Head gasket blown?
09-05-2010, 07:10 PM
#1
Head gasket blown?
Well, I'll give a little background info first. I drove my car to the gym earlier today, which is about a mile and a half away from my house. I drove it back from the gym after being there for about 2 hours, and I didn't get it in to the boost at all. As I pulled into my apartment complex I noticed the temp gauge was just shy of 3/4. Both my fans were on full blast.
I pulled into the garage shut the car off and opened the hood. The engine bay was hot, but it always is. I let it sit for about 45 minutes. Came back into the garage and tried to open the radiator cap and it was still boiling up. About 20 minutes after that it was cool enough to open up. The coolant looks good and the oil looks fine too. However, my coolant overflow tank was pretty low.
I started it up with the radiator cap off. I got back out of the car and looked at the radiator to see if it was flowing. Every few seconds a fairly big air bubble would come up like the radiator was burping.
What do you guys think, is it just a bad thermostat or did I possibly blow a head gasket and it is losing compression into the water jackets? I won't be able to do a leak down test tomorrow, but I am going to borrow an air compressor from my friend and he has a leak down gauge too, so when he gets back after the long weekend I will check that. Should I buy a thermostat tomorrow, replace it and see what happens? Or do you guys think it is a head gasket or something else?
I pulled into the garage shut the car off and opened the hood. The engine bay was hot, but it always is. I let it sit for about 45 minutes. Came back into the garage and tried to open the radiator cap and it was still boiling up. About 20 minutes after that it was cool enough to open up. The coolant looks good and the oil looks fine too. However, my coolant overflow tank was pretty low.
I started it up with the radiator cap off. I got back out of the car and looked at the radiator to see if it was flowing. Every few seconds a fairly big air bubble would come up like the radiator was burping.
What do you guys think, is it just a bad thermostat or did I possibly blow a head gasket and it is losing compression into the water jackets? I won't be able to do a leak down test tomorrow, but I am going to borrow an air compressor from my friend and he has a leak down gauge too, so when he gets back after the long weekend I will check that. Should I buy a thermostat tomorrow, replace it and see what happens? Or do you guys think it is a head gasket or something else?
Last edited by WTFMike; 09-05-2010 at 07:58 PM.
09-05-2010, 07:26 PM
#2
Well, I'll give a little background info first. I drove my car to the gym earlier today, which is about a mile and a half away from my house. I drove it back from the gym after being there for about 2 hours, and I didn't get it in to the boost at all. As I pulled into my apartment complex I noticed the temp gauge was just shy of 3/4. Both my fans were on full blast.
I pulled into the garage shut the car off and opened the hood. The engine bay was hot, but it always is. I let it sit for about 45 minutes. Came back into the garage and tried to open the radiator cap and it was still boiling up. About 20 minutes after that it was cool enough to open up. The coolant looks good and the oil looks fine too. However, my coolant overflow tank was pretty low.
I started it up with the radiator cap off. I got back out of the car and looked at the radiator to see if it was flowing. Every few seconds a fairly big air bubble would come like the radiator was burping.
What do you guys think, is it just a bad thermostat or did I possibly blow a head gasket and it is losing compression into the water jackets? I won't be able to do a leak down test tomorrow, but I am going to borrow an air compressor from my friend and he has a leak down gauge too, so when he gets back after the long weekend I will check that. Should I buy a thermostat tomorrow, replace it and see what happens? Or do you guys think it is a head gasket or something else?
I pulled into the garage shut the car off and opened the hood. The engine bay was hot, but it always is. I let it sit for about 45 minutes. Came back into the garage and tried to open the radiator cap and it was still boiling up. About 20 minutes after that it was cool enough to open up. The coolant looks good and the oil looks fine too. However, my coolant overflow tank was pretty low.
I started it up with the radiator cap off. I got back out of the car and looked at the radiator to see if it was flowing. Every few seconds a fairly big air bubble would come like the radiator was burping.
