I am preparing my 89 GV for the road and am compiling a pre-departure checklist.
One of the questions that arose involves valve adjustment. I have no idea when this may have been done on my 86K mile coach. What is the valve lash adjustment interval?
Thanks to all.
Factory recommends at 60K but a lot of bus companies don't do it until at least 100K. One bus company put one million miles on their engine before adjusting the valves.
You can do it with conventional tools. I bought the long bent wrench but it's more important to do it exactly like in the PDF below. I guess a lot of mechanics do it incorrectly so read it a couple of times before starting. All four valves are exhaust valves, no intake valves. Intake is through ports in the cylinders.
http://ww2.justanswer.com/uploads/JCTech012/2011-01-06_205248_v92_topset.pdf
Here is the shop manual with lots of pictures/diagrams: https://avtec.edu/sites/default/files/DDC%2092.pdf
Adjusting the valves is probably not going to make it start better cold. The 17 to 1 compression ratio on the turbo versions makes cold starting sluggish.
Pierce
Pierce,
Thanks very much. I appreciate the first-hand info and the docs.
In regard to cold starting, I have not seen a block heater on my engine (but didn't look very hard for one.) If I need to install one, is there a port or plug where I should put that?
What engine are we thinking about a valve adjustment.
DD6V92TA DDEC
On our 91 GV block heater switch located on bed pedestal. On foot of bed right below 12 volt fuse panel. A brown standard light switch. 120 volt breaker box has a 20 amp dedicated breaker for the heater. Make sure it is not tripped. I keep the breaker in the off position unless I am going to use the heater.
Thanks I'll look for it. It's likely I'll need it in eastern Oregon and northern Nevada in January.
Looking from your engine door, the block heater will be right under your AC compressor on the right hand side should be a 110 cord coming off it up to a 110 receptacle . If you have a plug coming off the thermostat housing they do not work as well.
Thanks very much. I will look for it.
Here's a picture good luck ^.^d
Much appreciated!
On my 91 the block heater is on the drivers side my cord hangs just to the left of the radiator when facing coach from the rear. When I get back in off the road I'll try and snap a pic and post it.
Here more info: Alternate Block Heater on 6V92 Detroits (http://www.foreforums.com/index.php?topic=23517.msg182835#msg182835)
John blazed the trail on this modification. I followed in his footsteps. :) It's one of the best mods I've done on my coach! I put in a new circuit breaker and switch so that I can run both heaters. I use them all the time for almost any cold start. (If I'm in a campground that is) If boondocking I park with my butt facing east to get the early morning sun. Solar heating. :)
Here is what you are looking for on eBay. Kim Hotstart Block Heater V71 Series Detroit Diesel DDV-151B. The DDV-151B is the important part. I watched ebay for quite a while and finally got one for $39. Good luck with your coach!
Hummmm.... all of the above only applies if your heater is mounted high on the drivers side. If it's behind the air conditioner compressor like Andy's you're good to go.
see ya
ken
Forgot to mention. For some reason the switches at the base of the bed seem to have the ability to turn themselves on for no reason. I installed this and haven't had that issue since.
Amazon.com: Westek Amertac CSG1 Switch Guard, White, 2 Pack: Home Improvement (http://www.amazon.com/Westek-Amertac-Switch-Guard-White/dp/B000NCV1SK/ref=sr_1_1?ie=UTF8&qid=1513864803&sr=8-1&keywords=westek+amertac+csg1+switch+guard%2C+white%2C+2+pack)
The link should be the Foreforums affiliate link so this site will get a few pennies from the sale. Not sure how to tell.
see ya
ken
Nice photo Andy plus John did a great job documenting changing out the AC compressor mount block heater.
I left the OEM thermostat block heater on overnight in Bishop, CA when the temps were in the teens and then in the morning shot all the associated parts with my IR gun. The block was only slightly warmer than the exhaust manifold, compressor, etc but the thermostat housing was nice and hot and the crossover coolant pipe was too hot to touch. Too bad it was all wasted. The engine started but only on a couple of cylinders and then killed all the mosquitoes in the area once it was running.
John make a good point about an external block heater adding complexity to the engine compartment. On the other hand, I met the Wanderlodge people with all their Detroits in Death Valley with one of them not able to change out his AC compressor located failed block heater as he didn't want to lose all the coolant with no way to catch it. The external would be pretty easy here.
Ether: My old 4107 bus had a flip up cap on the intake to allow ether to be squirted in to aid cold starting. This was intended to be used by professional drivers with training. The danger arises when an owner changes fuel filters on a warm engine, it does not start right away so they spray ether in the intake. The ether then explodes not near top dead center but when the piston is only part way up on the compression stroke. This creates a violent pressure wave that can easily break rings or even bend a connecting rod.
In exploring other options, the stock water heater on a U300 is a two way (or three with a hotrod) that uses engine coolant to heat the water while driving down the road. I bought a very small, low draw 12v pump that could be used to send warm coolant back to the engine during the night with the water heater on even while dry camping.
I explored installing a small tankless water heater to be used only for the engine but can't find a location where I get enough vertical distance for the exhaust so it will draw properly.
My latest idea is to install a normal RV water heater on the muffler side with it's own framework and outside cover. It then could do double duty not only circulating warm coolant to the engine at night but could also act like a AquaHot for cabin heat with heat exchangers.
Diesel cars start much better cold as they are not usually direct injection but use a pre-combustion chamber above the piston to initiate the combustion process. The diesel fuel is sprayed directly into the chamber, onto a glow plug and with the higher 21 to 1 compression ratio, the diesel explodes easily with the gases being forced out small holes in the pre-combustion chamber where they force the piston down. Our old 300SD will start well below freezing with 5 seconds of glow plug and fire on the first revolution. All without a block heater.
Randal, there are a lot of other PM things to do before you hit the road for an extended period. Inspecting the air cleaner along with a air intake modification so it like the OEM late 1993 design that Kent Speers has. More critical on a Detroit than the U280 as the 2 cycle uses twice as much air. The cooling system is less than optimal with careful driving habits needed in warm summer weather on the side radiator coaches. Perhaps not yours with the rear radiator.
You are on the right direction by asking questions as there is a great group of Detroit owners glad to make your RV experience a good one.
Pierce