Burning Coolant (BHG? Intake?)

[AJ'S 88NA]

a mechanic have told me after a compression (very good compression) and leak test that the leak is some where between the head and firewall but i cant see any coolant or wet spots. he said that i could be a hose or plate. or crack block. ? any suggestion. its supposedly BEhind the coolant hose that come out of the head by the firewall. i HavE replaced the thermostat and cap with geuine toyota parts a few weeks ago. By the way the car doesnt overheat just lose a little coolant......Meanwhile im doing a complete flush with a liter of radiator cleaner. just have to drive for 3 more hours. thankd

The heater hose comes out there and goes into the heater switch. There is a large fiting that goes into the head that the hose is connected to. It maybe leaking from either one, most likely the hose. It maybe small enough that it's just blowing down over the bellhousing not really dripping, and then drying after driving. CRE has some good sugestions.
Check the small rubber cap just under the header also, as it has a tendacy to dry out due to heat and slowly get worse until it completely lets loose. I fixed mine with a piece of heater hose and a large bolt. I was tired of replacing it with the cheap caps you find at the auto stores.

 

[ImperfectSupra]

thanks I will check the heater hose next after the weekend when I don't have my kids.

 

[Jkm3141]

subscribed, i have the same symtoms. losing coolant but not over heating. the car is still power ful and compression is at 140 all around, i cant see any physical cooant puddles but have to fill it up every three days. i do get a cloud of white smoke when cold starting. i will post in a few days afteri pull the tb and isc. CAn a small leak in the isc and tb cause over heating or the resvoir to overflow??? thanks.

Is your compression good when engine is cold and warm? i havent had a chance to compression test with engine warm due to time and the fact its burning so much coolant. Are you just putting a small puff of coolant smoke out when starting or are you activly burning coolant? Once the engine is warmed up for me its activly blowing coolant out the exausht and if i turn the car off and let it sit for a min or two and start up (warm the entire time) it puts out a blast the size of my car. are you sure they are the same symptoms? you said you are losing coolant rapidly, but do you know if its losing it by burning (to tell you can smell the coolant and see some visible smoke coming out the exhaust while idling.) Or are you losing via a broken line dripping onto the block. The more i think about it mine sounds like a BHG except for the good compression when the engines cold. Normally from waht i can tell a BHG will give you horrible compression if the engines warm and better while cold (such as slightly lower compression in 1 or two cyl or slowly losing pressure thru the BHG). My compression is steady good at 155PSI on all cyl for like 45 seconds I let each sit to see if its leaking. I need to fix this but really dont wanna deal with a BHG (read my other thread, winterization of a BHG supra). Thanks, and good luck on your own problem. If its the heater core line, then I would try and fix it or just bypass it. During the swap for me I kinda smashed a few of the lines going to the heater so i had to bypass it. just my 2 cents on your issue

 

[ImperfectSupra]

Is your compression good when engine is cold and warm? i havent had a chance to compression test with engine warm due to time and the fact its burning so much coolant. Are you just putting a small puff of coolant smoke out when starting or are you activly burning coolant? Once the engine is warmed up for me its activly blowing coolant out the exausht and if i turn the car off and let it sit for a min or two and start up (warm the entire time) it puts out a blast the size of my car. are you sure they are the same symptoms? you said you are losing coolant rapidly, but do you know if its losing it by burning (to tell you can smell the coolant and see some visible smoke coming out the exhaust while idling.) Or are you losing via a broken line dripping onto the block. The more i think about it mine sounds like a BHG except for the good compression when the engines cold. Normally from waht i can tell a BHG will give you horrible compression if the engines warm and better while cold (such as slightly lower compression in 1 or two cyl or slowly losing pressure thru the BHG). My compression is steady good at 155PSI on all cyl for like 45 seconds I let each sit to see if its leaking. I need to fix this but really dont wanna deal with a BHG (read my other thread, winterization of a BHG supra). Thanks, and good luck on your own problem. If its the heater core line, then I would try and fix it or just bypass it. During the swap for me I kinda smashed a few of the lines going to the heater so i had to bypass it. just my 2 cents on your issue

the compression check was when engine was fully warmed up. i just got home from a 200 mile trip 10 minutes ago. i was stuck at a stand still for an hour on the way back totaling about 4 1/2 hours of driving. most of it was at speed of 65mph+(80 for at least a third way.) no sign of overheating at all the meter didnt even budge. this makes me believe that i have a blockage in the rad or cooling line causing my over flow to spit. i will drive a few more hours on it and then flush the cleaner out of the system. then will see if that helps. the smoke i get is only on cold starts. one puff then its no more till i cold start again. it does loook white but doesnt smell sweet to me just gas like. most of the coolant i lose is throug the resvoir which sometimes spits and sometimes dosnt. dosent matter how hard i drive it happens in no particular order. im sure i dont have a bhg because after fixing the rad pipe thermostat, rad cap, it hasnt overheat at all. and no power lost.

