oops, I over reved

[Tractor Nubi]

Have a Dong Feng 354 and was plowing the drive way. Neighbour was stuck so I took off the load and went to help. I had the rpm up to ~2800 for no more than 5 seconds before I noticed it. I heard a pop (kind of like a poof) and then it started to smoke white smoke and loose power. It will start easily and run but I cannot get any measurable power and cannot get rid of the smoke.

Tractor is a diesel and has ~153 hours on it. When it was newer ~75hours I had a similar smoking incident (no overreving and no pop/poof sound) and people on the forum told me to put it under load (1800-2000 rpm) for a number of hours. It worked and it has been great. I tried that and it didn't work.

I added fuel (that had been in a jerry can for a month) that day and had changed the fuel filter at 110 hours.

any suggestions? Is there a governor that needs to be reset?

 

[greg_g]

I had the rpm up to ~2800 for no more than 5 seconds before I noticed it.

What does your engine manual show for max RPMs? On my KM454, I wouldn't really consider 2800 serious. Throttle stop is currently ~2650, but I'm sure I could get more out of it without incurring damage.

But the noise and the white smoke is curious. Have you looked for water in the sediment bowl?

//greg//

 

[Marc L.]

Good day,

Did the "Poof" came from the exhaust or from the engine (fuel pump). As well, did you check your coolant? Is the coolant turning darker or disapearing (would be a blown head gasket). Have a look at the oil, is the oil milky (head gasket again).

Water in the fuel could cause the engine to smoke with loss of power.

Good luck with this.

Marc

 

[Ranch_Hand_Supp]

Can you tell if the engine has droped a cylinder ?, not running / idleing smooth ?, sounds different ??


Ronald
Ranch Hand Supply

 

[Tractor Nubi]

I love this site! Lots of help. I think the poof was from the exhaust but I was looking at the tach when it happened. We have 2 feet of snow here and normally it does not dip below 0 (Vancouver Island BC Canada) in the winter here and we get lots of rain. I have ordered a fuel filter and a diesel conditioner as I am worried about gelling of the fuel.

Word to the wise in rainy climates, a tin can over the upright exaust will stop pin holes developing in the exhaust manifold outlet (learning the hard way).

It will start and run with blue smoke at idle and will pour out white smoke under load.

I am unsure where the sediment bowl is on this unit.

Any other suggestions are appreciated.

 

[dfkrug]

It will start and run with blue smoke at idle and will pour out white smoke under load.

Blue smoke means you are burning engine oil. That will be caused by a
broken piston ring, most likely, as your engine is young and valve guides take
a long time to wear out. Or a scored cylinder wall, which does not happen
suddenly, so I am ruling that out.

If you blew a head gasket, you would get low compression and low power
from 2 adjacent cylinders, most likely, and that would probably make it
impossible to start. I am assuming that is a 3-cylinder engine. A blown
gasket that affects only one hole IS possible as Marc suggests, and that
COULD allow oil from the head passages to get into that cylinder.

I would test for a dead hole, as Ronald suggests, and the easiest way is
to use a non-contact thermometer. $40 at Harbor Fright. DO this at
startup, before the engine heat-soaks the whole exhaust manifold.

 

[psj12]

White smoke can be from coolant (steam and will taste sweet like AF when breathed) or fuel which is oily and will stick to your hand or cardboard when held infront of the exhaust.
If it is fuel it could be you lost the tip of an injector. If it is coolant it could be a head gasket or broken cylinder liner leaking coolant into the cylinder. I also like the idea of the non-contact IR thermometer aimed at the exhaust ports for each cylinder to determine which cyl it is. Best when performed when cold and just started.

 

[Bob Rooks]

Blue smoke on startup of a newer engine that goes away after operating temperature is reached is indicative of an engine that has not been broken in yet, or improperly broken in. Piston rings have not seated yet or the liners are glazed. Also, it takes some time for engines to reach thermal equilibrium, where all heat related expansion stops.
White smoke also means unburned fuel; usually due to a dribbling injector, poorly seated poppet valve, or low compression.

 

[greg_g]

Blue smoke on startup of a newer engine that goes away after operating temperature is reached is indicative of an engine that has not been broken in yet, or improperly broken in.

The model year and engine in the OP DF354 wasn't specified, so this is a shot in the dark. But you just reminded me that there have been a few posts about problems with the EGR system in some EPA-certified engines too.

