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.

 

[eclipsetuner_21]

Ok, Do you still have the cometic head gasket?? If so....Re-use it, trust me you can and I have. Go to the autoparts store and purchase Permatex Copper Spray-A-Gasket and spray the headgasket on both sides evenly. I had the same sealing problems but fluids mixing and all. I finally spayed the cometic the third time and no problems. TRUST ME, spray it, and torque it and it will hold!!! Im running 20psi happy

 

[need2boostpsi]

you should never ever re-use a head gasket, once their torqued and compressed thats it, one time use. re using a head gasket is just asking for trouble later. do it right and do it once

 

[eclipsetuner_21]

Yeah, but with a cometic it will be fine. I was worried so I researched it and some said do and some said don't, I have done it three times and it works great.

 

[need2boostpsi]

to the OP have done a compression test?, are you overflowing your Coolant reserve? its normal for there to be some air trapped inside of your coolant after a HG job and it can take some time to work out. try taking the coolant cap off and starting the car with the heater on and letting it run for about 15-20 minutes to burp the coolant, you can also squeeze on the lower radiator hose to burp it. You could also try a Boost leak test with the radiator cap off and check for bubbles.

good luck

 

[BoredDSM]

Did you run the car with the cap off to burp the system? Your head gasket won't let air in the system it would burn coolant.

 

[Stainbox12]

Hey, lets get real here. If you are blowing head gaskets that way, and blowing air through the cooling system, then either your head or block is warped. Trust me i've been through it, my block and head were warped and causing compression to be thrown to water. And metal gaskets, can oftently be reused and more with a slight copper spray coat. Check your head studs and measure them to see if they are streched, it might be a good time to get some ARP's too. Slight warpage might not cause an overheat condition but it can cause what you described.

 

[Anarchology]

I would think that maybe your not looking at a problem with the head gasket, but maybe the head itself. There is a small possibility that there is a hairline crack letting a small amount of boost to leak into a coolant port.

Though not always able to see one with the naked eye, a compression test might pinpoint at least a certain cylinder.

Another thought... you are seeing air in your coolant system, so you might want to check the throttle body given it has the coolant lines running through it to heat up the air on cold days. Figure that there is a small possibility that there is a hairline crack allowing boost to creep into the coolant at that point too. To find that being the problem over it being on the head would be a much better thing!

 

[randyknightjr]

i have bought new head studs twice and i only have oe torque on this set, i used india head gasket shelack on this gasket and coper coat on the others. i have a hard time believing that there is a hairline crack considering how long they last before the start leaking. i have unhooked the cooling lines from the throttle body a long time ago. and whe i was doig my last head job i got the head re-surfaced and it didnt look warped to beging with. it has not over heated(as far as the temp gauge is concerned) i used a new snap-on torque wrench for this last head job to be safe. i checked my torque three times after final torque and let engie warm up and cool back down and retorqued the studs. i have built lots of motors ad none have given me this much trouble.
as far as have air trapped in the cooling system i burped the system and got all the air out when i filled the system after the last head job.and have not seen any air in there untill yesterday( remember i check it every time i park it for the night), im particular about my cars. i cant re-surface the head again, and i straight edged the block useing a straight edge and a 1 thousands feeler gauge and it is straight.and it runs perfict with no smoke and is pretty strong for what it is(13.8 in a quarter) but LOTS!of air i cooling system.
i pressure tested the coolig system at 15 psi and no leakdown, i did a compresson test and had 175 psi across the board. this thing is drivig me nuts!!

 

[need2boostpsi]

what kind of pistons are you running, 175psi seems a little on the high side for oem. and are you pushing coolant out, or just getting to much pressure in your coolant system?

 

[randyknightjr]

the head has been milled as far as it can go ad i have 8.5 to 1 compression ratio pistons. stock is like 155 psi.

i amn pushing coolat out because it fills my overflow up and dumps alittle and the ground, and there is lots of air pressure in the cooling system when i stop, i can let it cool for a while with fans on and fill it back up( about 1/2 to 3/4 of a gallon every time) and go drive it and when i stop again it has alot of air i it again. it doesnt matter if i dog it and boost full 15 psi or just ease around only boosting about 5 to 7 psi.

 

[Redwidow]

Ok so were the two previous head gaskets actually blown, like they were torn or had a split, or did you just assume it was a head gasket and replace it? If they were blown, i dont know what to tell you thats any different than the other guys, but if they are not i would start checking the cooling system, for cracks, small leaks or holes in any of your lines, maybe even presure test that. Sorry i cant be of more help but it sounds like everyone else has given you every option or you have done every option.

