what would cause extreme coolant pressure in the block

[tramp_drift240]

i have no thermostat, so that cant be blocking flow to and from the radiator, so i cant think of anything else that would be causing the coolant pressure to be to the point of making extreme leaks in all the freeze plugs i JUST INSTALLED THREE WEEKS AGO.

it makes no sense. i saw a few leaks a couple days ago, which was still kind of odd. but now there are streams of coolant coming from the freeze plugs.

i was in the process of adjusting my idle, and while i was messing with the idle adjustment screw with the tps unplugged, i noticed a large amount of coolant being drained from the block onto my garage floor.

what else could cause it, minus the thermostat? is it possible theres build up in the block from when the machine shop dipped my block in the cleaner stuff?

i really need to figure out whats going on, because i just rebuilt this motor and i dont have the money to just swap another one in.

[srpowered240sx]

have you tried to flush the coolant?? give that a shot.

[idahotuner]

is this thre thread you where refering to in the ^<V

thread

[tramp_drift240]

could you give me the procedure for coolant flushing? ive had multiple versions told to me so im not sure what i should actually do.

i know the water pumps not bad, because i can see the coolant being moved around with the rad. cap off.

and yes this is the ^<V thread reference.

[karmakaze]

you could also be loosing compression through your head gasket into your water jacket.

[tramp_drift240]

so like. if my headgaskets messed up, compression from the combustion chamber could be pressurizing the water jackets in the block?

im trying to gather every idea possible.

[srpowered240sx]

you could also be loosing compression through your head gasket into your water jacket.

good point. time for a compression test. preston makes diy flush kits, or just take to a radiator shop.

[Encryptshun]

I'm assuming you've taken your radiator hoses off to make sure they aren't clogged up with goop? Old hoses can sometimes slough off the inner linings, which will clog the radiator inlet.

Have you taken your radiator cap off and started the car to make sure the coolant is circulating through the core?

[574-240sx]

headgasket/warped head. Also why are you running without a thermostat?

[Tulsa_S-13]

Are you using the OEM style metal freeze plugs or are you using the rubber style Autozone type?

[tramp_drift240]

i had an overheating problem before, traced it to the thermostat. was told on here to just take it out to see if it'll overheat and it didnt.

the hoses are fine, got them new when i swapped the motor, and washed them out again when i got the new radiator.

i saw circulation with the radiator cap off, yes.

im using brass freeze plugs i ordered online, tapped them in with rtv.

im gonna do a compression test as soon as i can pick up a compression tester. hopefully tomorrow.

[Duce40sx]

Did you put any of those Radiator liquid seal repair ?They sell products that you pour in the radiator and it seals up the cracks.If yes, then it could be it that is causing the blockage.

Check all the passages. all the Pipes and rubber tubes, maybe there's a weird tube bend that is limiting the flow?

[tramp_drift240]

all my hoses are in the right spots with no odd bends. i made sure that was the case when i swapped in the motor, and when i pulled it out and put it back in. and i just got a new 2 row aluminum radiator, so theres no leaks in it.

never used any of that 'radiator stop leak' stuff in my life.

[carbully]

umm, look. The thing is that you don't know how much pressure you are building up yet. The right thing to do is put a radiator pressure tester on and pump it up to the pressure written on your radiator cap. Then look to see if the freeze plugs are leaking. If they start leaking before you get to that pressure, then you have the incorrect freeze plugs or they are incorrectly installed.

If you get to the maximum pressure with no leakage, better test your radiator cap. The cap has a pressure blowoff function and is supposed to blow off any pressure in excess of that pressure. So, say your cap is a 14psi cap, if your cap is working properly nothing in your cooling system is going to see anything more than 14psi, even with a severely clogged radiator. So, you can see a bad radiator cap could cause this, be sure and pressure test it too.

Before you go through the effort of flushing the rad, take temp readings on the hoses in and out. Your out temp should be like 160 or less if the fan is working. if it is more than that,you may need a flush, but don't expect it to fix leaking freeze plugs!

[carbully]

Also, this may sound strange, but not running a t-stat can actually make a car run too hot. You guys will propbably flame me for that statement, but I am an ASE certified technician with over 21 years of experience. The thermostat serves an importaint role in regulating the speed coolant flows through the radiator. Having coolant flow too fast through the radiator does not give it enough time to dissipate enough heat into the air. So, if you have say 200deg coolant coming in to the radiator, and it passes through the radiator in only 2 seconds it has only had enough time to get rid of "x" number of BTU of heat, leaving the radiator at say 175deg.

Slowing down the flow, it spends more time in the radiator. So let's say now it spends 4 seconds iflowing through the radiator that's going to get your outlet temp down to say 160 deg. Make sense? To some of you it won't, becuase I have this argument even with other technicians. All I know is that I have seen it and fixed it by simply installing a missing thermostat.

If you feel like you have to do something, look around to find an aftermarket 160 degrere t-stat, but be sure to run one!

Tramp, Good on you, never let anyone talk you into using radiator stop leak in your system!!!

