Rotate engine for valve adjust w/no access to lower nut? Ideas?

911Freak · 11-07-2009, 10:49 AM

Hey Pelicans

I'm doing a valve adjustment on my 1980 3.0 (930/08)

Problem is I can't get access to the nut on the main pulley to rotate the engine because this 3.0l came with A/C and thus there is little to no clearance between the engine mount bracket and the double crank-case pulley to get the 26mm socket attached?!

Bentley, 101 projects and Haynes simply state to use a 26mm socket to access this nut and rotate engine, however they offer no recommendation for an alternative

I have been trying to use the upper pulley (alternator/fan) but with the resistance from compression the belt slips

I'm sure a pelican out there knows a solution

Thanks in advance

Tigerrat · Tigerrat's Garage

Usually squeezing the belt together while turning alt. nut works. I think I used a work glove to avoid getting pinched. You could push on one side with an open end wrench too. Ken

sailchef · sailchef's Garage

you use the nut on the alternator not the crankshaft, and pinch the belt like tigerrat explained

Christien · Christien's Garage

Yep, that's the way I always do it. Just swab some glue around the pulley to hold the belt.

Just hold the belt to the pulley with your finger - doesn't take much pressure to stop it from slipping.

Walter_Middie · Walter_Middie's Garage

Put the car in gear and push it.

911Freak · 11-07-2009, 11:34 AM

Got it, Thanks guys!!

Canada Kev · 11-07-2009, 12:41 PM

Is the belt tight enough? Mine is, but it still needs a bit of a pinch. When I did my first valve adjustment, the belt was way too loose, so I needed to move some shims around. This gave me the opportunity to take a closer look at my belt. It was cracked a bunch on the inside. Time to replace. Maybe it's telling you something?

911pcars · 11-07-2009, 01:14 PM

Connect remote starter switch to the starter solenoid and bump the engine into position. Make sure the ignition is OFF.

Sherwood

Rob B · 11-07-2009, 04:40 PM

Pull the spark plugs first! Rob

docrodg · 11-07-2009, 04:51 PM

Pull plugs, bump engine. Then should be able to turn belt to final position.

911pcars · 11-07-2009, 10:00 PM

Quote:

Originally Posted by docrodg

Pull plugs, bump engine. Then should be able to turn belt to final position.

The "final position" doesn't have to be TDC. As long as the rocker arm for the cylinder is contacting the heel of the cam. That's the area the valve remains closed to adjust clearance.

While the engine can rotate easier with the plugs removed, leave them installed.
This reduces the chance of carbon flakes dropping off and temporarily lodging between valve and seat.

Sherwood

Brando · Brando's Garage

For the fan pulley nut, use a shorty extension. To turn the engine over, pinch the belt then turn clockwise. DO NOT TURN COUNTER-CLOCKWISE!

Formerly Steve Wilkinson · 11-08-2009, 04:36 AM

Rob's right. Pull the plugs. Way easier to do valve adjustment with the plugs out.

Gunter · Gunter's Garage

911Freak,

Along with valve clearance, I usually make sure that the rocker shafts haven't moved and check the torque on the head studs with a long 10mm Allen socket.

If you take the plugs out, you can check them for gap and condition.

pete3799 · pete3799's Garage

I wouldn't pull the plugs before doing a valve adjustment.
If you do you risk dislodging carbon build-up that could get trapped under a valve and
affect your adjustment.
Chances are it won't happen, but why risk it.

john walker's workshop · 11-08-2009, 07:21 AM

Quote:

Originally Posted by pete3799

I wouldn't pull the plugs before doing a valve adjustment.
If you do you risk dislodging carbon build-up that could get trapped under a valve and
affect your adjustment.
Chances are it won't happen, but why risk it.

this is correct. the engine will turn over with the alternator nut easy enough if you push in firmly on the right side of the belt as you turn the pulley with the wrench.

Gunter · Gunter's Garage

Yeah, never take the plugs out even if you need new ones after 50k Miles.

Every now and then, a thread appears like: Help, cannot get plug out.

Reason? Carbon build-up on the plug end. It'll move for a couple turns and then seize. It'll take some force to get it out. The danger here is that damaging the threads is quite possible because the plug is steel and the heads are ALU alloy.

If the plugs are left in for too long undisturbed, it might cause problems.

What to do?

IMHO, Nothing wrong with taking them out now and then to check condition, gap and carbon build-up.

bcgreen · bcgreen's Garage

Gunter, I bet you don't see many P cars in your town?

TheSt|G · 11-04-2014, 03:33 PM

Quote:

Originally Posted by bcgreen

Gunter, I bet you don't see many P cars in your town?

5 years later, he might not even have it anymore...

The cap'n · 11-04-2014, 03:34 PM

NEVER remove the spark plugs before you adjust the exhaust valves! There's a good chance you'll dislodge bits of carbon, and a very good chance (Murphy's Law) some of those bits will end up on a valve and/or seat, throwing off the adjustment. I recommend a remote starter button and watching for individual valves to fully open, adjusting the opposite valve each time that happens. As for the intervals, I would never run a spark plug in a 911 for more than 15K miles, especially in a turbo.

The Cap'n