Author Topic: CAT C7 350 HP lacking power (torque?)  (Read 24630 times)

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Offline Kimmohei

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CAT C7 350 HP lacking power (torque?)
« on: May 03, 2014, 08:14:28 AM »
During the past 11 months I've been driving almost 15 K miles with my RV that has a CAT C7 350 engine. The engine number is KAL59362. Total milage is almost 100 K. It has been running great until a couple of months ago. It has been climbing hills really well, accelerating well....I've been very happy with its performance. I've done all the regular maintenance according to recommendations.

A couple of months ago I was driving through the tunnel under Mobile, AL starting climbing the hill after the tunnel. I felt a mild jerk and right after that I noticed that there was a lack of power in the engine and climbing up the hill was slow and "painfull". Got to the top of the hill, took first exit, came to a stop sign. Accelerating from full stop my coach was just slowly crawling forward but gained normal speed after a while. On flat land I was able to drive with normal speed but anytime there was a hill the speed slowed down a lot.

I changed the airfilter and both fuel filters. The old airfilter was definitely very dirty. The recommended air filter brand was not available so I ended up buying another brand that was supposed to be matching with the original brand (cross referenced it).
I wasn't able to find CAT-brand primary fuel/water filter but the secondary filter for catching smaller particles I managed to get CAT-brand.
When changing the primary filter my friend filled (primed) the new filter before I installed it but when changing the secondary filter I didn't prime it. The engine started normally, then shut down but started okay again.

After the above described actions I went for a test drive. The coach definitely accelerated better than prior to the filter changes but it wasn't back to normal. It climbed hills a little better also but not as it used to. After reading more info online about engine issues, I figured that it might be a good idea to keep driving a few hundred miles and let the computer reset old settings.

The performance has improved a lot since right after the filter changes but still, after about 2500 miles, my coach is not performing as it was during the first 12.5 K miles. The biggest issue is when climbing long long hills (up to mountain passes) like what I have faced here in New Mexico. Before I was able to drive these kind of uphills at least 50 mph or faster and now the speed drops to 30 - 35 mph. Engine temperature, by the way, is perfect (I wash the radiator regularly and both thermostats are new).

Lastly, there are no oil leaks, oil consumption is as it was 15 K miles ago. Nothing else has changed except what I described above.

I'm hoping that there is someone out there that can tell me what I should do next. My biggest problem is lack of unlimited funds. If I had the money, I would go to a CAT service center and have those guys do whatever it would take to make my coach fly again.

Thank you,

Kimmo Heinstrom
2005 National Tropi-cal t370 LX




Offline Brett Wolfe

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #1 on: May 03, 2014, 12:42:20 PM »
Kimmo,

Has the initial valve adjustment been done-- should be done around 30k miles.  If done by a previous owner at a Cat dealer and they recorded it with Cat Corp they will have a record. Call with your engine serial number: 877 777 3126.

A sudden loss like that could indicate an issue with boost. 

Actually, other than verifying valve adjustment, your best bet is to pay the half hour or so and have a Caterpillar dealer check the computer for codes.

Brett

Offline Kimmohei

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #2 on: May 04, 2014, 05:03:08 AM »
Thank you Brett.

I will make that phone call and take my coach to a Cat dealer in Albuquerque, where I'm heading next.

Kimmo

Offline Kimmohei

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #3 on: May 16, 2014, 11:51:42 AM »
Here is an update:

I called CAT and according to their records the initial valve adjustment has not been done to my engine. I also scheduled an appointment with Wagner Equipment, a Caterpillar service company, to have them taking a look what's going on.

Wagner technician, Robert, super great guy, plugged his computer to my coach engine, got some readings, asked his supervisor, Will, to take a look at the readings. Based on the numbers they saw (I didn't understand a thing, even though they explained everything what they saw about what was going on). They said there is something going on with the boost (as Brett predicted).

