Doing the Valve Guides, Help Me!

[jaymanek]

Hi All,

Now that winter is setting in, I feel its time to take another look at why my car likes to throw out a cloud of blue smoke on start up.
We did the valve stem seals but this made no difference so my mechanic and I are looking at the valve guides.
This time we will take the head off and do it properly.

So question 1 - Does anybody know what size guides my car should have? There seem to be various choices shown in the parts catalogue. Ideally we want to do the job in one Sunday.

Also can you guys help me compile a list of the parts I need?

So far off the top of my head:

- Valve Stem Seals (May as well change these again)
- Valve Guides
- Head Gasket
- Hardened Valve Seats to convert to Unleaded?
- Gasket Set (Exhaust Etc) - As shown on SLS website

Thanks in Advance

Jay

[stickandrudderman]

Jay, unless you've got access to a very friendly machine shop, you're not going to do it in one day.
The differrent guides are for oversize, but these are very rarely required, usually std is the ones you require, but I always let the machine shop tell me what size they want.
Once the new guides are installed the valve seats will have to be machined for correct angle/seating.

[ja17]

Hello Jay,

The valve seats installedat the factory since the mid 50's are  tough enough to us with unleaded fuels.

Consider changing the timing chain if it has never been done.

[jaymanek]

Ok so im not going to bother with the valve seats then, I have ordered the guides, head gasket set etc from SLS in germany as they are much cheaper than the dealer.

Thanks All

Jay

[Naj ✝︎]

Ok so im not going to bother with the valve seats then,

Jay

Hi, Jay,

You're going to hate me for this!

I would make this job a winter mini-project.
Back flush (do a search on how to) the cooling system before you start any dismantling.
Remove bonnet to make room.
Pull radiator and oil cooler and get them pressure tested and if OK repaint. Do the header tank at the same time.
Have the relevent pipes and brackets cleaned and replated. The water pipes, pulleys, battery tray and top clamp etc. blasted and powder coated.
Replace crank seal if any signs of a leak.
Replace water pump.
Refurb alternator and starter (your call)
Replace all the water hoses (and clips?)
Check engine mounts.
Clean up engine bay while all the parts are away.
Timing chain as Joe suggested
Replace all O rings and sealing rings that you disturb.
Replace Oil filter seals if not recently done.
Did I miss anything?

Car will be fit to Monaco or Italy for next spring!

Happy fixing
Naj

[jaymanek]

Thanks Naj,

My engine bay is very clean, I think someone has been around it before.

Im really scared about removing the bonnet, last time I caught the paintwork and as ive just had the front end re painted, im going to be really careful.
Any tips on how to take the tension out of the bonnet stay? I was planning on wrapping the bonnet in a couple of bed sheets and then using a ratchet strap to hold the bonnet stay back.

But ill definately be replacing anything that looks even half worn as we go along.

Thanks

Jay

[wbain]

Use painters tape, either blue or green as available from the paint supply house, on the edges of the bonnet/hood. Don't use masking tape as it leaves a residue.

Thanks Naj,

My engine bay is very clean, I think someone has been around it before.

Im really scared about removing the bonnet, last time I caught the paintwork and as ive just had the front end re painted, im going to be really careful.
Any tips on how to take the tension out of the bonnet stay? I was planning on wrapping the bonnet in a couple of bed sheets and then using a ratchet strap to hold the bonnet stay back.

But ill definately be replacing anything that looks even half worn as we go along.

Thanks

Jay

[DavidBrough]

Hi Jay,

I have a painters S hook used for holding tins on the rungs of a ladder and this works very well for me, just cover the ends in tape and hook it round the stay and the underside of the bonnet.

[stickandrudderman]

Cut out a piece of old plastic oil container to make a sheild, warm and shape to fit around the bonnet edge and tape in place. Use the painters hook and rely on the plastic sheild in case of accident!
Taking the bonnet off REDUCES the risk of damaging it as you have no chance of it slammimg shut accidentally and having a nice bulge where you left your wrench on the rocker cover! It also make the engine much more accessible.
I always run tape around the front of the bonnet aperture to prevent chips.

[jaymanek]

Hi All,

Well I got:

- Valve Stem Seals - From Mercedes
- Head Gasket Set - From SLS but is genuine Mercedes
- Valve Guides - From SLS but look OEM quality

Im going to remove the bonnet tomorrow and as soon as my trusted mechanic has time, he is going to come over to do the job...
If we need anything else then it can be ordered from Mercedes but as we recently did the valve stem seals we are pretty sure everything else is in good order as we renewed various bits and pieces at the time.

[wbain]

The technical manual for your car has all the mechanical data. There are standard sized guides and several oversize guides as well, complete with part numbers. The book is rather inexspensive and well worth it. Rather than beat the guides out with a hammer and drift, freeze them with liquid CO2 and they will come out easily, and the new ones will drop in too.

[jaymanek]

Thanks, ill mention it to my mechanic.

He is an "old school" mechanic and has ingenious methods for doing most things... He has a self made tool for pretty much anything specialised! He was a race engineer on the African Rallies.

[ja17]

Hello,

There is a factory hole in the side of the hood already for your "S" hook to hold the hood tension rod. A "S" hook from a rubber bungy cord  works perfect.