Caterpillar C7 ACERT stalling question

[Ncostello]

Have a 2005 Caterpillar C7 in a GMC C8500 Chassis (volunteer fire truck). The miles are low at around 5000.

The truck has always ran fine with no real issues to speak of. It gets an annual oil change regardless of miles or hours. Upon changing oil the first few times I noticed that if I attempted to drive the truck without letting it "warm" up for several minutes it would be very sluggish with no acceleration or power. Almost like a dead pedal. But it would go a little. Just sputter and plug along, then it would wake up and be fine. Take about a half a city block to come out of this. So I'm figuring I had air in the HEUI injection system.

But recently I've noticed if the truck sits for several days, I'm getting this same situation. Had a fire call this past week and it just stumbled along and didn't have any power for about a half block. Then it was fine and picked right up and ran great the remainder of the call.

On a typical day, the truck is started, idled out the door and allowed to run at a 1200 rpm idle during truck checks. By the time you drive away it runs great.

But as stated, if you need it in a hurry, starts fine, idles out the door fine, idle for maybe 30 seconds fine....then falls flat on it's face for a short while until it finally comes out of it and runs great.

The only thing I can think of is perhaps our switch to WIX oil filters has caused some drainback issues allowing air to enter the HEUI injection system? Whereas the CAT filters never did this before? I don't know...just an idea. We've used Shell Rotella 15W-40 in the engine since new.

 

[SnoKing]

So throw a CAT filter at it! SNOKING

 

[mwilson]

Do you have the ESN handy??? Is it the WAX prefix serial number??

 

[EDankievitch]

The CAT Huei system sucks. I've got a pair of C9's on gen sets on one of the boat's I work on. I'm lucky if I can get the HUEI pump or the injectors to last more than a thousand hours run time. And not having the CAT laptop we're stuck with having to call CAT to service them. So I feel your pain. That said here's all that I can offer for help... Use only CAT filters aftermarket filters tend to break down and jam up the HUEI pump and cause premature seal failure on the injectors. Check all your fuel lines and connections. Make sure that the primary fuel filter is 10 micron or less. Check all your electrical plug connectors the ones CAT use really suck. If all common sense things look good then you have no choice but to call in the CAT tec or burn it. I'm to the point with these C9's that I'm all for burning it being the best way to fix it once and for all..

 

[Jim W]

The electrical connectors are manufactured by Deutsch. Cat has used them since the mid-80's through the time period of 2009 when I retired from Cat. I believe they are still using them in the electrical connection interface.

Has the engine had any service flashes down by the dealer at all? I know Cat will come up with service flash to either solve a performance issue or improve operation of certain programs on components; they usually send out notices but yours may have been missed check with the dealer. You will need the engine serial number, year manufactured and maybe vehicle serial number also.

For fuel filter one of the Cat part number for a 10 micron filter standard efficiency is 1R0750. There are advance efficiency filters also but you will need to see the dealer for the correct fuel filter for your engine. The Parts book for the C7 engine that was shipped with the the engine should contain the correct part number for fuel filter to use.

Jim W.

 

[mwilson]

I'm not going to be back in Bangor until tomorrow so I am without my dealership Cat tech whom we call "Scottapillar"......

If you can get me the ESN I will call my Maine CAT TEPS coordinator who just happens to be an excellent CAT tech and ask him. It would be my pleasure to do so but I really need the ESN when tapping a CAT source.

Mike.

 

[Ncostello]

The serial number is KAL21939. Performance spec is 0K-5097. The ECM software on the tag says 247-4618. It had been to CAT dealer once way back in 2005 or 2006 for an issue with a code showing up for the PTO circuit. That has been corrected. It's a 300HP version. Not sure if they flashed it back then or not.

Other numbers on this tag are AH number: 235-9214
Core AR number: 212-3648
OEM number: 15180443.

The truck uses a OEM installed primary fuel filter on the frame rail. It's a 30 micron I believe...Racor I think with a clear bottom bowl. The final filter is a 2 micron on a filter head mounted to the engine. We did install the optional hand pump on this final filter head when it was fairly new because there was NO way to prime the system after new filters were installed. No electric pumps or any hand pumps were provided. Dry filters and engine cranking won't put a drop of fuel in the new filters. And we never prefill them. Not sure what GM was thinking on that one.