What do you guys think, is it just a bad thermostat or did I possibly blow a head gasket and it is losing compression into the water jackets? I won't be able to do a leak down test tomorrow, but I am going to borrow an air compressor from my friend and he has a leak down gauge too, so when he gets back after the long weekend I will check that. Should I buy a thermostat tomorrow, replace it and see what happens? Or do you guys think it is a head gasket or something else?
09-06-2010, 11:04 AM
#3
i would think it is a bad thermostat too. However, I can't figure out why the radiator would be "burping" air. This is the first time I have had the radiator cap off in 4,000 miles. I would think that if there was a air pocket I would have had issues before now.
09-06-2010, 04:46 PM
#5
When my head gasket went the rad over flow tank was full/running over because all of the cylinder pressure pushes the coolant out of the block into the over flow tank. So i doubt you have a blown head gasket, with a blown headgasket I also got good compression/leak down numbers 
seems it would seal up again and only under boost did it push the coolant out. I would change the T-stat first since it is easy to do.
Another tought is if your overflow tank was low after driving it maybe it is/was empty whan cold and the cooling system sucked some air back in. So you could try to bleed the system again and see if you still have issues...just a few things to try.
seems it would seal up again and only under boost did it push the coolant out. I would change the T-stat first since it is easy to do.Another tought is if your overflow tank was low after driving it maybe it is/was empty whan cold and the cooling system sucked some air back in. So you could try to bleed the system again and see if you still have issues...just a few things to try.
Last edited by Sylvan Lake V35; 09-06-2010 at 04:48 PM.
09-06-2010, 05:01 PM
#6
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
fill it back with coolant and try bleeding it. When the engine is warmed up feel the lower rad hose. if the lower rad hose is hot then the thermostat is opening just fine and that's not the problem.
after you rebleed the system, let the car get heated up by driving around and then let the car cool off completely. leave the cooling system closed and the coolant should be sucked back out of hte overflow into the radiator. If the coolant stays high in the overflow then that means air is being forced into your cooling system from the cylinders.
after you rebleed the system, let the car get heated up by driving around and then let the car cool off completely. leave the cooling system closed and the coolant should be sucked back out of hte overflow into the radiator. If the coolant stays high in the overflow then that means air is being forced into your cooling system from the cylinders.
09-07-2010, 06:59 AM
#7
I think bleeding the cooling system is a misnomer..you will NEVER get ALL the air out. And the thought of a completely full sealed system that will only expand into the small *** overflow tank and back into the radiator is ridiculous...no offense to anyone but I have never been able to make that happen..
Trending Topics
09-07-2010, 08:07 AM
#8
I'm still trying to wrap my mind around this whole issue of air in the system causing the thermostat to stay closed and then over heat the engine. There is a line that comes from the left side upper radiator hose ( on the metal part) that goes through the oil cooler and then to the thermostat as well as the heater return and the bypass from the left side as well. That water is at engine temp so how can the thermostat not open? (known good thermostat checked on the stove) Does this mystical pocket of air form BEHIND the thermostat? which is crazy to me because there is a bleeder hole through the thermostat.
This is what happens in my car and why I do NOT boost the engine with the thermostat IN and why I take it OUT for about 8 months out of the year...
Course these threads have me thinking about it again and i have another road race coming up Oct. 15th....I looked at an almanac for Marfa Texas for average temps and it is around 40 degrees n the AM. I will have to have the thermostat in the car for this race or it will never warm up to operating temp. 140-150 degrees is the highest the engine will get to in that temp..
So I guess its time to put it back in and start the whole radiator funnel thing again...
This is what happens in my car and why I do NOT boost the engine with the thermostat IN and why I take it OUT for about 8 months out of the year...
Course these threads have me thinking about it again and i have another road race coming up Oct. 15th....I looked at an almanac for Marfa Texas for average temps and it is around 40 degrees n the AM. I will have to have the thermostat in the car for this race or it will never warm up to operating temp. 140-150 degrees is the highest the engine will get to in that temp..
