Tcat55371 Posted February 5, 2008 Share Posted February 5, 2008 I have a 86 Turbo XT. I have done headgaskets in it 3 times now. It will run fine for a few weeks and then it blows. So here is whats been done: Heads have been resurfaced once and checked the next time for cracks, etc. Block was checked to make sure it was flat. Cant even get a .002 feeler under the straight edge anywhere.... Using Felpro PT gaskets and torqued the heads down correct and added 5lbs over per old service tech report. What hasnt been done: Head blots have not been replaced ever that I know. Dont know if bolts can bottom out and thats what I torque to? Car is parked for the winter but I want to fix it in the Spring. Funny thing is I have 2 XT's that are both doing the same thing. Any idea's I may have missed? Quote Link to comment Share on other sites More sharing options...
Bucky92 Posted February 5, 2008 Share Posted February 5, 2008 Have you upped your boost at all? I dont really know turbos but I have read many problems with upping it just a hair to much can cause something like that...its just a thought..probably wrong though. Quote Link to comment Share on other sites More sharing options...
Andy FitzGibbon Posted February 5, 2008 Share Posted February 5, 2008 I have never worked on a turbo. But, on a N/A engine the head bolts can bottom out, particularly if there is dirt/gunk/ect. in the bottom of the bolt holes. The problem is made worse by surfacing the heads, as they are then thinner and more of the bolt extends into the block. Dig out the bottom of the holes with a screwdriver, then spray some sort of solvent in (carb or brake cleaner), then blow them out with compressed air. Then, take one of your old head bolts and grind four flutes in it, like a tap, and use it to clean the threads (I like this better than an actual tap, as there's less chance of removing metal from the holes). Also, you should replace your head bolts. Andy Quote Link to comment Share on other sites More sharing options...
mikeshoup Posted February 5, 2008 Share Posted February 5, 2008 You're probably overheating it. How's the temperature? It should never get above about 1/3 at normal operating temp, or 3-4 bars on the digidash. If it regularly goes over half on normal drives, they're probably blowing due to overheating. The head gaskets are really decently strong, as long as they never overheat or you up the boost too much. If you haven't yet, replace the radiator, thermostat, water pump, etc. Make sure it has a brand new cooling system. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 5, 2008 Share Posted February 5, 2008 Are you sure you don't have cracked heads in the exhaust port? This will cause coolant leaking into the exhaust. Also what brand of intake gaskets are you using? Should be OEM only. Also, have you tried a retorqueing after running the engine? Quote Link to comment Share on other sites More sharing options...
Tcat55371 Posted February 5, 2008 Author Share Posted February 5, 2008 Well I'm not overheating it and the heads have been checked for cracks and the guy who does my machine work has built engines for old street rods I had and I trust him. I have not checked the bolts for bottoming out, that idea has been in the back of my mind bothering me along with replacing the head bolts. The turbo has been rebuilt but it was down back to stock and I'm not changing the boost any. So I guess this spring I will order new bolts and check the length, also check to make sure the bolt holes are clean. As for gaskets, I was told by many people to only run the Felpro permatorque headgaskets and thats what I'm using. Just all kinda frustrating. I have read that once the EA82 starts having head gasket issues it always has them. I dont understand that if the heads are resurfaced and the block checked. Doesnt make sense. Oh and I have replaced all of the cooling system parts except the heatercore. Car is to nice to parts out and it just is getting to me.... lol Quote Link to comment Share on other sites More sharing options...
Andy FitzGibbon Posted February 5, 2008 Share Posted February 5, 2008 The head bolt holes need to be as clean as you can get them. If the bolts can't turn smoothly in the threads they are more apt to "pop" as you are torquing them, which gives a false torque reading. Andy Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 5, 2008 Share Posted February 5, 2008 What is the nature of the "failure" that leads you to the headgasket diagnosis? Perhaps you are having a different problem, like leaky intake gaskets? Other than that, I would thoroughly inspect the exhaust ports. Pull off the crossover pipe and look up into the ports. Pay careful attention to the portion where the dividing "wall" across the middle meets the sides. There can be hairline cracks in that spot. Good news is they can be repaired by a competent aluminium welder Quote Link to comment Share on other sites More sharing options...
94Loyale Posted February 5, 2008 Share Posted February 5, 2008 Well, besides everything mentioned above, which are all possible causes. A big problem I see is that the head bolts were never replaced. Every time you do a head gasket, those bolts should be changed. Head bolts stretch and they will never let the head seal correctly again. They may seem to tighten up correctly when you put them in, but they aren't. Quote Link to comment Share on other sites More sharing options...
