Compression tester show a blown headgasket???
Thread Starter
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
Compression tester show a blown headgasket???
Will a Compression tester show a blown headgasket??? I am fighting an overheating problem right now and already changed the thermostat and it didnt help 
: the coolant gets up to 220 before the oil temp even gets above LO on the gauge. I need to know what to check next...The coolant got to about 220 from a cold idle in about 3 minutes.....I checked the oil and the coolant on the dipstick and it looked ok however I havent drained either of them yet. 
: the coolant gets up to 220 before the oil temp even gets above LO on the gauge. I need to know what to check next...The coolant got to about 220 from a cold idle in about 3 minutes.....I checked the oil and the coolant on the dipstick and it looked ok however I havent drained either of them yet.
Team Owner
Joined: Jun 2002
Posts: 21,510
Likes: 0
From: On a Wisconsin Death Trip
Pull your plugs and check your oil - you should be able to tell from the spark plugs and/or oil if a bad head gasket is your problem.
More specifically, if coolant is leaking due to a bad head gasket it's gonna end up in one of these two places. your overheating problem in this case would be due to loss of coolant.
You can also pop your radiator cap off while the car is running and look for bubbles.
About the only nice thing on cooling leaks is they always leave evidence.
More specifically, if coolant is leaking due to a bad head gasket it's gonna end up in one of these two places. your overheating problem in this case would be due to loss of coolant.
You can also pop your radiator cap off while the car is running and look for bubbles.
About the only nice thing on cooling leaks is they always leave evidence.
Last edited by loiq; Sep 29, 2004 at 03:56 PM.
Pro
Joined: Aug 2001
Posts: 617
Likes: 14
From: Loudon, TN
It should give a good indication that there is a leak either from a blown gasket, warped head or cracked head. It will be real obvious if you have water in the crankcase because the oil will have a milky appearance. You won't necessarily have any sign of oil in the cooling system with a blown headgasket, etc.
Instructor
Joined: May 1999
Posts: 206
Likes: 0
From: Lebanon Ohio
It will only run like *** if the headgasket is blown around the cylinders themselves... For instance if the cylinder head gasket was leaking from a waterjacket to the outside of the block slowly then it would run FINE but get hot..
Typically when they run like crap is when the gasket blows between cylinders..So like #3 and #5 the gasket blows between them...then they fight each other and share air and shake the car...etc..etc..
they also run like crap if the coolant leaks between the cylinder itself...Then they hydrolock..
but not every case is that extreme>>> unfortunately however it blows reguardless of symptoms the install of new ones is no fun..
Typically when they run like crap is when the gasket blows between cylinders..So like #3 and #5 the gasket blows between them...then they fight each other and share air and shake the car...etc..etc..
they also run like crap if the coolant leaks between the cylinder itself...Then they hydrolock..
but not every case is that extreme>>> unfortunately however it blows reguardless of symptoms the install of new ones is no fun..
Last edited by Kenwood; Sep 29, 2004 at 04:02 PM.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by Wheelman
Will a Compression tester show a blown headgasket??? I am fighting an overheating problem right now and already changed the thermostat and it didnt help : the coolant gets up to 220 before the oil temp even gets above LO on the gauge. I need to know what to check next...The coolant got to about 220 from a cold idle in about 3 minutes.....I checked the oil and the coolant on the dipstick and it looked ok however I havent drained either of them yet.
: the coolant gets up to 220 before the oil temp even gets above LO on the gauge. I need to know what to check next...The coolant got to about 220 from a cold idle in about 3 minutes.....I checked the oil and the coolant on the dipstick and it looked ok however I havent drained either of them yet. When you say "fighting an overheating problem" what exactly are we talking about? What temps? How is the engine running? Any code(s)?
You'll need to verify that the fan is coming on and at what temp.
You'll need to verify flow through the system by running the engine with the radiator cap removed and checking for coolant flow through the radiator.
You'll need to make sure all the air is out of the system by doing the burping technique.
You'll need to verify that the temp gauge is close to being correct and that the gauge temp sensor is working properly.
You'll need to check the radiator for any obstruction to airflow such as leaves, newspaper, etc., that often gets sucked in.
You'll need to borrow a pressure tester from AutoZone, pressurize the cooling system and see if the pressure holds.
Hope this helps.
Jake
Thread Starter
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
Originally Posted by JAKE
As always, check the most obvious things first before diving off into things like head gasket failure, etc.
When you say "fighting an overheating problem" what exactly are we talking about? What temps? How is the engine running? Any code(s)?
You'll need to verify that the fan is coming on and at what temp.
You'll need to verify flow through the system by running the engine with the radiator cap removed and checking for coolant flow through the radiator.
You'll need to make sure all the air is out of the system by doing the burping technique.