They decided to check that all hoses and the fan related to boost (turbo, I think it was) are tight and in good shape. They found a couple of leaking hose connections (I saw them too). Leaks were easy to fix by just tightening the connections (joints). They also determined that the turbo and the fan were in good shape.

After they put everything back together the computer was plugged back to the engine. Some readings, according to them, looked better than before. Next, they "shut down" one one cylinder at the time. If I understood correctly what they said, they were able to see how the working cylinders were compensating the power when one of the cylinders was out (I'm positive I didn't explain this right even though I saw from the computer screen what was going on).

Bottom line was (is) that my #6 cylinder is not doing anything to move my coach, i.e., #6 cylinder's fuel injector is out. When I asked from Will and Robert why they didn't immediately test the cylinders and injectors their answer was that they wanted to eliminate boost leaks before further testing.

So the bottom line was, and still is, that I'm only having five cylinders working in my coach. Injector change cost would be around $500-$600 + labor. They also mentioned that the HEUI-pump might be a good idea to change. Upon my request they also gave me a quote to replace all six injectors and HEUI-pump. That would be approximately $5700. Unfortunately I don't have money to have anything fixed right now.

I want all of you out there to know one thing about Wagner, Bill and Robert in Albuquerque: Great people makes a great company! They were friendly, helpful, very efficient and explained everything to me what was going on and what I should do. I cannot tell you what they charged me from the approximately 2.5 - 3 hours they worked on my coach but I assure you it was next to nothing (litterally). Good, helpful people are still around...

Now I'm trying to gather some money together to by injectors and HEUI-pump...Maybe I can figure out how to change them myself...

Thank you.
Kimmo

Offline WILDEBILL308

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #4 on: May 24, 2014, 07:57:56 AM »
Kimmo, Sorry to hear of your problems. I have not worked on a Cat so I did some searching on the net. It doesn't look that hard to do an injector change. I wouldn't change the injector pump unless the shop could say it was definitely bad. 
Here are a few sources for parts and tools you might find useful.
http://www.shopinjectors.com/diesel/caterpillar/fuel-injectors/10r4763.htm#install

http://internetdiesel.reachlocal.net/detroitdieselinjectorsseries60early-2-1.aspx

http://www.injectorwhse.com/servlet/the-CAT-Medium-Duty-cln-C7-and-C9/Categories

http://dieselcranks.clickforward.com/?adid-2E343B92-B097-442c-BFA5-BE371E0325A2=1368258&kw-2E343B92-B097-442c-BFA5-BE371E0325A2=caterpillar+injectors

http://www.dpausa.com/makes.cfm
Please keep us informed as how this turns out.
Bill

2003 Bounder 38N,300 HP 5.9 Cummins
Allison 3000MH Trans.Towing 2014 Honda CRV. Home base Fort Worth, Texas
A man who carries a cat by the tail learns something he can learn in no other way.
-Mark Twain-

Offline akeyzoo

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #5 on: May 26, 2014, 06:23:39 PM »
I would only replace the failed injector.

Chris

Offline Kimmohei

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #6 on: May 20, 2015, 02:09:23 PM »
Here is an update of my engine issue that I wrote about over a year ago.

Thanks to Dave Atherton, a retired Cat mechanic, I was able to get my coach engine running well again. Dave contacted be after reading my description of the CAT C7 engine problems telling right away, that the lack of power cannot possibly be related to the injectors, regardless of the fact that CAT mechanics in Albuquerque, NM, narrowed down the problem being in  #6 HEUI injector.

