Valve adjustment results

[DieselFiend]

I had this annoying rattle at certain RPM and an idle tick so, just for piece of mind, I decided to check the valve lash this weekend. All the exhaust valves were in limits. 2 and 5 intakes were out by at least . 005. I tightened them down to . 010 like the manual says. The truck seems to run better. I've still got an idle tick but it's not nearly as loud as it was before. The rattle at certain RPM is hardly audible now. I'm surprised that a couple valves that weren't out by much could cause that much noise.

 

[steved]

I had this annoying rattle at certain RPM and an idle tick so, just for piece of mind, I decided to check the valve lash this weekend. All the exhaust valves were in limits. 2 and 5 intakes were out by at least . 005. I tightened them down to . 010 like the manual says. The truck seems to run better. I've still got an idle tick but it's not nearly as loud as it was before. The rattle at certain RPM is hardly audible now. I'm surprised that a couple valves that weren't out by much could cause that much noise.

HAHA! I did the same thing this weekend... night and day difference in noise! I also picked up the power I had felt I lost as well as a few MPG... All of mine were "within spec", but after adjusting them to 0. 010" and 0. 020" respectively, all I can say is I wished I had done it sooner!!! I had almost 94k on the truck.



I also did dad's 99 while we were wrenching... I had a reputable Cummins shop adjust the valves once before... it was about 100k ago... found all the valves on the very loose side and one intake set better than 0. 020"!!! Needless to say it runs MUCH better now!!



steved

 

[Joseph Donnelly]

A lot of shops use an . 008" and . 012" geuge and call anything between close enough to . 010". Similar thing with the . 020" spec. It is much better to set all valves right at the same clearance, with the same drag on the feeler gauge on each one. That evenness is more important than being exactly at . 010 or . 011, for example.

 

[mhenon]

I just did mine at 93K even though the manual says it will go to 150K. Big difference in the chatter. . especially when it warms up. Sounds like it's running in butter now... very smooth.

Mike

 

[nickleinonen]

A lot of shops use an . 008" and . 012" geuge and call anything between close enough to . 010". Similar thing with the . 020" spec. It is much better to set all valves right at the same clearance, with the same drag on the feeler gauge on each one. That evenness is more important than being exactly at . 010 or . 011, for example.

and if you want to be completely anal about the lash, get a dial indicator and set it that way... [or set one that way, then feel how it feels with a feeler gauge]

 

[Tryingit]

Is it hard to adjust the valves? Does any one where I could find some detailed instructions. Thanks

 

[gsbrockman]

Does any one where I could find some detailed instructions. Thanks

From Ye Olde Service Manual :



STANDARD PROCEDURE - VALVE LASH

ADJUSTMENT AND VERIFICATION

NOTE: To obtain accurate readings, valve lash measurements

AND adjustments should only be performed

when the engine coolant temperature is less

than 60° C (140° F).

The 24–valve overhead system is a “low-maintenance”

design. Routine adjustments are no longer

necessary, however, measurement should still take

place when trouble-shooting performance problems,

or upon completion of a repair that includes removal

and installation of the valve train components or

injectors.

(1) Disconnect battery negative cables.

(2) Remove cylinder head cover (Refer to 9 -

ENGINE/CYLINDER HEAD/CYLINDER HEAD

COVER(S) - REMOVAL).

(3) Using the crankshaft barring tool #7471–B,

rotate crankshaft to align damper TDC mark to

12:00 o’clock position.

(a) If both number one cylinder rocker levers are

loose, continue to next step.

(b) If both number one clylinder rocker levers

are not loose, rotate crankshaft 360 degrees.

(4) With the engine in this position, valve lash can

be measured at the following rocker arms: INTAKE

1–2–4 / EXHAUST 1–3–5. Measure the valve lash by

inserting a feeler gauge between the rocker arm

socket and crosshead (Fig. 32). Refer to VALVE

LASH LIMIT CHART for the correct specifications. If

the measurement falls within the limits, adjustment/

resetting is not necessary. If measurement

finds the lash outside of the limits, adjustment/resetting

is required.