-Andy

Edit: Sounds crazy but maybe a slight crack in the block that only opens when its warm? Something to think about.

 

[randyknightjr]

well when i took the head off the other few times to replace head gasket the metal gaskets didn't look bad, but you could tell on the fel pro where it was blown. the HKS gasket that was on it when i bought it never leaked i just wanted to rebuild motor to get rid of all the oil leaks and i had a little blowby. im thinking of just replacing the head and see how it goes with that. i don't know what else it could be.

 

[No_Skillz]

Why are you suspecting your headgaskets so much and not your cooling system?

First, make sure you have no air in the system - burp, warm up with the cap off, etc.
Then, make sure your cooling system can push coolant out at high temps (normal).
Then, make sure your cooling system can suck coolant BACK IN.

Just some things that can affect the last point are shitty radiator caps, lack of hose going to the bottom of your overflow, poor seal of hoses coming from thermostat housing to overflow bottle.

 

[randyknightjr]

i have already burped it twice, and when i crank it up with the cap off it shoots a 3 inch gieser of coolant out of it so i know the water pump is working. i bought a new cap and before i was getting lots of air in the system it was displacing some coolant and was pulling the coolant back in when it cooled down.

 

[ohnoz]

Replace your thermostat.

 

[randyknightjr]

You're going to have to explain to me why i need to replace my thermostat. not because i don't believe you, but because i don't understand how a bad thermostat could make me have lots of air in the cooling system..

 

[need2boostpsi]

so im trying to understand exactly whats happening, you start your car and when it heats up it blows coolant out into the reserve than onto the ground, or is it just pressurizing the system to an excessively high pressure.

 

[randyknightjr]

ok i can crank the car up and let it idle for as long as 35 min (cause that's the longest i have let it idle, when i was burping it) and it doesn't over heat and it doesn't displace an un usual amount of coolant, and when it sits and cools it sucks it back in.

but when i drive it like 10 to 15 mile down the road and return it has lots of air i the the cooling system. pressure in the cooling system is not too excessive, most of the pressure is air pressure. when i stop after driving i can pull up the pressure release on the cap and all the air comes rushing out into the overflow.

 

[need2boostpsi]

ok i can crank the car up and let it idel for as long as 35 min (cause thats the longest i have let it idol, when i was burping it) and it doesnt over heat and it doesnt displace an un usual amount of coolant, and whe it sits and cools it sucks it back in.

but when i drive it like 10 to 15 mile down the road and return it has lots of air i the the coolig system. pressure in the cooling system is not too accesive, most of the pressure is air pressure. when i stop after drivig i can pull up the pressure release on the cap and all the air comes rushing out into the overflow.

well if you drive without getting into any boost, does it still get air into the system. If you have answered yes than you need to do a leakdown test, with your coolant cap open. put about enough pressure into your engine to almost make the engine turn over, if you do this on all four cylinders and there is no bubbles in the coolant then its not the head gasket.

 

[randyknightjr]

I have more compression pressure than my air compressor can put out. my compressor can put out 145 psi and my compression is 175 psi. i get no bubbles when it is running with my dummy cap on it and hooked up to a 1 gal jug of water hanging from the hood. and the pressure in the cylinder is much higher when combustion is taking place than when you are doing a compression test due to the small explosion taking place. what else could it be, that's what i need to know. thank you all for your input, it is very helpful in my brainstorming.

 

[BIGMIXX]

hmm well imo i would check the thermostat... why the thermostat you say??? well if the thermostat is stuck shut and you "fill the system". no matter how hard you try or how long you "burp" it, you will still more than likely have air trapped behind the t-stat. any air , as you know, will allow the system to "boil" off the coolant, creating alot of air. also would explain why you have a gieser shooting out the cap. honestly imo just the cheapest fix to maybe solve your dilemma. definately think it's in the cooling system .... blockage!

 

[randyknightjr]

if the thermostat were stuck closed then i would tend to think that i wouldn't see any water flow considering that there is no relief or (wiggler valve) on the thermostat. i have a 150 degree thermostat and the temp still gets to half way while im driving, it has never went past it. i flushed the cooling system when i rebuilt the motor and it was clear and the water pump is pumping like hell. but i may still replace it anyway.

 

[DSMopar]

Ok simple question, does it overheat? Does it puke out tons of coolant on the ground?

If no and no it's called NORMAL OPERATION.

 

[randyknightjr]

[it doesnt puke alot of coolat out, but it does overflow the overflow alittle. but it doesnt overheat. it never has. if it gets low on coolant the temp gauge could be reading the air temp instead of coolant temp. they did put the temp sensor for the gauge at just about the highest point in the cooling system.