Valve Adjustment - drives better /sounds worse

[Birdie]

This evening I performed a long awaited valve adjustment on my stock m10.  My first time.

I recorded the current clearance of each valve - they were consistently .0055 (.005 to loose / .006 too tight).

I set them all to the 'proper' .008.  Started the car up and almost immediately I could tell that the car was running better than before.

I also noticed that one of the valves was making a very loud clicking.

 

Before jumping right to "what should I do?" let me offer up some context in case it is helpful.

- the car sat for almost 2 decades before I bought it last year.

- I have spent the year bringing it back to life.

- I drives great and I put between 100 - 200miles a week on it... every mile with a grin.

- it has always emitted pretty strong exhaust fumes - no smoke to speak of.

- the spark plugs were fouled. I replaced them and within a day the new one showed identical fouling: both the oily threads and flaky electrodes (not each plug the same as the other but we can shelf the specifics until someone suggests it is useful) 

 

Hopefully this is enough information for someone to suggest some direction or ask more questions. If further information is needed please let me know as I am happy to oblige.

 

Okay what should my next steps be?

Isolate the clicking valve and return it to its previous clearance? Any tricks for isolating the loose valve?

 

[Son of Marty]

My recommendation is to drive the car hard for a couple of hours and then getting a set of go-no=go feeler gauges the reset the valves with the .006-.008 gauge making sure the rocker arms are off the cam ramp completely.

Edited May 18 by Son of Marty

[Birdie]

@Son of Marty Thanks for the prompt reply.

To clarify, I did use feeler gauges to first document the existing gap (.005 go / .006 no go) and then set those gaps to .008. Therefore, are you suggesting that the clicking may subside after a few hours of driving - if it does subside, problem solved? However, if it doesn't subside, then I should double check my work and repeat the valve adjustment process, double checking that the rocker is completely off of the cam ramp? Lastly, I am confused by your specification for .006-.008. I was under the impression that I should set them all to .008. Why do you mention a range of clearances? thanks.

 

[7502]

BMW offered a valve range 006 to 008 as marty mentioned.  First thing I wold do is re-check the gaps, and go from there.

Eric

[Whitesell]

What carb are you running?

 

[Birdie]

7 hours ago, Whitesell said:

What carb are you running?

 

Weber 32/36 (guess I’m not totally stock huh?)

Edited May 18 by Birdie

[Birdie]

8 hours ago, 7502 said:

BMW offered a valve range 006 to 008 as marty mentioned.  First thing I wold do is re-check the gaps, and go from there.

Eric

It would be great to get some context/reasons why these suggestions have been made. I want to start planning for "go from there".

 

I guess what I am still trying to understand is: If when I head out to the garage this morning to check the gaps, if all gaps are .008

a) is there some mechanical scenario where - as Son of Marty suggests - I drive it for a time and it will 'change'.... ie something is stuck because of the previous clearance setting and it will possibly unstick? If so please explain.

b) if I find that at .008 one of the rockers is looser than the others - do I simply tighten the gap on that valve immediately. ie - while all others are fine at .008 this one will forever be tighter? If so please explain.

c) obviously if I find that my workmanship yesterday was subpar and one valve is greater than .008 then I will delete this thread in shame.

 

thanks.

 

btw - @7502 my Friday night valve adjustment was planned around my son's visit home from Bellingham (he graduates in a few weeks) and we are going to spend the day working on the car. He is Engineering and much better all such things than myself so I need to get as much done as possible before he leaves again.

 

 

 

[gracer]

As previously stated, BMW specified clearance between .006" and .008".

I set mine to a tight .008 so that I have to drag the feeler gage out.  Then I check the clearance with the .007" gage.  It should slip in without any drag.

[TobyB]

If you recheck a few times after a few drives, and the measured clearance stays where you set it,

pull the noisy eccentric- 

chances are, it has a flat spot, and I'll bet some (if not all) of its friends do, too.

