[Liam]

I have been wondering about doing the “overhead” adjustment too. It adjusts valve clearance, injector height and Jake brake. My understanding is that it should be done once around 100k and then every 250k. Truckers seem to do the “overhead” whenever fuel economy or performance takes a dive. On a truck the cost is somewhere around $400-600. On our installations it would be more given that lack of easy access.

I have 157K on the engine and it is running great, good power, low temps and brakes work well. It is noisy at low idle but they all seem to do that. I have decided to hold off. There is always a chance of a maintenance induced failure. Not worth it as long as it is running well.

Gerald

[gary]

I will give my findings. I have owned a 99 Marathon XLV 45 and a 01 Marathon XLII 45, both had about 112,000 miles on them when I bought them. At about 120,000 or 125,000 I did the top end. On both motors there where roller rockers that the hard face was starting to come apart. I think on the 99 I changed 3 roller rockers and on the 01 I had to do 6, but I also did one of the cams as well on the 01. I sold the 99 with about 155,000 and the 01 I still have with about 166,000.

I have no clue if they would have failed but I belive that prolonged sitting without starting the motor is the killer, all oil drains from the top end and it is very slow when you start the motor to get oil up to the cams and rollers. I strugle with runnimg my bus without driving it because I keep mine inside a bldg and it is a big PIA to get it in and out but I do run it about every 30 days making sure the water and oil get up to temp, it takes about 1 hour with cardboard covering the radiator.

My 2 cents worth, you just got to love a Detroit motor!!

[Paul]

Our 87 had the 8V92. We got it with 42,000. Ran the mileage to over 200,000 and never adjusted or did anything. Had to rebuild it because it started to get coolant into the cylinder. Turns out we did not have to rebuild it because it was a crack in the head. But we rebuilt it anyway. Point is, I did nothing except change fluids and filters un until the rebuild and it ran OK.

On my 97 Series 60 we got it at 155,000 and put approx. another 100,000. Same story. Never did anything. Service people said unless it was running bad or getting worse mileage leave it alone. So I did.

Speaking of mileage…….I have recorded every gallon of fuel ever put in my coaches. My mileage went down over the course of ownership and it corresponded with changes to fuel. ethanol, low sulfur and ultra low sulfur. Maybe Mark will share his recent experience.

[Peter]

I just completed about a 4000 mile trip out west and back. In Jamestown, NM I bought fuel at the Pilot that is right next to a refinery. After I left there and drove on, I noticed that my fuel mileage was going steadily up on the instant gauge in the info display. I went from my usual 5.5 to 5.6 all the way up to 6.2 or 6.3. This lasted until I put more fuel on, where it went back to the usual 5.5 to 5.6.

On the way back, I fueled again at the same Pilot and my mileage once again improved back to the above mentioned 6.2 to 6.3. This lasted again until I put more fuel in.

The only thing that was different was that I did not see a sign on the dispensers about bio-diesel at this stop. I believe it was straight diesel, not contaminated with bio additive.

Seemes like a good thing to NOT have bio in our fuel.

[Bill]

Did you smell french fries with at Bio junk Mark?

[Archived]

I didn’t notice any…..

The government at waste again. hmmmm….less mileage, less performance but better because the government says so….NOT!

[Archived]

You guys with the EGR engines need a little more attention than the non EGR guys the EGR engines put so much soot back in the engine if the valves get to far out of adjustment the soot builds up and will take a turbo or the number 6 cylinder out on those engines $$$ 400 or 500 bucks could be a good investment for you.

Regardless what people say those engines are not maintaince free if you expect a long life engine

One other item is use the API rated CI-4 oil not the CJ-4 15/40 DD service letter 7SE270 and as it was approved earlier the NOTA coolant now is a no/no the 12,000 mile oil change stayed the same with the CI-4 oil

good luck

[Bill]

CI-4 seems to be for high sulfur fuels than are currently being sold at the pumps. Could it be the CI-4 requirement is for off road use engines that may be ran of higher sulfur fuels?

http://www.apicj-4.org/2009_ENGINE_OIL_GUIDE.pdf

[Rick]

Nope CI -4 is for on the highway engines with the EGR I rembember the letter came out in 2006, some series 60 had the wrong oil cap saying CH-4 if you ever get a chance to see a 60 series EGR torn down for a rebuild they are nasty.at the number 6 cylinder the only bearing on the crankshaft on a series 60 that will ever show wear will be # 6

If you want to by pass the EGR all it takes is programing change from the1200/2000 rpm for the operating range for the EGR to something in the 3000 rpm range which they never would see one of the members here knows how to do it

We just done one Sat to improve the fuel mileage on a 14L legal or not I don’t know but we will find out when emission testing come around in AZ next year but right now we are going to enjoy the extra mile per gal of fuel

good luck

[Archived]

I really appreciate the heads up on the tune up. My coach has about 105,000 miles. Had a long talk with Detroit today and they defintely recommend this for motorhome applications of series 60 engines when you hit 100,000 miles. Mine will have the tune up this week.

[Archived]

Can we change the EGR settings with the Nexiq reader? Or do we need a password to access changes like that?

And as far as a tune up being an easy thing, not so. There can be as much as a day required just to disassemble a portion of the bedroom or closet to be able to open the cover over the engine so the engine valve cover can come off. An H3 doesn’t need that but the XLII does.

[Archived]

The valve adjustment on my Liberty was a slam dunk. Apparently, because there is no jake, the valve cover(s) could be slipped off horizontally requiring no bedroom floor disassembly.

[Archived]

Luvrbus: What’s the deal on coolant?

[Archived]

Thanks again for the heads up on the need for a tune up at 100,000 miles. Work just completed. Valves defintely needed adjustment. More important though they found that the fan for the turbo was loose and showing abnomal wear. Ended up replacing turbo. I would have not known this problem existed until it became a major problem without this tune up.

[Archived]

Good move on the turbo, I saw I guy at Prevost Jax that had to be towed in for turbo failure at 130K. Not a pretty site.