Howto change a head gasket on a 12v 3ltr M103 - Page 2

Ian B Walker · 15-04-2008, 10:37 PM

Once the Cylinder head is unbolted lift on the exhaust manifold and break the gasket seal. Have an assistant help in lifting the head over the chain tensioner guide and wiggle the head out of the hose going to the thermostat.

This is what we found when the head had been removed. You can see where water has got into the cylinder, sorry the picture is poor but the gasket had eroded away around a 1/4 of the cylinder circumference.

Remove the head to a safe working location (i.e. bench) and remove the exhaust manifolds. be prepared for studs to shere. Use a 12mm spanner and socket for removal of nuts.

To remove a shered stud screw on two nuts and lock them together by screwing them against each other. Then with a spanner on the rear nut start to unscrew. They will come out, promise.

Ian B Walker · 15-04-2008, 10:47 PM

Take out all the sensors from the head and note where they are fitted. Remove the valves and lay them on the cardboard adjacent to the caps they belong to. (Lost a few pics here, will take some at work tomorrow and slot into the thread).

When the valves are removed the will look like the one on the left in the following photo. What we wish to achieve are all valves looking like the one on the right of the photo.

I put mine in a pillar drill and use some emery to remove the carbon deposit

Now that the head is bare, send it away to be cleaned up. This will cost approx £35 - 55, depending on your location. Get onto your local dealers and order up a head gasket, exhaust manifold gaskets, inlet manifold gasket, set of valve stem oil seals and a front upper timing cover gasket. Total cost in the region of £110 but money well spent. My head people supply me with new head bolts inclusive of the machining costs.

stats007 · 16-04-2008, 12:40 AM

How long has it taken so far? Big old valves there on the 12V!

big x · 16-04-2008, 01:04 AM

Thanx for taking the time to post pics Ian.

Years ago I changed the head gasket on a six cylinder BMW on my own. I lifted off the head with attached exhaust and inlet manifolds by standing on the suspension towers and keeping my back straight lifted it off.

Where did you get that nifty little slide hammer ? Most of the ones I've seen are to long and you have to remove the rad for access.

adam

Ian B Walker · 16-04-2008, 08:38 AM

Quote:

Originally Posted by stats007

How long has it taken so far? Big old valves there on the 12V!

Left alone and with everything to hand I can do a 103 head in about 7 hours.

Quote:

Originally Posted by big x

Where did you get that nifty little slide hammer ? Most of the ones I've seen are to long and you have to remove the rad for access.

adam

Found one in a local Motor Factors, measured it, made a few adjustments and made one.

grober · 16-04-2008, 09:28 AM

Great post Ian-- immortality beckons --- at least in MB circles.

Once everyone has commented and its tidied up--i.e. a few pictures of the cleaned up head +gasket etc and the rebuild details especially the timing chain tensioner reassembly sequence where many re-builders get it wrong and the "piece de resistance" -the completed rebuilt engine picture--- its should take pride of place in the HowTo section.

dka-66 · 19-10-2008, 12:05 AM

I just found the site, read through this post, and had to register so I could ask if there has been any progress on this and if there has if the poster going to give an update.

ps2cho · 19-10-2008, 12:30 AM

Hello UK from California!
Got sent this link by dka-66 above me

I'm doing my first head gasket job next week and I am sure this thread will see me through everything!

Gotta get the gasket done on my 1988 300TE M103 engine 90k miles.

Just wanted to say thanks for the thread!

ms500 · 19-10-2008, 01:35 PM

If only the M104 was as simple

nick mercedes · 19-10-2008, 01:50 PM

Quote:

Originally Posted by ps2cho

Hello UK from California!
Got sent this link by dka-66 above me

I'm doing my first head gasket job next week and I am sure this thread will see me through everything!

Gotta get the gasket done on my 1988 300TE M103 engine 90k miles.

Just wanted to say thanks for the thread!

Don't forget that you can leave the manifolds in situ, there's no real need to take them off.

dka-66 · 19-10-2008, 06:38 PM

Quote:

Originally Posted by nick mercedes

Don't forget that you can leave the manifolds in situ, there's no real need to take them off.

I heard it was a real pain to pull the head with the manifolds still on.

nick mercedes · 19-10-2008, 07:20 PM

Quote:

Originally Posted by dka-66

I heard it was a real pain to pull the head with the manifolds still on.

Just lift it up.

Putting the head back needs two people to line it up.

If you strip everything off it you're just making work for yourself.

coupe deville · 19-10-2008, 08:53 PM

well done mate, good job, I wouldn't tackle that for immortallity in a french knocking shop

ps2cho · 22-10-2008, 11:35 PM

Quote:

Originally Posted by nick mercedes

Don't forget that you can leave the manifolds in situ, there's no real need to take them off.

Ok I'll take your advice!

