speeder Posted October 25, 2002 Share Posted October 25, 2002 Not a Z problem (I wish it was ), but- I have an '87 GN with a newly rebuilt engine that is losing water.( can see it coming out the tailpipe, and if run hard water gets in the oil.) My question involves troubleshooting this problem - I have one of those pump type radiator testers with the pressure guage , and have pressurized the cooling system. It holds 17-20 psi indefinitely, hot or cold. I then bled pressure to about 5psi in the radiator, started the engine, and checked for pressure fluctuations on the tester guage - saw none. I see no bubbles in the radiator water with the engine running. I then checked every cylinder with my leakdown tester and found less than 5% on all. All plugs look the same - a little too clean IMO. Any of you know something specific to the Buick that can cause this problem? - I have limited experience with non- L6 motors - Or do I have a problem with my test methods? My first inclination was to just change head and intake gaskets, but thought I'd try for some expert advice before engaging in that PITA - the motor has head studs that make pulling heads not fun in the big Buick body. Thanks for any help, Quote Link to comment Share on other sites More sharing options...
Guest Zachb55 Posted October 25, 2002 Share Posted October 25, 2002 well i cant tell you where your water is coming from, but im pretty sure its not from your radiator. its pretty common for water to drip out of your muffler, im not quite sure how it happends but it aint that bad in any case... now to get in your oil, hmm, that seems like it almost certainly has o come from the radiator, does it keep on happening? how did you find out there was water in it? -Zach Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted October 25, 2002 Share Posted October 25, 2002 Not a Buick x-pert by any means but I think Scottie-GNZ had a leaking head stud problem on his motor. Might want to send him a PM as he is the source for GN tech here. Doug Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted October 25, 2002 Share Posted October 25, 2002 As I read the post I was thinking head gasket or misaligned intake gasket until you said head studs. I am guessing you are using ARP head studs. If this is the case and you already have leaked a lot of water, I hate to say it, but the heads and pan have to come off. Been there, done that. Head studs naturally act like a wick and a lot of them on the Buick go into the water jacket so you have to do a little prep work and use a special sealant on the studs. Drop me an email. Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 25, 2002 Share Posted October 25, 2002 What's the science there Scottie? I assume that the clamping force is transferred to the fine thread portion of the stud and nut leaving more clearance between the threads in the block than if you use the stock bolts? I can see where the problem comes from but would like to know why studs make it more likely? Maybe because GM uses sealer on the bolts originally and when studs are put in people forget? What is the likelihood of someone replacing a head gasket with OEM fasteners and having a leak then? I know the Buicks are notorious for blown head gaskets when you turn the boost up, but that is much better than the bent con rods in the Sy/Ty motors when you do same! Quote Link to comment Share on other sites More sharing options...
speeder Posted October 25, 2002 Author Share Posted October 25, 2002 During assembly, I used a teflon sealer on the head studs after getting the threads in the block super clean - IMO it has to be something other than a head gasket problem because of the way it reacts or doesn't react) to pressurizing the cooling system with the test pump. Another weird symptom it has is that the cooling sytem never pressurizes itself as the engine heats up. While idling I can look in the radiator and see the water level slowly go down as it spits out the tailpipes. Looks as if you recognize this condition, Scottie - you have mail. Quote Link to comment Share on other sites More sharing options...
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