Low power and lots of smoke(complete overhaul)D6H

[Construct'O]

I had the engine on my D6H overhauled after 16K hours but???

Too back up a little it was starting to get low on power,slow to rev up and smoked a lot more.First thought was turbo getting bad.With excess oil use, leaks,hours and the other problems decided to do the complete overhaul.

The Cat dealer did an out of frame overhaul.Complete rebuild from top to bottom.Most everything was new or rebuilt to spec.New turbo, fuel pump complete rebuild.Was run on dino!

After getting it up and running everything was good except the power! It has been weak every since and still blows excess smoke.I complained ,but they said just needed broke in.

The rpm is great, just when you start to push half way into the blade full of dirt engine starts lugging down.

Haz of smoke from stack without load and the same with load.Same problem as before so?????

I was reading about the left pump on the backhoe thread ,could it be that? Also talked to my Cat mechanic and mention bad(new reman turbo).His response was it either works or it fails? I asked to check boast,but never got around to it.

Would like some suggestions where to start looking?:usa

 

[roddyo]

Just a Thought

I had the engine on my D6H overhauled after 16K hours but???

Too back up a little it was starting to get low on power,slow to rev up and smoked a lot more.First thought was turbo getting bad.With excess oil use, leaks,hours and the other problems decided to do the complete overhaul.

The Cat dealer did an out of frame overhaul.Complete rebuild from top to bottom.Most everything was new or rebuilt to spec.New turbo, fuel pump complete rebuild.Was run on dino!

After getting it up and running everything was good except the power! It has been weak every since and still blows excess smoke.I complained ,but they said just needed broke in.

The rpm is great, just when you start to push half way into the blade full of dirt engine starts lugging down.

Haz of smoke from stack without load and the same with load.Same problem as before so?????

I was reading about the left pump on the backhoe thread ,could it be that? Also talked to my Cat mechanic and mention bad(new reman turbo).His response was it either works or it fails? I asked to check boast,but never got around to it.

Would like some suggestions where to start looking?:usa

Have you unhooked your fuel line and blown back into the tank with compressed air. Maybe you have some trash in your fuel line.:beatsme

The good thing about blowing out your fuel line is it don't take long and doesn't cost much.

I hope it's a simple fix for you.

 

[feroracing]

Do not forget to check the air filter also and the air ways

 

[Construct'O]

More Details

https://www.heavyequipmentforums.com/Forum/showthread.php?t=10033

Here is the thread on lift pump for backhoe ,so that was part of why i started this thread and my problems with the dozer.

As far as fuel to pump that was checked and had good fuel flow from tank to pump before engine overhaul.Plus there is prinary fuel filter before pump with metal screen.That was checked and ok.Plus did the air cleaner thing.

Before the overhaul the engine was getting slow to gain rpm and more smoke.With 16k hours just figured it was the turbo was getting weak?

The turbo thing has been discussed on here a lot.

My thought was it has to be the reman turbo or the rebuilt fuel pump. The pump was suppose to be a complete rebuild to spec alone with everything else.May not have replaced the lift pump? I can see this for rpm ,about what about the extra smoke?????

Don't know about the lift pump thing,so the above thread got me to thinking.

Machine still smokes as before and slow to gain and hold power underload,same as before complete overhaul.Better ,but you can notice it just the same!

I was hoping for new ideas as far as the fuel pump,lift pump, and turbo ?

I have over forty year experience with dozer ,but this is a new one and Cat didn't want to deal with it when on warranty,now i would like to try and find the problems.

Sorry for the long post ,but just tring to get all the info as to what has happened or didn't happen.Thanks:usa

 

[surfer-joe]

I'd have to say initially that someone messed up the pump settings when the pump was gone thorough. There is no reason for a completely O/hauled engine to smoke or have low power problems. Do they have a dyno printout?

On the other hand, you may have transmission or convertor trouble that is bogging the engine down. If it was plugged fuel lines or filters, you would not have a smoke problem. Same with the transfer pump.

I see that this problem started before the O/haul. You may want to get your drivetrain checked out before spending more on the engine.

 

[Cmark]

Hi Constructo. Jut a few thoughts on your problem.

