Valve Adjustment Questions
 

I'm going to adjust my valves this weekend, it'll be my first time (1989 911 3.2). I'm following the process in the Bentley manual as I can't find my 101 Projects.

Questions -

1. Do I need any special tools other than the special valve feeler? I'm particularly wondering if I should go buy a special stubby screwdriver or wrench to work on the less accessible cylinders.

2. I had to run the motor for 3 minutes this morning, to turn the car around in the garage. I know the valves have to be adjusted cold. How many hours should I wait for the engine to be "cold enough"?

3. I'm also doing some other service stuff while I'm at it. Here is the current list of tasks for the weekend - please suggest any other routine maintenance tasks I should do while I am in there. Current plan: adjust valves, replace valve cover gaskets, replace and gap plugs, replace rotor, replace plug wires (Clewetts), change oil (Mobil 1 20W-50) and oil filter (Mahle), change air filter. Am I missing something?

The car has been driving somewhat poorly in the last few months - slight stumbling at low revs/open throttle, and seems down on power. I want to get it back on form, and to start getting ready for AX season. I also have to pass a smog check this month. It has been about 20K miles since the last valve adjustment and about 10K since the last oil/filter change.

Good luck to you. Take your time and be patient.

Try this thread: http://forums.pelicanparts.com/showthread.php?s=&threadid=207455&highlight=450kno toffice

"It has been about 20K miles since the last valve adjustment ..."

That's a long time as you know. It'll run much better after a proper valve adjust.

John,
I would check to make sure the fan belt is in good shape and is adjusted properly with the right number of pulley shims, etc. Wayne's book is good on this and I think Bentleys may have good info. too.

An offset wrench makes the valves a little easier, and replacement blades for your feeler tool

yes, a schtubby screwdriver is good for the intakes and sometimes one of those Z shaped offset screwdrivers is needed on the lower left side, under the converter if you can't get your schtubby in there.

Hi John,

I would recomend if you are using the feeler gauge holder that has "screws w/nuts" is to use Loctite on the nuts!

The last thing you want to do is go hunting for one of those little nuts when doing a valve adjustment....don't ask how I know.

Have fun! Not everyone will try to do a valve adj.

I use a remote starter switch that connects to the starter so I can rotate the engine while under the car. They are cheap and worth the effort.

How the heck does this work if you can't see the hashes in the fan pulley? Doesn't it make the engine turn way faster than you could keep up?

jyl: The most important tool I can recommend is patience. :D

Might as well change the fuel filter and spark plugs while your in there too....and as was already mentioned check the condition of your belts.

an offset 13mm box end wrench and a short stubby screw driver has worked the best for me. also a small mirror might be helpful when getting into the top #3 & #6 w/the feeler gauge.

VaSteve, you don't necessarily have to use the hash marks on the pulley, they are just a convenience. I don't. All you have to do is make sure you are on the heal, backside or base circle (whatever you want to call it) of the cam when you are adjusting. A quick tap on the switch from under the car and I can put the cam exactly where I want it. I find this much easier than trying to figure out if I am on the right cylinder and valve for the right hash mark. This way I never have to crawl out from under the car and rotate the engine from above.

Paul, it's too bad you're so far away, I would love to come over and see how you do it. :) I'm ccertain it would end in disaster for me.

I just finished my first valve adjustment on my car. I've only owned it a few weeks but it was due an adjustment. It is not really that bad as long as you have some mechanical inclination. I've yet to start my car since the valve adjustment since I found out my plug wires were pretty bad. I'm about to order a maintenance kit and plug wires from pelican. Just make sure you can move the feeler guage without too much force, and that the rockers have no up and down play with the feeler guage in. Always double check yourself. Put the job off if you are sick. I had a sinus infection that didn't help matters. When I bent over my nose would stuff up more and sometimes it would run when my hands would be occupide. Okay too much info.....:rolleyes:

Finished But - Well, Not So Good
 

I finished the valve adjustment yesterday and installed the new plugs and wires today. I like the Clewett wires, look nice and fit well once I drilled out the Beru wire holders.

The valve adjustment was terribly confusing on the first cylinder then got much easier. In retrospect I would have started with an exhaust valve from #4-5-or-6 as those are easily visible. Anyway I aimed for a smooth drag when pulling the feeler through the gap, and I only found 3 or 4 valves that seemed "off", typically these were too loose. The car fired right up and now has appreciably less "clickety clickety" noise while running.

My old plugs looked okay for #2-6 as far as I can tell, while #1 was rather oily - bummer. I'll post pics later for those who know how to "read plugs".

HOWEVER - the car is not running appreciably better, in fact it is running rather worse. Specifically: at idle and low revs there is occasional "popping" (kind of like a faint backfire sound, but it's not really a backfire). The engine doesn't run smoothly at idle and low revs, sort of stumbles and hesitates, just a little - a passenger might not notice it. When sitting in neutral, if I give it a lot of throttle from idle, the revs get to 2000 and sort of hesitate before heading on up to redline - rather than quickly zinging to redline. There's a spot around 2500-3000 where the engine shakes a little. The car also feels well down on power - at 4000 rpm in first at full throttle the car is accelerating briskly but you'd hardly call it impressive.

Unfortunately I'm headed out of town on business for a few days, and will have to figure this out upon my return.

Any guesses? My thought is that perhaps I failed to fully seat a plug or perhaps more likely a plug connector, so that one cylinder is not firing properly.

Go after the obvious points first..just as you mentioned in your last two sentences...

If you find out you need to do it again....there might be an easier way by rotating the crank at 240 degree intervals ( instead of 120)..that way you get to work on "one side" of the car at a time...insted of jumping back and forth across the engine using 120 intervals.

Wil

Since you seem to have adjusted the valves properly, my guess is the plug wires (including the coil wire) and or the distibutor cap. What you're desribing sounds more ignition related than valve related.

I'd recheck all the wires and the cap and rotor. Who knows...you might even have a crack somewhere in a plug wire, which would cause erratic firing of that plug and sometimes even cause an adjacent plug to fire out of sequence.

Let us know how it turns out.

I didn't change the distributor cap or rotor - the contacts on these didn't look so great even after a bit of sanding, so I may have to place another Pelican order.

Definitely do the rotor and dist. cap.
Then you've replaced the whole circuit from rotor to plug.

Well, things are okay. I went through the plug wires and found #2 wasn't seated on the plug - pulled it off with a pinky finger, and the engine sound didn't change - so after I re-installed it, I went for a drive and the car now feels normal. No more hestitation, revs quicky/smoothly to redline, normal power is back - feels better than it did before the major service/valve adjust but that could be me imagining things.

I may have to redo the valve adjustment, though - one cylinder seems to be noisy, think it is on the left side (#1-3) so access will be easy. Perhaps it is #1 since I had so much trouble with that one the first time.

Tested the old plug wires and #5 was bad (infinite resistance). The others were all 2,600-3,000 ohms. The coil wire was almost zero reistance (<5 ohms), not sure if that is normal.

I've put the longest of the old plug wires and the old coil wire in the "emergency spares" part of the car's toolkit. Any reason to hang on to the other wires or their connectors? This sounds like a dumb question, but I am cheap enough that I'm always looking for a reason not to throw something away . . .

go over the valve adjust again, now that you have some experience.