Valve Adjustment, but should I do stems as well?
 

Ok, just finished putting the Monarch Nozzles in my 300D and I really like how is just makes everything feel better.

So now its onto adjusting the Valves. I order some wrenches off of ebay and I am pretty sure I understand how to adjust the valves. But here are some questions.

1) To rotate the motor more easily, should I remove the glow plugs? Can I rotate the motor by the power steering pump bolt like the Diesel Giant write up says - especially if I remover the glow plugs?

2) While I have the valve cover off, should I replace the Valve Stems or are they simply a lot of works for little payoff? If I am to replace:
a) Do the rocker arms (set of 2) and (set of 3) just bolt on and off? Is there anything special about removing these and later reinstalling them?
b) Can anyone make more clear the procedures of replacing the valve stems - especially in regards to rotating the engine. What I understand (which is little) is that you need to remove all the the spring hardware from the valve, then replace the stem. BUT, if you remove the spring hardware for a valve and the piston is not at the top position, the valve will fall into the piston chamber? So how do you know if that piston is at its top positions?

3) While the valve cover is off, is there anyway to check the timing chain and if so, what am I really looking for? My mechanic says its fine, but I would like to check it as well.

Thanks
Doug

1983 300D (turbo)
170k.

There Valve Stem Seals. The Valve Stems are the cylinderical part of the Valves.

I will send some info on changing the Valve Stem Seals.

If you want to change them you could wait until the 2nd Valve Adjustment to do them.
Also read the DIYs and see which are the Best Valve Stem Seals to use. Some people have complained about the fit if some of the aftermarket ones.

DIY Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/

http://www.peachparts.com/Wikka/DoItYourSelf

You can rotate the engine with the power steering pump, sometimes you think it's not going to turn but just keep going, it will. But do yourself a favor, get a 22mm wrench to turn it with. Don't use a crescent wrench. Diesel giants DIY article is a great article for adjusting valves so follow that. You don't need to pull the glow plugs to adjust valves. Once you get the hang of it you can adjust the valves in 30 minutes. Including disconnecting and reconnecting linkages, etc. Oh, and drinking a cold one. :)

It's much easier to rotate from the crankshaft bolt. By easier, I mean you'll reduce the risk of slipping the PS belt, stripping the PS bolt, etc. The crank bolt makes it much easier to get enough torque to turn the motor. You'll need a 27mm deep socket. If you adjust each cylinder in the same sequence of the firing order, it goes pretty quickly.
Why do you feel that you need to change the valve stem seals? What symptoms are leading you toward that? Just playing devil's advocate... Want to see if they REALLY need replacing.

Here's the Timing Chain Stretch DIY. If you have a dial indicator, follow the first procedure. If you don't, jump down to the second one (the method using notches @ TDC).

I've never heard of any real issues being solved by replacing the valve stem seals.

When I have used the Powersteering Pump to turn the Engine (Glow Plugs out) I found I had to tighten up the Belt a little before I started.
When I was done I returned the Belt to the tension it had before.

Bump for the dieselgiant valve adjustment tutoral. It is easy if you go by that. Make a simple sketch of the intake and exhaust valves with the gap listed next to the valve. I put tape on one of my feelers and the same tape on the sketch to color code the process. Use a new cover gasket. The stem seals are probably fine. I wouildn't mess with them unless it was necessary.

X2..

And a person who has never done it before will absolutely drop a valve into the cylinder..........and be back on here crying about it.:eek:

With my SD, I used to have a problem with big smoke plumes (burning oil) out of the tail pipe when pulling away from a stop light or in stop and go traffic. I'm sure I got MF'ed many a time by the unfortunate drivers behind me. The old seals were in pretty bad shape, very brittle, and no doubt not doing much 'sealing'. Well, after replacing the valve stem seals that issue went away. I also noted a significant reduction in oil use between changes. Been 20k miles or so since the repair and I'm still in good shape.

I think seals should be replaced if they are causing issues.
I also think you should ONLY attempt changing the seals if you've read and re-read and re-re-read the instructions...
turning the motor, when the exhaust valve STARTS to open, the piston is dropping...

And if you do want to change the seals, change the rotocaps too.

It is probably a better idea to use the crank bolt but its such a bugger to get to, just how do you do it? Crawl under, rotate a little, opps not enough, back under, I have never had any problems using the P/S bolt, including getting the pulley off but if theres a better way i'm up for hearing about it.

a better way, is to use a starter jump switch... about 8.00 at any auto parts store, and the 123's and 126's have an easy panel on the fender to clip to!

Eh, I guess it's just personal preference. It's not a big deal to me to get down and turn the crankshaft bolt, and pop up periodically to check the lobe position. I figure that the work is sent to the crankshaft, and then sent to the power steering pump. I guess I just like the idea of maintaining that unidirectional flow of work, and maybe the motor likes it, too :)

Yah, I have one of those, but I,m still curious as to how its done with the crank bolt. It would be a good idea to check things out down there once in a while, I'm one of the folks that had a crank pulley come adrift once.:eek:

I dont think I have one of those panels on the fender of my 240D or my two Euro 123, NA cars either. I have hooked the switch up at the starter motor, pretty easy also.