So I guess its time to put it back in and start the whole radiator funnel thing again...
09-07-2010, 12:42 PM
#9
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
Ok, here's the reason it won't open.
as you know there is a spring behind the tstat valve. When that spring heats up it compresses thus opening the tstat. You know this because you tested it in boiling water as did I when i had all of my problems.
Now, on our cars the tstat is in the front and how it's designed it is VERY easy for an air bubble to get trapped behind the thermostat in the area of the spring. The coolant goes up into the heads to the rear of the tstat so when the air gets trapped by the spring it gets pushed forward and stays there. That air never gets close to being hot enough and the spring won't compress and open.
That's why we have to rev the engine and get the coolant moving at different speeds and also with the heater on full blast so not only are you getting bypass coolant to the rear of the tstat you are getting the coolant to the back of the tstat from the heater core. So it has double flow to move that bubble. If you have no flow to the rear of that tstat then you aren't able to unlodge that air bubble.
I fought this for a long time until i got a spill free funnel and could free rev that engine very high to release this bubble.
I guess another thing that could help is lifting the REAR of the car. That will also allow the air bubbles in the heads to flow to the rear cooling pipe. One you get the air back there then drop the rear of the car they will get pushed to the radiator where they can come out. This will also tip the tstat forward allowing the air bubble to move to the rear port where it can go up into the heads.
Also, when i first started to fill you are supposed to fill VERY slowly. By filling really slowly the coolant won't rush in forcing air into pockets. It will gently trickle into the tstat area and fill up.
as you know there is a spring behind the tstat valve. When that spring heats up it compresses thus opening the tstat. You know this because you tested it in boiling water as did I when i had all of my problems.
Now, on our cars the tstat is in the front and how it's designed it is VERY easy for an air bubble to get trapped behind the thermostat in the area of the spring. The coolant goes up into the heads to the rear of the tstat so when the air gets trapped by the spring it gets pushed forward and stays there. That air never gets close to being hot enough and the spring won't compress and open.
That's why we have to rev the engine and get the coolant moving at different speeds and also with the heater on full blast so not only are you getting bypass coolant to the rear of the tstat you are getting the coolant to the back of the tstat from the heater core. So it has double flow to move that bubble. If you have no flow to the rear of that tstat then you aren't able to unlodge that air bubble.
I fought this for a long time until i got a spill free funnel and could free rev that engine very high to release this bubble.
I guess another thing that could help is lifting the REAR of the car. That will also allow the air bubbles in the heads to flow to the rear cooling pipe. One you get the air back there then drop the rear of the car they will get pushed to the radiator where they can come out. This will also tip the tstat forward allowing the air bubble to move to the rear port where it can go up into the heads.
Also, when i first started to fill you are supposed to fill VERY slowly. By filling really slowly the coolant won't rush in forcing air into pockets. It will gently trickle into the tstat area and fill up.
09-07-2010, 01:08 PM
#10
Ok, here's the reason it won't open.
as you know there is a spring behind the tstat valve. When that spring heats up it compresses thus opening the tstat. You know this because you tested it in boiling water as did I when i had all of my problems.
Now, on our cars the tstat is in the front and how it's designed it is VERY easy for an air bubble to get trapped behind the thermostat in the area of the spring. The coolant goes up into the heads to the rear of the tstat so when the air gets trapped by the spring it gets pushed forward and stays there. That air never gets close to being hot enough and the spring won't compress and open.
That's why we have to rev the engine and get the coolant moving at different speeds and also with the heater on full blast so not only are you getting bypass coolant to the rear of the tstat you are getting the coolant to the back of the tstat from the heater core. So it has double flow to move that bubble. If you have no flow to the rear of that tstat then you aren't able to unlodge that air bubble.
I fought this for a long time until i got a spill free funnel and could free rev that engine very high to release this bubble.