You'll need to verify that the temp gauge is close to being correct and that the gauge temp sensor is working properly.
You'll need to check the radiator for any obstruction to airflow such as leaves, newspaper, etc., that often gets sucked in.
You'll need to borrow a pressure tester from AutoZone, pressurize the cooling system and see if the pressure holds.
Hope this helps.
Jake
When you say "fighting an overheating problem" what exactly are we talking about? What temps? How is the engine running? Any code(s)?
You'll need to verify that the fan is coming on and at what temp.
You'll need to verify flow through the system by running the engine with the radiator cap removed and checking for coolant flow through the radiator.
You'll need to make sure all the air is out of the system by doing the burping technique.
You'll need to verify that the temp gauge is close to being correct and that the gauge temp sensor is working properly.
You'll need to check the radiator for any obstruction to airflow such as leaves, newspaper, etc., that often gets sucked in.
You'll need to borrow a pressure tester from AutoZone, pressurize the cooling system and see if the pressure holds.
Hope this helps.
Jake
This morning I changed the thermostat, refilled and let it run at idle with the rad cap open and filled it up, the car coolant temp went to 220 before the oil temp even got above LO. The coolant looked normal however I noticed some bubbles coming out the area of the radiator cap opening. Definatly not normal for my car. Both fans are operating as they should. The radiator has been recently cleaned and checked for debris. I havent yet checked the system with a pressure checker. Anything else I should try??
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Thread Starter
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
Originally Posted by CentralCoaster
Does your oil look like this?
I don't get off til 930 tonight though...so I wont know until then....Thats why I'm trying to gather everything I need to check all at once.... As soon as I get home I am going to drain all of the oil and take a look at iit.
Pro
Joined: Aug 2001
Posts: 617
Likes: 14
From: Loudon, TN
If the water temperature is 260 degrees it should be boiling out of the cap like mad when you take it off. Actually taking the cap off with a temperature of 260 it should be nearly a guyser. Water boils at 212 so you should see a lot more than a few bubbles at 260. Get an antifreeze tester that has a thermometer in it and take a sample out of the radiator and double check the temperature. It could be a defective guage or sensor. The water hoses should be so hot that you won't be able to keep your hand on them. Has the system been blowing water out of the overflow tank? If not then I don't think you are running too hot. I've been trying to follow your multiple posts on this problem so I might have missed if it was loosing coolant.
Thread Starter
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
It was slowly losing coolant a few days ago, but I hadn't really payed much attention to it. I saw the low coolant light but the day before I had been working on the car and lost a bit of coolant through the rad hose when I pulled it to install a new fan motor. So I assumed the low coolant light was just from air in the system. When I drove to my friends the other day the first time I noticed it overheating it was blowing water out the overflow tank for sure.
Burning Brakes
Joined: Apr 2002
Posts: 934
Likes: 0
From: MO
Just a thought here...
You just installed an new fan motor, is it possible it is wired backwards? Which would turn the fan the opposite way pushing through the radiator instead of pulling towards the engine.
You can take a piece of paper and hold it behind the fans if it sucks into the fan it is going the wrong way.
I just re-wired my fans back into the original harness from a manual switch i had rigged up and I got one reversed, caused the car to run 30* more than normal. switched the wires and right back 170*!
Just a thought... Goodluck!
You just installed an new fan motor, is it possible it is wired backwards? Which would turn the fan the opposite way pushing through the radiator instead of pulling towards the engine.
You can take a piece of paper and hold it behind the fans if it sucks into the fan it is going the wrong way.
I just re-wired my fans back into the original harness from a manual switch i had rigged up and I got one reversed, caused the car to run 30* more than normal. switched the wires and right back 170*!
Just a thought... Goodluck!
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
With all the posts and suggestions on 2 threads I've been just lurking. Since I hate to face the difficult without looking into the simple first (guess I'm lazy) I just had to ask. Have you checked to see if your water pump is circulating? Take your pressure fill cap off (not overflow tank) while cool and start car and let warm and see if there's flow after thermostat opens. If it overheats and you never see flow, your waterpump has gone south. I'd hate to think all this scare about a head gasket (although a possibility) was the result of something relatively simple like a bad water pump. I think you should back pedal a bit and rule out the simple stuff first.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by skateparkdave
With all the posts and suggestions on 2 threads I've been just lurking. Since I hate to face the difficult without looking into the simple first (guess I'm lazy) I just had to ask. Have you checked to see if your water pump is circulating? Take your pressure fill cap off (not overflow tank) while cool and start car and let warm and see if there's flow after thermostat opens. If it overheats and you never see flow, your waterpump has gone south. I'd hate to think all this scare about a head gasket (although a possibility) was the result of something relatively simple like a bad water pump. I think you should back pedal a bit and rule out the simple stuff first.
Jake