Cummins 555, but radiator and oil leak question

[Branden]

Hi all, this is also posted in the projects section under the Lucinda Lowdown, but it seemed like it would be appropriate here, too.

Hi Skoolies,
First the fun: I took Lucinda (1981 BB AA FE) from Seattle to Nevada for her 5th Burning Man this year, as well as a couple weeks in Montana, Idaho, and Wyoming for summer fly-fishing. We made the West Yellowstone paper, what with her sweet murals and my standard poodle traveling companions...skoolie travel is awesome!

Now the backstory: she's an old bus and has been slowly but steadily leaking oil, and it's gotten worse. The last trip in September was the final straw (1 gallon down to Nevada, one back, 1500 miles total). She was also putting out some MAJOR clouds of black smoke (on the previous trip to Montana) when highway driving and letting off the accelerator (say, down a grade) and then stepping on it hard. I attributed it to low oil and new diesel fuel treatments. Maybe-it had somewhat cleared up with an oil add/change. By the middle of the Nevada trip we had to put cardboard under her anytime we stopped--she leaked a tablespoon in ten minutes or so of sitting. Once shut down and cool, though, no more leaking.

But wait, there's more! In the last 150 miles home, an unlabeled red light on the dash came on, with associated scary buzzer, for the first time in my ownership (5 years). It started coming on in the passes of I-5, particularly when going from slogging up to cresting and heading down. We thought it was likely the automatic transmission fluid. The dipstick is a bear to read, so I'm not clear we were perfectly correct in our assessments of levels (very low) but the light went off when we added two quarts. After 75 miles, it all happened again--light, buzzer, refill transmission fluid. We went through TWO GALLONS of automatic transmission fluid before we got home. About 75-90 miles was all we went before lights and buzzing!

Some additional info: the radiator has been (now) diagnosed (with a heat sensor) to be only moderately functional. 40% of it has some amount of blockage and is not heating/cooling the radiator fluid. Up until the last 50 miles of the trip, the engine temp (water) and oil temp gauges were reading fine. Hot uphill, but cooled off right away. The last bit of the trip, though, the oil temp went near redline zone, I don't recall the number but I think around 390. I was able to keep it low enough (below redline) to get home and it's been in the shop on their back burner ever since.

The oil is a leaking valve gasket, easier than expected. The tranny fluid problem, though, is a bit mysterious. Transmission shifts fine, and there are no signs of fluid leaks according to the mechanic. The theory is that the radiator is not working well enough to keep the tranny fluid cool, and it is vaporizing--this idea is supported by some amount of vapor leakage evidence in some seals or something.

So now the question(s) at hand:
The radiator is too old to rod out without damaging it, so I'm thinking of having it replaced. It's a little unclear but it seems like this is basically the only solution (or the band-aid solution of a transmission cooler). The question is, does this sound like the right thing to do, and what should I expect this to cost in rough figures? The mechanic happens to have an old "new" radiator from the same bus, but I don't know what he wants for it, nor a reasonable price. The old radiator is off (to fix the oil leak) so that part of the job is done.

The other question is about the amazing black clouds of smoke. They're not the normal cold-engine smoke, nor are they light gray, or blue. They're black, and full of soot. Enough to cover the back of my bus. Maybe the two problems are related, and I'm burning vaporized transmission fluid? The smoke clouds have mostly gone away, but I hate to not mention useful symptoms...

Ideas GREATLY appreciated. Will share the outcome of the mechanic visit as well.

Drive on,
Branden

[frank-id]

Wow, ya need a mentor. The obvious information is missing. I will try to enlighten you with just a few sentences.
Black diesel smoke is a visual reflection of unburned fuel. Every diesel can make black smoke at any time. The smoke is usually caused by using the wrong gear climbing a hill/mountain. Using the wrong gear causes low power, lots of smoke increase in engine/trans temps, and poor fuel economy.
Every oil leak can be fixed. Engine oil is mostly black and auto trans fluid is red. Shiney bright red is da best color. The darker the color, the more quickly, the fluid needs changed. Please tell all about bus as maker, length, GVW, and drive train. Is the trans cooler in the radiator? Not great. Trans model? Post some bus and engine pics. Frank

[Branden]

Hi Frank,
Indeed I do need a mentor. I've got a 35' Blue Bird All American Front Engine with a Cummins 555 9.1 liter and Alison 545 (I think). GVW? Don't recall, 24-30Kish.

