Smoker

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My 98 Ca. 3500 12 valve,loaded with a heavy camper has developed a heavy(massive amounts) bright blue smoke after coming down steep grades in a lower gear then upshifting to higher gears at the bottom. I've been stopped twice for this by park rangers. It's currently at Dodge getting disassembled,and about all they have found to date is a sooted head. Any body else had this problem?

 

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That engine will never run right until the EGR valve is removed and you can get COOL,CLEAN AIR in!
CA was way off on their pollution control for these engines.
Get a normal intake, then bomb to about 300hp. This gained me 4 miles to the gallon and wiped out my smoke problem.
The EGR is killing the top end of that engine.

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1997 Cummins Dodge 4x4 Bombed & Amsoiled
Member of TDR,LIC-ROC,GLTDR,NRA

 

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MGM
I recieved call from dealer late this afternoon. So far they found a warped head which they have ordered a reman. unit from Cummins. They have not recieved word on the injectors and pump. Hard to believe at 22k miles this happened. Never once did I notice high temp. They still think it's overfueling.
I have ordered a dual pod from Geno's and will be installing a pyro and boost. Next month will be the Jake. Everything I've read points to mounting the pyro before the turbo but I don't recall a fitting to tap into.
Thanks for the info.

 

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Sorry to hear about the warped heads. This sounds unusual to me for the Cummins. I have had a couple of experiences with warped heads on other engines which was due to incompatable metals being used between heads and block (anyone remember the Vega?)

However, as a reference there are generally four kinds of smoke. Clear = everything ok, Black = too rich (clogged air filter poorly adjusted fuel system) , Blue = oil (rings and valves), and White = water (head gasket, cracked block). This is just a general guide, but can be used as a starting point for trouble shooting.

There is not a fitting to tap into for the pyro. You have to drill and tap it out. This requires removal of the turbo so that you do not leave any metal shavings in the manifold. It is not too difficult to do - a little time consuming.

You will probably have a 1/8" npt fitting on the EGT probe, which will require drilling with 7/16" and taping with 1/8 -18 npt tap. However, drill a pilot hole first.

There should be some installation instructions with your gauges. Take the time to install it before the turbo, as it is very important to get the most accurate EGT reading you can when bombing.

Good luck

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1995 4X4 std cab 12 valve, original owner, 100k miles, banks stinger plus (14cm turbo, 3 1/2" exhaust, EGT and Boost guage, #7 torque plate in TST lingo, 215 injectors, AFC spring kit, Pscotty air on the way, 3. 54 rear, 17. 5" American Racing aluminum wheels, Mickey Thompson MTX's, Rancho's and Helwig on the way, Starcraft camper and assundry dodad's. Only thing faster than a 12 valve is my Ducati 4 valve

[This message has been edited by A-bomb (edited 09-16-2000). ]

 

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The blue color of the smoke caught my attention and I would bet that it is oil. On a gas engine you get this phenomenon and it can be worn valve guides. While decending a grade you aren't on the throttle so you create a negative pressure when the piston drops in the cylinder. This sucks in oil around the intake valve stem. While a turbo diesel engine is different, maybe it could be the same problem. While decending a grade you will have no boost and possibly a negative pressure in the intake manifold. Then when you get to the bottom of the hill you upshift and give it throttle and out billows a smoke cloud as the oil is cleared from the head and combustion chamber.

 

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Could this smoke be a sign of a bad turbo bearing seal?
Don

 

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It is a very small possibility, but given the description of the problem, I do not think it would be the seal, as the oil would have to travel a long way to get to the intake valves. One could remove the air intake hose to verify turbine integrety.

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1995 4X4 std cab 12 valve, original owner, 100k miles, banks stinger plus (14cm turbo, 3 1/2" exhaust, EGT and Boost guage, #7 torque plate in TST lingo, 215 injectors, AFC spring kit, Pscotty air on the way, 3. 54 rear, 17. 5" American Racing aluminum wheels, Mickey Thompson MTX's, Rancho's and Helwig on the way, Starcraft camper and assundry dodad's. Only thing faster than a 12 valve is my Ducati 4 valve

 

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I think you're all wrong #ad


I'd guess your engine is timed badly. OR, you have a bad pressurizing valve (overflow valve) on the injection pump. I have heard of these problems before, and every time it's been timing or some other relatively minor problem.

