Head Gasket

[mlkey]

Coolant getting excessively pressurised and blowing cap vent, tried replacing the cap, made no difference. Guess I need to do a head gasket :unsure:. Anyone done one of these on a 2.0L 2002 110 HDI 8V?

 

Just wondering if there were any tips / tricks / special tools?

 

Thanks in advance.

[techbod]

main tools required are for the timing belt only difference is your removing the cylinder head so you should fit a new timing belt ( water pump/tensioners at own discretion ) but definitely change the thermostat as this could be the cause of the problem which you need to find out, not sure if you can skim the head on these due to the closeness of the valves to the pistons but as its the 8 valve that might not be the case,

 

no special tools required as you can make bolts to lock the timing gear

[coastline taxis]

main tools required are for the timing belt only difference is your removing the cylinder head so you should fit a new timing belt ( water pump/tensioners at own discretion ) but definitely change the thermostat as this could be the cause of the problem which you need to find out, not sure if you can skim the head on these due to the closeness of the valves to the pistons but as its the 8 valve that might not be the case,

 

no special tools required as you can make bolts to lock the timing gear

Hi

Before you take the head off make sure you can get the injectors out as the one nearest the g/box often siezes in. We have found it easier to remove siezed ones with the engine in place, If the end one is siezed in then turn it a bit to the left and right (using the bottom of the injector) and keep squirting wd 40 down in whilst turning sometimes its took 4 to 5 hours to work it loose. Head gasket has notches on it to tell you what thickness youl need also head bolts need tohave lenght measured to see that they havent stretched to far. also when you have the head of give the inlet manifold a good clean inside so that the engine gets a good smooth airflow also clean out the egr valve and al pipes. in the past we have used discount stores for parts but have found that the dealers are better yes you pay a little bit more but if you asked youl get a print out on the correct tighten procedure and lenght for the bolts also they will be the right parts and they will give you any advice that you need.

[techbod]

failing that I have all the data required for this and will post here if required

[coastline taxis]

failing that I have all the data required for this and will post here if required

forgot to mention that i think you need to get a sniffer test done first as it could be water pump/blockage or as said b4 a thermostate issueand you could be pulling the head of 4 nothing what millage is on it

best regards

steve

[techbod]

good advice im sure :unsure:

carbon detection in the coolant? good stuff there ct

[mlkey]

good advice im sure :unsure:

carbon detection in the coolant? good stuff there ct

 

Thanks all for the replies so far. Mileage is 117000, had the car since 81000. Did the timing belt and water pump when I first got it, and until this, I have not had to put a drop of coolant in.

 

Started it up a week ago, and got the low coolant warning. Topped it up, and put it down to the fact it may of finally wanted some, did not take a lot, less than half a litre. I cover about 100 miles of mainly motorway per day, 500 miles a week, normally at a nice sedate 60ish, so the motor is just ticking over at 2k RPM. 300 miles later, got the top up coolant message again.. Topped up again, drove to work. Popped the bonnet when I got to work, the expansion bottle cap was hissing a little, and coolant was being pushed out of the cap vent, it was not overfilled when cold.

 

Released the valve cap by the thermostat slightly and got a lot of air before getting back to coolant. Thought maybe the expansion bottle cap was duff, so fitted a new one, but the symptoms remain.

 

Today, I tried driving to work with the valve cap by the thermostat loosened very slightly to allow a controlled slow bleed. When I got to work, I checked it. The expansion bottle was ok, level at min, and no hissing. Would say an almost as expected pressure in the hoses, released the valve cap a little more to find a small amout of air.

 

Also noticed the top and bottom hoses were almost completey cold, yet the small hose from the top of the rad to the expansion bottle was nice and hot?

 

I am thinking of trying a thermostat, as tbh, I really don't want to pull the head. Can't seem to find anyone who can do a quick sniffer test. The temp guage has never gone over half way, in fact, only stays at the midway point when I am cruising. Each time I slow down, the temp starts to fall. Heater nice and hot, car feels fine, oil is good, no water in there.

