, 2005 I think an HC test is done with a sniffer just like the one they stick in your tailpipe when doing an emissions test. I can't answer your question directly, but I would be surprised if retorquing would fix a head gasket leak. I'd make sure I had a head gasket leak before I did anything. Unless you have a buddy that works in a tune up shop with an emissions machine, it might be easier to just do a compression test than trying to find someone to do an HC test. A much better test if you have a compressor is a leakdown test. A compression test will not always detect a small head gasket leak. Too many other things besides a head gasket can cause the symptoms you describe. Quote Link to comment Share on other sites More sharing options...
Sister7 Posted July 15, 2005 Share Posted July 15, 2005 You can buy a "block tester" from NAPA for like $50 (it looks just like this: http://bestproducts.asiannet.com/detail/25557/195425557.html ) But it's a waste of money. It has this fluid that is suppost to change from blue to yellow if there are exhaust gases in your coolant, but it's never worked, even when my car was puking exhaust gas/coolant foam. I don't know what they use in shops to test for HC, but I'm assuming it's something slightly more reliable. Quote Link to comment Share on other sites More sharing options...
Ru_ Posted October 14, 2005 Share Posted October 14, 2005 here is a good trick to check for a head gasket leak....Let the car sit over night, and before you start it the next day, pull the rad cap off....if the coolant is up to the top, all is ok. If it's down then more than likely the head gasket is shot. (keeping in mind, cracks in the exhaust port like the EA82's are so common for may cause this same problem). If the coolant is down, remove all spark plugs and apply shop air to the clylinders (one at a time of course) and turn the engine over on to the compression (against the shop air pressure in the cyl) make sure the rad is full before you start of course.....if bubbles come out, the head gasket is shot. Do this for all cyl's. If no bubbles, no bad head gasket... Just thought I'd throw in my 2 cents. BTW if anyone knows where I could get my fingers on Bi-metal head gaskets for my EA82 turbo, I'd be glad to hear it. Or if some of you guys are interested let me know. I am looking to go with copper, since they are available, but I'd rather bi-metals. agerlach@hotmail.com Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 14, 2005 Share Posted October 14, 2005 if by puking coolant you mean it's bubling into the overflow tank when it starts overheating....this sounds like head gasket issues indeed. are you loosing any coolant? can you drive awhile without "puking coolant" so you can take notice if you're loosing any? i agree with starting with a compression test. autozone has a tool loaner program, borrow tool and bring it back all at no cost to you. they may or may not have compression testers available. they arent' that expensive anyway. radiator being plugged and thermostat can also cause overheating ...verify this isn't an overheating problem. if it's overheating now, remove the thermostat at least so it doesn't keep running hot, that will only degrade the leak faster. you just won't have any heat.....brrrrr..... Quote Link to comment Share on other sites More sharing options...
Bobby_boucher Posted October 14, 2005 Share Posted October 14, 2005 You can buy a "block tester" from NAPA for like $50 (it looks just like this: http://bestproducts.asiannet.com/detail/25557/195425557.html ) But it's a waste of money. It has this fluid that is suppost to change from blue to yellow if there are exhaust gases in your coolant, but it's never worked, even when my car was puking exhaust gas/coolant foam. I don't know what they use in shops to test for HC, but I'm assuming it's something slightly more reliable. I've used the block tester 3 times and it has worked very well for me. Quote Link to comment Share on other sites More sharing options...
jasinwa Posted July 23, 2006 Share Posted July 23, 2006 I heard there are 2 types of tests... 1. The sniffer that sniffs HC's in the coolant. I think most shops have this tester and will charge. For example, I am thinking of buying a 98 Leg GT and would have this test run.....(I think, see below) 2. Some type of dye test, also as noted in this thread. What I don't know but hoping someone can verify: Is HC buildup accumulative of momentary, for testing? For example, what if the owner just flushed their radiator/fluids a day ago? Would both tests still catch a HG problem (this would assume accumulation is not needed)? I am thinking the sniff test is most accurate, as it seems most soobie mechanics have it...some have the dye test.. Nice little article here Quote Link to comment Share on other sites More sharing options...
idosubaru Posted July 23, 2006 Share Posted July 23, 2006 you're talking about the newer generation subaru's when you say "98". that's a completely different animal than the older generation motors. the 2.5 in that Legacy GT can and does pass the HC test and nearly every other headgasket test even with a bad headgasket when they first start to go. very common to go misdiagnosed due to this. it's happened multiple times on the board and i've seen a mechanic do the HC test on a bad headgasket 2.5, but it still passes. he knew nothing about Subaru and just couldn't believe it...he did the test about 10 times. then he saw the light and ended up installing another motor with some advice from myself. for your problems....more details will help diagnose. where is it puking coolant from? hoses, radiator caps, gaskets, water pump...lots of things can cause puking, we need to know where it's coming from. headgasket issues will cause bubbling into the overflow tank when the car is overheating or shut off. bubbles are bad here. if you're looking for a cheap and easy fix, retorquing the headbolts is not the way to go. like you said, best just to replace the gasket if you're already down to the heads. but...subaru adds a conditioner to mitigate the 2.5 headgasket issues in the earlier 2.5 motors. i'm still wondering if this "conditioner" that they sell for the 2.5 wouldn't help a minor headgasket issue on other motors. still an aluminum block, i'd give it a try. a flush would likely remove most of the HC from the sytem as you suggested. Quote Link to comment Share on other sites More sharing options...
jasinwa Posted July 23, 2006 Share Posted July 23, 2006 ooops yup, I posted in the wrong topic.... I did a search and just figured to add to one already there, not realiziung it happened in older models too. If the mod could del my reply if they feel it is not appropriate, please do! Otherwise, I am in process of buying it...either a 98 gt ltd or a 92 or similar svx... Quote Link to comment Share on other sites More sharing options...
nipper Posted July 23, 2006 Share Posted July 23, 2006 there is a home test, Also there is a new "if all else fails" stop leak for HG's you may want to try made by stop leak. in theory if done right it should work nipper Quote Link to comment Share on other sites More sharing options...
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