Tcat55371 Posted February 5, 2008 Author Share Posted February 5, 2008 Well I drive 100 miles a day back and forth to work. After doing the head gaskets it runs fine for a few weeks and then starts smoking and using antifreeze. The longer it runs the worse it gets after this. Right now you start the car and it blows out the rad cap right away. I checked the intake with a straight edge also. That was another thing I thought could be wrong. I wire brushed the head bolts before I put them back in but I did not by new ones. I guess the thing to do is order a set of head bolts and try one more time and this time check the depth of the holes to the length of the bolts and also flush out the threads. I have not tried to retorque the bolts after it has ran because you all know what a pain it is in the car to do that. Just running this by you folks to get more idea's that I might have over looked. Thanks for all the help folks. Quote Link to comment Share on other sites More sharing options...
screwbaru2 Posted February 6, 2008 Share Posted February 6, 2008 I would change the head bolts. They do streach with time Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 6, 2008 Share Posted February 6, 2008 AH - incorrect information alert, someone save the future noobs that will read this!!! A big problem I see is that the head bolts were never replaced. Every time you do a head gasket, those bolts should be changed. this is not true and should be edited to avoid confusion. subaru's do not require head bolt replacement. there is more than one kind of head bolt and Subaru's do not need to be replaced every time. do some reading online about head bolts, torque to yield and other similar reads to learn more. but you're possibly steering him in the wrong direction. at this point he really does not need to be guessing. TCAT - think you need to find out where you're using coolant. leak down test that thing. have you noticed a compromise in the head gasket when removing the blown ones? if not, it might not be your head gasket. i doubt new bolts will fix your issues. is there a chance the cylinder sleeves are shifting (they can come loose) or there's a crack in the block? Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 6, 2008 Share Posted February 6, 2008 Well, besides everything mentioned above, which are all possible causes. A big problem I see is that the head bolts were never replaced. Every time you do a head gasket, those bolts should be changed. Head bolts stretch and they will never let the head seal correctly again. They may seem to tighten up correctly when you put them in, but they aren't. I've never used a new EA82 bolt. I've never even seen a new EA82 bolt! I've never read anything from Subaru that indicates that these are torque to yield bolts or that they need replaced when servicing. In fact IIRC there is a portion of the FSM that describes inspecting them, for reuse. I agree with Grossgary that to avoid confusion the above info should be removed or edited. BUT..... I'd like to know where to find M11 Cylinder head bolts or studs??? I would like to use a set for my upcoming *medium-performance* EA82t build. But Again, I do not believe it is required to replace bolts, and I believe the OP's problem is from something else. Quote Link to comment Share on other sites More sharing options...
Tcat55371 Posted February 6, 2008 Author Share Posted February 6, 2008 Well the last time I changed them on the awd xt is ran 3wks, about 1500 miles before it started smoking again. Now as soon as you start the car you can see the pressure in the radiator with the cap off. Had the neighbor help me put it back together and we didnt see anything wrong. Could be a crack in the block, dont know but why would it go 3wks first? To me it seems like the headbolts are coming loose. When I take it apart this spring I will double check torque on bolts first. That should tell me if they are plus check the depth of the bolt holes to the length of the bolt. The worse part is both cars have done the samething which really baffles me. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 6, 2008 Share Posted February 6, 2008 leak down test time. - can you do a compression and leak down test on it, that's what i think needs to happen here. The worse part is both cars have done the samething which really baffles me. you've got some REALLY bad luck with subaru's! that is strange that you have two doing something that i can't really ever recall seeing before (in experience or on the boards). odd indeed. bottoming out sounds like it might be a good call, but the leak down test should be performed to see where it's going. Quote Link to comment Share on other sites More sharing options...
cobcob Posted February 6, 2008 Share Posted February 6, 2008 To me it seems like the headbolts are coming loose. When I take it apart this spring I will double check torque on bolts first. That should tell me if they are plus check the depth of the bolt holes to the length of the bolt. Are you using Fel-Pro Permatorque head gaskets? I believe other brands of head gaskets (including the OEM ones) require re-torquing after a certain length of time... Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 6, 2008 Share Posted February 6, 2008 Are you using Fel-Pro Permatorque head gaskets? yes he is.Using Felpro PT gaskets Quote Link to comment Share on other sites More sharing options...
Andy FitzGibbon Posted February 6, 2008 Share Posted February 6, 2008 Are the EJ head bolts torque-to-yield? Seems like I remember that being the case. That might be the source of the confusion. It should be noted that the bolts should not be reused if they have damage or rust. This ties into the section of the manual which explains how to inspect them for reuse. Andy Quote Link to comment Share on other sites More sharing options...
