Valve adjustment

[Mike Nunn]

would one or more of you please give me a little insight as when to have the valve adjustment  done on the c9 400 hp or perhaps the answer is not to do it. As far as the engine Manuel recommends we are probably some past the mileage. We have about 40,0000 miles. No engines issues that I am aware of and fuel is same as it  has been.
I am just really reluctant to let anyone fix anything that's not broken. Thanks mike

[Dave Atherton]

Mike, let me give info. stright out of Cat Service manual ( valve Settings ) Recommend valve
check after first oil change. Valve Lash Check, an adjustment is Not Nessary if the measurement
of the valve lash is in the acceptable range. Acceptable Range For Valve Lash.
Intake ( ,015 + -, .003 )
Exhaust ( .025 + - .003 )
If measurement is not within this range adjustment is nessary. food for thought Look real close
at task at hand. (under bed is there enough room to get at all valves ) Second there is a Cat
way to set valves and valve bridge. before start correct setting of valve on engine via of Pin
lock to flywheel on engine at number 1 cylinder. many people set valves but I would have a
Cat Dealer check valve adjustment than adjust if nessary. there is lot of miss understanding
about valve clearance and adjustment. Dave Atherton Retired Cat Mechanic

[Joel Ashley]

One of the "aftermarket" service schedules I was given at BCS when we bought our coach says valve lash adj. every 10,000 miles.  But I've since taken that to mean "upon the first 10.000 miles".  That schedule was not specific to our coach or a C9, but meant for general purpose diesel motorhome reference.   My CAT manual recommends after that initial 10k check, do it every 100,000 miles, 15,000 gallons of fuel, 2000 service hours, or 2 years.  If you know whether or not the initial one was done, great.  Otherwise it's something to consider as a protective move in case it was never done;  that initial one is to be sure valve seating is appropriate following some break-in.  If you aren't the original owner and don't have a service history, perhaps you can ferret it out by way of CAT and your engine serial number.

Then consider the fuel and service hours parameters.  2 years seems a bit short of a period for coaches that aren't on the road all the time, so I'd be more inclined to go with one or more of the other parameters.

Joel

[Marty and Suzie Schenck]

Mike, this may be different than for your C-9 but this is what my Cat Operation and Maintenance Manual says for my C-12."Between 15,000 and 60,000 or Between first and fourth oil change" inspect/adjust engine valve lash. Because my coach doesn't get used a lot (5000 miles a year) I chose to go by the mileage. At 42,500 I had the valves checked and adjusted. They were within spec's but a couple did need to be adjusted. I was very fortunate, I found a Cat employee that went into business for himself to do mine. Saved money and still got a warranty. If I were you, I would have it done. You are at or near the mileage point. Peace of mind. Marty

[Dan Murphy]

Mike
we had the valve lash adjustment done by Cat at 36000 miles. Like Marty"s ours was within specs but did require some adjustment according to the tech.

 

[Mike Groves]

I am just really reluctant to let anyone fix anything that's not broken. Thanks mike

Mike,

You exactly state my fear.  As does yours, mine runs great.  Mine gets 8-9mpg even though the average speeds have been around 40mph.  The Jake brakes work fine (which for mine that adjustment is also performed C-12).  I purchased mine at 65000 miles, have been back and forth across country since, and this was supposed to have been done in the 20,000-40,000 mile mark, and the first owner who paid an awful lot of money for it would probably have had it done, but obviously there's no sure way to know.  I gave my engine serial number to CAT but that shop found no record of it having been done.

I just hate to think of having that engine opened up and a stranger work on this and then my fuel economy or what I consider a normal engine idle changes.  Though I do consider my idle rough compared to a car.  There is vibration to the point that the bedroom pocket door can make some noise rattling.  Not sure what other Marquis owners in the 99 to 01 year range experience after start up and during warm up.  I don't think that has been discussed on the forum.

But having said that, can others here who've had it done to theirs, give both you and I some confidence that to a CAT mechanic this is like changing a light bulb or something else so that we two Mike's can feel better about it given the likelihood that its already been done by the original owner.

