Valve adjustment: need help to decide, please

[Frank Langer]

Hi,

I am trying to ensure that I am doing all the maintenance needed to maintain my Universal 5416 diesel engine. The engine has 875 hours on it, but it was rebuilt at about 250 hours due to a major overheating by a previous owner. I have had it since 570 hours, and have been religious about oil changes, alignment, fuel filter and coolant replacement. But I don't know when a valve adjustment is needed, and how to tell.

The engine runs fine (though leaves a bit of soot on the transom). I don't want to mess with it unnecessarily. Can anyone tell me what the appropriate intervals are for a valve adjustment? Is there any way to tell if they need it--ie. symptoms of valves not properly adjusted?

Thanks for any advice on this.

Frank

 

[Greg Ross]

Servicing Instructions-

Page 30 of the Universal Diesel Manual I located stated;

VALVE ADJUSTMENT:
The best performance and life of the engine may be achieved by maintaining optimum valve clearances at all times.

Here's the link;
http://www.ewmanchester.com/CalDocs/Universal Diesel_5416_5424_Service.pdf

Also found this later manual, yours' would be an "M-20"
Still no specific interval indicated for valve adjustment.

http://www.westerbeke.com/OnlineManuals/200157_M12-M50_Operator_Man.pdf

Excessive mechanical noise? Valve train clatter?​

 

[rwthomas1]

Valve adjustment IMHO is a fairly simple task and should be done every 100hours or so, or as needed. The issue is you can't really be sure how often it needs to be done until you have some history on the engine performing the task.

For example: I have an old Mercedes diesel car. MB specs valve adjustment every 15K. My experience is that after 15K there is no need, every time I've checked at 15K the clearances are fine. Now I check at 30K and infrequently there is a minor adjustment needed. I maintain based on my experience with the vehicle over time.

Depending on how many hours you put on the engine, once a season or every other season may be reasonable. With 570 hours on it I'd say you are quite overdue. If the clearances are too tight the valves do not seat correctly. This can carbon up the seats, burn the valves and reduce compression. If the clearances are too loose there will be excessive play in the valvetrain, a chance of excessive wear and the valves will not open all the way causing a slight decrease in performance.

My preference on an engine that is overdue for valve adjustment is to set the clearance to spec if the valve was loose. If it was too tight I like to set the valve 0.0001 looser than the spec range. So if the manual called for 0.008 I would go 0.009 instead. My thinking always has been that a tight valve may have crud on the seats. Setting to spec will now let the valve wear in through the crud but end up too tight again. A 0.001 extra won't hurt anything.

The other key is finding out how out of spec the clearance is. If they are pretty close then adjust and don't worry about it. If they are way out of spec, say 0.0010 or more then adjust and check them again after 5-10hours.

Regarding valve noise, hard starting, etc. I've never really been able to diagnose a diesel just by listening to it. By the time its making enough mechanical noise to alert you to a problem its just too far gone. A diesel slightly "off spec" will still run and start reasonably well and you just won't hear the problem due to the injector and combustion noise.

Bottom line-adjust the valves. Its a pretty simple process.

RT

 

[Frank Langer]

Thanks for your very helpful replies. Aside from wrenches and a gauge, are any other tools or supplies needed for this job?

Thanks again!

Frank

 

[Greg Ross]

Besides tools and a feeler gage set.

Frank,
I would suggest you have a replacement valve pan gasket on hand, you might not need it but,

 

[Frank Langer]

Thanks for your advice, Greg.

Frank

 

[rwthomas1]

If your engine is like my 5432 then you will need minimal tools. Remove the valve cover, a combination wrench of the correct size and a flat screwdriver is all that is needed to actually adjust the valves. You just need a set of feeler gauges and the spec. Work your way aft forward, one valve at a time. There are two valves per cylinder, intake and exhaust. Rotate the engine by hand until the rocker of the valve you are not adjusting is depressing the valve. The intake and exhaust are never open at the same time so this will assure that the valve you are adjusting is on its base circle of the cam.

With that many hours a new valve cover gasket is mandatory.

RT

 

[Cory B]

Valve Adjustment

I did this last summer on our 5424 (3 cylinder). The engine had 1200 hrs on it, and this was probably the first time it was done. It was pretty easy (instructions above are right on - I also tried to err on the loose side as Rob did), and a couple of the valves were quite off according to the feeler guage - I went through and double and triple checked them all. I also had the nozzles tips replaced on the injectors at the same time, according to the shop they were pretty bad.

After I got everything back together, I expected to hear a smoother running engine. Nope, sounded exactly the same to my ear. But it was the right thing to do, and I like to think it helped the health and longevity of the engine.

 

[Tom Metzger]

Checking valve clearance

According to my Kubota service manual which covers many of the blocks used by Universal the service interval for checking valve clearance is 800 hours.

Yanmar GM series engines call for checking initially after 50 hours or one month, and then every 500 hours.

YMMV

 

[bob smith]

valve adjustment.

If the valves and seats were ground during the overhaul ,you usually have clearance changes as valves remove the sharp edges during grinding. So i think valves should be checked 50 to 100 hrs. after initial start up. (besides you can not adjust the valves to soon but you sure can to late). After first adjustment follow recomended intervils

 

[Frank Langer]

Thanks for all the helpful comments. I have ordered the valve cover gasket, and then we'll get going with it.

Frank

 

[mherrcat]

If I didn't want to tackle doing a valve adjustment myself, what kind of cost would I be looking at to have a mechanic do it?

What if it was more than an adjustment and the valves needed to be ground?

 

[rwthomas1]

If I didn't want to tackle doing a valve adjustment myself, what kind of cost would I be looking at to have a mechanic do it?

What if it was more than an adjustment and the valves needed to be ground?

I don't know your boat but I could probably do mine in an hour. Regarding the valves being "ground" that is a different issue entirely. I can't really imagine a situation that would have the valves so out of spec that you cannot adjust them, that did not also present itself as a very obvious problem first. I think maybe you have it confused with a valve job, which is essentially a top end rebuild of the engine needed only when the valve guides/seats are shot. This is usually diagnosed by low compression and burning lots of oil. Assuming that you have neither of these problems a valve adjustment is just basic maintenance. If you do not think you can handle it get a knowledgeable friend to help or pay a mechanic. While generally pretty easy to do, if you do screw it up it can get expensive.

RT