My 84 Xantia 1.9D (95,000 miles and good condition) seems to have blown a head gasket after a minor overheat (coolant disappearing, bubbles in the radiator). Was going to pull it apart to have a look, but it seems to be a bigger job than it should be!
Is the head likely to be warped on this model? Is it worth the effort of repair? Do the heads skim OK?
The overheat occurred after i replaced the plastic manifold on the lower back of the engine. The coolant circulation also seems to be disrupted, with nothing going through the radiator. Could the manifold not be drilled correctly?
Xantia head
Moderator: RichardW
Hi Andrew -
I belive you mean a '94 Xantia [8D]
Replacing a headgasket is by no means a minor job, but defo not as time consuming & costly as replacing the engine.
It's a common repair replacing the headgasket, and it's right : even a short term overheating causes this on modern engines.
It is in fact the cylinder head warping rather than the gasket failing.
This means the head MUST be skimmed, otherwise replacing the gasket is a time (& money) waster. It's only a few 10's of a mm skimming, just exactly to get the cylinder gasket face even & square again.
The non-turbo diesel is a fair DIY job to replace the gasket, but not a job for the faint hearted beginner. It will be the best part of a full workday in labour cost in a garage.
Before considering the job, you must find the cause of overheating, i.e. the missing coolant flow.
Chances are you either got the wrong manifold or gasket, or something is fitted incorrectly.
Any chance you replaced and reverse fitted a new coolant thermostat ?
You may check the coolant flow by removing the coolant thermostat, as this will prevent the engine reaching normal temperature, i.e. it will run cold for longish time, but you should then be able to test for coolant flow with coolant filler cap open, or any small hose removed to check for flow.
I belive you mean a '94 Xantia [8D]
Replacing a headgasket is by no means a minor job, but defo not as time consuming & costly as replacing the engine.
It's a common repair replacing the headgasket, and it's right : even a short term overheating causes this on modern engines.
It is in fact the cylinder head warping rather than the gasket failing.
This means the head MUST be skimmed, otherwise replacing the gasket is a time (& money) waster. It's only a few 10's of a mm skimming, just exactly to get the cylinder gasket face even & square again.
The non-turbo diesel is a fair DIY job to replace the gasket, but not a job for the faint hearted beginner. It will be the best part of a full workday in labour cost in a garage.
Before considering the job, you must find the cause of overheating, i.e. the missing coolant flow.
Chances are you either got the wrong manifold or gasket, or something is fitted incorrectly.
Any chance you replaced and reverse fitted a new coolant thermostat ?
You may check the coolant flow by removing the coolant thermostat, as this will prevent the engine reaching normal temperature, i.e. it will run cold for longish time, but you should then be able to test for coolant flow with coolant filler cap open, or any small hose removed to check for flow.
I'm surprised you have water flow around your inlet manifold. I thought there was no point in heating inlet manifolds on diesels as cold air was considered beneficial.
I entirely agree with Anders - you must find out why the engine overheated. as a matter of interest why did you remove the inlet manifold? Is there a connection there.
xantia overheating and waterflow seems to be extensively discussed recentlty - have a good look around this forum.
jeremy
I entirely agree with Anders - you must find out why the engine overheated. as a matter of interest why did you remove the inlet manifold? Is there a connection there.
xantia overheating and waterflow seems to be extensively discussed recentlty - have a good look around this forum.
jeremy
Andrew,
Are you talking about that plastic coolant elbow on the back of the engine just above the offside driveshaft.....with the one large hose, two smaller ones and a blanked stub??
What exactly happened for you to find out the plastic manifold had gone? Did the car overheat several times or just once...a lot??
When you replaced it did you bleed the cooling system using a header tank and the bleed nipples?
David
Are you talking about that plastic coolant elbow on the back of the engine just above the offside driveshaft.....with the one large hose, two smaller ones and a blanked stub??
What exactly happened for you to find out the plastic manifold had gone? Did the car overheat several times or just once...a lot??
When you replaced it did you bleed the cooling system using a header tank and the bleed nipples?
David
Thanks Anders
Yes it is 94!
I bought the manifold from a Citroen dealer, and it looks exactly the same. I didn't touch the thermostat.
Perhaps the blow back into the coolant system is disrupting the flow?