//greg//

 

[AKfish]

I'm bettin' it's a blown tip on one of the injectors... (starts easy - white smoke - no power).

Best of luck.

AKfish

 

[mffarmall]

I would say your best bet is to make a list of what is being said then looking up these topics and reading a little. From that you can then put what you know with what your reading about. The injector and the gasket are not a bad place to start. From this you can learn about removing the top cover and following the fuel line to the injectors and also see where the glow plugs.

Your fuel bowl might be on the left side just under the cover by your clutch pedal and your dip stick.

When I'm working on something new and I don't really understand what I'm looking at I try to stay away from my tools and out of overalls. That way I have to think it through before I head in with both feet.

You said that you got a lot of snow. Are you still able to use your FEL to move it out of your way?

 

[Bearcats]

Hi guys, sorry to butt in here but I don't think you have given Tractor Nubi any indication where to start looking for a cure. It may be a simple injector fault, this will cause white smoke and lack of power. I would start by cracking each injector line on idle and determine which cylinder does not change the idle speed. That is the faulty cylinder. Remove the injector and re-connect the injector line to the injector out of the engine. The return line removed from the top of the injector will need to be pluged with a small bolt, washer, washer, nut otherwise fuel will be sprayed everywhere. Start the engine and look at the spray pattern from the injector. It should be a fine mist, anything else would indicate a clogged or faulty injector. If there is carbon buildup on the tip, clean with a wire brush and also check the four holes on the tip. These holes can be gently cleared using one strand of the wire brush. Re-connect the injector out of the engine and check spray pattern again. Also check the fuel stops flowing immediately the engine is shut off. If it continues to dribble after the engine is shut off the injector is faulty. This will cause too much fuel in the cylinder (flood) and it will not ignite.

 

[mffarmall]

The information here is great. And it's a process. There is never a one shot answer.

 

[greg_g]

If there is carbon buildup on the tip, clean with a wire brush and also check the four holes on the tip. These holes can be gently cleared using one strand of the wire brush. .

Good way to make a small problem big. Short of being a little messy, just observing the spray pattern won't hurt anything - if the observer knows what to look for. Beyond that, anything suspect should be turned over to the guys that do it for a living.

From what I can gather, it's easier to buy new Chinese injector(s) from a Chinese tractor dealer - than it is to find a repair shop willing to rebuild Chinese injectors. Same goes for the pump. Even if you do find a willing shop, a new one may even be cheaper than the rebuild cost.

That said, I haven't yet seen enough evidence to conclude that it actually is an injector problem.

//greg//

 

[Bearcats]

Good way to make a small problem big. Short of being a little messy, just observing the spray pattern won't hurt anything - if the observer knows what to look for. Beyond that, anything suspect should be turned over to the guys that do it for a living.
//greg//

The advise I offered is a simple, no cost way of eliminating a possible cause. How can this make a small problem big? The injector either sprays a fine mist from all four holes or it doesn't. If it does spray a fine mist then look elsewhere, if it doesn't then there is an obvious injector fault and cleaning with a wire brush can not make it any worse. Another alternative is to pay a mechanic to do the exact same thing.

I have repaired many chinese engines with the exact same symptoms and injectors have been the majority of the cause. Of these probably 30% have been put back in to service with a simple clean with the wire brush. You are right however, it is cheaper to replace the injector rather than repair.

I don't believe we have concluded anything yet. This is a process of elimination.

Tractor Nubi, just crack open each injector line one at a time and see if there is a lazy cylinder.

One other note if the injector is the problem. When it comes time to re-install the injector after repair/replace. Run the engine with the line loose for a short while then slowly tighten. This will give the cylinder time to clear any excess fuel. Even with a good injector, if there is excess fuel in the cylinder it will not ignite.

 

[greg_g]

How can this make a small problem big?

Well - since "if the observer knows what to look for" apparently wasn't clear enough, let me rephrase; It's a good way for a novice to make a small problem big. I was actually referring to your suggestion to arbitrarily stick wire in the injector tips. It's safer and more efficient to clean them from the inside out - rather than poke at them from the outside in.

I prefer to install temporary supply and return lines > start the engine > run an $8 can of Diesel Purge through the pumps and injectors > change fuel filter > reconnect fuel and return lines > and faithfully treat all subsequent fuel with Power Service or Lucas.