Below is the story of how things went once I called Dave:

- He asked me to get access to my engine, specifically to #6 cylinder, from my bedroom. It was a bit tricky to open the access panel that was partially under my bed but not too difficult to do, though.
- Dave then told me to remove the valve cover from the top of the engine (lots of bolts). Once the cover was off, he asked me to call him, which I did.
- He then told me to turn on the engine (no, oil was not flying all over the place). While the engine was running he asked me to unplug power cord from #6 injector (it's the one under the bed, of course) and see what happens. When I unplugged the cord, the noise from the engine pretty much scared the crap out of me! I plugged the cord back to the injector and the engine calmed down. I then decided to see what happens if I'm doing the same thing to #5 injector. The result was same. The engine was running like crap and was sounding very noisy and irregular. I put #5 injector cord back in its place and I then called Dave who was waiting for my call.
- Once I described to Dave what happend, he then told me that I had just proved to myself that the injectors are working just fine. It made sense to me.
- Next step: Dave was suspecting (without being absolutely 100 % sure) that most likely my lack of engine power (torque) is caused by a defected atmospheric pressure sensor. He gave me instructions where and how to find it and how to remove it. Only difficulty to remove it, by the way, was that it was impossible to see what I was doing. Instead, I had to feel what I was doing.
- Once the sensor was out I took it to Caterpillar service center and bought a new sensor. The cost was approximately $145.
- Dave's instructions to me at this point was to install the new sensor and make sure that valve cover, cords and everything else is properly back in place and then go for a test drive.
- Of course I did that, with beautiful end result! My coach was running like there would have never been any problems.

So, thanks to Dave, I fixed my coach with $145 instead of hundreds (or thousands) of dollars. AND I am not a mechanic. I'm just a "crazy Finn" that decided to give a shot, because I felt good about this Dave fellow and his instructions.

Thank you and I hope that this will be helpful information for someone else.

Best Regards,
Kimmo

Offline Brett Wolfe

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #7 on: May 20, 2015, 04:28:57 PM »
Excellent update.

Kudos to  Dave Atherton!

Offline aamkajutsu

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #8 on: May 22, 2015, 05:42:32 PM »
Thank you so much for posting this. I recently purchased a used 2005 Phaeton with a Cat 350 C7. I am experiencing the exact same problem. I was about to schedule an appointment with the Cat service folks to have it diagnosed but I think you've described the symptoms exactly.

Can someone please tell me where on the engine to find the Atmospheric Pressure Sensor?

Phil

Offline aamkajutsu

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #9 on: June 14, 2015, 07:00:32 PM »
I would like to send out a big "Thank You" to Dave Atherton.

I recently purchased a 2005 motorhome with a CAT 350 hp C7. I'm pretty good with gasoline engines but I don't know anything about diesels. So, when I noticed that there was a problem with acceleration and a problem with power I did what  a lot of folks in my situation would do and I used Google to search for an answer to the problem.

That's how I discovered this thread and Dave Atherton. Dave helped another person, Kimmo with a similar problem and I was sure the answer to my problem was the Atmospheric Pressure Sensor also.

I sent Dave a private message and asked him if he thought my problem was exactly the same as Kimmo's.  Dave wasn't so sure and suggested that I check out some other things first. As it turned out my problem was more complex than Kimmo's. At this point I'd like to say that Dave was more than willing to help a complete stranger (me) and never gave up on me or the problem with my engine.

Dave believed that it was probably my Boost Pressure Sensor. He said that he didn't like throwing parts at a problem but since I was not able to check the fuel line for air or check the fuel pressure that this was a logical part that could be bad based on the information I'd given him about what was going on with the engine. I had already replaced both fuel filters and the air filter without resolving the issue.

The Boost Pressure Sensor alone did not fix the problem. He suggested that more information was needed to determine the next step. I told him that I could take it to a nearby CAT service place and ask them to hook it up to their diagnostics computer and give me a print out on any stored codes. He thought that would be a good idea. The folks where I took my coach were very helpful and gave me a 9 page printout showing a bunch of codes and stuff that I did not fully understand.

I emailed a copy to Dave. From that information he was able to tell me that there were a number of issues. The Boost Pressure Sensor was bad, the Atmospheric Pressure Sensor was bad an so was the Boost Regulator thingy. I don't remember the technical name for it but you get the gist.
After walking me through (holding my hand is more accurate) replacing these other two parts he suggested that I take the rig for a spin.
I immediately noticed an improvement in acceleration and power. Unbeknownst to me I had driven the rig from Houston to San Diego and then to Seattle without any turbo.

