puffing white smoke and low compression in one cyl. after head install

[dtshelton]

i just got finished putting on a newly machined head and new oem head gasket with arp studs on my 92 gsx. started it up and it is puffing white smoke(coolant i think) out the exhaust after it warms up. i took it for a short drive and it seems like it runs decent when above idle but i am losing coolant from monitoring the overflow tank. so i did a compression test and it was 160-160-160-90. i did a wet test and no change to the 90 cyclinder value so i figure its not the rings. i think its the head gasket i just put on but not positive. i torqued it down to 80lbs in steps(maybe too low???) with moly lube and now i'm at a standstill. should i pressurize the cooling system and/or leak down test to see where the coolant/compression is getting lost? this was my first time doing anything major to my motor and i thought i did everything right but now i am running into problems with white smoke and also the idle is kind of rough. it sort of sounds like a motor with a bigger cam in it. any help would be appreciated. this is my only car and it needs to be fixed fast. thanks.

 

[1gjosh]

Did you make sure the block deck surface was very clean? did you have the head resurfaced? The heads on our cars are made out of aluminum and they warp pretty easily when exposed to extreme heat from over heating. sounds to me like its definatly the headgasket , well hope this helps

josh

 

[FORMONTOYA]

Did you do a compression check BEFORE you removed the head (if so, what were the numbers?)? Was the block surface cleaned (a small chunk of gasket material will screw you)? Did the shop machine the gasket surface of the head? When you say "torqued in steps", what were the steps (should really be around 25%, 50%, then 100%)? If the final "step" is too close to the final torque value, sometimes the bolt/nut can't overcome the friction and doesn't actually "apply" the proper torque.

Did you "place" the head on yourself? Or have a buddy help "place" it? With leaning over the car (for me being a little guy) it's sort of awkward to place the head on without "buggering up" the gasket.

 

[1gjosh]

copy cat

 

[dtshelton]

yes i cleanded the block surface with a scraper and used lacquer thinner afterwards to clean it up. i also had a friend help put the milled head on the block. the torque steps i used were 30, 60 ,80. maybe that was my problem. can i retorque them without putting on a new head gasket?

 

[dtshelton]

forgot, i did do a compr. test before taking it off-----160 across the board.

 

[FORMONTOYA]

yes i cleanded the block surface with a scraper and used lacquer thinner afterwards to clean it up. i also had a friend help put the milled head on the block. the torque steps i used were 30, 60 ,80. maybe that was my problem. can i retorque them without putting on a new head gasket?

I would definitely give a re-torquing a try as it couldn't do any worse than it already is. However, I would be willing to bet that this is going to pan out as a learning experience.

But yes......loosen all the bolts/nuts (sticking with the proper torque order), and then re-torque them in 3 steps. Just don't go as high on the 2nd step (25%, 50%, 100%).

And to add.......I will double check all at 100%, just because I'm anal that way.

 

[crazy_quick]

are you sure the timing marks are in place when you retimed it?

 

[dtshelton]

yes, i had all the timing marks lined up when i put the timing belt back on. i guess i'll try to retorque the studs down tonight after i get off work. do i need to drain the coolant before i loosen/retighten? thank you guys for all the suggestions. also, i have another head gasket, one from a mr gasket kit i bought(non turbo kit). do you think i could use it instead of ordering a new oem one if it comes down to having to replace it. i'm not sure how high of a quality it is. don't want to have to pull the head for a third time if it goes out on me. probably should just get a new oem one huh?

 

[Jeff822]

Change the valve seals?

 

[crazy_quick]

is it a mls or a paper/metal one?

 

[crazy_quick]

valve stem seals wouldnt effect the compression. it would only make a constant small amount of white smoke.

 

[dtshelton]

the mr gasket one looks almost like the stock oem one. its that gray/graphite looking stuff. it says 4g63k on it if that helps any? not sure if its paper/metal. and yes i replaced the valve stem seals.

 

[crazy_quick]

from my expierience the stock is paper/metal

mls= multi layer steel its a 3 or 4 layer metal gasket. they are better then the compund ones (paper/metal)

 

[dtshelton]

does mitsu make the mls gasket? if so do you happen to know the part number for it?

 

[crazy_quick]

They do I dont know the part number, just ask them for the mls when you order it. If not go to vatozone or oryle's and order a mls with the appropriate bore.

 

[1gjosh]

Did you torque it starting with the middle head studs then going outwards? If you didnt that could very well be your problem also. It makes since seeing as how the last cylinder is the one with low compression. sounds like you went from one end to the other. and you started on the side that has low compression, right?

 

[dtshelton]

no, i followed the proper torque sequence as shown in my haynes manual. i'm really confused to why there is this problem. tonight i started taking everything back off to pull the head again after trying to retorque the studs down(which didn't help). i guess i'm just going to put a new one on there shortly, being very careful to do it right this time. i was so excited to have it finished and now i am right back where i started a week ago. oh well, live and learn. still love my dsm, maybe a little less though.

 

[tsi4ya]

whoa . . .sound like your having a lot of problems. . .hope everything works out great in the end . .i wish i had that kind of time to put into the car. . but i dont. So i would just buy a copper head gas. and pay someone to do it. . .and am pretty sure thats going to to soon because every now and then i get white smoke too. . .but now its happening a little more often then before. .well heres to good luck friend.