 

All advice welcome, have ordered my Haynes today too :(

[techbod]

it doesn't sound like the head gasket now you explained a little more so here is what I think,

1/. stuck thermostat.

2/. failed coolant temp sensor and the above.

3/. fans not working could be relays or fuses.

 

pressure from the cap is caused by all the above or just one of them and the next problem if used on a long run is the head gasket will fail so a fix is imperative.

 

a quick edit: also check both pipes going to the header tank are free from sludge build up which would prevent the coolant circulating

[coastline taxis]

it doesn't sound like the head gasket now you explained a little more so here is what I think,

1/. stuck thermostat.

2/. failed coolant temp sensor and the above.

3/. fans not working could be relays or fuses.

 

pressure from the cap is caused by all the above or just one of them and the next problem if used on a long run is the head gasket will fail so a fix is imperative.

 

a quick edit: also check both pipes going to the header tank are free from sludge build up which would prevent the coolant circulating

Hi you can get a sniffer of ebay for 30quid use it and put it back on ebay or sell it on here or to me. Your problem though sounds like you need to bleed the system as there is another bleed valve that you need to ooen its on the hose that goes into the heater matrix get engine running then open heater matrix bleed screw till its just water then go onto other bleed screw but only after the engine has done 3 cycles(fan cumming in). Weve never bothered with the last bit and it works fine

[mlkey]

it doesn't sound like the head gasket now you explained a little more so here is what I think,

1/. stuck thermostat.

2/. failed coolant temp sensor and the above.

3/. fans not working could be relays or fuses.

 

pressure from the cap is caused by all the above or just one of them and the next problem if used on a long run is the head gasket will fail so a fix is imperative.

 

a quick edit: also check both pipes going to the header tank are free from sludge build up which would prevent the coolant circulating

 

Cheers for the thoughts techbod.. removed stat and shoved it in a suacepan, opening and shutting fine, rated at 88, sound about right?

I think the sensor is ok, as it seems to be giving sensible readings, am thinking the reason it drops away is when it is out of water due to air build up??

Have seen the fans working today.

 

Drained coolant, checked pipes all clear, then filled and drained with water a few times to clear old coolant. Filled with fresh coolant and run up to temp, now letting it cool, before checking level.

[mlkey]

Hi you can get a sniffer of ebay for 30quid use it and put it back on ebay or sell it on here or to me. Your problem though sounds like you need to bleed the system as there is another bleed valve that you need to ooen its on the hose that goes into the heater matrix get engine running then open heater matrix bleed screw till its just water then go onto other bleed screw but only after the engine has done 3 cycles(fan cumming in). Weve never bothered with the last bit and it works fine

 

Never spotted that other bleed valve, thanks, all coolant, no air, all seems to be by the thermostat. See post above, but basically, changed and refreshed coolant, any idea of the capacity of cooling system? I have put 3.5L of concentrate in and have a 50/50 mix for topping up.

 

I think I will order a head tester, was not sure if it would read for diesel?

 

Long shot I know, but the coolant could of been very weak, therefore lowering the boiling point and creating gases in the system and building up air? So hoping it may be ok, although suspect it will continue.

 

Suposed to be off to Winchester tomorrow, which is 100 miles each way... :o

[mlkey]

UPDATE:

 

Let it cool down, then checked, no additional coolant required. Drove about 5 gentle miles and then checked, hoses pretty hard, but coolant level looking good, no air at either bleed valve. Did another 5 miles on dual carriageway, 70ish with a few full throttles.. Stopped again, checked.. coolant all over the top of expansion bottle, although level had returned to normal, air at thermostat bleed valve.

 

Drove home, another 6 miles, steady 50. Not sure if any more coolant had disharged, expansion bottle cap hissing slightly, small amout of air from theromstat bleed.

 

Thoughts please...

[Randombloke]

Thoughts please...

 

Start it up from cold with the expansion tank cap off, and look for very small bubbles in the tank.

[paul.h]

Did you put the old thermostat back in and did you check the actual opening temperature ? They do not last forever. You could try running the car temporarily without it or with the cabin heater and fan on full to help remove the heat instead of the engine radiator to overcome a late opening thermostat. If these do not work then it looks as though it is the headgasket.