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by AndersDK</i>
Hi Andrew -
I belive you mean a '94 Xantia [8D]
Replacing a headgasket is by no means a minor job, but defo not as time consuming & costly as replacing the engine.
It's a common repair replacing the headgasket, and it's right : even a short term overheating causes this on modern engines.
It is in fact the cylinder head warping rather than the gasket failing.
This means the head MUST be skimmed, otherwise replacing the gasket is a time (& money) waster. It's only a few 10's of a mm skimming, just exactly to get the cylinder gasket face even & square again.
The non-turbo diesel is a fair DIY job to replace the gasket, but not a job for the faint hearted beginner. It will be the best part of a full workday in labour cost in a garage.
Before considering the job, you must find the cause of overheating, i.e. the missing coolant flow.
Chances are you either got the wrong manifold or gasket, or something is fitted incorrectly.
Any chance you replaced and reverse fitted a new coolant thermostat ?
You may check the coolant flow by removing the coolant thermostat, as this will prevent the engine reaching normal temperature, i.e. it will run cold for longish time, but you should then be able to test for coolant flow with coolant filler cap open, or any small hose removed to check for flow.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Yes it is 94!
I bought the manifold from a Citroen dealer, and it looks exactly the same. I didn't touch the thermostat.
Perhaps the blow back into the coolant system is disrupting the flow?
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by AndersDK</i>
Hi Andrew -
I belive you mean a '94 Xantia [8D]
Replacing a headgasket is by no means a minor job, but defo not as time consuming & costly as replacing the engine.
It's a common repair replacing the headgasket, and it's right : even a short term overheating causes this on modern engines.
It is in fact the cylinder head warping rather than the gasket failing.
This means the head MUST be skimmed, otherwise replacing the gasket is a time (& money) waster. It's only a few 10's of a mm skimming, just exactly to get the cylinder gasket face even & square again.
The non-turbo diesel is a fair DIY job to replace the gasket, but not a job for the faint hearted beginner. It will be the best part of a full workday in labour cost in a garage.
Before considering the job, you must find the cause of overheating, i.e. the missing coolant flow.
Chances are you either got the wrong manifold or gasket, or something is fitted incorrectly.
Any chance you replaced and reverse fitted a new coolant thermostat ?
You may check the coolant flow by removing the coolant thermostat, as this will prevent the engine reaching normal temperature, i.e. it will run cold for longish time, but you should then be able to test for coolant flow with coolant filler cap open, or any small hose removed to check for flow.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Hi Jeremy
I didn't touch the inlet manifold, it is the small plastic coolant manifold down the bottom of the engine.
Thanks
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jeremy</i>
I'm surprised you have water flow around your inlet manifold. I thought there was no point in heating inlet manifolds on diesels as cold air was considered beneficial.
I entirely agree with Anders - you must find out why the engine overheated. as a matter of interest why did you remove the inlet manifold? Is there a connection there.
xantia overheating and waterflow seems to be extensively discussed recentlty - have a good look around this forum.
jeremy
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I didn't touch the inlet manifold, it is the small plastic coolant manifold down the bottom of the engine.
Thanks
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jeremy</i>
I'm surprised you have water flow around your inlet manifold. I thought there was no point in heating inlet manifolds on diesels as cold air was considered beneficial.
I entirely agree with Anders - you must find out why the engine overheated. as a matter of interest why did you remove the inlet manifold? Is there a connection there.
xantia overheating and waterflow seems to be extensively discussed recentlty - have a good look around this forum.
jeremy
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Thanks David
Yes, that's the one. The car didn't overheat dramatically while the old elbow was on, it was leaking slowly and I kept topping it up with water. THe real problem came after I replaced it. Suspect you are right in that i didn't get enough water into the cooling system since i didn't use a header tank. Damn!
I still don't understand the lack of circulation though.
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by D J Woollard</i>
Andrew,
Are you talking about that plastic coolant elbow on the back of the engine just above the offside driveshaft.....with the one large hose, two smaller ones and a blanked stub??
What exactly happened for you to find out the plastic manifold had gone? Did the car overheat several times or just once...a lot??
When you replaced it did you bleed the cooling system using a header tank and the bleed nipples?
