How do you change a cylinder head gasket?

Answer 1

When initialy reading this question, the first thing that comes to mind is why one would want to change the cylinder head gasket. Well, I must say, when I was faced with this question after buying a "Sparkling , good as new" second hand Matiz, I thought I was going diddly wing wang bang, when my daughter informed me that her newly acquired, lovely vehicle was "using" water. After the initial basic testing (which I should have done when purchasing the vehicle) I was horified to see the bubbles in the water resorvoir. Basics tell me, this means the vehicle was overheated at some stage, inflicting the damage I was witnessing.So, after this was diagnosed, I realised I need a workshop manual. This was a challenge in itsself, but I was able to get one at http://www.workshopmanuals.co.UK. Although this is a very comprehensive manual, it lacks some information, as admitted on the dowload page. Unfortunately this information includes fairly critical info like the head torque settings. Now, as anyone who has spent a Saturday, carefully removing all parts on a "foreign" car has found out, these settings are quite important when re-assembling an engine. Firstly, one needs to have a "Top gasket set". This transaltes roughly into needing a gasket for every item one has to remove in order to replace the head gasket. Now, seeing as I am from South Africa (no I am not a racist, I just live here "Viva Sprringboks), I first had to locate a dealer who stocks Daewoo spares."After a few cycles I was able to get most the spares I needed for the job at hand. The removal cycle went quite well and helped me identify other parts which needed replacement. The Matiz has quite a few aluminum water system elbows that do take stress after time. So it is a good idea to replace them while you're at it. Behind the engine, just above the alternator is a specific one that could give you hassles. It also links into the internal heater pipe. Now that is more or less the background. The head is now in your hands (hopefully). This is where your local, friendly, engineering shop comes into play. The head needs skimming. If you're not sure if the head is warped..........skim it. OK, this done, the engineering shop will also be able to check the valve guides, valve settings etc. While you have the engine "exposed", you might as well check the barrels for any wear. If so, replace the rings and the big end bearings. It will just simplify your life after another couple of kilometres(miles in UK).

And now it is more or less where I start loosing my mind. The manual I was able to download from the abovementioned website, does not include the torque settings for the cylinder head. Reminds me of a song a young man called Freddie Mercury once sang. "I'm going slightly mad". But that is another phase in my life. Back to the topic.I phoned the dealers in SA who deals in Daewoo (after they don't represent themselves here anymore) and I phoned th service centres for Daewoo and after phoning 7 different dealers, I got 7 different answers. They vary from 30Nm to 95 Nm. The best answer I got was from a very helpfull gentleman who suggested I do the following: 1st stage 30 NM, Second stage another 30Nm, last stage 90 degrees. This one makes the most sence to me so this is what I will be doing this Saturday.

Admittedly, I am not a mechanical engineer of trade, but I do try and assist my budget when it comes to motorcar repears.

Bottom line.This is a very nice, economical, affordable, vehicle which will carry you for miles. I know I am sold, so I hope tech info becomes more available on the net for the Matiz.

Watch the spanners on your toes.

Regards

Wouter

An extendedWhen initialy reading this question, the first thing that comes to mind is why one would want to change the cylinder head gasket. Well, I must say, when I was faced with this question after buying a "Sparkling , good as new" second hand Matiz, I thought I was going diddly wing wang bang, when my daughter informed me that her newly acquired, lovely vehicle was "using" water. After the initial basic testing (which I should have done when purchasing the vehicle) I was horified to see the bubbles in the water resorvoir. Basics tell me, this means the vehicle was overheated at some stage, inflicting the damage I was witnessing.So, after this was diagnosed, I realised I need a workshop manual. This was a challenge in itsself, but I was able to get one at http://www.workshopmanuals.co.UK. Although this is a very comprehensive manual, it lacks some information, as admitted on the dowload page. Unfortunately this information includes fairly critical info like the head torque settings. Now, as anyone who has spent a Saturday, carefully removing all parts on a "foreign" car has found out, these settings are quite important when re-assembling an engine. Firstly, one needs to have a "Top gasket set". This transaltes roughly into needing a gasket for every item one has to remove in order to replace the head gasket. Now, seeing as I am from South Africa (no I am not a racist, I just live here "Viva Sprringboks), I first had to locate a dealer who stocks Daewoo spares."After a few cycles I was able to get most the spares I needed for the job at hand. The removal cycle went quite well and helped me identify other parts which needed replacement. The Matiz has quite a few aluminum water system elbows that do take stress after time. So it is a good idea to replace them while you're at it. Behind the engine, just above the alternator is a specific one that could give you hassles. It also links into the internal heater pipe. Now that is more or less the background. The head is now in your hands (hopefully). This is where your local, friendly, engineering shop comes into play. The head needs skimming. If you're not sure if the head is warped..........skim it. OK, this done, the engineering shop will also be able to check the valve guides, valve settings etc. While you have the engine "exposed", you might as well check the barrels for any wear. If so, replace the rings and the big end bearings. It will just simplify your life after another couple of kilometres(miles in UK).

And now it is more or less where I start loosing my mind. The manual I was able to download from the abovementioned website, does not include the torque settings for the cylinder head. Reminds me of a song a young man called Freddie Mercury once sang. "I'm going slightly mad". But that is another phase in my life. Back to the topic.I phoned the dealers in SA who deals in Daewoo (after they don't represent themselves here anymore) and I phoned th service centres for Daewoo and after phoning 7 different dealers, I got 7 different answers. They vary from 30Nm to 95 Nm. The best answer I got was from a very helpfull gentleman who suggested I do the following: 1st stage 30 NM, Second stage another 30Nm, last stage 90 degrees. This one makes the most sence to me so this is what I will be doing this Saturday.

Admittedly, I am not a mechanical engineer of trade, but I do try and assist my budget when it comes to motorcar repears.

Bottom line.This is a very nice, economical, affordable, vehicle which will carry you for miles. I know I am sold, so I hope tech info becomes more available on the net for the Matiz.

Watch the spanners on your toes.

Regards

Wouter

Answer 2

To do this you need to drain the coolant and oil and take the rocker box and cylinder head off the engine to get to the gasket. You then replace the old gasket with a new one (you may need to use gasket cement also) and replace all the bits you had to take off and tighten up the bolts (these have to be tightened in a specific order to a specific tension). You then need to add new oil and coolant.

Note that a head gasket problem can pit the cylinder head surfaces and could be caused by a deformed cylinder head. If this is the case, then the parts will need to be sent off to be ground flat/resurfaced (this may change the engine volume) first.