M20 Valve Adjustment DIY Guide

[richardb]

How to adjust the valves on your M20. Super easy, just takes a little patience.

https://youtu.be/9tyT6YhHWH0

[dnguyen1963]

Why do you feel the need to post the same video in four different threads? This topic has been covered many times here. Slow day?

[shoshottz]

i dont mind it, if there is anymore resources on valve adjusment plz link me.

[Idrisu]

i dont unsterstand what you mean by having it top dead center and where are the camshaft lobes?

[TobyB]

on the camshaft....


t

[dnguyen1963]

i dont mind it, if there is anymore resources on valve adjusment plz link me.

https://www.youtube.com/watch?v=tkkKGcDXnz8

[digger]

i dont unsterstand what you mean by having it top dead center and where are the camshaft lobes?

another way to do it is

adjust/check the inlet just as the exhaust valve on the same cylinder starts to open.
adjust/check the exhaust just as the inlet valve on the same cylinder closes

i remove the fan clutch and shroud and use a ratchet from the top on crank nut

[estoguy]

When I started doing mine not long after I got the car, research online suggested the easiest way was to have the lobes for the cylinder you're working be positioned in an upside down V over the valves - this is relative to the head and valves. This way, there is no tension on either the exhaust or intake side and you can check both on the same cylinder at the same time. You can test it by giving the rocker arm a shake. You should feel just a hint of movement and should hear a faint click when you do it. I start with cylinder one, then proceed by firing order. I use the "transmission in 5th and turn a jacked up rear wheel" method to rotate the engine. About a 1/4 to 1/3 turn of the wheel will get you to the next cylinder in firing order.

This method has never steered me wrong.

[dnguyen1963]

When I started doing mine not long after I got the car, research online suggested the easiest way was to have the lobes for the cylinder you're working be positioned in an upside down V over the valves - this is relative to the head and valves. This way, there is no tension on either the exhaust or intake side and you can check both on the same cylinder at the same time. You can test it by giving the rocker arm a shake. You should feel just a hint of movement and should hear a faint click when you do it. I start with cylinder one, then proceed by firing order. I use the "transmission in 5th and turn a jacked up rear wheel" method to rotate the engine. About a 1/4 to 1/3 turn of the wheel will get you to the next cylinder in firing order.

This method has never steered me wrong.

This is an upside down V. I don't think that you really mean this position over the valve?



It should be this direction.

[estoguy]

Sorry... a little unclear... both cam lobes combined should create an upside down V over the valves. This takes the load off both rockers at the same time, making it possible to check both clearances at the same time.

From a BF thread I bookmarked way back:

"You want to hit the spot where play will be greatest, and adjust it at that point. I typically adjust at the point where both lobes are pointing down, since that saves me the trouble of rotating the engine for each valve. So I rotate six times instead of twelve. When both lobes are pointed down, you are TDC for that cylinder, since both valves are as closed as they will be and the piston is at the top of travel.

Edit: I see how you got confused now lol. When I said upside down V, I'm talking about both lobes, not just one. If you were to draw a line straight through and out the point of each lobe, the two together would describe an upside down V at tdc."

Page 75 on Google of the 101 Performance Projects for your BMW 3-series, shows a pic of the camshaft and what that "V" is supposed to look like.

[digger]

it is possibly to adjust both in/exh at the same time but the window of opportunity is smaller so a novice may get it wrong

[whodwho]

The easiest way is use the diagnostic connector with jumper wires (or convert/make a remote starter with pins) and bump the starter as needed.

Instead of trying to see the lobes under the cam look at the opposite cylinder of the firing order and they are on the top and easier to to view.

Firing order - 1-5-3-6-2-4

Just split to match up pairs
1-5-3
6-2-4

Easier way to remember
1-2-3
6-5-4

So
1-6 XOOOOX
2-5 OXOOXO
3-4 OOXXOO

Use diagnostic connector pins - 11 & 14

[whodwho]

OP, you should replace your head bolts, the old hex ones were know to break and wipeout the head.

[estoguy]

OP, you should replace your head bolts, the old hex ones were know to break and wipeout the head.

I dunno about that... I only learned about the hex bolts a little while ago... my E30 Eta has been running for 30+ years and almost 450K km. I've put almost 225K km on it in 3.5 years... If they haven't yet, I don't think they will.

[whodwho]

I didn't say they would just that they are known to, I have replaced a couple heads from it in the past. For $20 in bolts I wouldn't gamble on it.