Possibly the hydraulics are loading the engine down. Does it seem kind of sluggish to rev up when in neutral? If you run it at high idle and top-out the blade/tilt cylinders, does it make a difference to engine speed? Does it have a ripper valve fitted but no ripper? Is the hydraulic temperature OK?

Check for brakes binding. Put it on a slope and into neutral. It should freewheel easily even on a slight grade. Is the tranny temperature OK?

Does it have radial seal air filters or the old style with the bolt-in secondary? If it has the old style, make sure the secondary filter is new. You can't easily tell if these are clean by looking at them and they often get overlooked because they're not so easy to replace.

If the engine has been rebuilt and dynoed, I would say the chances of it being an engine fault are slim (but not zero). If the fuel pump has been overhauled then the transfer (lift) pump would have been done at the same time.

Let us know how you go. Good luck....

 

[Construct'O]

Update to questions

No dyno printout that i know of,but will check.Had Cat mechanic call and ask a bunch of questions.

Transmisson and hydraulics has been fine before and after,the problems is it still act as before ,with some better performance,but by not much.Should witht he wear factor from 16k hour to 0 or you would think.

At the time i did the engine,i did complete redo from raidator to the trans(but not the trans

Roded and boiled the raidator,new fan pullys,new engine oil cooler,new transmisson oil cooler, rebuilt the convertor,lots of new hoses why we we where we could replace them.Also converted the air filter over the adapter to use the new style air cleaner.

The engine doesn't heat or does the convertor run hot.

This a dif steer machine and everything works great.Transmission is strong.No binding of the brakes and roller easily on incline in netrual.

So thats why i'm confused with all this done acting much like it did before all the above work.

Still looking for help here,can they still check boost on the newer turbos,like they could the older ones.Mechanic says it either works or it don't.

I keep going back to the why before and still now thing,with all this work:beatsme:usa

I might add that i bought this machine new(one owner) 1988 S/N3ZF0848

 

[Cmark]

Yes, boost pressure can be checked. Also try a stall test with an accurate tachometer. Let us know the serial number of both machine and engine and I'll let you know what the figures should be.

 

[Construct'O]

Yes, boost pressure can be checked. Also try a stall test with an accurate tachometer. Let us know the serial number of both machine and engine and I'll let you know what the figures should be.

The dozer is a D6H XL machine 1988 model.I have the manufactures certificate of origin even ,believe it or not? Invoice date 11/22/88 21years old

Bought new from Gibbs/Cook Equipment Co. Des Moines,Iowa
Correction the machine S/N is 3ZF00878

Engine S/N 08Z48770 engine arr# 7C0501
Transmission S/N 20E01120 trans arr# 9W1720

6SU Blade S/N 1CH01557 $178,225.00
Cab H/AC 7 roller frame.
It has been kind of my proud and joy until now just needs a little help) like all us when we get old:Banghead.Really don't want to give up on it,unless it giveup on me completely,besides a little late now :beatsme

When i did all the above work above i always try to do things right the first time,and plan on keeping the old tractor until i retire or die off first?

With the clock at 16K the machine had the orginal turbo,everything except waterpump,batterys,starter,belts,and of course undercarriage.

Anyway what else can you think of trying ???? I will be getting the mechanic back over sometime when the weather gets better,when ever that will be and work like to try something if you all can come up with some new?

Any way to check fuel pressure? Again thanks:usa

 

[willie59]

I would think that a fellow that has done this much work to his machine has for sure replaced the air filters and checked the air ducts. Is it excessive black smoke or blue smoke? I'd be surprized if you said blue. You seem confident it's not a problem in pumps, hydraulics, or drive train. The thing that bugs me is your original post. Your "Cat" dealer did an out of frame overhaul on the complete engine and put it on a dyno. You said when you put it in service you noticed a lack of power. It seems that if Cat did everything properly, if the engine had a power problem, or anything out of spec for that matter, it would have shown up on the dyno. As for the "just needs broke in" response, it's just my opinion, that's what I call bull excrement! It seems you can only have one of two possible problems; 1) excessive load on the properly running engine from whatever, or 2) you still have an engine problem. If you in fact do not have an excessive load problem and your getting excessive black smoke, then the fuel to air ratio is off, more fuel than there is air in the combustion chamber to burn the fuel, black smoke. Fuel pump not calibrated correctly or turbo not providing air properly. Could muffler possibly be clogged up??? Just a thought. Good luck and keep us posted.