94Loyale Posted February 7, 2008 Share Posted February 7, 2008 The EA bolts are not TTY, I never did say that. However, considering the amount of times he has had these heads on and off, I would say the bolts could possibly be an issue. The bolts will inevitably stretch, overtime, they are going to elongate and not contract back to their normal length. Running the bolts in and out, over and over again, and torquing them each time is also going to damage the threads, and they are not going to hold like new. I admit, I stepped too far stating they should be replaced every time you do a head gasket, as that is just my personal preference. However I do not enjoy doing a job twice. I agree, it may not be necessary to do so every time, but knowing the amount of load and pressure the bolts are under, and the range of temperatures they are quickly exposed to, I replace them. So if I offended anyone with that statement, I apologize. Please accept this as my edit to my previous post. Quote Link to comment Share on other sites More sharing options...
94Loyale Posted February 7, 2008 Share Posted February 7, 2008 Just to clarify, I was incorrect in my saying "you should replace the head bolts every time". This was only a matter of preference, and I am at fault. To Gary, and Gloyale, you are completely right, the head bolts do not need to be changed every time. I made a mistake in my post, and I'm glad there are other competent Subaru mechanics to clarify for everyone else. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 7, 2008 Share Posted February 7, 2008 The bolts will inevitably stretch, overtime, they are going to elongate and not contract back to their normal length. The 11mm bolts used in the EA82's would require a LOT more than 47 Ft/lbs to stretch any amount they would be unable to recover from. Trust me on this one. They do stretch, but the amount is so tiny after they recover when removed that it would take hundreds of uses to even notice it. Perhaps thousands. You can easily test this by taking a thread pitch gauge to them. If they stretched any noticeable amount then the thread pitch would change and the guage wouldn't match up. Try it and see. I've stretched a few bolts in my line of work . You would be amazed what all-thread will handle when used with various pullers and hydrualics GD Quote Link to comment Share on other sites More sharing options...
MilesFox Posted February 7, 2008 Share Posted February 7, 2008 just to throw this out there, and so that you know, the 3 bolts in the middle of the head are shorter than the rest. SO, if you have the short bolts on the outer edged and the longer bolts in the middle, there is your bottoming out issue, and probably what is wrong with your torque each time if you had not known or noticed this before. Quote Link to comment Share on other sites More sharing options...
Tcat55371 Posted February 7, 2008 Author Share Posted February 7, 2008 Yeah I know the 3 bolts are shorter in the middle, thats not it. I still think I will replace them, whats another 80.00 at this point. lol The second XT I bought with overheat issues so I really dont know much about it and all I did was pull the heads, had them resurfaced and put it back together. Have not spent anytime checking into anything else on it. My awd that came from Ratty2Austin is the one that I really want back on the road. It's been a great car up until now and I have racked the miles up on it. Before I put the motor in last time I had it on a stand with the intake off. I filled the coolant holes in the heads up to the top where the intake would bolt on. At that point I used my little air compressor and compression tester and pressurized each sparkplug hole one at a time and let it sit for about 10 minutes a hole with 40lbs of air in it. Never saw one bubble come out of the intake antifreeze holes. Now thats not to say it wasnt going anywhere else but you could not hear ait leaking and when I sprayed watery soap around the outside of the heads I got no bubbles. (like checking a tire for a leak) I did not want to go thru all this work again so I took the time to run the test. Neighbor was there double checking all my findings. Ok, now to putting the motor in. Since the heads were resurfaced and the intake sides also I took a 2x4 and put some sand paper on it and ran it across the bottom of the intake on both sides to make sure it was flat. Then I went to Dodge and got some of thier black sillicon and sealed the gaskets on both sides. That suff glues everything down and is a bear to get off next time. I put the motor in and like I said it went about 1500 miles before it started smoking again. I guess the next steps would be pull the motor and do the leak test again before I take it apart and see if I can hear anything. It has to be going into the radiator because you can see it right away now with the cap off when you first start the car. Next step would be to pull the intake and test it again to see it bubble but if it's going into a water jacket it could transfer between heads so I dont know how good of a test it would be. I have another set of FELPRO PT headgaskets. I will also buy new bolts. This will be the last time I do this motor. Next would be to buy a JDM motor again. I also had the turbo rebuilt and just to make sure that wasnt it I changed that with one of the others I have off my old XT parts car. Just need Winter to go away so I can get it out of the barn and try again I guess. Anybody close want to come watch to make sure I dont miss a step? lol Why couldnt this have happened when Austin was still out here. Then atleast I would have had another set of eyes. john Quote Link to comment Share on other sites More sharing options...
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