The triple nickel is not by reputation a powerful engine, and I use the auto transmission as a manual when going up and down hills. I'm unable (and unconcerned) to focus on speed up hills, but rather keep an eye on my tach, keeping the rpms near 2000-2400. Military specs for that engine suggest a peak optimal operating rpm of 2500 or 2600 if I recall.

I'm not worried about the oil leak--I've known about it for some time and it can be fixed, I was just waiting until it needed to be. The reason I detailed color in the smoke is that I believe it's probably being "contaminated" by additional material--perhaps vaporized transmission fluid, perhaps soot cleaned from the injectors and such from the new cleaner(s) I'm using as diesel additives to improve lubricity. I'm using FPPF products now. The interesting thing is the change, from intermittent smoking at common times (hills, start-up, after not being driven) to tremendous amounts more, and while on downgrades, when I hit the gas after coasting. I mean, it's like a spy car and a smokescreen! Very James Bond-y. One other thing to note: my fuel economy went up by 25% when I started using that diesel treatment. I used something else for a while, or nothing, and got about 7.5--it went up to about 9.5 for awhile, then down to about 8.

I know the transmission fluid is red, and mine was shiny and clean--probably because I was replacing it like crazy. The reading is a challenge because the dipstick is really long and bends around into the engine, so it always seems to be smeared when it comes out and is thus tough to read. Don't know about a transmission cooler--I thought this was an additional feature, as my mechanic and I have been talking about adding one (maybe that's an additional one?). As for pictures, Lucinda (that's the bus name) has a slew in the albums detailing her build--roof sealing, floors, roof deck, mural paintings. No engine pics, though, and I don't have access to it now.

Hope that's helpful. That's about all I know with regard to your questions.
Thanks!
Branden

[bus-bro]

Off hand, it kinda sounds like you lost a tip on an injector.

[Jarlaxle]

Hmm...yes, black smoke out the exhaust is unburned fuel...but I wonder...are you SURE it's out the exhaust? Could the smoke be coming out from under the bus? If so...I wonder if it's oil leaking out of the valve cover(s) and hitting hot exhaust manifolds? From experience: that will give black smoke. ATF will usually smoke gray-white.

If it is fuel smoke, it means the engine is dumping excess fuel. Ergo, it has to come from someplace: this is a slightly long-winded way of saying that if it's doing a "six days on the road" imitation, your mileage will dive. rereading your last post, it seems to have done so, if I'm reading things correctly. (8 down to 9.5 is about an 18% drop!)

Unfortunately, the triple-nickel has a poor reputation...part availaibility might be a problem. I e-mailed a link to my uncle (retired after 40+ years wrenching on trucks), he knows the old diesels much better than i do.

My advice is to call a Cummins shop, and talk to the oldest guy there...because anyone under 45 has probably never HEARD of a 555 Cummins, much less having any idea how to fix one. I suggest an oil analysis and an IMMEDIATE oil change--if it is dumping extra fuel into the engine, it will contaminate the oil.

[Jarlaxle]

Dang, that was fast. My uncle just replied to my e-mail, here it is:

"The post before yours got it, he lost an injector tip. DO NOT RUN THIS ENGINE UNTIL IT IS REPAIRED!"

[Branden]

We're now looking for a new radiator, and the front engine/cummins 555 combination leaves little room up there. They are talking about $1200 for a recore, but the shops don't know what to do about the transmission cooler part, and I'll bet that'll need work, too.

As for the cummins shop, they are unwilling to even comment on the engine unless I bring it in, and my guess is that my bus is older than the guy I spoke with on the phone. After i told him it was a triple nickel, he asked me what kind of engine it was. he also wouldn't comment on the potential injector tip problem, though I now have the dealer mechanic checking on that.

At almost a hundred bucks an hour this is going to be really painful.

On the smoke, it's definitely coming out the exhaust pipe at the back of the bus. Again, somewhat better now, but still worse than it was.

Of course, all this is somewhat theoretical as the bus has been in the shop now for three months. Sheesh.

[Branden]

Oh, and hey, thanks for all the suggestions. Not only do I appreciate it and am forwarding them to the mechanic, but I'm also enjoying learning the troubleshooting and can always use the advice.
Branden

[Jarlaxle]

Again, I suggest going to the Cummins shop & asking to talk to the oldest guy there. You need someone who has done this for 20+ years for fixing a 555 Cummins.