 

[zhkent]

Construct"O,
What a mystery.
So the culprit was thought to be the engine.
The engine was overhauled put on the dyno and passed.
To me that kind of rules out the engine, providing it is getting air and fuel.
So next would be what all hooks to the engine.
Atcoequip asked; Could muffler possibly be clogged up??
That to me seems like a possibility if the muffler was reused or incorrect.

To me there are 2 basic possibilities,
Air out restriction like the muffler
Or an extra load somewhere

Converter has been rebuilt so wouldn't think it would have the exact same symptoms again.

Somebody didn't switch your motor oil for 90 wt did they?

First guess Muffler.
Next guess: the hydraulic pump is causing the load, but don't think there is anything wrong with it. Think there is a hydraulic accessory valve that has somehow gotten to the raise or lower position causing a constant steady pull.

 

[australian pete]

i am not a mechanic however have owned lots of diesel engines in trucks and earthmoving equipment, me experience is that no matter how worn out a diesel engine is the power does not change much, i own a 1985 volvo 4600 front end loader, the cylinders were so worn it had practically no compression, had to use aerostart to start it even when it was hot, used heaps of oil,ran hot, it was down a little on power but not much, rebuilt it eventually because it kept running hot. to sum up being worn should not have much effect on power, you have another problem and they have failed to find it.

 

[Construct'O]

Can't post enough info everytime with out writing a book sorry !

I would think that a fellow that has done this much work to his machine has for sure replaced the air filters and checked the air ducts. Is it excessive black smoke or blue smoke? I'd be surprized if you said blue. You seem confident it's not a problem in pumps, hydraulics, or drive train. The thing that bugs me is your original post. Your "Cat" dealer did an out of frame overhaul on the complete engine and put it on a dyno. You said when you put it in service you noticed a lack of power. It seems that if Cat did everything properly, if the engine had a power problem, or anything out of spec for that matter, it would have shown up on the dyno. As for the "just needs broke in" response, it's just my opinion, that's what I call bull excrement! It seems you can only have one of two possible problems; 1) excessive load on the properly running engine from whatever, or 2) you still have an engine problem. If you in fact do not have an excessive load problem and your getting excessive black smoke, then the fuel to air ratio is off, more fuel than there is air in the combustion chamber to burn the fuel, black smoke. Fuel pump not calibrated correctly or turbo not providing air properly. Could muffler possibly be clogged up??? Just a thought. Good luck and keep us posted.

The muffer might be a check,but was thinking we put new one on when reinstalled the engine ,if not will start there.Good idea,i know it doesn't rattle or anything like the baffle is lost inside.Need to check to see if it was changed.

The smoke is black,looks like to much fuel,but runs like its low!!!!!!

As far as the dyno ,the mechanic questioned them on it and they said it was with in spec,to them and you or me who knows what was spec.I did find out later that since the engine was going to have 2 year or 2 thousand hr, warranty that is probably was set up on low spec or fuel.

If low fuel why the smoke thing,sorry still stuck on that as an issue?

Just doesn't make sense it acts(slow to gain rpm) and blows smoke like before the overhaul.

I also have a older D6R that blows very little smoke and will blow the doors off the H. When the H was new is was a strong runner,but not anymore.

Guys i know my machines,with forty plus years and as an owner operator and one man machine most of it's like you can feel and tell when your machine isn't performing.I have always been a person that can walk around anyone machine and pick things apart that the operator couldn't see.

Anyway the warranty is over,the two years is gone,so i'm on my own.This has been on going for two years.

More to the story after the warranty went off the mechanic admitted that it was probably set low spec.So he turned the fuel up 3/4 turn and its helped,but some power wise?????? The smoke stayed the same.If anything the RPM is higher then before because when backing up it will outrun the R(which is running 2050 rpm by the in dash tac)

I have had and have turned up older D6D (they have to be shimed) not just turn the screw.It would kick a$$. and blow smoke like the H does now.

I'm not looking to make a hotrod just good old study power.

I hate to repeat my self,but when you decelrate and then open it up it dogs along not that snap to wide open rpm ,like the D6R does.

