Valve adjustment

CONAN-J64 · 11-03-2004, 08:39 AM

I am new here. I just bought a 2005 Titan 4x2 SE King Cab.

The maintenance manual states that a valve adjustment has to be done if the valves become noisy. That's very scientific.

I have a F150 5.4, and an Explorer 4.0 SOHC. Both have self adjusting valves. I just bought a Buell Firebolt, in part because the twin engine has hydraulic lifters. I also own KLR 650 Kawasaki and an XT350 DOHC. These two require regular valve lash work. They both use the shim system. No tool is available to keep the valves opened so I have to remove the camshafts. It is a pain.

A couple a threads here mention the valve lash situation. Has anyone dealt with this yet? I plan to purchase a service manual but in the meantime I wanna know. I realize that car valve adjustments, when needed, are far apart, but this is a rather complicated job on a DOHC 32 V8. I love the truck, and the power train is a beauty, but my pragmatic mind is shaken.

I should have done my homework. Any feedback is appreciated.

bestatchess · 11-03-2004, 08:49 AM

Valve adjustment is accomplished by using a spacer of the appropriate thickness, selected from numerous different available spacers of different thicknesses. The manual calls these spacers "lifters".

Tom Roper · 11-03-2004, 09:47 AM

Quote:

The manual calls these spacers "lifters".

Those are the shims. Even on a 12,500 rpm Yamaha R1, the valve service interval has been extended to 26,000 miles.

In the case of the Titan for me, I'll trade it before it needs that service. Even if you don't, I'm not sure it ever will.

In any case, they don't usually get noisy. They usually get QUIET, until such time as they don't close, in which case the engine has a hard time trying to stay running at all.

The dynamics are this, when the valves close they pound on the valve seats, causing the valve stem to appear to elongate, closing up the gap on clearance.

4 valve per cylinder engines have more valve area, thus the valve lift and valve speed in inches per second are lower, extending life.

I'm not losing any sleep over this. A far bigger worry for me would have been if I had chosen the Toyota Tundra, with a rubber timing belt over an interference engine. I feel much more comfortable with the hi-vo silent chain in the Titan 4 cam engine.

*OnebadSE* · 11-03-2004, 09:20 PM

Never heard of having to adjust self adjusting hydrolic lifters, which is what's on the Endurance V8.

**loufish** · 11-03-2004, 09:43 PM

Quote:

Never heard of having to adjust self adjusting hydrolic lifters, which is what's on the Endurance V8.

I'm not sure about that, there's a lash call-out, never heard of hyd lifter/followers with a lash dimension...

Tom Roper · 11-04-2004, 02:24 AM

They are not hydraulic lifters on the Titan. Loufish is correct.

mjw357 · 11-04-2004, 04:41 AM

Quote:

Originally Posted by OnebadSE

Never heard of having to adjust self adjusting hydrolic lifters, which is what's on the Endurance V8.

don't have a manual, and I'm not a mechanic or automotive engineer, but why would an OH cam engine need lifters?

CONAN-J64 · 11-04-2004, 06:32 AM

Of course a DOHC does not have lifters, but the Buell motorcycle does.

Push rod engines, SOHC, and DOHC engines can have hydraulic lash adjustment systems, which is maintenance free. It is one of the many systems available out there. I was under the impression that the shim system was usually used on higher revving engines like motorcycles and small cars.

The Mustang Cobra has a DOHC 32 valve engine with hydraulic lash adjustments. So one does not exclude the other. It is a matter of choice at the engineering level.

With regards to the allowable play, I've read somewhere that it can open or close over time, depends on the engine. When the gap closes, the valves eventually remain opened, and burn as mentioned by Tom. It happened to me on a old water cooled VW engine. Conversely, the logic is that if the gaps open, the valves do not open completely over time and only power is lost, but there is no mechanical damage to the valve. I wonder if it is the case with the Titan. Also when the gap opens, noise increases accordingly. This brings me to the statement in the Nissan manual mentioning valvetrain noise increase which should induce a valve lash check.

I agree with Tom - it won't happen overnight.