I start tomorrow evening

I have a oil pump seal to do as well....with the head off...how much more time would I be looking at to get at the seal?

dka-66 · 13-11-2008, 11:13 PM

Finally got around to pulling the Head today and all I have to say is "Thank you"

I printed this out and kept it on the Fender.

Ian B Walker is my personal savior

15-04-2008, 10:37 PM	#16
Ian B Walker Hardcore MB Enthusiast Threadstarter Join Date: Jun 2003 Location: Kirkham Car: 300-24, E220 Coupe, E220 saloon, 190D Posts: 7,912	Once the Cylinder head is unbolted lift on the exhaust manifold and break the gasket seal. Have an assistant help in lifting the head over the chain tensioner guide and wiggle the head out of the hose going to the thermostat. This is what we found when the head had been removed. You can see where water has got into the cylinder, sorry the picture is poor but the gasket had eroded away around a 1/4 of the cylinder circumference. Remove the head to a safe working location (i.e. bench) and remove the exhaust manifolds. be prepared for studs to shere. Use a 12mm spanner and socket for removal of nuts. To remove a shered stud screw on two nuts and lock them together by screwing them against each other. Then with a spanner on the rear nut start to unscrew. They will come out, promise. __________________ *Guaranteed MB OEM parts fitted* 124Works: I am listed here on MBClub please click to see services and discounts available.

15-04-2008, 10:47 PM	#17
Ian B Walker Hardcore MB Enthusiast Threadstarter Join Date: Jun 2003 Location: Kirkham Car: 300-24, E220 Coupe, E220 saloon, 190D Posts: 7,912	Take out all the sensors from the head and note where they are fitted. Remove the valves and lay them on the cardboard adjacent to the caps they belong to. (Lost a few pics here, will take some at work tomorrow and slot into the thread). When the valves are removed the will look like the one on the left in the following photo. What we wish to achieve are all valves looking like the one on the right of the photo. I put mine in a pillar drill and use some emery to remove the carbon deposit Now that the head is bare, send it away to be cleaned up. This will cost approx £35 - 55, depending on your location. Get onto your local dealers and order up a head gasket, exhaust manifold gaskets, inlet manifold gasket, set of valve stem oil seals and a front upper timing cover gasket. Total cost in the region of £110 but money well spent. My head people supply me with new head bolts inclusive of the machining costs. __________________ *Guaranteed MB OEM parts fitted* 124Works: I am listed here on MBClub please click to see services and discounts available.

16-04-2008, 12:40 AM	#18
stats007 Hardcore MB Enthusiast Join Date: Aug 2003 Location: Hampshire Car: 575M Posts: 6,348	How long has it taken so far? Big old valves there on the 12V!

16-04-2008, 01:04 AM	#19
big x Hardcore MB Enthusiast Join Date: Aug 2004 Location: somerset Posts: 1,259	Thanx for taking the time to post pics Ian. Years ago I changed the head gasket on a six cylinder BMW on my own. I lifted off the head with attached exhaust and inlet manifolds by standing on the suspension towers and keeping my back straight lifted it off. Where did you get that nifty little slide hammer ? Most of the ones I've seen are to long and you have to remove the rad for access. adam

16-04-2008, 09:28 AM	#21
grober Hardcore MB Enthusiast Join Date: Jun 2003 Location: Perth SCOTLAND Car: E220 COUPE Posts: 8,968	Great post Ian-- immortality beckons --- at least in MB circles. Once everyone has commented and its tidied up--i.e. a few pictures of the cleaned up head +gasket etc and the rebuild details especially the timing chain tensioner reassembly sequence where many re-builders get it wrong and the "piece de resistance" -the completed rebuilt engine picture--- its should take pride of place in the HowTo section.

19-10-2008, 12:05 AM	#22
dka-66 New Member Join Date: Oct 2008 Location: Houston, TX Car: 300TE Posts: 9	I just found the site, read through this post, and had to register so I could ask if there has been any progress on this and if there has if the poster going to give an update.

19-10-2008, 12:30 AM	#23
ps2cho Member Join Date: Oct 2008 Posts: 31	Hello UK from California! Got sent this link by dka-66 above me I'm doing my first head gasket job next week and I am sure this thread will see me through everything! Gotta get the gasket done on my 1988 300TE M103 engine 90k miles. Just wanted to say thanks for the thread!

19-10-2008, 01:35 PM	#24
ms500 Banned Join Date: Jun 2008 Posts: 342	If only the M104 was as simple

19-10-2008, 08:53 PM	#28
coupe deville Hardcore MB Enthusiast Join Date: Aug 2008 Car: 93 E320 coupe sportline Posts: 482	well done mate, good job, I wouldn't tackle that for immortallity in a french knocking shop

13-11-2008, 11:13 PM	#30
dka-66 New Member Join Date: Oct 2008 Location: Houston, TX Car: 300TE Posts: 9	Finally got around to pulling the Head today and all I have to say is "Thank you" I printed this out and kept it on the Fender. Ian B Walker is my personal savior

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