The D6R pump went bad(not start good when hot) so took the pump off and rebuilt at local injection shop,the pluggers and barrels was shot ,worn bad,but other then hard start still pushed hard.Put back on and it really performs and very little smoke.Go figure?

Anyway getting off some here,just trying to fill in more blanks.

You know how the turbo on most good running machine usually always squark,the H just doesn't cut it there either.Still looking????? Hang in there with me guys,if you got any ideas:beatsme:usa

 

[Cmark]

Hi Constructo

Hi idle should be 2130rpm +-60.

Stall speed should be 1600rpm with boost of around 10psi.

Full load speed is 1958rpm with a boost of 12psi.

As you say, the smoke is a good indicator. The bottom line is smoke+low rpm=overload, assuming the engine is in good condition, which it is.

So, first thing would be to check the engine high idle rpm. If you can't make 2130rpm and you're getting black smoke then you've got a parasitc load somewhere.

I think you need to confirm that the hydraulics are OK. Does it have a ripper valve? Does it have a ripper? I ask this beacause if it has no ripper and the lines have been blanked off, the ripper valve could be stuck open and dragging the hydraulics down.

You also have the transmission pump driven direct from the engine. This is a (I think) 3 section pump. (Assuming this is a TC and not direct drive machine). It's possible (but not probable) that this could also cause extra load on the engine.

 

[OCR]

You know how the turbo on most good running machine usually always squark,the H just doesn't cut it there either.Still looking????? Hang in there with me guys,if you got any ideas:beatsme:usa

Hello Construct'O,
Can you get to your turbo and spin it with your fingers... see that it spins free?

Also... your machine does not have a waste gate???

One more thing... you mentioned a modification to your air filter... is there anything that might be out of whack there?


OCR

 

[Cmark]

The muffler theory is good.

You may also want to check you have the correct turbo fitted. It should be a 7C8632 or an 0R6342, but this is an outside bet.

 

[willie59]

I mentioned the muffler trying anything possible. I don't know what the D6 has, but a lot of modern machines have spark arrestor mufflers which can clog with carbon over time. If the muffler gets clogged up and doesn't provide a relatively free path of exhaust, then exhaust pressure on the exhaust manifold increases. When the piston is on exhaust stroke, this pressure keeps some of the exhaust gases in the combustion chamber, which would have an affect on the air/fuel ratio of intake and compression stroke. One thing you could try, remove the muffler. Remove the covers on the side of the engine compartment, then operate the machine with no muffler and see if it makes a difference. If there's no difference, we keep looking. Good luck

 

[Construct'O]

The muffer might be a check,but was thinking we put new one on when reinstalled the engine ,if not will start there.Good idea,i know it doesn't rattle or anything like the baffle is lost inside.Need to check to see if it was changed.

The smoke is black,looks like to much fuel,but runs like its low!!!!!!

As far as the dyno ,the mechanic questioned them on it and they said it was with in spec,to them and you or me who knows what was spec.I did find out later that since the engine was going to have 2 year or 2 thousand hr, warranty that is probably was set up on low spec or fuel.

If low fuel why the smoke thing,sorry still stuck on that as an issue?

Just doesn't make sense it acts(slow to gain rpm) and blows smoke like before the overhaul.

I also have a older D6R that blows very little smoke and will blow the doors off the H. When the H was new is was a strong runner,but not anymore.

Guys i know my machines,with forty plus years and as an owner operator and one man machine most of it's like you can feel and tell when your machine isn't performing.I have always been a person that can walk around anyone machine and pick things apart that the operator couldn't see.

Anyway the warranty is over,the two years is gone,so i'm on my own.This has been on going for two years.

More to the story after the warranty went off the mechanic admitted that it was probably set low spec.So he turned the fuel up 3/4 turn and its helped,but some power wise?????? The smoke stayed the same.If anything the RPM is higher then before because when backing up it will outrun the R(which is running 2050 rpm by the in dash tac)

I have had and have turned up older D6D (they have to be shimed) not just turn the screw.It would kick a$$. and blow smoke like the H does now.

I'm not looking to make a hotrod just good old study power.

I hate to repeat my self,but when you decelrate and then open it up it dogs along not that snap to wide open rpm ,like the D6R does.