I guess another thing that could help is lifting the REAR of the car. That will also allow the air bubbles in the heads to flow to the rear cooling pipe. One you get the air back there then drop the rear of the car they will get pushed to the radiator where they can come out. This will also tip the tstat forward allowing the air bubble to move to the rear port where it can go up into the heads.
Also, when i first started to fill you are supposed to fill VERY slowly. By filling really slowly the coolant won't rush in forcing air into pockets. It will gently trickle into the tstat area and fill up.
as you know there is a spring behind the tstat valve. When that spring heats up it compresses thus opening the tstat. You know this because you tested it in boiling water as did I when i had all of my problems.
Now, on our cars the tstat is in the front and how it's designed it is VERY easy for an air bubble to get trapped behind the thermostat in the area of the spring. The coolant goes up into the heads to the rear of the tstat so when the air gets trapped by the spring it gets pushed forward and stays there. That air never gets close to being hot enough and the spring won't compress and open.
That's why we have to rev the engine and get the coolant moving at different speeds and also with the heater on full blast so not only are you getting bypass coolant to the rear of the tstat you are getting the coolant to the back of the tstat from the heater core. So it has double flow to move that bubble. If you have no flow to the rear of that tstat then you aren't able to unlodge that air bubble.
I fought this for a long time until i got a spill free funnel and could free rev that engine very high to release this bubble.
I guess another thing that could help is lifting the REAR of the car. That will also allow the air bubbles in the heads to flow to the rear cooling pipe. One you get the air back there then drop the rear of the car they will get pushed to the radiator where they can come out. This will also tip the tstat forward allowing the air bubble to move to the rear port where it can go up into the heads.
Also, when i first started to fill you are supposed to fill VERY slowly. By filling really slowly the coolant won't rush in forcing air into pockets. It will gently trickle into the tstat area and fill up.
09-07-2010, 01:25 PM
#11
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
That's a theory of mine that seems to make good sense. I managed to get mine unlodged by using a spill free funnel and doing some really high revs while it was bleeding. Also with the very slow filling at the begining. It probably took me 30 minutes to slowly add coolant before i started bleeding. Then while it was running after the engine was up to temp i did some 3k revs and hold, then 5k revs and hold and then i did a bunch of high reves and keeping the engine changing rpms to hopefully create turbulance and break up all the bubbles.
Then you leave the spill free in place, let the engine cool all the way down to ambient temps and then start all over again. I did that 3 times and so far the car has been great since May.
09-07-2010, 01:45 PM
#12
i'm not sure i would raise the front, just lower the rear back down.
That's a theory of mine that seems to make good sense. I managed to get mine unlodged by using a spill free funnel and doing some really high revs while it was bleeding. Also with the very slow filling at the begining. It probably took me 30 minutes to slowly add coolant before i started bleeding. Then while it was running after the engine was up to temp i did some 3k revs and hold, then 5k revs and hold and then i did a bunch of high reves and keeping the engine changing rpms to hopefully create turbulance and break up all the bubbles.
Then you leave the spill free in place, let the engine cool all the way down to ambient temps and then start all over again. I did that 3 times and so far the car has been great since May.
That's a theory of mine that seems to make good sense. I managed to get mine unlodged by using a spill free funnel and doing some really high revs while it was bleeding. Also with the very slow filling at the begining. It probably took me 30 minutes to slowly add coolant before i started bleeding. Then while it was running after the engine was up to temp i did some 3k revs and hold, then 5k revs and hold and then i did a bunch of high reves and keeping the engine changing rpms to hopefully create turbulance and break up all the bubbles.
Then you leave the spill free in place, let the engine cool all the way down to ambient temps and then start all over again. I did that 3 times and so far the car has been great since May.
just curious what hp does your car make and at what boost? Mine is 14.5 psi and 530 hp 500 tq on high boost..curious more than anything about your boost psi..
on edit... did you use the bleeder valve while it was lifted in the rear?