 

t

 

[Son of Marty]

The reason for the drive is referred to as a "Italian tune up" driving the car hard will help keep the carbon deposits from the valve face so after letting it cool down your setting the valves that are well seated. It maybe a old wife's tale but I found that BMW designed the m10 to work hard and a good hard drive seems to make them run better.

[Mike Self]

4 hours ago, gracer said:

As previously stated, BMW specified clearance between .006" and .008".

I set mine to a tight .008 so that I have to drag the feeler gage out.  Then I check the clearance with the .007" gage.  It should slip in without any drag.

An excellent way to do it.  And remember, a clicking valve isn't a burning valve.  Better they be a thousandth or so loose than too tight.  The clicking sound you hear may be something as simple as

• a valve you didn't quite adjust correctly (or one you just missed)
• a worn rocker arm
• a flat spotted eccentric adjustment disk or one that the bolt won't tighten properly
• you've actually run out of adjustment due to rocker/shaft/disk wear.  Ireland (and others) make oversize adjusters if you encounter this.  More prevalent on early cars that don't have bushed rocker arms.

Go for the easy first--check each one for proper adjustment and that doesn't uncover the noisy valve then start checking for wear.

 

mike

[popovm]

7 hours ago, Birdie said:

c) obviously if I find that my workmanship yesterday was subpar and one valve is greater than .008 then I will delete this thread in shame.

 

 

 

Nope, not aloud. 😁 Posting about something mundane that’s tripping you up is a right of passage. One of my first threads was after I broke down and got a tow home. I couldn’t figure out the no-start. It turned out one of my wires to my coil had worked its way out on an uphill and was unhooked. Plugged it back in and I was good to go. I am learning something from this thread, btw. I have yet to do my first valve adjust and there is lots of good knowledge here I’ll be keeping in mind. 

['76mintgrün'02]

I use .006" and .008" feelers as go/no-go.  I did it a year ago, before taking a 3K mile road trip at 4K rpm most of the way.  I'm tempted to check them again.

 

 

I made a wooden handled eccentric turning tool out of an Allen wrench.  The feelers I've been using are brass.  I used the two-valves-at-a-time technique, doing the intake and exhaust valves that are completely closed.  The note pad shows which ones pair up, using triangles, circles and squares.  It also shows how I found them. 

 

I'm glad I found this photo, because I'll pay attention to the number three intake, to see if it's loose again.  I'm sure my eccentrics have flattened bottoms.  I should have a look at the underside next time.

 

Tom

[Mike Self]

23 hours ago, '76mintgrün'02 said:

I made a wooden handled eccentric turning tool out of an Allen wrench. 

Much more elegant than mine, made from a long 8d finishing nail, properly bent with the point filed flat.  I actually like yours better as you can't drop it down through the oil return hole.  Gonna make a handle for mine!

 

mike

[Birdie]

I am happy to report that by the end of the weekend - with all of the helpful advice from 2002faq - my car seems to be running better than ever.

 

I drove the hell out of it first thing Saturday morning. That afternoon, I verified/adjusted the valves again. Indeed, 2E was a bit over .008. As well, it was nearing if not at the limit of it's eccentric. It was pretty tough to get it much tighter.

 

I also, really appreciated the triangles, circles and squares method illustrated above. I had previously gone cylinder-by-cylinder and in hindsight was not as confident that I was 100% on the heel of the cams. However, on the redo adjustment, using the triangles, circles and squares method I was much more confident that each valve was in the optimal position for adjustment.

 

I will also be making a valve adjustment tool like the one above. I am not sure how everyone on Youtube, etc does this with a coat hanger and it was pretty tough with just an Allen wrench in my hand - maybe it's because I have maxed out my eccentrics and the adjustment hole was approaching the head wall. Therefore, said tool would allow me to adjust the eccentric pushing from the inside of the head toward the outer wall - just like the picture above. A much better line of force.

 

Lastly, I did have to adjust the carb a bit to get everything smoothed out. 

 

If you are new here and wondering if you should do a valve adjustment - the answer is a resounding yes. A very fun and straight forward project with the help of the folks here at 2002faq. 

 

Thanks for all the input

Edited May 25 by Birdie