VALVE LASH LIMIT CHART

INTAKE EXHAUST

0. 152 mm ( 0. 006 in. )

MIN.

0. 381 mm (0. 015 in. )

MIN.

0. 381 mm (0. 015 in. )

MAX.

0. 762 mm (0. 030 in. )

MAX.

note:

If measured valve lash falls within these

specifications, no adjustment/reset is necessary.

Engine operation within these ranges has no adverse

affect on performance, emissions, fuel economy or

level of engine noise.

(5) If adjustment/resetting is required, loosen the

lock nut on rocker arms and turn the adjusting screw

until the desired lash is obtained:

² INTAKE 0. 254 mm (0. 010 in. )

² EXHAUST 0. 508 mm (0. 020 in. ) Tighten the

lock nut to 24 Nm (18 ft. lbs. ) and re-check the valve

lash.

(6) Using the crankshaft barring tool, rotate the

crankshaft one revolution (360°) to align the

damper TDC mark to the 12 o’clock position.

(7) With the engine in this position, valve lash can

be measured at the remaining rocker arms: INTAKE

3–5–6 / EXHAUST 2–4–6. Use the same method as

above for determining whether adjustment is necessary,

and adjust those that are found to be outside of

the limits.

(8) Install the cylinder head cover (Refer to 9 -

ENGINE/CYLINDER HEAD/CYLINDER HEAD

COVER(S) - INSTALLATION).

(9) Connect the battery negative cables.



Mine were as follows at 42k miles (August 2006) :



Cylinder #1 Intake : . 007 Exhaust : . 016

Cylinder #2 Intake : . 014 Exhaust : . 014

Cylinder #3 Intake : . 013 Exhaust : . 021

Cylinder #4 Intake : . 015 Exhaust : . 016

Cylinder #5 Intake : . 011 Exhaust : . 013

Cylinder #6 Intake : . 012 Exhaust : . 013



I'll most likely re-check mine again in another 40k miles or so.



After the adjustment, I could tell a tad different exhaust note..... but, the big difference is the ability of the truck to pull the same hill I see frequently in 6th gear... . at 1100 or 1200 rpm the truck pulled better under the load of the hill.



Greg

 

[Briman]

Please correct me if I'm wrong. I have always set any valves I have adjusted to the min. allowable lash limit. So from what Greg posted that would be . 006 intake and . 015 exhaust. Why did you use . 010 and . 020 Steve? I realize too tight equals burnt valves, at least on a gasser, yet I have never burnt any valves adjusting to the tight tolerance. It seems to me the tighter the better in regards to performance and noise. I have not set the valves on my truck yet and it is over due at 92K. I will do them soon.

 

[cerberusiam]

Please correct me if I'm wrong. I have always set any valves I have adjusted to the min. allowable lash limit. So from what Greg posted that would be . 006 intake and . 015 exhaust

The min and max are extremes that are affected by temps and are what is expected if the normal set specs are followed. Setting at the bottom of the range is dangerous as you run the chance of piston meeting valve. The general rule is you can 2 thousandths less than posted specs and be pretty safe but more than that you are running a risk.

 

[steved]

Please correct me if I'm wrong. I have always set any valves I have adjusted to the min. allowable lash limit. So from what Greg posted that would be . 006 intake and . 015 exhaust. Why did you use . 010 and . 020 Steve? I realize too tight equals burnt valves, at least on a gasser, yet I have never burnt any valves adjusting to the tight tolerance. It seems to me the tighter the better in regards to performance and noise. I have not set the valves on my truck yet and it is over due at 92K. I will do them soon.

That is what my 2004 and 2001 FSM both state... they give the acceptable range, then state to set the intakes at 0. 010" and the exhaust at 0. 020" if needed...



I also figured out what happened with that one valve that was way loose on the 99... I had a Cummins shop do the adjustment last time. He was using two feeler guages a 0. 010 and a 0. 020, both on rod handles, not the typical backyard mechanic's fold out style. I feel he simply picked up the wrong guage when he set that valve.



steved

 

[Tryingit]

Thanks greg for the information. Oo.