David
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Yes, that's the one. The car didn't overheat dramatically while the old elbow was on, it was leaking slowly and I kept topping it up with water. THe real problem came after I replaced it. Suspect you are right in that i didn't get enough water into the cooling system since i didn't use a header tank. Damn!
I still don't understand the lack of circulation though.
Andrew
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by D J Woollard</i>
Andrew,
Are you talking about that plastic coolant elbow on the back of the engine just above the offside driveshaft.....with the one large hose, two smaller ones and a blanked stub??
What exactly happened for you to find out the plastic manifold had gone? Did the car overheat several times or just once...a lot??
When you replaced it did you bleed the cooling system using a header tank and the bleed nipples?
David
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Andrew,
That plastic elbow is proving troublesome as Xantia's age, so much so that I'm replacing them now as a matter of routine if I have the driveshaft out.
My fear is that if you topped up the coolant after that work without a header tank and/or bleeding air off using the correct procedure you will have a slug of air trapped in the thermostat housing. The thermostat will not open in this condition so no circulation and rapid boiling.
If you are very lucky it is possible doing it properly now may save the day.
Here is a previously posted method of mine...
<<<<First locate all the bleed points on your particular engine. These may include one on the radiator opposite the filler cap, two on the thermostat housing, one on the small hose that leaves the thermostat housing, one on the metal heater feed pipe just behind the camshaft cover, one on the heater hose just to the rear of the engine, one on a small hose running just behind the radiator, one just above the diesel injector pump where three pipes join. I do not want to be specific to a particular model/year as I have seen cars with odd combinations of the normal set-up, just carefully look for them all.
With the engine cool remove the filler cap and fabricate some sort of header tank that will give about an extra 300mm head of water. Mine is very simple. It is a large plastic funnel for filling up tractor fuel that has a nozzle about the same size as the filler hole and holds 3 litres of coolant. I cut the nozzle at a point so that the taper just goes into the radiator/expansion tank filler hole and a firm push will keep it wedged there. I have seen loads of other clever solutions to this with little tanks held on a stand and filler hoses that connect to a modified radiator cap boss.
Now top up the system with coolant and allow the funnel/header tank to fill about 2/3rds. Bleed each coolant bleed point in turn until bubble-free coolant is seen. Close them all firmly. Start the engine and allow it to run at a fast idle until the thermostat opens and the radiator becomes fully hot. During this period you should see loads of small bubbles appear in the funnel/header tank, and as the thermostat opens a huge amount of air often bubbles up. Now stop the engine and bleed each point in turn again. Use great care as the coolant will be scalding. Top up the funnel as needed during this to keep it about 2/3rds full at all times. Close all bleed points finally and re-start the engine. Allow it to run for up to another five minutes for all the remaining small air bubbles to bleed off. When you are happy stop the engine and remove the funnel. Put the radiator cap back on with the coolant still right to the top (ie overfilled by cold standards). Allow the car to cool completely then check the level and add/remove coolant as needed. Give the car two days normal use then check the level again when completely cold. Again add/remove to get the level spot on. Only now consider this an accurate level to monitor from.
Why is this bleeding crucial? Well the thermostat and coolant temperature gauge/warning sensors are in a position that is easily left air-locked if this procedure isn't properly carried out. And these do not work properly in air, only if the water is in contact with them. So it is possible after a water loss, and re-filling without bleeding, for the engine to go above the thermostat opening temperature without it allowing coolant to the radiator. Then because the temperature senders are also in the air lock they don't indicate a problem. Result engine cooks and the head gasket/head are damaged. Many head gasket problems follow a simple loss of water incident after a few days. It is my belief this is often due to the problem of bleeding the system rather than the initial fault damaging the head.>>>>
Hope this helps.
David
That plastic elbow is proving troublesome as Xantia's age, so much so that I'm replacing them now as a matter of routine if I have the driveshaft out.
My fear is that if you topped up the coolant after that work without a header tank and/or bleeding air off using the correct procedure you will have a slug of air trapped in the thermostat housing. The thermostat will not open in this condition so no circulation and rapid boiling.
If you are very lucky it is possible doing it properly now may save the day.
Here is a previously posted method of mine...
