Just like the title says. A customer of mine has a D6R with the C9 and the engine makes an un-godly fluttering sound under load. Doesn't seem to matter if its got a big load of dirt or just tracking across the field. It sounds a bit valvey so we pulled the head, had it checked out, found one burnt valve and thought "good, we found it". Wrong, still does the exact same thing. I've ran the overhead 3 or 4 times and its never changed or been off. Local dealer has been out half a dozen times running cut out tests, replacing sensors, updating flash files, trying anything they know. About the only thing they've changed is made the smoke go completely away (used to give out a puff of smoke slightly at initial acceleration). Anybody else ran in to this or any Cat mechanics have any ideas? My gut tells me its the Heui pump or an injector but I can't sell 6 injectors and a pump on a gut feeling.
You mean the dealer can't figure it out? There must be a way to test the pump & injectors. Cam is OK?
Totally in left field here but an operater I know was bad about feathering the decelerator and it sounded as if it was not really missing but just sounded weird. This makes me wonder if the decel pedal is loose or the switch is defective. Are there any codes? The machine I am referring to had a fluttering sound. It ran fine and pushed as good. Even sounds like its bumping the governer on and off. I think the pump is good or bad based on pressure , the injectors another story how many hours?
Had a d6 in the shop not to long ago...same issues, found #5 pin in electrical connector in rocker box for internal harness to have pushed itself back a bit and was not makeing a good connection but enough to not generATE any codes or such.......just sayin good luck. P.s. Sorry for yellin caps lock is stuck....lol:usa:drinkup
6800 hrs. Dickjr. - Every 6R I've been around does exactly what you're describing when the op feathers the decel but this one sounds like that all the time, but that was my first thought too, I'll take that pedal apart and check it out just in case. I haven't actually had the cam out to inspect it but that was a suspicion of mine too. I've ran the overhead 3 times and measured rocker lift once and everything seems to be uniform, and nothing was overly loose the first time I checked to indicate a lobe knocked off or something. The wiring deal has always been on my mind but it seems almost to rhythmic to be a loose wire, but still I should check that and I will. It's had wiring issues in other areas. My brother works at am injection shop and they just bought a common rail injector test bench. As soon as they get it set up I'm taking the injectors to them if I don't have it figured out. Thanks for the help guys, its nice to have some real world suggestions and experience. My local dealer is decent but when an unusual problem like this comes up its pretty much just blank stares and them asking me to let them know what it was when I get it figured out.
also, no codes. Anybody know what the pressure is supposed to run on those Heui pumps? Fuel pressure is 60lbs.
Please let us know when you get it. Just bought the same machine, heui is new to me, dealer tech said to watch oil samples for aluminum which is a sign the pump is failing
Not alu, Heui pumps is known to fail but then it is all steel parts that fail, leaving high readings of iron but usually you'll notice it when injectors start getting mechanical errors or it is hard to start due to low heuipressure. Checked the return fuel for air? Maybe running it with one injector at a time shut off completely?
If you have ET, monitor the injection actuation pressure. desired and actual will be within 50psi of each other. If not its either the sensor but probably the pump. You can remove the top of the pump and look inside, there is a coil in there that attracts any metal debris so you can see if the pump is failing. You can also remove one of the plugs in the high pressure galley of the head. If the pump failed and you find metal on the plugs it will need cleaned out along with new injectors. I too have found loose connector and bad crimps on the harness inside the valve cover. Cat sells new plugs that plug onto the injector if you have a bad one. Engine oil with high hours also can make it rough so if its close to its change interval that could also be it.
02, ran into this a few months ago on a 385 hoe. May or may not apply but it had an intermittant misfire. It would not do it under increasing load or steady full load. It would misfire only when you reduced the load slightly. With the excavator it's easy to vary the load but not so easy on your dozer. What found our problem was to get it into the misfire condition and then use ET to cut out individual cyls to find the bad injector. Later Bob
The D6R s that i have worked on the heui pumps run very high psi and cause the problem your talking about also takes out your injectors i have replace acouple pumps and injectors at the same time. i also have seen junk inbetween the magnet that pulls the injectors open. but cat ET should show up on the injector cut out
Thanks guys, its coming into the shop hopefully over the weekend and we'll pull that cover off the pump and see whats in there. It's been doing it long enough that the oil has been changed multiple times so I can rule that out. Cat dealer put another injector in it and it sounded better for a couple hours, now it sounds worse than it ever has. I don't really want to find a bad pump but I hope I do so this problem can be solved and put behind us. lol
I wonder if these have the same style injector seats as the 3126? Those would become unseated and allow compression back into the fuel supply. If you stick the return line in a bucket of fuel and it bubble during a torque stall then its a seat. Would give similar symptoms.
That would be easy enough to check if they're the same setup. Maybe Lee-online will chime in but I think its the same setup. No longer than it would take to check I might just do it anyhow.
Yes, the injector cups can leak compression if the injetor isn't seating properly, that's why I asked earlier if it's been checked for air in the return line. The fact it got worse after an injector were replaced points to this as well.
