Valvetrain issues

[nino]

The other day my car starts missing badly and I initially thought it was the fuel pump because one had failed me recently and it felt the same when the pump went. Then I thought it could be my timing belt because its due for a change. I thought it might have skipped a tooth possibly.
I decided to go ahead and do the timing belt and hope once I got in there that everything would be ok and the timing wasn't off. Turns out the timing belt is fine and I changed it.

I also decided to adjust the valves because its already overdue :oops:. Well I think i found the problem. The last time I adjusted the valves I forgot to get new rocker plugs so I reused the old ones :oops:. Well they were disintegrating(!) and one on the firewall end of the head was basically gone. I assume all the air getting in there downstream of the afm explains it?

Anyways, besides that, one of the rocker shafts has slid towards the firewall but it was held by the locator key thing (which is slightly bent now). The other one looks like it might have slightly slid the other way.
What would cause this? How do I fix it? Will it happen again?

Be warned: I dont have much experience with engines, but Im learning. Here are some pictures. Thanks.

[E30_fiend]

First off, you need to replace those shaft plugs immediately. I think what is pushing the lock is the plug falling apart and pushing on that lock. Get new plugs, and clean the plug ports as well as you can thrn reinstall.

Second, YES YES YES those plugs being bad can cause unmetered air to be entering and exiting the motor whenever it pleases.

Fix it all and report back.


Taylor

[Ceeker]

^+1 like he said. hammer the locator flat and reinstall doesn't do much except hold the rods in place.

[nino]

Update: Ok got the rocker shafts pretty much back to normal, reinstalled the locator, new rubber bungs, new valve cover gasket, adjusted the valves, new spark plugs, etc etc. Getting ready to put the radiator and hoses back in and discovered the metal water pipe is rusty under the old hoses. Should I reuse this if I sand the rust off or should I replace it? Pictures:

[paperplane94]

Mine was about as rusty as yours. Just give it a light sand flush some water through and then flush the rest of the system with that prestone flush stuff. It'll do fine.

[FLG]

Its fine, wire brush, paint it, reinstall.

[nino]

Ok I've got everything buttoned up and it starts and idles fairly normally! I say fairly because while not rough it surges between about 600 to 800 rpm. Its a pulsating idle. Also the valves seem loud to me. Maybe its just me being paranoid though and not having the car running for a while. I know m20s have nosiy valvetrains. I should note that I'm flushing the coolant with some prestone coolant flush. Im letting it cool now and then flush with distilled water, then cool and fill and bleed with bmw coolant.

Ill see if I can get a video of the idle and valve sound.

My uneducated guess is that while I cured the massive vacuum leak from the rocker plugs, there is another smaller vacuum leak somewhere else in the intake. Maybe? Maybe I should just take the whole intake and intake manifold off and replace all the gaskets and hoses. Or maybe its the injectors or fuel pressure regulator or even the pump like I originally suspected (it is fairly new though). I dont really know.

[paperplane94]

You can have a smoke test run to pinpoint the source of a vacuum leak.

[delatlanta1281]

Icv?