[tramp_drift240]

ive got a 16 pound radiator cap that came with the radiator. ill check it out though, i suppose.

i know i have the right freeze plugs though, and i put them in how theyre supposed to be installed, so that shouldnt be the problem.

and im not having an overheating problem, my gauge hasnt been showing any excessive heat.

im just getting a lot of pressure in the block somehow.

this whole situations confusing the hell out of me.

[carbully]

Right, but again you need to know how much pressure it is taking to make those plugs leak. Borrow a pressure tester. Then you will have something to go off of and won't have to lay awake at night worrying about head gaskets!

It's real simple. Either the plugs leak at less than 16psi so you know you need to re-install them, or the plugs hold at 16psi, and your cap does not blow off at the pressure it should. It's that basic.

Assuming your cap is good, if you had a head gasket problem or anything else causing excessive pressure you would see your cap blowing all the coolant into your recovery bottle. I promise!

[tramp_drift240]

i dont have an overflow tank, but, i havent seen anything leaking out of the hose that runs from the filler neck...

i have no one to borrow a pressure tester from, so ill probably pick one up from advance or something tomorrow. hopefully your info will ease my mind.

but hell, if i have to replace the plugs again, what was i doing wrong last time?

and also, im pretty sure theres some leakage from the plug on the back of the block, covered by the bellhousing and the flywheel. how am i supposed to get to that by myself with no cherry picker and no air tools?

or better yet, if my plugs have to be changed again, and thats all the problem is, how much would that cost at the dealer or somethin'

[carbully]

Idon't know what it would cost to do. Have to call them.

If you have something leaking coolant, get it fixed, though! Left leaking for a long time it can start to corrode the metal of the block where it has been leaking and damage the block. Take coolant leaks seriously, man!

Good luck, let me know what you find!

-Mark

[mutiny]

I'm not sure if you are supposed to do this but I put permatex grey gasket maker stuff on the sides of the plugs before I pressed them in the block. did you do that?

[tramp_drift240]

dude, i know coolant leaks are serious. thats why ive been stressed and pissed since i found out since i thought i fixed that problem weeks ago.

i didnt use grey, i used blue rtv. its all basically the same.

[dickie]

not really.

thanks for sharing that info, carbully.

[PapaSmurf2k3]

I, along with the others, immediately thought "HEADGASKET" when I read the title. I think its the only thing that can overwhelm the radiator cap's ability to blow off pressure. But also remember, if your freeze plugs have leaked, then chances are they have blown whatever seal was on there in the first place, and you are probably going to have to get them all replaced.

[tramp_drift240]

well yeah, im gonna have to replace them for the second time after the rebuild...but im needing to figure out what's causing them to leak so i dont have to replace them a third time after that.

so. coolant system pressure test...combustion chamber compression test.

im guessing i'll be able to figure out what the problem is after those tests, most likely.

[carbully]

I

I'm not sure if you are supposed to do this but I put permatex grey gasket maker stuff on the sides of the plugs before I pressed them in the block. did you do that?

I know some guys swear that they have to go in dry, others swear by "lubricating" them with RTV. I have never done them dry, but have seen them done dry and they work fine. So do mine with RTV. So, I am not sure it matters. Remember though if you use RTV you should make sure they holes are completely clean and dry first, and then let the RTV "cure" for like 15 minutes before dumping any coolant in the engine. Not a problem if you have the motor out to replace them, but on many cars you can replace them without pulling the motor. As long as the holes are clean, dry, and the RTV is cured before exposing it to coolant you should be fine.

All sealants are not the same, eahc has it's own speicalty and some are not resistant to ethelene glycol. Read the package before you buy it to make sure it will do what you need it to do! My favorite for this kind of stuff is the "ultra black".

[tramp_drift240]

the old plugs were out, and the engine sat like that overnight til the next day, then i started working on it again, made sure everything was clean and dry, then used the blue rtv.

i suppose ill use ultra black next time, ive got two or three unopened packages of it.

can anyone think of a way for me to acces the freeze plug on the rear of the block without having a cherry picker? that's the only reason im thinking ill have to take it to the closest dealer for replacement.

[Duce40sx]

You know, it could just be a radiator Defect.

What brand is it? Chances are if it is a Made In china Radiator, then there could be something wrong with the manufacturing process and something got stuck in the radiator itself.

Have you had previous problems with the engine blockage before? or just after you installed the new Radiator?

One way to find out if it is the radiator is take it out and run a garden hose to it, and check it the water comes out evenly.

[tramp_drift240]

nah, i was having this problem before i got the radiator, thats actually the reason i got it.

alas, the new radiator did not cure the pressure thing, ill do the hose thing though just to make sure.

now, after all the above information, what would "inflated hoses" say to you?

[srpowered240sx]

flush your system, put in a thermostat, put on new hoses. that would be my plan.

[tramp_drift240]

im still iffy on the thermostat. why would i need new hoses?

im going to get the compression tester today. ill see what numbers im getting in each cylinder, then continue from there. i dont want to replace little things just to have my freeze plugs leak again. im getting tired of replacing them.