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I bought a 2004 xjr. It's having over heating problems. I'm getting coolant pushed out of the overflow tank cap. It seems to be building lots a pressure. I'm not getting any coolant in the oil, neither any smoke coming out of the exhaust.
I'm not getting any hot air out of the heater vents.
Sometimes it feels like it is getting hot but then the air cools back down.
Also when I keep the cap off the overflow tank coolant pushed and blows out when I give it some gas.
Or if I just keep the bleeder screw off the overflow it bubbles and pushes coolant out, sometimes doesnt push any coolant or bubbles out, like if it is dried out. It's like a cycle of pushing coolant then bubbles then nothing the. Bubbles and coolant again.
The owner before me replaced the radiator only because it had a dent in the original radiator (""I'm assuming thats why"") so he decided replace it, plus water pump, thermostat, spark plugs. And did a oil change also. Which makes me think he was trying to cover up something major.
He said it's been over heating and he couldn't get the air out after he replaced the radiator.
So I decided to give it what I had maybe thinking I can figure it out.
Well it's becoming a pain it the butt.
I've took the thermostat out thinking maybe I can get the air out. Still over heated.. I'm new to this bleeding out the system and still can't figure out why I even keep trying for this air pocked or how and air pocket can get stuck in the system..
Honestly I'm thinking it's a headgasket but still question it. Because of the heater not being hot even when it's overheating.
So I ended up doing a compression test to see maybe if I can find something.
I'm going to start on the right hand side (passenger side) working my way down towards the firewall then on the left hand side (driver side) towards the fire wall.
I did 5 rotations on each Cylinder.
The engine wanst really warmed up.
My compression where
I'm not to sure what compression I'm looking in to.
Does anyone know if these compressions are okay?
Or do you think I have a blown head gasket?
I would of picture of a bigger difference in compression if it is blown. But maybe someone on here would know more about it.
I'm going to back track when I first got the car.
Not to sure if any of this will help but I'm going to add this in here
When i picked up the car I was driving down the street I noticed it was overheating and thank God O'Reillys was just down the street and noticed the check engine lights and decided to get the codes scanned. While I let this car cool down. But here where the codes (the battery is bad so I'm summing most of these where because of the low volts., The car didn't start afterwards untill I jumped it.)
It really does look as if a head gasket has blown and or a warped cylinder head because of over heating.
Not getting heat when the heat is on high full blast is an indication of a big air pocket.
Many people try topping up coolant with the nose of the car raised as well as the heat on high full blast.
Also the only sure way to bleed this coolant system is with a vacuum applied and sucking in coolant because of the vacuum.
Does it happen with the engine cold? It could be high pressure because of over heating however try the following to see if anything changes:
Try is taking a spark plug out of 1 cylinder at a time, starting the car and revving a bit to see whether you still get coolant overflowing.
I would start with the lowest compression cylinder and work either side of that.
My theory being that IF the gasket is blown in a small area around a single cylinder with no compression, spark plug out, you might not get coolant overflow.
It really does look as if a head gasket has blown and or a warped cylinder head because of over heating.
Not getting heat when the heat is on high full blast is an indication of a big air pocket.
Many people try topping up coolant with the nose of the car raised as well as the heat on high full blast.
Also the only sure way to bleed this coolant system is with a vacuum applied and sucking in coolant because of the vacuum.
Does it happen with the engine cold? It could be high pressure because of over heating however try the following to see if anything changes:
Try is taking a spark plug out of 1 cylinder at a time, starting the car and revving a bit to see whether you still get coolant overflowing.
I would start with the lowest compression cylinder and work either side of that.
My theory being that IF the gasket is blown in a small area around a single cylinder with no compression, spark plug out, you might not get coolant overflow.
Alright I can try that test. Will I need to unplug the injector to the cylinders I test each time or just leave them hooked up?
Not sure if it would wash all the oil off the cylinder walls?
I'll have to see when the coolant starts actually pushing out.
But I want to say it does it when it's warm up. Also I could be wrong.
There was times when I'm just idling at first and it would not over heat for the longest time and then when I drive it around my shop I get overheating about 1 -3 laps around.
Yesterday I opened that big Allen bolt on top that's connected with the supercharger hoses and turned the ignition to on and it pushed out so much coolant. I shut it off. Filled it back up with water from the Allen bolt hole. Seen it start building up the water level in the overflow tank (I'm only using water for right now until I find reason why it overheats). I put the bolt, overflow cap back on. Started the car and it over heated while it was idling. Usually it wouldnt or would take a long time idling to get it to over heat.
So I shut it down, let I cool enough to take off the bleeder bolt and cap on the overflow.
Stared up the car with the caps off and a minute later put the cap back on while leaving the bleeder screw open and it started to push bubbles out of the bleeder slowly or just coolant.