The D6R pump went bad(not start good when hot) so took the pump off and rebuilt at local injection shop,the pluggers and barrels was shot ,worn bad,but other then hard start still pushed hard.Put back on and it really performs and very little smoke.Go figure?

Anyway getting off some here,just trying to fill in more blanks.

You know how the turbo on most good running machine usually always squark,the H just doesn't cut it there either.Still looking????? Hang in there with me guys,if you got any ideas:beatsme:usa

Cmark thanks for the info ,will try to print it off,so we can test some things out,Yes my machine has ripper valve,no ripper,but i put a hydraulic valve on my machine to pull a hydraulic scraper and im using the valve when i have scraper on.It is electric over hydraulic.

Use ripper(lever) valve for one function for scraper and use thumb button for the other on the scraper which has a squence valve for the third function.

Where would i start to check for drag on the hydraulic pumps because you can usually tell if something is running over top the relief and it just doesn't show any signs of doing that.Nothing like when you lift blade to top of stroke and then you can hear the engine pull down at idle ,but that is normal.

I get what your trying to tell me what ever was wrong before rebuild is still there.Right? Unlikly bad turbo or bad pump and with rebuild on both being bad again ,so back to problem before, still their.

I need to try and get a itemized list what actually was done and parts,but might be a little late now(two years),but will check that out.My mechanic is reall great abotu helping get info.Just like other hands are tied a little,as you well know sometimes.

I like the thought on the muffler to start with.As for the engine i was starting to loose anti freeze out through the exhaust,so would that plug or build up in the muffler?

More info, i did oil sample every oil change during warranty,no excess fuel or water by the sample.I had the Cat mechanic pull up the sample with me every oil change to see if things looked okay.PLus if major problem down the road i could go back and show them i had pointed these thing sout.

NO major failure,other then the problems talked about and things being to spec was all they said?

Bewteen work and the wet weather the last two years i didn't really get as good as break in as i would like.The machine used no oil in the first 600 hour and then started to use a little maybe 1 gallon over a 180 to 200 hour period between change.

The oil sample showed a jump in aluminum ppm of 2 upto 6 ppm at just about the time of oil usage.Which the next oil change stayed at 6 ppm.

The oil usage runs about the same with now same where 1000 hour.In the the test explanation for wear meatal it has listed aluminum as...... from main or rod bearing,pistons,rocker shaft in same engines,and turbine?????

Just adding this info .Well is late so getting off here.This(typing) is wearing me out about as bad as work:usa

 

[Construct'O]

I mentioned the muffler trying anything possible. I don't know what the D6 has, but a lot of modern machines have spark arrestor mufflers which can clog with carbon over time. If the muffler gets clogged up and doesn't provide a relatively free path of exhaust, then exhaust pressure on the exhaust manifold increases. When the piston is on exhaust stroke, this pressure keeps some of the exhaust gases in the combustion chamber, which would have an affect on the air/fuel ratio of intake and compression stroke. One thing you could try, remove the muffler. Remove the covers on the side of the engine compartment, then operate the machine with no muffler and see if it makes a difference. If there's no difference, we keep looking. Good luck

It's late so i'm out of here .Thanks for hanging in there with me:usa

My mechanic has computer access ,so i can have him download the site from his truck about what your posting,he will help if you guys can come up with stuff to check and do !

 

[Construct'O]

Hello Construct'O,
Can you get to your turbo and spin it with your fingers... see that it spins free?

Also... your machine does not have a waste gate???

One more thing... you mentioned a modification to your air filter... is there anything that might be out of whack there?


OCR

As for getting to turbo ,not so easy,but will see.As posted problem was before the fact,don't think there is a waste gate ,at least not that i can see,like on a dodge cummins turbo,right?

I change the air filter when dusty conditons are really bad every time i change the oil,haven't seen anything there wrong.Like said on other post changed it over to the new style adapter for the slip on inter filter.

Well i'm out of here for sure.You guys sleep on it tonight and come up with more idea and then will give it a rest until i get the mechanic over which looks to be a while.

Just for added info i mentioned the hydraulic pump having 16K hours on it if thought need replaced.He said if that the dif steer was acting up that the pump is usually getting weak. The dif steer still works like a new machine.Actually bettter and smooth then the D6R with around 6 K on it,So go figure.

Good night and thanks for all the help and ideas.:usa