//greg//

 

[Bob Rooks]

In all my years spent around diesel fuel systems, I have never heard of using a steel wire brush to clean tips. Ultrasonic solvent cleaning is the preferred method, brass brush if you insist, but never poke anything into an orifice, it can alter the spray pattern. That's why there are diesel shops with a clean room and thousands of dollars worth of testing and calibration equipment and trained personell. Most all fuel injection equipment is high tolerance work even if it is '50's technology, and beyond the scope of the average shade-tree mechanic.
And what's this about running an injector with the return plugged with a bolt?? Please explain.

 

[Bearcats]

Oh for Christ sake you guys. Now I remember why I never registered earlier, all this *****'n. I have detected this attitude in so many threads. So here we go, some attitude back at ya.

How much effort do you want to put in to a $40 injector? If it works, great. If it doesn't then throw it away and buy a new one. So you will travel to a service centre (fuel and time), wait a week, travel back to the service centre, pay for the clean then travel home again? I don't know about you but I am no where near an injector service centre. I doubt many farms are and time is more important than money to me. Remember we are referring to carbon on the outside of the tip, not an internally blocked injector. The strand of the wire brush (which is smaller than the diameter of the hole in the injector) only breaks up the carbon and it is expelled when the injector is pressurised. Obviously it is pressurised connected to the pump but off the engine. One stubborn injector I had was done while the engine was running. I am curious, have you actually tried it? Then don稚 knock it until you try it. Go on, be a devil, give it a go. I mean how can you live with yourself risking destroying an already faulty $40 injector? If you actually want to make a big deal out of it then go for it.

You don't block the fuel return with the bolt. You use a 6-8mm bolt in the 10mm hole of the return line with a washer each side, the fuel goes around the bolt back to the tank. Simple everyday things people have in their shed. This is common sense and should not need explaining. Did I say a steel wire brush? I don't recall saying steel. Hmm maybe I should have written a 1500 word step by step guide including which direction you hold your tongue when undoing a bolt.

Greg, we are talking about an injector with an obvious fault not a general clean and I'm sure everyone has a spare set of fuel lines in their shed just waiting for an injector to fail.

I have 37 diesel engines on my 4870 acre farm. What I have outlined has worked for me and has got the engines running immediately. Either use it or don't use it, I don't care.

Anyway you "experts", I don't see you offering any suggestions to the original thread. I leave it up to you now, I'm out of here and de-registering.

And for your information Bob we don't have shade-tree mechanics here, only bush mechanics.

 

[greg_g]

we are talking about an injector with an obvious fault not a general clean and I'm sure everyone has a spare set of fuel lines in their shed just waiting for an injector to fail.

Even with 37 tractors, it's clear you've never done this before - or you'd know that my "spare set of fuel lines" are nothing more than two lengths of clear poly tubing. The procedure for doing this on my Mercedes is here: Diesel Purge Mercedes diesel maintenance tips, I simply modify it slightly when doing my tractors.

Anyway you "experts", I don't see you offering any suggestions to the original thread. I leave it up to you now, I'm out of here and de-registering.

Can't offer meaningful "suggestions" without answers to pending questions. Still waiting on NUBI.

I don't think enough evidence has been presented so far to point the blame at a bad fuel injector. When NUBI responds with amplifying info, perhaps we can move on with a little more decorum.

NUBI by the way, is very likely about 36 tractors short of your total. As such, I'm reasonably confident he won't take offense at the word novice. And it definitely pays to consider skill level indicators when formulating responses to those seeking advice.

But if leaving the room is your ultimate solution, so be it. Ciao.

///greg//

 

[Reg]

I'm bettin' it's a blown tip on one of the injectors... (starts easy - white smoke - no power).

Best of luck.

AKfish

That is my guess too, probably a lot of work to pull all the injectors and find which one(s).

A simple/easy way to find a clue about a head gasket is to take a look in the top of the radiator, if the antifreeze has an oily film on it - that is NOT good news.
If it doesn't, that doesn't necessarily mean that your head gasket is still good.
It is one of those "absence of evidence is not evidence of absence" situations.

I think I would approach it sequentially, starting with the injectors.
If those check out (all look pretty much the same) a compression check... take it from there, probably pull the head anyway.