230CE Valve Adjustment

[Gizzardio]

Hi

I had to replace my rocker / valve cover gasket and thought whilst I was in there I'd check the valve clearances on my 1983 W123 230CE. I believe the engine reference is M102.980. It's the 2.3 litre in that model anyway. The service manual I have found shows the valve clearance values on cold engine for inlet and exhaust as 0.15mm and 0.30mm respectively. So I went in the feeler gauges but I can't understand where this gap should be. In the manual it shows the location as between the rocker arm underside and the top of the valve spring cap. But there is no gap here at all even with my smallest feeler gauge. It feels like there wouldn't be a gap there as the spring is pushing under compression up onto the rocker arm in any position of the cam. Any ideas what I should be looking for here?
Thanks

 

[Bellow]

as the spring is pushing under compression up onto the rocker arm in any position of the cam.

That cannot be the case. The cam train always acts on the tip of the valve - never ever on the spring cap. If it did, the collets would fly and the valve drop.

 

[pcthrillrider]

the gap should be under the camshaft lobe on top of follower the camshaft pointy bit upwards

 

[Gizzardio]

Hi

Thanks for replying. What I meant was where this diagram indicates to feel the gap below, there was no gap I could tell. Even my smallest gauge would not pass. So I was thinking that with the valve fully seated, the spring would still be in compression pushing upwards, and seemingly touching the rocker arm 'tip' underside against tip of the valve stem. I was just scratching my head. Unless my valves are so badly gapped that whoever's done it before has left no gap in the position below?

 

[Bellow]

Go very slightly above where those arrows are pointing.
Arrange the cam to check whichever valve, push/pull the rocker arm towards the cam. and at the other end there will be a gap beneath the tip of its adjusting screw and the valve's tip. If not, someone before you has adjusted it out and it needs reinstating.

 

[190]

In the first instance forget the feeler gauge and where it goes. On the valve to be checked grab the rocker arm with your fingers and rock it to feel if there is any movement. It's what every mechanic does before he inserts the feeler gauge to check he is on the correct valve.

It's very easy to feel a gap of that size as you try to rotate the rocker arm back and forth. If you can feel no clearance at all then either you are checking the wrong valve ( the manual should provide guidance but easy solution to start with is try all of them) or the clearance has closed up due to lack of correct maintenance.

Once you can feel the clearance it should be easy to insert a feeler gauge in the correct place, in fact look carefully enough and you will see where the gap is as you rotate the rocker arm back and forth.

 

[Gizzardio]

Thanks guys. I'll try as you said and see how I get on.

I watched a 280CE valve gapping video and that was the gap between the cam itself and the valve tip as it acts directly without rocker arms in that case which makes sense to me.

 

[optimusprime]

What problems are you having ? are you hearing a tic tic sort of noise ..Your M102 is a smaller version to the M103 .With hydraulic tappet compensators that take up the gap . If its tapping then these need changing out for a set of new ones 8 in total .

 

[optimusprime]

This is the hydraulic tappet compensator and how it works .

 

[Gizzardio]

Hi, this seems strange to me as mine look exactly as in my diagram with the screwthread and locking nut. They don't look like those above in the hydraulic type diagram you sent.

In terms of problems, there wasn't anything significant but I just thought whilst I have to change the cover gasket, I'll check the gappings and opened up a can of worms all over myself. But I'm learning. There is a tapping sound but not so massively loud. Part of me is - if ain't broke don't fix it, but I was advised to check the gaps whilst inside this area as it's a serviceable item. I may end taking it in to my local specialist

 

[optimusprime]

Gaz your right But i tend to do jobs that dont need doing and find another one in the process . What is the engine in your car ? Your picture shows its not the same type as i had in my mind .And yes they are adjustable but to do it you need the setting sequence where you turn the crank so the camshaft is in the right place to check each of the tappets like check no 4 with 6 rocking etc .

 

[Gizzardio]

i assumed it was this. It looks like mine, has the same power output, matches my model and year.

 

[ray_hennig]

If its tapping then these need changing out for a set of new ones 8 in total

We decided to replace these on mine as the engine was apart. 35 quid each. And mine has 24 of them!

Luckily your 8 should not be so painful.

RayH

 

[optimusprime]

Ray po has the M102 in a W123 the engine is a push rod with tappet adjustment on ther top. Yous is like mine other than 24 valves ..no adjustment other than shims in the buckets ours have hydraulic tappet compensators . i only used 12 on my in line 6 cylinder . Yes expensive for the 24 you hjad to buy .

 

[Bellow]

Hi, this seems strange to me as mine look exactly as in my diagram with the screwthread and locking nut. They don't look like those above in the hydraulic type diagram you sent.

Then they are adjustable and should be checked and adjusted as required.
Ignore the hyd stuff - needless distraction helping no one.

In terms of problems, there wasn't anything significant but I just thought whilst I have to change the cover gasket, I'll check the gappings and opened up a can of worms all over myself. But I'm learning. There is a tapping sound but not so massively loud. Part of me is - if ain't broke don't fix it, but I was advised to check the gaps whilst inside this area as it's a serviceable item. I may end taking it in to my local specialist

It is so easy on an engine like this. Just arrange the cam such that the lobe is directly opposite the tip of the arm who's valve you are checking.
There is no need to cross-reference other valves. Just tackle them individually with the rocker arm on the lobe's base. You'll have it done faster than you can arrange an appointment with a specialist.

 

[optimusprime]

Yes the problem is turnning the engine to get the tappets in the right place to use the feeler gauge and set each gap you need to know the inlet valve from the outlet valves they have two settings do you know how to adjust them ?..Have you done any before ?.

 

[Gizzardio]

I bought the workshop manual for my car and engine and here's all the info I think I need in the pic.

 

[Gizzardio]

Happy to say I readjusted everything and all is good. Super smooth. Thanks for everyone's input. I got there in the end.