Mike

[Mike Nunn]

Thanks for the responses, the coach had 11000 miles on it when we purchased it so I doubt any valve adjustment had been preformed.
While I suppose cost has something do with everything it really would not be the deciding factor in Having this preformed.
I suppose I was just looking for someone to say yes it should be done or no there is  a chance someone would create more problems than they will fix.
I do not think I would let anyone but a cat dealer do this but I have had great service at cat and I have had one create way more problems than I had when I got there.  Thanks again mike

[Mike Groves]

At 11000 miles I would have had mine done, so any objections you might have inferred from my post have now been taken off the table.   Let me know if you experience an improvement.  One thing I would hope for is less vibration when at idle.

Mike

[Jerry Emert]

Any idea how much this would cost?  Just rough ball park.  Thanks
Jerry

[Marty and Suzie Schenck]

The cost depends a lot on the access to the engine and how much prep work the mechanic has to do. For example, cover carpeting, move or remove bedding and mattress, remove access panels to engine compartment and so on. On my 98 Monterey I prepped everything and the cost was $140. total and on my 2002 Thunder I prepped everything again, including the mode to the closet, and the cost was $250. There is a member here on the forum that paid around $800. to have his 02 Thunder done and the dealership did everything. Marty

[Joel Ashley]

Jerry, I think Marty's right about cost... "it depends".  A lot of it is labor since the only part needed is a gasket for the cover.  For example, if you have a bed that's configured in line with the coach, rather than streetside to curbside, the mechanic may have better access and take less time.  Many diesel owners do this themselves, but not without some experience.  A large wrench can facilitate turning the shaft to get top dead center (TDC), but again it's all about access - whether or not a tech has to run in and out of the coach and you pay "travel time" or they use two techs, one in and one out, etc.  If you do it yourself, the gasket is maybe $60?, but if the original is in great shape, some just reuse it - I'd guess most CAT shops would replace with new regardless.

Numbers I've seen on other forums lead me to think $350-$500 would be today's range.  But if you do like Marty and spend some prep time doing stuff a tech would have to do otherwise, you can cut the cost a good deal.  A CAT shop should be forthright with a quote though.

-Joel

[Jerry Emert]

Thanks, I'm a bit gun shy.  I tend to think changing a light bulb is going to cost 2k because it's an RV.  Sadly so far I haven't been worrying unnecessarily!

[Mike Groves]

The quotes for me last fall were $425 from Peterson CAT in Portland, Oregon and $450 from Pape Kenworth in Donald, Oregon.  These include the exhaust brake adjustments. I think I have the right bed configuration for the $140 job!  Wishing!

Mike

[Roy C Tyler]

Don't most places do it by the "book" price?  I was quoted $2500 to $4500 to replace my exhaust manifold in Arizona.  When I got home, I took it to Cummins Northwest and they did it for $1200 because that was what the price in the "book" was.

[Dave Atherton]

I have to agree with Jerry thoughts, the sky is not falling. every seems to forget your engines were
built tested of which at operation temps. and load to set rings etc. We talk about setting valves soon
after one or two oil changes than we can forget drill again to 150, to 300,000 miles than we run the
drill again. If everyone read my thread look at valve lash adjustment, if feeler gauge falls in this window
don't touch the valves there is a .006 thousands window. In different  terms, a piece of typing paper
is .004 thickness per sheet so 1/2 sheet would be .002 thickness. It is very rare providing no major
repairs been made to head of engine after 150,000 miles feelers gauge will still fall in the .006 window
of correct .015 intake and .025 exhaust valve adjustment. I have been around the do it yourself
valve adjustment where not  following Cat SOP caused more problem than if not looked at. this was
counting all the dirt that was knocked inside open engine.Again the engine everyone is running are
long life engine. Engines in motorhomes there is no set rule how to approuch getting into the valves without
 use of a chain saw. Dave Atherton Retired Cat Mechanic