[techbod]

testing the temp sensor is done with a multimeter ( the colder it is the higher the reading in ohms ) after removing the thermostat its not really worth re-using it as its pennies to replace,

the head tester (compression tester ) wont work with a diesel you need to check the pressure at the header tank and there are special tools for that ie: one tests for carbon in the coolant and another tests the actual pressure which would tell you if the head gasket is the fault,

 

when bleeding the system always put the temp setting in the car to hot because if you don't you will not bleed the heater matrix therefore leaving air in the system

[mlkey]

Did you put the old thermostat back in and did you check the actual opening temperature ? They do not last forever. You could try running the car temporarily without it or with the cabin heater and fan on full to help remove the heat instead of the engine radiator to overcome a late opening thermostat. If these do not work then it looks as though it is the headgasket.

 

Yes and yes. It opened before the water got to boiling. I purchased a new one today, and tried them both side by side, have to say, no difference, except the old one closing slower. Have put the new one in. Hard to try without stat due to the way the seal is fitted, but happy its opening.

[mlkey]

testing the temp sensor is done with a multimeter ( the colder it is the higher the reading in ohms ) after removing the thermostat its not really worth re-using it as its pennies to replace,

the head tester (compression tester ) wont work with a diesel you need to check the pressure at the header tank and there are special tools for that ie: one tests for carbon in the coolant and another tests the actual pressure which would tell you if the head gasket is the fault,

 

when bleeding the system always put the temp setting in the car to hot because if you don't you will not bleed the heater matrix therefore leaving air in the system

 

Have not tested the sensor, but happy its reading correctly as only gets to centre, fan cuts in correctly, and uses the same sensor, have now fitted new stat.

 

Heater matrix is constant flow on C5, no control valve, all done by airflow.

 

Having made a header tank for the fill and done things according to the book, the problem is still evident, although maybe to a lesser extent.

 

Definately pressurising the system. Going to take the car off road, and do the work, also rework the EGR and check the turbo etc. May as well do it all while I am at it, thanks for all the help gents!

[techbod]

all done by airflow? now that's a system to be seen water pipes go into the matrix so a valve is required to shut the hot water off ( diverter valve ) doesn't actually shut it off but diverts it into the block allowing the matrix to cool down but good luck on your venture :o

[mlkey]

all done by airflow? now that's a system to be seen water pipes go into the matrix so a valve is required to shut the hot water off ( diverter valve ) doesn't actually shut it off but diverts it into the block allowing the matrix to cool down but good luck on your venture ;)

 

Not the case I am afraid, as with many vehicles these days, diverter valves are not fitted, instead, the air is channelled differently within the heater unit. If you trace the pipework from the bulkhead, you will see they connect directly to the matrix, no valve/diverter. Think back to the old days, maybe a mini, where it took at least 30 seconds for the water in the matrix to cool when the valve was closed, the C5 takes only as long as it takes the motor to adjust the internal air flows.

 

And thanks for the good luck! :o

[techbod]

matter not up for debate, unless you know how the system works fully im not wasting time explaining it ( im not here to teach ) only help but good luck anyway :o

 

deleted that bit as its considered bragging ;)

[mlkey]

matter not up for debate, unless you know how the system works fully im not wasting time explaining it ( im not here to teach ) only help but good luck anyway ;)

and the mini ;) had a new one back in the old days £500 around there now im driving a £50k car that cost me £2k :o

 

Not debating anything, just giving you the facts... Even tells you the same in the new Haynes manual... ;)

[techbod]

been there seen it and done it :o

[DaveHerns]

been there seen it and done it :o

Mlkey,

 

Changing the subject a bit , is the Haynes manual worth the cost ?

 

Dave

[techbod]

is the haynes worth it? yes it is but my data is more to the soil ( auto data )

[mlkey]

Mlkey,

 

Changing the subject a bit , is the Haynes manual worth the cost ?

 

Dave

 

I would say yes, gives you much useful info that is not generally easy to find.. £20 well spent I think.