4cyl sohc head gasket
 

hi

my son's car needs a new head gasket (yeah, and probly more...)
its a 230te body but the engine has been replaced sometime last century.
so i took off the rocker box cover. lots of mud!
i also took off the thermostat housing and i notice tstat seems to be stuck wide open.... hmmm.
this donk has a single row timing chain and psteering pump on the front end of the camshaft.
i,m guessing the best strategy is to pull the head, exh mani and injection manifold off in one unit.
can anyone help me with the timing chain and how to get it off (erm, and back on...)?
i see the head bolts easily accessible either side of the camshaft but peering down the timing tunnel i can see some big allen screws. i think there are three.
i'm a newbie when it comes to merc engines but i'm looking forward to the experience:dizzy2: btw what a GREAT website. took a bit of finding tho...

cheers from peter vk6fun beckenham western australia

Thats a M102 engine. the "power steering pump" you refer to is actually the hydraulic suspension pump.

undo the exhaust manifold at the head and move it aside and loosen the 6mm allen bolts holding the intake to the head and to the bracket underneath and push it back as well. One of the easier head gasket jobs to do on MB's.
good luck.

Set the engine to TDC by rotating the crank pulley, take off the chain tensioner located right below the alternator. Mark sprocket, chain and cam shaft then take off the sprocket from the cam shaft. Don't let chain drop to the crank shaft but put it in the chain 'box'.

There's also a long hex bolt by the sensors and one at the rear of the engine. you also need a 6mm puller for the pins holding the top chain guard rail.

It's easier to unbolt intake manifold from head to minimize unplugging too many parts.

There is a dyi article on this site on how to replace timing chain. Different engine but the same principle.

Goodluck.

thanx for your quick replies! sounds fairly sf. its after midnite here in perth so i'll be into it tomorrow. i've been reading a few other posts in the archive and getting a good feel for the main issues.
any other tips are greatly appreciated.
the forecast is for another 40C day yippee

gnite for now from vk6fun

here in indiana we would kill for a 40F day.

it was 9 F today. the last week it has been mostly colder than that!

tom w

how do i get the sprocket off the camshaft???
also, the inlet appears to be held on by 4 studs with two brackets on top which also bear the injectors.

24mm open wrench at the back ot the shaft to hold it and use whatever size wrench for the bolt. you have to take off all bolts holding the head down. if you decide to take off the intake manifold, take off all bolts holding it to head. there are a few bolts holding the intake to the block, take those off so you can pull the manifold from the head (you need a little play to clear the studs). NOTE: there is a hex bolt by the cold start injector. there is a matching bolt on the same vertical line right below the intake manifold.

Dont force anything off with crowbar! a hard tug usually is all you need. if it doesnt come off increase strength accordingly after ascertaining no bolt is holding the part down.

Before putting things together dont forget the torque specs on all bolts.

without a service manual there are just too many things to take off and unplug. i suggest separating the intake from the head if can't wait for a manual.

as after thought, drain the coolant, radiator and block. to drain block there's a bolt under 3rd exhaust manifold.

ok thanx. so far so good.
manifolds are off, the tricky camchain slider thingy is out, the engine is at tdc, a dob of paint so chain goes back on the right tooth and the camchain is off the top sprocket and hanging by a wire from above.
i still can't figure out this cam sprocket. There is this hydraulic suspension pump thing on the end of the camshaft which i have unbolted by 2 bolts but it still wont come off the end of the shaft. The timing sprocket appears to be an integral part of the camshaft! There is a o-ring between the sprocket and the hydraulic pump where the shaft exits the rocker-box that i dont want to damage it.

still having fun

peter vk6fun beckenham Westoz

If you're talking about the pressure oil pump, then it has to come off. No need to disconnect the hoses. I don't have one but I think it has 4 bolts taken from the front.