Son of a.... screwed up my valves. Help!

1985 325e 5spd

Hello all,
Greetings from the land of stranded after getting in to deep with my daily driver. I did a valve adjustment tonight, but apparently I got it all wrong- I started it up and was greeted with some very loud valve clatter. Way too loud and angry to drive. Getting to work tomorrow will be interesting.

So, I'm not sure what to do. I am scared of diving in again unless I know what to look for. What are the common things to screw up on a valve adjustment? I thought I had them all at TDC and with a slight drag on a .010 feeler gauge. Is anyone in the west Chicagoland area looking for something to do tomorrow night and want to help me get this sorted out?

what TDC did you have it at? id have to research it, but there are two TDCs, one on the compression stroke and one on the exhaust stroke. iff the top of my head, you need to do it when both the cam sproket and crank sproket have their respective lines pointing at a little line on the block, its roughly the 1 oclock position on the crank, and 11 oclock on the cam, but i havent done it for several years now.

i assume couve researched the procedure???

whatever you do, DONT drive it to work tomorrow

On an overhead cam engine the lobe on the cam for the valve that you are adjusting should be pointing up. The valve must be completely closed to adjust it.You will have to keep turning the engine over by hand each time you move to a different valve but at least will can get it done . I mark mine with chalk on a paint stick as I go so that I know what I have adjusted.

Originally Posted by john@eac

On an overhead cam engine the lobe on the cam for the valve that you are adjusting should be pointing up. The valve must be completely closed to adjust it.You will have to keep turning the engine over by hand each time you move to a different valve but at least will can get it done . I mark mine with chalk on a paint stick as I go so that I know what I have adjusted.

On our M20 engines, with the lobe pointing up, the valve is OPEN, not closed. You want the lobes of both valves on the cylinder where you're adjusting the valves to point DOWN toward the head. Turn the crank until both cam lobes on cylinder #1 are pointed toward the head. Adjust those two valves (0.012" cold or 0.010" at operating temp), turn the crank 1/3rd of a turn (normal running rotation) and the valves on #5 will be ready for adjustment. Set those valves, turn another 1/3rd and #3 will be in position for adjustment. Repeat and #6 comes up, then #2 and finally #4. It takes two revolutions of the crank to set the valves.

And remember, you set the valve lash on the adjuster end, not the cam contact end.

Originally Posted by hornhospital

On our M20 engines, with the lobe pointing up, the valve is OPEN, not closed. You want the lobes of both valves on the cylinder where you're adjusting the valves to point DOWN toward the head. Turn the crank until both cam lobes on cylinder #1 are pointed toward the head. Adjust those two valves (0.012" cold or 0.010" at operating temp), turn the crank 1/3rd of a turn (normal running rotation) and the valves on #5 will be ready for adjustment. Set those valves, turn another 1/3rd and #3 will be in position for adjustment. Repeat and #6 comes up, then #2 and finally #4. It takes two revolutions of the crank to set the valves.

And remember, you set the valve lash on the adjuster end, not the cam contact end.

Listen to Horn grasshopper, and some day you will leave the nest.

Originally Posted by john@eac

On an overhead cam engine the lobe on the cam for the valve that you are adjusting should be pointing up.

This is completely wrong! The cam on an M20 actuates the valves via rockers. The lobes should be pointing down when adjusting.

Originally Posted by nedfunnell

1985 325e 5spd

Hello all,
Greetings from the land of stranded after getting in to deep with my daily driver. I did a valve adjustment tonight, but apparently I got it all wrong- I started it up and was greeted with some very loud valve clatter. Way too loud and angry to drive. Getting to work tomorrow will be interesting.

So, I'm not sure what to do. I am scared of diving in again unless I know what to look for. What are the common things to screw up on a valve adjustment? I thought I had them all at TDC and with a slight drag on a .010 feeler gauge. Is anyone in the west Chicagoland area looking for something to do tomorrow night and want to help me get this sorted out?

.10 what? mm or " ? I assume you did a cold adjustment? Did you rotate the cam for each cylinder to it's respective flat spot prior to adjusting the eccentric?

I did my last adjustment by feel. I know, I know a big big NO NO. But that was 5k miles ago. It still hums like a sewing machine and runs really well. But when I used the feeler gauge and did it by the book.. go to start it and its louder than when I started.
( I've had 3 other e30's so I know the correct procedure to do it, just this car was not cooperating.)

Once the valves are correctly adjusted do a compression test, just in case you have bent something.

Newman & those that do not know this
All followers are ground a eliptical shape
with time, wear & lack of maintenance the cam wears a dish into it.
Should you then stick your feeler gauge between lobe & follower you will not take this ground out hollow into effect & get noise
maybe even big noise
New followers or I just resurface them if they are not too bad
Just want to mention this, as it gives the fits to many mechanics.
Therefore I only give a guarantee on a reground cam if we regrind the lifter too, or new ones get installed !