 

[AJ'S 88NA]

How humid has it been there? Could just be condensation in the exhaust.

 

[ImperfectSupra]

How humid has it been there? Could just be condensation in the exhaust.

yes it is humid here. weather channel always call for rain but it never comes. i had never thought of that. in a month when the air get really dry ill know for sure thanks.

 

[Jkm3141]

Yea it doesn't sound like you and I have the same problems. I'm almost sure I have a BHG, where as you have loads of coolant problems except for burning the coolant. Be happy you don't have a BHG... lol

 

[ImperfectSupra]

Yea it doesn't sound like you and I have the same problems. I'm almost sure I have a BHG, where as you have loads of coolant problems except for burning the coolant. Be happy you don't have a BHG... lol[/QUOTE
sorry, but reading your thread lets me know that i dont have a bhg. maybe u can help me with my issue. earlier today after topping off the resevoir and rad i drove the car a few miles until engine warmed up then i pushed it a little harder than usual the resevoir overflowed again, a lot this time. the temp was at normal and the coolant that was coming out wasnt even hot. usually when this happen the coolant would be boiling. its very strange. do u think my rad is clogged or do i need a high pressure cap? any suggestions?

 

[AJ'S 88NA]

Yea it doesn't sound like you and I have the same problems. I'm almost sure I have a BHG, where as you have loads of coolant problems except for burning the coolant. Be happy you don't have a BHG... lol[/QUOTE
sorry, but reading your thread lets me know that i dont have a bhg. maybe u can help me with my issue. earlier today after topping off the resevoir and rad i drove the car a few miles until engine warmed up then i pushed it a little harder than usual the resevoir overflowed again, a lot this time. the temp was at normal and the coolant that was coming out wasnt even hot. usually when this happen the coolant would be boiling. its very strange. do u think my rad is clogged or do i need a high pressure cap? any suggestions?

Sounds like you may have overfilled it. Another name for the resevoir tank is expansion tank.

 

[Jkm3141]

Sounds like you may have overfilled it. Another name for the resevoir tank is expansion tank.

I know this sounds stupid but i remember reading somewhere where someone had similar happen and it turned out his gauge was reading wrong and he was overheating...

 

[ImperfectSupra]

I know this sounds stupid but i remember reading somewhere where someone had similar happen and it turned out his gauge was reading wrong and he was overheating...

the gauge works fine it moves when i turn on or off the car and the needle was twitching moving up the other week when my upper rad hose collapsed.

 

[ImperfectSupra]

Sounds like you may have overfilled it. Another name for the resevoir tank is expansion tank.

thanks for the term, i forgot that one. and i dont think i over fill mine. after the overflow happens and it cools down. there wouldnt be any coolant in the expansion tank and the rad would be low too. so something is pushing it out without overheat me.

 

[cuel]

FYI: I've run compression tests on some cars with all the spark plugs in and got good readings, but when I took them out, I'd find 2 cylinders next to each other that were low. HG could be blown between 2 cylinders, and they're holding pressure together. They'll even hold good pressure as they aren't leaking anywhere else.

Just something you might want to try...

 

[ImperfectSupra]

FYI: I've run compression tests on some cars with all the spark plugs in and got good readings, but when I took them out, I'd find 2 cylinders next to each other that were low. HG could be blown between 2 cylinders, and they're holding pressure together. They'll even hold good pressure as they aren't leaking anywhere else.

Just something you might want to try...

i will look into that and retourqe the head and get a 1.3bar radiator cap. the dont think thelast owner retorqe the head after a mhg install. if all of this dont work out im taking it to toyota cause im tired of playing guessing games thanks.

and sorry i didnt mean to take over this thread.

 

[Jkm3141]

FYI: I've run compression tests on some cars with all the spark plugs in and got good readings, but when I took them out, I'd find 2 cylinders next to each other that were low. HG could be blown between 2 cylinders, and they're holding pressure together. They'll even hold good pressure as they aren't leaking anywhere else.

Just something you might want to try...

when i did my compression test i took the plugs out as I went and left them out. Doesn't matter anyhow i know i got a BHG based on that amount of burnt coolant.

 

[AJ'S 88NA]

i will look into that and retourqe the head and get a 1.3bar radiator cap. the dont think thelast owner retorqe the head after a mhg install. if all of this dont work out im taking it to toyota cause im tired of playing guessing games thanks.

and sorry i didnt mean to take over this thread.