Anyway, without making this any longer, I'd like to thank Dave Atherton for taking me under his wing and helping me resolve the problem I was having with my coach. The world is truly a better place because of people like him and I have a better understanding of diesels and how they work.

Thanks Dave!!

Offline robertsjae

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #10 on: June 15, 2015, 06:22:53 PM »
Nice to know we have Dave and others like him that a willing to help us on this forum.
Thanks Dave and the many others that have helped.
« Last Edit: June 15, 2015, 08:14:04 PM by Brett Wolfe »
Bob Jae
2006 Beaver Monterey
C9-400

Offline Stevet79

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #11 on: January 24, 2018, 02:46:30 PM »
Excellent update.

Kudos to  Dave Atherton!

Hey is anyone still talking on this subject.
This post sure sounds like my c7 problems.
Would really appreciate any advice I can get on this subject.

Offline David.e.atherton

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #12 on: January 24, 2018, 09:20:25 PM »
Stevet79, can you review your low power problem again so I can assist you.
Dave Atherton Retired Cat Mechanic

Offline Stevet79

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #13 on: January 25, 2018, 07:17:31 AM »
Thanks for your response.
I have a cat c7 350 hp in 2006
Itasca ellipse W.
It just seems to go over the hills very slow. It will drop down to around 35 mi/hr on some long hills. The rig had about 48K miles when we bought it and now about 66K. It weighs in around 30K lbs with about 4K lbs TOAD behind it. It's always ran good but cranks a long time if cold out and you don't use the block heater to warm it up.
After talking to people with similar rigs same engine and reading this form I'm thinking it's not performing as well as it should be.
It has had the oil changed as required and I installed synthetic the last change. I'm in Quartsite AZ now and would like to find a good CAT shop that would plug it in and check it out.

Offline David.e.atherton

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #14 on: January 25, 2018, 05:49:59 PM »
Stevet79, reading your post and you indicated you are in Quartzsite, Az. It just
happens, I live in Quartzsite and have Cat ET where I Can help find your problem.
Can look at your engine Saturday afternoon or Sunday Dave Atherton Retired Cat
Mechanic.   Phone 605 999 0720

Offline seeing the sights

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #15 on: January 25, 2018, 06:42:17 PM »
please keep us posted

Offline Stevet79

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #16 on: January 28, 2018, 08:57:52 PM »
Met with Dave and he did the CAT Scan on my C7 and I'm very
impressed with with him and his knowledge about these engines.
He educated me more on a couple of hours than I would have ever guessed. We did find the engine running cold and in lower boost mode.
I now have a list of things I will address over the next few weeks since I'm on the road now. If you ever get a chance to get into one of Dave's classes it would be time well spent. I will provide updates as I make changes and the results I get. A friend of mine was along with me when Dave went through all the possible issues and we both came away with the same opinion of Dave and his knowledge. We are both what I call Gear Heads. The type that has rebuilt engines and do most all of our own repairs. Thanks for all positive feedback.

Offline Hey Dave

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Re: CAT C7 350 HP lacking power (torque?)
« Reply #17 on: January 30, 2018, 09:20:47 AM »
 Cat C-7 low power, looked at his motor home in Quartzsite. Finding for low power located in two
Areas. First engine is staying into the cold mode with ECM for a real long time. Possible cause heat Temperature
Gauge reading incorrect temperature and engine ECM reading temp keeping engine cold mode all the time, max
Temperature climbing steep grades between 180 deg f and 190 deg f. Thermostat for engine opening 191 deg f.
and full open at 207 deg f. Intake air temperature to engine 90 to 105 deg f. Second low fuel pressure owner
plans to install the Caterpillar electric fuel pump.

Dave Atherton Retired Cat Mechanic

Dave Atherton, Retired Caterpillar Mechanic