jmai86 Posted January 26, 2010 Share Posted January 26, 2010 I put in a new head gasket, torqued bolts in sequence properly, and after maybe 100-200 miles I'm noticing a VERY tiny leak where the head mates to the block. I can see a line of green along the seam. The car drives fine and I'm not noticing any internal burning coolant. Should I retorque? Or is the new gasket just bad.. again? Sorry if this is a dumb question, I'm quite new to major engine work. It's a 71 btw. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted January 26, 2010 Administrators Share Posted January 26, 2010 What brand of gakset did you use and did the instructions call for a retorque? Was the head deck and block deck surfaces checked to be true and flat, i.e. no warp or wave across the deck using any measuring equipment? How was the block and head surface prepped, i.e. surfaced at a machine shop, biscuit style air tool used to remove the old gasket, belt sanded, old gasket nmaterial was not removed, etc? Any chemicals/sealants/cleaners used on the gasket, block, or head surface prior to reinstallation? Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 26, 2010 Author Share Posted January 26, 2010 What brand of gakset did you use and did the instructions call for a retorque? Was the head deck and block deck surfaces checked to be true and flat, i.e. no warp or wave across the deck using any measuring equipment? How was the block and head surface prepped, i.e. surfaced at a machine shop, biscuit style air tool used to remove the old gasket, belt sanded, old gasket nmaterial was not removed, etc? Any chemicals/sealants/cleaners used on the gasket, block, or head surface prior to reinstallation? I don't remember the brand, but I purchased from Winchester auto, who usually has quality stuff in stock (never had an issues with their parts or gaskets). My mechanic checked for flatness and it was to spec. The block and head were cleaned and scraped thoroughly of all materials using hand tools and scrapers, head was sanded lightly with higher grit sandpaper. No chemicals that I remember using during re assembl, just motor oil for the head bolt threads if I recall correctly. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted January 26, 2010 Share Posted January 26, 2010 Happened to me too last time I did the head. I used some of that sealant stuff you pour into the radiator......stopped the weeping very quickly and I've had absolutely zero problems with it since. That was 25K kms ago! I have changed the coolant many times since and haven't needed to use any more sealer. Guys on here will probably slam me for suggesting this stuff. There is an opinion that it reduces the effectiveness of the cooling system by forming an insulating layer over all the metal surfaces, reducing their ability to transfer/liberate heat. The other problem mentioned is that the 'stuff' can block off the small radiator tubes in the radiator, reducing its cooling ability. I was aware of these potential problems before I put the sealer in. The problem was fixed though without any apparent complications from its use. Good luck mate. Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 26, 2010 Author Share Posted January 26, 2010 Happened to me too last time I did the head. I used some of that sealant stuff you pour into the radiator......stopped the weeping very quickly and I've had absolutely zero problems with it since. That was 25K kms ago! I have changed the coolant many times since and haven't needed to use any more sealer. Guys on here will probably slam me for suggesting this stuff. There is an opinion that it reduces the effectiveness of the cooling system by forming an insulating layer over all the metal surfaces, reducing their ability to transfer/liberate heat. The other problem mentioned is that the 'stuff' can block off the small radiator tubes in the radiator, reducing its cooling ability. I was aware of these potential problems before I put the sealer in. The problem was fixed though without any apparent complications from its use. Good luck mate. Hm, would you happen to remember the brand/type? Quote Link to comment Share on other sites More sharing options...
hoov100 Posted January 26, 2010 Share Posted January 26, 2010 Hm, would you happen to remember the brand/type? I use alumna-seal from vatozone, comes in a little tube. It's just basically a bunch of extremely fine aluminum shavings. It's saved my ass a couple times. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted January 26, 2010 Share Posted January 26, 2010 Hm, would you happen to remember the brand/type? Mate, I live a long way away from you. Chances of having the same stuff in our shops is slight. You basically know what's needed now, go and get some and try it. Tell us how you get on. Cheers. Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 26, 2010 Author Share Posted January 26, 2010 Mate, I live a long way away from you. Chances of having the same stuff in our shops is slight. You basically know what's needed now, go and get some and try it. Tell us how you get on. Cheers. Ah jut noticed your location haha! I'll try some bars leak tomorrow and see if that helps the slight weeping. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted January 26, 2010 Share Posted January 26, 2010 Ah jut noticed your location haha! I'll try some bars leak tomorrow and see if that helps the slight weeping. Buggar me...that's what I used!!!!!! Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 26, 2010 Share Posted January 26, 2010 I have never had good luck with the sealant stuff - yes it stops the leak, but I've also clogged two heater cores. If you are going to use it, make sure that the water to the heater core is blocked off, and flush the system after the leak stops. Now on re-torqueing... Seriously guys? Just re-torque the damned thing. If its already leaking what's the worst that could happen? There - I said it out loud. Back each bolt off 1/4 turn and torque to spec (with the engine stone cold of course) and see what happens. Do each bolt one at a time and in the proper torquing sequence (i.e., loosen the first bolt, then re-torque it, then move on to the second. Don't loosen them all at once) FWIW, I always retorque a new head gasket at least twice with a few heat cycles between each retorque. Granted I am using a different gasket - it's the Nissan comp gasket that requires machined recess for the separate fire rings, so its easier to have small leaks like this. Retorqueing has solved this problem at least once for me. Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 26, 2010 Author Share Posted January 26, 2010 Well my heater core was removed and bypassed by the previous owner, so I'm not concerned about blockage there. My only concern with retorqueing is causing more damage. I don't remember if the gasket was one of those "do not retorque" or "no retorque needed" types, and since it's such a small weep, if the bars leak can plug it up I'd rather do that than risk more damage by retorqueing. Unless retorqueing wouldn't hurt anything regardless of the gasket type... I really wouldn't mind torquing again if it's safe and correct to do so. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 26, 2010 Share Posted January 26, 2010 Well my heater core was removed and bypassed by the previous owner, so I'm not concerned about blockage there. My only concern with retorqueing is causing more damage. I don't remember if the gasket was one of those "do not retorque" or "no retorque needed" types, and since it's such a small weep, if the bars leak can plug it up I'd rather do that than risk more damage by retorqueing. Unless retorqueing wouldn't hurt anything regardless of the gasket type... I really wouldn't mind torquing again if it's safe and correct to do so. I guess I'm having trouble imagining how the procedure I mentioned above could cause any damage to any head gasket. Maybe if you loosened all of the head bolts at once and then retorqued them it could be a problem, but if you do one at a time I can't see how this could possibly hurt anything. This isn't some sort of difficult invasive procedure - it takes maybe 10 minutes and most of that is R&R'ing the valve cover (I am assuming that you have proper tools and a decent torque wrench). This used to be an "every 10k mile" service item. Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 26, 2010 Author Share Posted January 26, 2010 I guess I'm having trouble imagining how the procedure I mentioned above could cause any damage to any head gasket. Maybe if you loosened all of the head bolts at once and then retorqued them it could be a problem, but if you do one at a time I can't see how this could possibly hurt anything. This isn't some sort of difficult invasive procedure - it takes maybe 10 minutes and most of that is R&R'ing the valve cover (I am assuming that you have proper tools and a decent torque wrench). This used to be an "every 10k mile" service item. Oh well I was just worried about the effect of re-torquing on a gasket that's not meant to be re-torqued, if it would ruin the gasket or anything, you know Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted January 26, 2010 Administrators Share Posted January 26, 2010 Oh well I was just worried about the effect of re-torquing on a gasket that's not meant to be re-torqued, if it would ruin the gasket or anything, you know Nope, it will be fine. Now just go do it already. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 27, 2010 Share Posted January 27, 2010 Nope, it will be fine. Now just go do it already. Maybe Paul can confirm - I've always taken the "no-retorque" thing to mean that they've tried to design the gasket so that it doesn't have to be re-torqued, not so much that it can't be re-torqued. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted January 27, 2010 Administrators Share Posted January 27, 2010 Maybe Paul can confirm - I've always taken the "no-retorque" thing to mean that they've tried to design the gasket so that it doesn't have to be re-torqued, not so much that it can't be re-torqued. That is my interpretation as well. Quote Link to comment Share on other sites More sharing options...
Ben Posted January 29, 2010 Share Posted January 29, 2010 Have you re-torqued it yet? If not, what's the hold up? And the next time you assemble the block/head, use a bit of Hylomar adhesive spray - it's good stuff... Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 30, 2010 Author Share Posted January 30, 2010 Have you re-torqued it yet? If not, what's the hold up? And the next time you assemble the block/head, use a bit of Hylomar adhesive spray - it's good stuff... I retorqued, no weepage so far! Thanks for the tips Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 30, 2010 Share Posted January 30, 2010 My mechanic checked for flatness and it was to spec. Did the same guy check the head and the block? What was his definition of 'to spec'---0.004"? Understand that both surfaces can be 'to spec' and you can have a 0.0075" mismatch. How do you think that will seal? NEVER accept 'to spec' answer from any 'mechanic'! If they can't give you a number, they eyeballed it. Anybody asks me what the warpage check was, I can give them a number, and where. I might say 'it was to spec' but unless it was GLASS FLAT there's warpage that can add up and that (IMO) it is incumbent upon the inspector to pass on to the person paying for the work. I've seen 0.008" combined. The previous shop had said "it's a the edge of spec, but it should be fine. Of course the head was piecemealed to a 'head specialist' separately who had a similar tale to tell. And then the first head gasket blew... Other than that, 'what braap said' -- if the gasket calls for a retorque, then do so. I have always put half a tube of Aluma-Seal in the coolant system since seeing Ford adding it to every car coming off the production line (later I found that Volvo does this as well...) People can say what they want about it, but nusiance leaks like what you are experiencing likely will be taken care of by 1/2 a tube, and when you flush your coolant next year (er, you do flush you coolant annually, right?) it goes away leaving the little pluggies doing their thang... Quote Link to comment Share on other sites More sharing options...
jmai86 Posted January 30, 2010 Author Share Posted January 30, 2010 Ah that's good to know, thanks. Thinkin about it know, the guy wasn't very thorough at all. I really don't know much about engine internal work, so "to spec" sounded like a good thing to me at the time Quote Link to comment Share on other sites More sharing options...
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