While I work on industrial gas engines (project engineer - ignition), I am no valvetrain engineer either, so I don't pretend to know that part. I am just curious why Nissan picked one system over the other. I think the X-terra uses the hydraulic system.

rholland · 11-04-2004, 07:34 AM

I build and work on motorcycle engines for dragracing. I have done a lot of valve ajustments on these engines. The valves get tight not lose, from the valve seating deeper in to the valve seat caused by the edge of the valve rolling or deforming. On the bigger, heavier valves used in an automotive engine, this probably want happen very soon.

garo1 · 12-04-2004, 09:21 AM

Quote:

Originally Posted by CONAN-J64

I am new here. I just bought a 2005 Titan 4x2 SE King Cab.

The maintenance manual states that a valve adjustment has to be done if the valves become noisy. That's very scientific.

I have a F150 5.4, and an Explorer 4.0 SOHC. Both have self adjusting valves. I just bought a Buell Firebolt, in part because the twin engine has hydraulic lifters. I also own KLR 650 Kawasaki and an XT350 DOHC. These two require regular valve lash work. They both use the shim system. No tool is available to keep the valves opened so I have to remove the camshafts. It is a pain.

A couple a threads here mention the valve lash situation. Has anyone dealt with this yet? I plan to purchase a service manual but in the meantime I wanna know. I realize that car valve adjustments, when needed, are far apart, but this is a rather complicated job on a DOHC 32 V8. I love the truck, and the power train is a beauty, but my pragmatic mind is shaken.

I should have done my homework. Any feedback is appreciated.

Conan, can you tell me the page number of the manual you are looking at? I would like to read this too. My engine has slowly gotten louder and I have traced it back to the valve train. I only have 9000 miles on it and it gets so loud I've actually been asked by people that have pulled up beside me what the noise is. Mine comes and goes but is usually happening when I stop at a light after the engine is warmed up.

the head · 12-04-2004, 09:52 AM

Quote:

Originally Posted by rholland

I build and work on motorcycle engines for dragracing. I have done a lot of valve ajustments on these engines. The valves get tight not lose, from the valve seating deeper in to the valve seat caused by the edge of the valve rolling or deforming. On the bigger, heavier valves used in an automotive engine, this probably want happen very soon.

Ditto. Shouldn't loosen up - just get tighter.

HEMI-SMOKER · 12-04-2004, 11:58 AM

Quote:

Originally Posted by garo1

Conan, can you tell me the page number of the manual you are looking at? I would like to read this too. My engine has slowly gotten louder and I have traced it back to the valve train. I only have 9000 miles on it and it gets so loud I've actually been asked by people that have pulled up beside me what the noise is. Mine comes and goes but is usually happening when I stop at a light after the engine is warmed up.

I only have 3800 on mine and my engine has a lot of noise too. It sounds almost like a diesel engine sometimes. Especially at idle in gear.I was thinking loud injectors, but could it be valves. I hope not!!

Tom Roper · 12-04-2004, 05:03 PM

Quote:

Originally Posted by the head

Ditto. Shouldn't loosen up - just get tighter.

Dittos again.

*OnebadSE* · 12-04-2004, 08:18 PM

Quote:

Originally Posted by HEMI-SMOKER

I only have 3800 on mine and my engine has a lot of noise too. It sounds almost like a diesel engine sometimes. Especially at idle in gear.I was thinking loud injectors, but could it be valves. I hope not!!

Do what I do if I don't believe either the service dept of whomever, have them throw you the keys to a new one on the lot. Yours should be no louder than a new one. Have a noise or a shudder or a pull...etc?, drive a new one. Could be helpful, even if it just shows you that yours is normal. If not, you use it to prove to the dealer that you do in fact have a problem.

CONAN-J64 · 12-06-2004, 07:04 AM

Garo1, the paragraph about valve adjustment can be found 1 or 2 pages before the 1st service page (3750 miles) in the maintenance manual (sorry i don't have it with me, can't be more precise). You can also refer to the Service Manual, available online (Module MA, page MA-6, 9 of 30) - see note 5 on next page, or click on hot link to go to module EM, page 52 for detailed explanations.

The procedure for adjusting the valve clearances, if needed, is lengthy. And a special tool is needed if the distribution chains have to be removed. I can do it on a motorcycle, but I am sure I would attempt it on the Titan.