This isn't a simple problem, BTW, the TDC pin MUST be accurately re-located, and then your pump taken off and the internal pointer set to at least 13 degrees (6. 5 pump) and best 14 degrees (7 pump). Then, when it's put on, you'll have your timing truly set.

Just my $. 02 worth

 

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Big_DQ I believe once that seal starts leaking unless you have a dry chemical fire extinguisher your going to have engine run away.
Especially when were talking big enough cloud of smoke to get pulled over for it.

 

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PowerWagon,

Please enlighten us... .

Pump timing seems plausable, but it appears to me the timing would have to be very advanced - accompanied by a power loss, epsecially under load. Also, since the truck has relatively few miles on it how could the pump timing all of the sudden change to the accute condition mentioned? Would'nt the smoke be black?

The overflow valve seems plauseable, but how exactly would it cause blue smoke instead of black smoke?

What do you think?

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1995 4X4 std cab 12 valve, original owner, 100k miles, banks stinger plus (14cm turbo, 3 1/2" exhaust, EGT and Boost guage, #7 torque plate in TST lingo, 215 injectors, AFC spring kit, Pscotty air on the way, 3. 54 rear, 17. 5" American Racing aluminum wheels, Mickey Thompson MTX's, Rancho's and Helwig on the way, Starcraft camper and assundry dodad's. Only thing faster than a 12 valve is my Ducati 4 valve

[This message has been edited by A-bomb (edited 09-17-2000). ]

 

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Originally posted by A-bomb:
PowerWagon,

Please enlighten us... .

Pump timing seems plausable, but it appears to me the timing would have to be very advanced - accompanied by a power loss, epsecially under load. Also, since the truck has relatively few miles on it how could the pump timing all of the sudden change to the accute condition mentioned? Would'nt the smoke be black?

Actually, retarded timing causes blue or blue-white smoke. Advanced timing can contribute to more black smoke under load.

The pump timing can slip... Ask any number of TDR folks what happens - however, I doubt your timing has slipped... If it's off, it always was off.

What happens, is that when you go downhill, there's no fuel injected, and lots of cool air rushes through the engine, cooling the combustion chamber and then when you do hit the pedal you get smoke until the chamber heats up. This can be exacerbated by late timing, which tries to inject fuel past the point of maximum heat, resulting in poor burning and white smoke.


The overflow valve seems plauseable, but how exactly would it cause blue smoke instead of black smoke?

A faulty overflow valve holds no pressure at all in the galley of the injection pump, causing the fuel inside it to be alternatively pressurized and then under a vacuum. My guess is the diesel forms small bubbles, and the attempts to inject send non-solid fuel to the injectors, resulting in poor injection quality. Cavitation can happen easily enough when there's no pressure and the plungers are moving rapidly.

Understand, this is a guess on my part. But, it does not sound like an oil burning or turbo failure problem to me.


What do you think?

 

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Power,

Thanks for the reply.

It's always a treat to learn new things.

Your description of possible causes are in line with the Service manual. They suggest checking pump timing, air leaks, exhaust leaks, in op turbo, injectors, overfueld pump, then piston rings (blue smoke). However it does not provide a description on the color of smoke for the other possible causes.

So, advanced timing = black smoke, and retarded = whiter/blue smoke. Great to know this for bag of tricks.

I was familiar with overfueling causing black smoke, which leads me to conclude that advancing the timing will overfuel. And of course we have all seen whiter smoke when the engine is cold.

Would you know why the smoke is whiter/blue with too retarded timing. Is the air/fuel cooler? Is the fuel cavitaded? What would be your . 02 on this?




[This message has been edited by A-bomb (edited 09-17-2000). ]

 

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phicks
A friend of mine had a cracked head replaced on warranty by a Cummins dealer who said he could not use recon parts on warr. job, must be new only. Check it out. If that was my motor, esp. with only 22k, I would INSIST on new parts. Just my $. 02!

CPFF

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CUMMINS POWERED FAST FORD

 

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Power Wagon,A-Bomb,Missouri Mule,Hvac
Thanks for all the input, and for the record I will be faxing all your replies to the dealer.
The heaviest smoke happened after 12 miles of 8% grade,no throttle,third gear and sometimes second on the hairpins. This was the case in both instances. The smoke was blue with white puffs every so often and it was thick. I have noticed a power loss especially running flat out on grades. And very poor fuel milage, the best being 13 and averaging 12 loaded. My feelings now is what ever is wrong probably came from the factory that way. I understand the dealer sent the head and injectors out for testing, it will be interesting what the results are. I will keep you all informed.