09-07-2010, 01:53 PM
#13
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
I had the bleeder valve open while i was doing the super slow filling. that was it. After that it stayed shut for me.
I only filled the funnel about half way up and i didn't do very high revs until the engine was warmed up and the level went down. Once the level started going down i kept filling the funnel until it was 1/4 full. When it was 1/4 full i did my high revs and it got high but never enough to come out. Then when i shut it down and let it cool i added more coolant to the spill free funnel and i kept checking it as i let it sit to make sure the level didn't drop too low.
We couldn't finish testing high boost runs because my mickey's were getting too hot and causing inconsistant dyno readings along with my turbine housing being to small. I have a .96 housing coming and i'm going to go back with street tires so we don't have a tire issue again.
I put down 463hp on a DD (add 13% for a DJ hp) at 13psi. He did a few pulls up to 17psi but i didn't get any numbers and wasn't there when he did that. Going from 10psi wastegate to 13psi pulled me 60hp so roughly 20hp per psi.
This is all on pumpgas too. Hopefuly when i get everything lined out i'll tune on e85 since i have a twin pump.
I only filled the funnel about half way up and i didn't do very high revs until the engine was warmed up and the level went down. Once the level started going down i kept filling the funnel until it was 1/4 full. When it was 1/4 full i did my high revs and it got high but never enough to come out. Then when i shut it down and let it cool i added more coolant to the spill free funnel and i kept checking it as i let it sit to make sure the level didn't drop too low.
We couldn't finish testing high boost runs because my mickey's were getting too hot and causing inconsistant dyno readings along with my turbine housing being to small. I have a .96 housing coming and i'm going to go back with street tires so we don't have a tire issue again.
I put down 463hp on a DD (add 13% for a DJ hp) at 13psi. He did a few pulls up to 17psi but i didn't get any numbers and wasn't there when he did that. Going from 10psi wastegate to 13psi pulled me 60hp so roughly 20hp per psi.
This is all on pumpgas too. Hopefuly when i get everything lined out i'll tune on e85 since i have a twin pump.
09-07-2010, 01:56 PM
#14
got it..cool... I will do this and let you know..one last question..AFTER doing all this what was the coolant level in your overflow and where would you want it? i have always had it on the low level and maybe i am sucking all that in and THEN some air with it..possibly my issue..what do you think?
09-07-2010, 03:20 PM
#15
I keep mine at least 1/3 full when cold. It will be at the lowest point when cold..
I ended up bleeding mine by topping off the overflow for about 5 days straight until it finally stopped going down
. I too, thought the headgasket was blown at first...
I ended up bleeding mine by topping off the overflow for about 5 days straight until it finally stopped going down
. I too, thought the headgasket was blown at first...
Last edited by djamps; 09-07-2010 at 03:21 PM.
09-07-2010, 07:49 PM
#17
New Member
iTrader: (8)
Join Date: Jan 2007
Location: terre haute, IN; STL, MO
Posts: 6,457
Likes: 0
Received 7 Likes
on
6 Posts
got it..cool... I will do this and let you know..one last question..AFTER doing all this what was the coolant level in your overflow and where would you want it? i have always had it on the low level and maybe i am sucking all that in and THEN some air with it..possibly my issue..what do you think?
not really practical for daily drivers unless you live in an area that temps stay up above the 70's. Even in the 70's my car gets down to tstat opening temp (180*) when i'm cruising.
09-22-2010, 12:41 PM
#19
New Member
iTrader: (13)
....you want to warm it up......but i mean... if the tstat is to prevent coolant flow from going to radiator until that happens why would you want coolant to go in so soon?....i guess its really up to you, but IMO you want to let it get to "design" engine conditions (Fº) before driving it, and that tstat allows you to get it happen quicker...then you will get less engine wear, deposits and emissions 2.
Last edited by IIQuickSilverII; 09-22-2010 at 12:49 PM.