Gave it some gas and coolant comes out of the bleeder hole.
So I put the bleeder bolt back on and left it cracked to maybe let it run and get some air out.
Noticing the hoses get very hot.
So I tried to drive it around the shops yard and when I pulled up to park it because it was about to over heat. Parked it, Shut it off. And now I'm here on this forum.
Before I've even tried unbolting the front Lamba O2 from the passanger side exhaust before the cat to see maybe it could of been a badly clogged cat. But it even over heated then.
When you turn the ignition on, engine not running, and coolant comes out of that allen plug hole that to me suggests a blockage somewhere.
I have never had that happen and only get coolant sucked in by the SC pump with the engine relatively cool.
So I am thinking the pump is pushing coolant against a blockage causing pressure and an overflow.
With a head gasket blown you do often get a lot of moisture coming out the exhaust and you say that you do not.
Have you looked at the underside of your oil filler cap? If there is a lot of whitish crud that is an indication of too much water vapor in the sump and therefore
a possible head gasket issue.
When you turn the ignition on, engine not running, and coolant comes out of that allen plug hole that to me suggests a blockage somewhere.
I have never had that happen and only get coolant sucked in by the SC pump with the engine relatively cool.
So I am thinking the pump is pushing coolant against a blockage causing pressure and an overflow.
With a head gasket blown you do often get a lot of moisture coming out the exhaust and you say that you do not.
Have you looked at the underside of your oil filler cap? If there is a lot of whitish crud that is an indication of too much water vapor in the sump and therefore
a possible head gasket issue.
Correct. I'm not getting any moisture from the exhaust and I'm not getting any moisture under the oil cap.
That's why I'm super confused on what I can be.
And like what can cause a blockage?
Correct. I'm not getting any moisture from the exhaust and I'm not getting any moisture under the oil cap.
That's why I'm super confused on what I can be.
And like what can cause a blockage?
If there is no gel then the only thing I can think off is the thermostat. I think you stated that it was replaced. Could it have been installed the wrong way round or even stuck closed.
Also I wonder if the hoses connecting the coolant reservoir to the charge coolers are installed correctly. This is a remote possibility but I would certainly check them.
Since you are not getting heat in the cabin then for sure there is no coolant passing thru the heater core. Check the correct installation of those hoses/pipes as it may not be
just an air pocket given all the symptoms.
If there is no gel then the only thing I can think off is the thermostat. I think you stated that it was replaced. Could it have been installed the wrong way round or even stuck closed.
Also I wonder if the hoses connecting the coolant reservoir to the charge coolers are installed correctly. This is a remote possibility but I would certainly check them.
Since you are not getting heat in the cabin then for sure there is no coolant passing thru the heater core. Check the correct installation of those hoses/pipes as it may not be
just an air pocket given all the symptoms.
I have the thermostat out.
Is there a diagram on the hoses to see if they are installed correctly?
The above lower half of the scanned document shows the inter-cooler hose connections.
Difficult to see how they could be incorrectly attached.
One thought is that you could try disconnecting each connection one at a time with the SC pump running to see if you get flow of liquid through each charge cooler and thru the hoses.
Messy but might give a further clue.
Also I wonder if your heater pump is working. It is completely separate from your SC pump. If it is not than that could explain a no heat situation. It would not explain the coolant overflow. I forget the fuse# for that pump.
The above lower half of the scanned document shows the inter-cooler hose connections.
Difficult to see how they could be incorrectly attached.
One thought is that you could try disconnecting each connection one at a time with the SC pump running to see if you get flow of liquid through each charge cooler and thru the hoses.
Messy but might give a further clue.
Also I wonder if your heater pump is working. It is completely separate from your SC pump. If it is not than that could explain a no heat situation. It would not explain the coolant overflow. I forget the fuse# for that pump.
Okay thank you.
I'm going to over look it when I get off work and probably going to try and flush the system with a hose back and forth on every side.
And I would like to fine the heater hose so I can also flush that.
Then I fill it back up with the car lifted with my jack. And go from there.
And I'll give an update also later. Do you know what that pump is called?
The thermostat may have been changed, but the housing tends to fall apart internally and block coolant flow. I would change the entire housing, which includes the thermostat, temp sensor, etc.
The thermostat may have been changed, but the housing tends to fall apart internally and block coolant flow. I would change the entire housing, which includes the thermostat, temp sensor, etc.
Dave
How would it fall apart? I pulled the thermostat out and looked okay.
But when I didnt pull it out, not much coolant came out.
My 07 VDP's had a small section that was broken off, & was inside the water pump so the coolant flow was not very good.
The car ran fine, and never overheated, but the fan would continue to run, when shut off, when temperatures outside reached 45 to 50 degrees.
08-26-2019, 10:46 PM
Bought a 2004 XJR. Came here to find help