Were's your drive, your passion, your wallet? Take it to toyota and it's going to cost you. Didn't you say you wasn't burning coolant? Test your oil, I think you can get a test kit at AZ or someplace for the coolant. If it's not a BHG then have the cooling system at a regular shop. It could just be something simple. You have a car that is 20 years old it deserves some respect and TLC.

By the way for some reason you are miss quoteing me....

 

[ImperfectSupra]

Were's your drive, your passion, your wallet? Take it to toyota and it's going to cost you. Didn't you say you wasn't burning coolant? Test your oil, I think you can get a test kit at AZ or someplace. If it's not a BHG then have the cooling system at a regular shop. It could just be something simple. You have a car that is 20 years old it deserves some respect and TLC.

By the way for some reason you are miss quoteing me....

sorry if i miss quote u. the drive is here. i do give my supra a lot of respect and tlc. i go under the hood at least once a day at work. sometimes after reading a related thread i would be outside messing with the car at 2am. since having the car in feburary ive already replace or fixed whatever wrong i can find. this is where i stumble at. for last 2 or 3 months of everyday reading threads and replacing hoses and things. if i cant figure it out professional help is the last so that way i can do other things i enjoy with the car, upgrading stuff, raising the hp and boost and kicking ass without being scared.....of blowing up. im not a quitter because i wouldnt have bought this latest supra(my 4th). it have came along way from how it was in feburary. i even went drove to jersey city to bring it home to richmond va. all the ideas in this thread is new info to me. so i will try it. im not giving up yet.

 

[ImperfectSupra]

update. my exhaust is now smoking like yours. i have a bhg. did u fix yours yet?

 

[akito]

I, also have a coolant leak....SOMEWHERE. First of all the hose from behind the head was cut at the clamp so i had to replace it with a new one. There was a leak because i couldn't tighten down that one clamp behind the head. Fixed the leak, but now i have another one, im not sure where it is but it is a slow leak. If say i have to refill my resevoir then it will have to take 3 weaks for the "bird cage" to lit. Im irritated, however I havent done the coolant compression test yet. I will try to to that this friday. For a fact i cant find where it is leaking and all i could get a notice of it is the smell. Im paranoided to the smell of coolant. It tells me theres a leak or something is wrong. Well, one time after a good drive i stopped, turned off the car and popped my hood. There was a little bit of smoke coming from the exhaust side. I tried to smell it and i was sure it was coolant. But i could hardly tell where it was coming from.

For BHG, would there be smoke coming from the side of the exhaust mani? Isnt there a coolant line also run right below the mani? Im afraid it would be that line since then i will have to remove the exhaust manifold. The smoke was visible but it was like a line and that was the only time i saw it. And it was after the car was running. I would like to cure this since i hate having the fact that my car is leaking coolant. I wouldnt want to be stranded somewhere because my car ran out of coolant. O yea, there is a little white smoke at the tail during start up, only if it is like 5 hours sit or over night. The smoke will go away in about 2 mins and it doesnt smell like coolant at all but more like gasoline.

I would like to solve this problem. Any suggestion is appreciate. Sorry for thread jacking since i think it is relevant.

 

[AJ'S 88NA]

I, also have a coolant leak....SOMEWHERE. First of all the hose from behind the head was cut at the clamp so i had to replace it with a new one. There was a leak because i couldn't tighten down that one clamp behind the head. Fixed the leak, but now i have another one, im not sure where it is but it is a slow leak. If say i have to refill my resevoir then it will have to take 3 weaks for the "bird cage" to lit. Im irritated, however I havent done the coolant compression test yet. I will try to to that this friday. For a fact i cant find where it is leaking and all i could get a notice of it is the smell. Im paranoided to the smell of coolant. It tells me theres a leak or something is wrong. Well, one time after a good drive i stopped, turned off the car and popped my hood. There was a little bit of smoke coming from the exhaust side. I tried to smell it and i was sure it was coolant. But i could hardly tell where it was coming from.

For BHG, would there be smoke coming from the side of the exhaust mani? Isnt there a coolant line also run right below the mani? Im afraid it would be that line since then i will have to remove the exhaust manifold. The smoke was visible but it was like a line and that was the only time i saw it. And it was after the car was running. I would like to cure this since i hate having the fact that my car is leaking coolant. I wouldnt want to be stranded somewhere because my car ran out of coolant. O yea, there is a little white smoke at the tail during start up, only if it is like 5 hours sit or over night. The smoke will go away in about 2 mins and it doesnt smell like coolant at all but more like gasoline.

I would like to solve this problem. Any suggestion is appreciate. Sorry for thread jacking since i think it is relevant.

Yes there is a rubber cap just below the exhaust manifold towards the firewall. It gets brittle from the heat usally starts with a slow leak. Have you noticed any coolant under the car? Start up smoke that goes away usally is just moisture in the exhaust.