 

[Briman]

I adjusted mine today. All but one of the intake valves were at . 013, the other one was . 014. I found the exhausts to be pretty consistent as well at . 023. I set them to . 008 intake and . 018 exhaust. I have to agree that the valve train noise is greatly diminished but could not tell any seat of the pants difference in performance. I'm curios what the performance guys are using for clearance, assuming a stock deck, piston height, and valve train dimensions. The "performance" side of my brain wanted to go to the tight side of the tolerance but the "don't break it" side of my brain won out. In the 70's one of my drag racer friends was setting his solid tappet motor 2 thousandths tighter than the minimum spec. It was a Ford.



I forgot to mention that I used the alternator pully hold down bolt to turn the engine to TDC.

 

[CumminsBu]

What about retorqing the injectors down I heard this help clean up some of the noise.

 

[Turbo1Ton]

I see where the service manual states that the coolant temp should be less than 140 F to check and adjust the valves.



My concern is just the opposite, I was going to try and run the valves this morning but it is like 45 F outside. I'm just concerned about setting them while that cold and them being too tight once it warms up. Anyone have experience with this?



Thanks,



Jeff

 

[Briman]

I did retorque one side of the injector hold down bolts. They were just a little loose. In other words, the torque wrench handle moved very little. To get to the other hold down bolt you have to take out the exhaust valve rocker assembly. I didn't want to spend the time. I'll do that when I get new injectors.

 

[Tomeygun]

I had this annoying rattle at certain RPM and an idle tick so, just for piece of mind, I decided to check the valve lash this weekend. All the exhaust valves were in limits. 2 and 5 intakes were out by at least . 005. I tightened them down to . 010 like the manual says. The truck seems to run better. I've still got an idle tick but it's not nearly as loud as it was before. The rattle at certain RPM is hardly audible now. I'm surprised that a couple valves that weren't out by much could cause that much noise.

I just got done with my valves. Nothing WAY crazy but all but two of them were off - I had only 2 that were within . 001. The one that was most off was an exh that was at . 013



Afterwards I did notice the idle much smoother, not so lopey as if was before. Before it sounded like a had a slight rod knock. Now that is about 70% gone.



A road test showed that the low end seems to have gained a little. Seems like I could lug it down further and still pull right out.



Anyway, its worth the time, IMO



BTW - One tip, take it out of gear when you are turning the motor over by hand, Its much easier that way :-laf :-laf

 

[Briman]

Tomey, did you set them to the recommended . 01 and . 02? I'm glad to hear that your exhaust anomaly was . 013. That's a couple thousandths tighter than close tolerance spec and apparently you weren't having piston clearance problems. I want to set mine to the minimum specs but still don't have enough info to go ahead with it.

 

[Tomeygun]

Tomey, did you set them to the recommended . 01 and . 02? I'm glad to hear that your exhaust anomaly was . 013. That's a couple thousandths tighter than close tolerance spec and apparently you weren't having piston clearance problems. I want to set mine to the minimum specs but still don't have enough info to go ahead with it.

No piston slapping that I noticed... But I would not set them tighter then . 020 - I actully set mine a tight . 020. I mean I the . 019 went in very easy, the . 020 was a quite tight. I just tried to make them all the same.



The ones that were a bit tight already (like the . 018 would not go, but . 019 would), I left those as good.

 

[Cattletrkr]

As someone who knows how to turn a wrench, but has never seen the underside of a valve cover, how hard of a project is this? Will I be able to tell which is intake and which is exhaust?



I had mine done about 30K ago and I wouldn't mind doing it myself soon. Dad's '03 has over 80 and they've never been checked that I know of. Might be a fun snowy saturday afternoon project.

 

[Tomeygun]

As someone who knows how to turn a wrench, but has never seen the underside of a valve cover, how hard of a project is this? Will I be able to tell which is intake and which is exhaust?

Haha, Funny you ask. I wondered the same thing, Then I tried the . 010 in a few valves passenger side and none would go. It made sense that the valves on drivers side were the intake, and the passenger side the exhaust.



If not, well... at least I know it will run with them switched