<<<<First locate all the bleed points on your particular engine. These may include one on the radiator opposite the filler cap, two on the thermostat housing, one on the small hose that leaves the thermostat housing, one on the metal heater feed pipe just behind the camshaft cover, one on the heater hose just to the rear of the engine, one on a small hose running just behind the radiator, one just above the diesel injector pump where three pipes join. I do not want to be specific to a particular model/year as I have seen cars with odd combinations of the normal set-up, just carefully look for them all.
With the engine cool remove the filler cap and fabricate some sort of header tank that will give about an extra 300mm head of water. Mine is very simple. It is a large plastic funnel for filling up tractor fuel that has a nozzle about the same size as the filler hole and holds 3 litres of coolant. I cut the nozzle at a point so that the taper just goes into the radiator/expansion tank filler hole and a firm push will keep it wedged there. I have seen loads of other clever solutions to this with little tanks held on a stand and filler hoses that connect to a modified radiator cap boss.
Now top up the system with coolant and allow the funnel/header tank to fill about 2/3rds. Bleed each coolant bleed point in turn until bubble-free coolant is seen. Close them all firmly. Start the engine and allow it to run at a fast idle until the thermostat opens and the radiator becomes fully hot. During this period you should see loads of small bubbles appear in the funnel/header tank, and as the thermostat opens a huge amount of air often bubbles up. Now stop the engine and bleed each point in turn again. Use great care as the coolant will be scalding. Top up the funnel as needed during this to keep it about 2/3rds full at all times. Close all bleed points finally and re-start the engine. Allow it to run for up to another five minutes for all the remaining small air bubbles to bleed off. When you are happy stop the engine and remove the funnel. Put the radiator cap back on with the coolant still right to the top (ie overfilled by cold standards). Allow the car to cool completely then check the level and add/remove coolant as needed. Give the car two days normal use then check the level again when completely cold. Again add/remove to get the level spot on. Only now consider this an accurate level to monitor from.
Why is this bleeding crucial? Well the thermostat and coolant temperature gauge/warning sensors are in a position that is easily left air-locked if this procedure isn't properly carried out. And these do not work properly in air, only if the water is in contact with them. So it is possible after a water loss, and re-filling without bleeding, for the engine to go above the thermostat opening temperature without it allowing coolant to the radiator. Then because the temperature senders are also in the air lock they don't indicate a problem. Result engine cooks and the head gasket/head are damaged. Many head gasket problems follow a simple loss of water incident after a few days. It is my belief this is often due to the problem of bleeding the system rather than the initial fault damaging the head.>>>>
Hope this helps.
David
First be certain whether gasket seal is intact.
A leak can take several forms : From cylinder to coolant system is common, so gas blows past relief valve in cap of coolant reservoir. This can be tested by making a plug to fit the neck of the expansion chamber, with a flexible tube running to below water level in a transparent bottle. If she continually blows bubbles, there is repair work to be done. In the meantime, increased pressure in the coolant system can blow your heater matrix . . . something you don’t want to happen.
Blown head gasket can also result in water mixing with the engine oil, which turns the oil on the dipstick a milky grey.
In theory, a minor headgasket leak may be the result of an overheating incident where the alloy head has not reached the temperature at which stess-relieving (warping) can occur. In this case, the gasket may be subject to extra compression due to the difference of thermal expansion between the alloy head and the hi-tensile steel bolts. I have recently sealed a leak like this by backing off each headbolt, and torquing up to 85Nm. Long term effectiveness of this has yet to be established, but if it is good, I will pass it on.
A leak can take several forms : From cylinder to coolant system is common, so gas blows past relief valve in cap of coolant reservoir. This can be tested by making a plug to fit the neck of the expansion chamber, with a flexible tube running to below water level in a transparent bottle. If she continually blows bubbles, there is repair work to be done. In the meantime, increased pressure in the coolant system can blow your heater matrix . . . something you don’t want to happen.
Blown head gasket can also result in water mixing with the engine oil, which turns the oil on the dipstick a milky grey.
In theory, a minor headgasket leak may be the result of an overheating incident where the alloy head has not reached the temperature at which stess-relieving (warping) can occur. In this case, the gasket may be subject to extra compression due to the difference of thermal expansion between the alloy head and the hi-tensile steel bolts. I have recently sealed a leak like this by backing off each headbolt, and torquing up to 85Nm. Long term effectiveness of this has yet to be established, but if it is good, I will pass it on.