I think it's time to change the valve seals in my 240D. She has about 280k miles on her and the oil consumption is a little more than I like. I've done multiple searches here and can't find a step by step procedure. My haynes book doesn't cover it at all.

So if anyone has the procedure for a 240D, I would appreciate it.

Joe

I think it is pretty much the same as the 5 cylinder.

I'm interested in seating in the new seals. I remember someone saying this was kind of tricky but I don't remember what the trick was...something about 2 notches....???

Joe

yes,,, you do need to be sure you get it down the right amount.. I think the real trick is to be SURE and use the plastic protectors which come with them so you do not score the inside of the seals with the very sharp edges where the channel in the threads are on top of the valves.
They do make an offset tool for pushing straight down on them with them under the cam.

Yes, apparently you can damage the new seals if you don't use the tool. Maybe the whole thing is self explanitory.

My 240D runs well but it has been using about 1 qt every 500 to 600 miles, especially when temps are at 90+. I do run it hard everyday at high speed (85 mph) which I think is where the governor limits the speed. I do get a little blue smoke on start up which I believe is indicative of bad seals.

thanks

Joe

The tool may make it easier to get them seated the right amount...
But I am sure that it is the thin plastic throw away tubes which protect them as they are installed...

240Joe,

Make sure not to drop a valve into the engine. The piston must be near TDC on the cylinder you are working on. This easy to figure out for a 4 cylinder but much harder on a 5 cylinder.

P E H

Yes, that would ruin my day. I'll get it to TDC on cyclinder 1 by setting the crank on 0 degrees and making sure the lobes are up on both number 1 valves. Then I'll find the cyclinder that just closed the exhaust and will be openning the intake. That cyclinder will be up at the same time as number 1. Off hand, I don't know which it is but suspect it is number 4. I'll then do both of those cyclinders.

Then I'll rotate the crank a whole turn and do the other two.

I understand you can loosen the nut on the valve a little and then feel it hit the top of the cyclinder if it is up.

Thanks for the reminder.

Joe

I have done a couple heads that were off the engine. I used a socket to drive them home, cant remember what size but dig around and find the one that fits just right on top of the new seals. Drive them down till the sound and feel changes. I ruined a couple the first time I did it but I had some extras as I was warned. they are cheap and they must go all the way down. Also on one I forgot to put in the rotater thingie so I had to take the seal back off which ruined another. be sure and use the little condoms as was mentioned above.

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

240Joe,

After you do the first 4 valves, only rotate the crankshaft ****1/2**** turn or the next valves you do will fall into the cylinder. You can do 2 cylinders at the same time without turning the engine. This is because when 2 pistons are at TDC (in a 4 cylinder engine), the other 2 are at BDC and 1/2 revolution will bring these 2 pistons to TDC. It doesn't matter where the cam lobes are because engine can be at the end of the compression or the exhaust stroke for the 2 cylinders you are working. In fact one cylinder will be at the end of the compression stroke and the other will be at the end of the exhaust stroke.

I forget the zundfolge of the MB 4 cylinder Diesel engine but you want do #1 and #3 cylinders in the firing order (NOT cylinder#3). Then turn crank 3200 mills (180*) and do the other 2 cylinders #2 and #4 in firing order (again not cylinder #2 and #4).

I think you can see how much harder it is to figure where the pistons are on a 5 cylinder, but you don't have to worry about that on your 4 cylinder.

Its been a long time since I did a valve guide job, but I think you can get to the valves by removing the cam follower.

P E H

This really sounds like a good excuse to pull the injectors and precombustion chamber and clean and set them.... easy to see that your pistons are up with them out...

Leather,

Do you know how hard it is to pull the pre-chambers? Even with the correct puller tool (how many people have one) it can sometimes be difficult or impossible to remove the pre-chambers.

I consider pulling the pre-chambers and injectors a waste of time and energy for a valve seal job.

P E H

You are never for pulling the precombustion chamber so that does not surprise me...

Leather,

You are right about me not wanting to pull the pre-chambers unless there is something wrong with them. Usually they last the life of the engine.

I doubt if any competent technician would suggest pulling the injectors and pre-chambers to do a valve seal job just to see where the pistons are.

I say again: If it ain't broke don't fix it !

P E H

I still say that due to the extreme importance of the ( seven ?) tiny holes in the precombustion chamber to the efficiency of the diesel and the fact that most people have engines with a lot of miles on them.... with no paperwork suggesting that the holes have EVER been checked for being plugged.... and therefor have no way of determining how many miles per gallon they might gain by doing the cleaning which the shop manual calls for... that once in a while an operation like the valve seals would be a good time to pull the precombustion chambers and see if any of that oil which was sucked down the valve stems caused any carbon build up in the precombustion chamber...

And speaking directly to your " if it ain't broke".... YOU DON'T KNOW IF IT IS BROKE OR NOT IF YOU HAVE AN OLD CAR AND IT HAS NEVER BEEN CHECKED.... So once in a while . on a critical interface like this, it would be smart to to the preventative checking and cleaning.