this DSM is givin me hell!!

[randyknightjr]

i have a 92 laser AWD turbo, i just rebuilt the motor and have replaced the head gasket 3 times already. this last one lasted the longest(about 300 miles).
here is what happens- no white smoke, no water in oil and no oil in water. just lots of air in my cooling system. when i rebuilt it i used a HKS tri-metal gasket bought new ARP studs and torqued them to 95 foot pounds. it lasted a week (about 80 miles) then air in cooling system. i replaced it with a felpro gasket, it lasted about 2 weeks(95 miles) then air in the cooling system. the one that is in it now lasted the longest i went and got my head re-surfaced and used a cometic gasket and bought new head studs again and torqued them to 100 foot pounds and i have put 300 miles on it and it has been about a month, but today i checked my coolant and oil when i got home like i always do and well and behold there is LOTS of air in my cooling system again. i have been checking it every time i get home since the gasket was replaced and today is the first time there was air in the cooling system since the cometic gasket was used and there was a lot of air. it seems like the gasket is gone again. what could be causing this? im ready to sell this piece.
im only running 15 PSI of boost and i rebuilt the motor stock, it runs great with no leaks. the only problem is this head gasket issue. please someone told me to just buy another felpro gasket and torque the studs to 100 foot pounds, but i don't trust those gaskets under boost. someone help if you can. thanks.

 

[tkelly27]

The coolant has to go somewhere. It's not going through the head gasket if you get 175 across the board. If there is hole big enough to leak water, it will leak combustion gasses too.

So if you take it around the block, take the cap off, top it off, then take it around the block again what happens? No matter how much burping or idling or whatever I do, I always have to top the coolant off after the first time I drive it.

It's also misleading how much is needed. It will look like it's way down on coolant, but it will really only require half a cup or so.

 

[randyknightjr]

read this whole thread before you reply please, i have stated several times that its ALOT of air! and i just replaced my thermostat and it was failsafed to the open position, i remember now how it got that way i stuck a screw driver in it to force it open rigt before i rebuilt the engine and never replaced it. i just put a new 165 degree thermostat in it and i will post later to let yall know what i find. i will be shocked in disbeliefe if thats what was causing all the air. do any of you think that was my problem??? i have like 12 hours to wait while my rtv dries.

ok you guys and gals i have some new news. i just replaced my thermostat and gasket, and while i was at it i back flushed water through my system with a hosepipe and then i went ahead and replaced my lower radiator hose(it was old and worn out). i let the rtv dry for 2 hours before adding water i figure that's enough time with a new gasket as well. i filled with water and coolant and started burping the system with engine running like i always do. it had been at operating temp for about 5 to 6 min when i went to squeeze the bottom radiator hose and it was cold as hell!!! looks like this time its the water pump and not the head gasket, it was pumping a week ago, i know this because i took the cap off and let it run and it was flowing. thanks for all the help, i should have checked it again instead of just assuming it was good. thank God for parts warranty!

 

[Defiant]

Sounds like the radiator may be done for.

Get rid of that trigger radiator cap, and replace with a solid one. You need a 190°F thermostat, or you'll never get the ECU out of closed-loop.

And please, work on your typing. We're dicks about it here.

 

[randyknightjr]

the radiator is good i back flushed it, and i did buy a solid cap.

my wierless keyboard has been acting up. it misses key strokes and sometimes adds them where it wants to. maybe some new batt's are in order.

 

[need2boostpsi]

Nobody said it so I will. Have you checked the engine deck? Is it warped? You had the head milled, because it was out of spec, I assume, and generally the engine deck warps at the same rate/pace.

if the deck of the block or head were warped, his compression wouldn't be 175psi, problem lies elsewhere. any air escaping the burn chamber would be subtracting from the compression. if he can put 145psi into the cylinders with a leakdown test and not see any bubbles in thermostat housing than chances are, there's not going to be any warping.

 

[randyknightjr]

[someone has i fact mentioned the deck surface and i explaied that i flat edged it and it wa fine, i had the head re-surfaced because i thought it may be warped, but it wasnt. the water pump has gone out and the air was a result of my coolant boiling in the water jackets. thak you all for your help. i should have checked it and not just assumed it was still good.

 

[olmytsi]

Use a stock oem hg. They seal easily and handle alot of boost with the right tune. My buddy runs 32 psi on his daily on pump and meth. I'm running 26 psi on mine with stock headbolts.

If the stock hg doesn't seal either, than you have another problem. The metal gaskets need PERFECT surfaces to seal.

 

[randyknightjr]

[i see your point, but i thik i will replace my water pump them see what happens. thankss for all the help from everyone.

 

[kodeelittle]

this may be a dumb suggestion, but this issue sounds exactly like a problem I had on my 300zx, and I couldnt figure it out until I discovered the only problem was a stupid heater hose sucking in air. Might wanna check that out too. Was a stupid $5 fix.

 

[randyknightjr]

ok i just got the old water pump off and it looks fine!???
a re-cap-- i had air in my coolong system and replaced my hoses and my thermostat, i crunk the car up and let it run untill it was at operating temp (gauge straight up and down) and was burping the system. when i grabbed the lower radiator hose to squeeze it it was cold. so i blew water through the radiator to make sure there wasnt a blockage, then i back flushed the head and block to make sure there wasnt a blockage there and they were both clear. when i pulled the water pump off it looked fine. all the water pumps i have seen that were bad and not pumping the impeller had come loose from the shaft. the only thing i could see was were it looked like it may have been leaking from the weep hole. any comments, thoughts???????

(besides my typing)

 

[olmytsi]

Sounds like thermostat is stuck? Might as well change the water pump, timing belt and tensioner while you have it apart unless you know they were recently changed.