I must have missed that in your post. But I thought the same when it got worse after injector replacement.
hey 02... I would also check the return fuel check valve in the back of the head... see if you can pinch the return line off somewhere.. another this is to plumb a guage directly into your high pressure rail and watch it while operating, I think it should be around 800 psi *you"ll need to look up spec* this may tell you if your control valve section of the heui pump is faulty. If you do find steel like lee-online has mentioned, the best thing to do (not what most costumers like to hear though) is a "heui overhaul" which consists of changing the pump, 6 injectors and flushing the rail. costly but effective, if you dont you will more then likely find yourself chasing and changing injector after injector...
I replaced that check valve at the back of the head. Ya, I already told him that if its the pump its going to also need new injectors to properly repair it and get all the contaminant out. I think of it as a small hydraulic system (which it is) and in a hydraulic system when something fails and you don't flush everything you'll be chasing problems forever.
hey 02dmax what did you come up with on the weekend?
Well, nothing! Lol. The machine wasn't in the shop before I left for vacation and I won't be back until the 14th. Customer is supposed to clean it up and put it in the shop, pull the air cleaner can and all the easy stuff out so I can pull the lid and replace injectors if I have to. I'll update you when I get back to it. Weather got nasty before Christmas and doesn't look like they'll be working anytime soon. I've got an urgent job when I get back but planning on starting on it the 15th or 16th.
It is better to figure out the problem first.I think the local dealer should solve this problem for you.If not them,who will be responsible for it?
Don't bother with the cleaner and all that stuff, pull the floor and put a transparent hose on the return first.
Had a 6 doing the same thing. took a 3 foot section of clear plastic hose and put it in the return fuel line. no bubbles till it started missing then it was pure foam. thats where i would start for sure.
Aron - the dealer has been out there 7 or 8 times, they've done less troubleshooting than I have and made less progress and they charge about 1200 bucks every time they show up to sit there on their computer and scratch their head. We're done with the dealer. I'll start with the clear hose, sounds like a quick and easy test.
Makes me sick when a dealer charges top dollar and no results, they should wave the charges. Interested in what you find in the end.
Well I just got back to town and talked to the customer. The only way he can get his money back from the dealer for all the fruitless service calls is to let them keep working on it and they'll credit him however many hours he's already paid for. So its at the dealer getting a new HEUI pump and injectors put in it. That's pretty much bull$hit on the dealers part in my opinion but if that's the only way to get your money back I'd be doing the same thing. I just hope they get it going for him. This is the same dealer that won't refund money for parts though either, they'll just write you a credit for future purchases, which is fine because I'll always have future purchases there but when they mess up a parts order twice the last thing I want to think about is ordering from them again. Lol. I'll keep you posted on whether this fixes it. It was supposed to be done yesterday morning and still no call.
How convinient, now they get the chance to cover up their mistakes and blame it on the pump or an injector maybe, would be fun though if they don't solve it this time either.......
^^^^^^
I'd like to be the one that finds air in the return line. Supposedly some guys from Peoria were even in there poking around on it. I find that hard to believe though. I doubt they have time to do anything but design more complicated equipment that's impossible to work on.
I call ******** on the Peoria saga, that would take an act of congress to get CAT to get involved in small stuff like this.
Prob wouldnt be fun if they don"t solve it this time since this is my dozer and I have spent around 10 grand on trying to get this prob solved! Can't complain about the dealer at all they bent over backwards to get it fixed and they credited my account for two of the three service calls they have made for this problem.
I had the Peoria out with me before. Mine was a safety issue though. Keep posting the results, I want to know what you find just in case I ever run into this problem and Good Luck!
Don't go too hard on the dealers. They're only human. I had a 3176 in a 140H with what sounds like the same problem; an intermittent fluttering missfire under heavy load. Spent hours with ET trying to pinpoint the bad injector but no luck. As the customer didn't want to spring for six reman injectors, and it wasn't causing him any operational problems, we left it. It gradually got worse and six months later we could pin it down to #1. I suppose the takeaway is, if it only sounds broke, don't fix it.
Have you checked fuel transfer pump inlet pressure? You'll have to put a tee with a gauge in the inlet of the transfer pump. At high idle if you see more than 11-12inHg vacuum change your water separator first. If it's still got lots of vacuum start looking for a kinked or twisted fuel supply line or a tank valve that isn't open all the way. Once diesel gets below around 12inHg it turns to foam and causes strange things to happen.
6 injectors and a HEUI pump fixed it! I haven't talked to him since he started working it but he said it sounded great at the CAT shop when he went to see it. I'm just glad its figured out and fixed. I'll definitely be keeping this one in my notebook for future reference and I'm sure the guys at the dealer will too. I heard through the grapevine that they ended up finding some pieces in the injectors or oil galley but I haven't talked to C130 eng to confirm that.
Tell him to change the oil bang on 250 hrs from now on and even use Cat branded oil and filters. This will go a long way to keeping in with the dealer if some goodwill situation arises in the future. Use there SOS aswell, it,s a 2 way street at the end of the day.
just was reading your thread from a couple of years ago about a d6r/c9 that was fluttering under full and heavy load. I am having the same problem, little puffs of black smoke. mine seems to be doing it at full rpm but not full load like a stall. unit has 11k hours on it, pump and injectors have been done, I have ran the overhead. no difference. was wondering if you had found the problem with yours.