 

[Jim W]

I am sure that Cat has had a software update since 2006 on that series of engines. I would schedule an appointment for the dealer to re-flash the software if needed. At least to do an electronic diagnostic scan of the engine.

The 247-4618 on the tag is a Caterpillar part number for that software version. The other two similar numbers such as 235-9214 and 212-3648 are also Caterpillar part numbers for that engine.

Jim W.

 

[mwilson]

Thanks for the ESN. I wanted to get with the CAT guys Friday but accounting is beating me to death as they are trying to close 2014 and every little mess that each store has hanging is coming to me for resolution. They are being wicked needy right now.

I WILL get out in the shop Monday afternoon and see if it may be an update as suggested by Jim.

 

[mwilson]

Just sitting here researching and thinking, does that have the hand primer pump? If so those can cause a bunch of trouble when they go bad and start sucking air....

 

[Ncostello]

Yes it has a hand primer. We added it to the CAT filter head as neither CAT nor GMC gave us ANY way to prime the two fuel filters, yet warned not to prefill them. We did that the first servive when the truck couldnt be started. The first one vibrated out and fell apart. About caught the truck on fire going down the highway. The one on there is basically brand new.

 

[Ncostello]

The truck seems to be sluggish and stalling every day now during the initial start up and run. It's pretty consistent. Without seeing the truck, Cat dealer suggested that we try an oil change since the injectors are HEUI type. We perform annual oil changes so it's about time anyway. I'll try that.

Otherwise they suggested I get the truck in for a software flash update (hasn't had one for 9 years) and they will look at perhaps a check valve on the high pressure oil pump and some kind of valve on the back of the head known to fail. They are going to do live monitoring from a cold start and drive and check some parameters/pressures.

I'd hate to think that the Rotella 15W-40 we use isn't good for a years worth of use in this low mile/hour application. If it's not the oil this could get expensive for a small volunteer fire department to afford. We've been using Rotella since new and never really had this situation occur...EXCEPT....after an oil change. If you change the oil and attempt to drive away immediately it will act this way. If you let it idle at 1200 rpm for a few minutes it's fine. Which is happening now but we've not changed the oil.

 

[mwilson]

Sorry for the delay in suggestions, they have kept me on the run here.

What if you take a union and temporarily bypass the frame mounted fuel filter just to rule that out. Where it exists on the suction side it concerns me.

Also, is that GM new enough so that it has plastic fuel line instead of braided stuff??

 

[Ncostello]

I'll have to rule that out. I kinda had a feeling like you about this filter. It's a Racor setup with the clear bowl on the bottom. 30micron if I recall.

I can't recall but I don't believe the fuel line is plastic. I know on the tank it has those GM stainless quick connect fittings. As far as the line I'm not sure. I'll have to run it down from the tank all the way up to the engine. I keep thinking it has a black plastic braided cover over it. But as to whats inside I don't know.

 

[mwilson]

My Cat rep is here right now, he agrees with testing the fuel system first. Also agrees with the the thought process from your Cat dealer. The oil can be an issue.

He thinks that you should switch to 10W30 Rotella for year round use. KAL series are very sensitive to oil viscosity.

 

[Ncostello]

Thanks again! I had wondered about the use of 10W30. I know many 6.0L International owners swear by 10W30 HDEO in their HEUI applications. Ill try that as well.

 

[Ncostello]

We've switched to Rotella 10W-30 for a few months now and have not had any stalling issues thus far. I've had it sit for a week with no start-ups and it then started easily, idled for about 30 seconds (as if waiting for firefighters to get on board) and runs out fine after. No loss of power, no stalling. I've tried this several times and each time it has ran well.

I'll just keep testing the 10W-30 oil change out over time. Perhaps take it to the local CAT dealer at some point if the problem comes back.

 

[Ncostello]

November now and still no more stalling issues after switching to the Rotella 10W-30 DEO. Seems to have really helped this engine.

 

[JUeckert]

Thanks for the info on the 10-30 oil.. I have two 6.0's, one runs fine on just about any oil, the other prefers 5-40 or 10-30.. Strange how an engine can respond to a difference in oil, but it wouldnt be the first time i have witnessed it..