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| Forum name | Performance/Engine |
| Topic subject | HG still leaking after rebuild....? |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=83864 |
83864, HG still leaking after rebuild....? Posted by Semperboost, Dec-27-04 04:52 AM
So about 2 weeks ago I pulled off the the head, replaced two piston rings slapped on a new OEM HG and some ARP headstuds. I don't have any blow-by but I still have a little white smoke, losing a coolant and overheating. My HG was installed with the overlapping edge on the back of the block and the #s up, but I'll double check again when I pull it off. I'm thinking either a hairline crack OR my head wasn't totally flat (didn't get it decked). Here are some pics of the head and block...
http://www.cardomain.com/memberpage/673437/3
Notice the buckshots on #4..what would cause that, detonation?..would that also cause my head not to seal?
I'm gonna pull the head off again this week to inspect everything. Do I need to pull the cams off too, or is there a way to do it? THanks Alvin
http://www.cardomain.com/id/96rst
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83866, RE: HG still leaking after rebuild....? Posted by thedawg, Dec-27-04 05:41 AM
Normally the cams have to come off to get the head bolts out. But since you have ARP studs, I bet you could get away with a swivel socket.
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83885, RE: HG still leaking after rebuild....? Posted by MetalJim, Dec-27-04 11:30 AM
Take the head to a machine shop that can Magnaflux the head. If it doesn't have any cracks have them check the flatness.
 95 Eclipse RS : 5 speed 15.7 @ 87.9mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html
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83901, How bout that pitting?... Posted by Semperboost, Dec-27-04 02:59 PM
Can I just take off the intake and exhaust manifolds and have em deck it with the valves still in. I haven't gotten that deep into taking apart the head...Is that shotgun blast = detontation? Thanks
Alvin
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83917, RE: How bout that pitting?... Posted by MetalJim, Dec-27-04 09:15 PM
Nope. You gotta take all the valves out for them to do any work like that on the head.
If you look really really close at that picture with the closeup of cc #4 you can see inside the lower left coolant passage in the picture. It looks like its cracked. I would just get a new head if it is actually cracked - really I'd get a used one, but one thats not cracked.
That pitting is wierd too. Lik you have alot of damage in the squench area on that one side, what looks to be only 2 pits on the other, and nothing in the dome area. Just wierd. I have no idea what thats from.
 95 Eclipse RS : 5 speed 15.7 @ 87.9mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html
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83928, RE: How bout that pitting?... Posted by thedawg, Dec-28-04 05:39 AM
The pitting is damage from something metal bouncing around in the cylinder. Probably a spark plug conductor or other hard metal (probably not aluminum) object that came in from the head. The piston top should have similar damage to it too, although I can't tell from the pics if it does.
Shouldn't affect the sealing surface since it was bouncing around inside the cylinder. It could have cracked something in the head, or the metal chunk could have cracked off something, which could obviously cause a leak.
Metaljim- Is it even possible to Magneflux an aluminum head? I was under the impression Aluminum didn't conduct magnetic energy. I thought they had to use some sort of dye or other chemical on aluminum heads.
EDIT: Semperboost- are those 95/96 Talon sideskirts? If so, I have a set of doorcaps in great condition for them. Let me know if you want em.
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83931, RE: How bout that pitting?... Posted by turbo8u, Dec-28-04 05:50 AM
oooh that shit looks familiar, those marks DONT LOOK GOOD :( i had something extremely similar in my cyl 2 combustion chamber when my last motor popped, but im pretty sure when the piston grenaded it had something to do with it. i dont know what your damage is from but its definately not good. im betting on the spark plug electrode bouncing around though like dan (thedawgie) said
only a cast iron head can be magnafluxed.
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83929, RE: How bout that pitting?... Posted by cougar694u, Dec-28-04 05:46 AM
Originally posted by MetalJim Nope. You gotta take all the valves out for them to do any work like that on the head.
Maybe for magnaflux, but I took mine to be milled/decked and left the valves in it. Guess it depends on how extensive the work being done is.
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83955, RE: How bout that pitting?... Posted by Semperboost, Dec-28-04 08:34 AM
I used to have 95-96 skirts no door caps but I put em on. I think when my piston land went it mut have sent some shrapnel up to the chamber. I replaced that piston. Is there some sort of test to find out which cylinder is leaking? I've searched for a Leak Down test, but got different results on how to perform one? Thanks for the replies guys. Alvin
http://www.cardomain.com/id/96rst
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83956, RE: How bout that pitting?... Posted by DarkOne, Dec-28-04 08:39 AM
Originally posted by Semperboost I've searched for a Leak Down test, but got different results on how to perform one?
If any of those results involve oil, they're wrong. Pressurized air fed into the combustion chamber is how it's done..
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83961, RE: How bout that pitting?... Posted by thedawg, Dec-28-04 09:33 AM
Originally posted by DarkOneOriginally posted by Semperboost I've searched for a Leak Down test, but got different results on how to perform one? If any of those results involve oil, they're wrong. Pressurized air fed into the combustion chamber is how it's done..
Take the check valve out of your Compression tester Remove the Compression tester's gauge and connect what's left to your aircompressor. Put the cylinder to be tested at TDC and pressurize. Repeat for each cylinder.
Air rushing in Intake mani = Intake valves Air rushing in Exhaust = Exhaust valves Coolant bubbling or tiny rise in level at waterneck / movement of any kind = Headgasket Bubbles in oil = Headgasket Air rushing out crankcase = broken piston or rings
Thats the ghettofied way to do it, and the whole test won't really tell you if there's cracks in your head.
The real "leakdown test" gauge sets cost hundreds of dollars and basically do the same thing as above, they just tell you how big the leak actually is.
I think you just need to drop off the head at a machineshop and ask them to find any cracks.
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83966, Sorry one more question.... Posted by Semperboost, Dec-28-04 10:24 AM
So when it's at TDC #1 and #4 is at the top...to to check #2 and #3 I just turn the crank till it the arrow is opposite of the mark? Thanks Alvin
http://www.cardomain.com/id/96rst
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83967, RE: Sorry one more question.... Posted by thedawg, Dec-28-04 10:46 AM
Exactly.
Just remember the crank revolves 2x for each cam revolution. So #2 and #3 won't be at TDC at the same time. You'll need to go an additional 360* I think after doing #2 at TDC to get to TDC on #3.
All the valves need to be closed, and the piston needs to be at the top of the bore to be tested. If the valves are open it'll be obvious though, so don't worry about exact timing.
Oh, and watch out for the crank spinning when you pressurize the cylinders. I almost got hurt when the engine decided to do a compression stroke while I was trying to fine-tune the crank to TDC... ;)
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83996, RE: Sorry one more question.... Posted by MetalJim, Dec-28-04 10:17 PM
Keep the cam cover off while you're doing the test. That way it'll be easy to see if you're at the TDC on the compression or exhaust stroke. Also, you can stick a long screwdriver down the spark plug hole to use as a gauge for TDC. Just watch for it to crest.
Magnaflux...doh! :wallbash
 95 Eclipse RS : 5 speed 15.7 @ 87.9mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html
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