Cat 3126E power loss after fuel filter change

[Tha_Rooster]

Originally Posted by Phaeton04

I Changed the filter Nov. 9th and went on a 3 day trip Nov 10th. While driving to our destination the engine would shake/raddle when I try to accelerate to gain speed, I would either have to back off pedal or floor the pedal to get engine to smooth out. Only flooring it would get it to gain a little more speed, but it seriously lacked power.

I have the cat 3126E with 1 fuel filter, which is a water/fuel separator filter mounted in the of motorhome near radiator. The last eight of the vin is 3CM04844 and the serial number is HEP20882. I also, pushed the reset button for the air filter.

Any Idea as to what is wrong?

Why would you push reset on air filter unless you changed it?
If it showed you needed a new one that might be your problem.

[Phaeton04]

I installed the new filter and made sure the old gasket on the thread end was removed and new gasket installed. Filled up the new filter with fuel making sure to plug the center hole. installed the new fuel filter and started it up and text drove it.
It still has the same problem. Very low power when accelerating.
I also installed a new air filter.

What could be wrong, It ran great up until I changed the fuel filter. This is on a Cat 3126E (HEP20882) with only (1) fuel/water separator.
I have installed 3 new filters with the same results. using the following filters Cat 1752949, Baldwin BF1268 and now Wix 33783 w/bowl.
Freightliner said the original filter was Racor 3203 (Alliance ABPN12232FRT03)
Totally confused. What do I need to try now.

[Jon_C]

Do you have a boost gauge? If so is turbo boost pressure same as it was?

If not check for boost leaks or loose clamps or torn boots on the air piping going in and out of the intercooler.

Maybe it was a coincidence and you also developed a new problem

[bigb56]

Originally Posted by Jon_C

Do you have a boost gauge? If so is turbo boost pressure same as it was?

If not check for boost leaks or loose clamps or torn boots on the air piping going in and out of the intercooler.

Maybe it was a coincidence and you also developed a new problem

This is kind of a double edged sword, a fuel starvation issue won't allow the rpms to build as fast resulting in the turbo not spooling up as fast resulting in lower boost, so he could still have low boost with no leaks or turbo issues caused by the fuel starvation. Not saying he shouldn't check for a boost leak, just saying if he's low on power I would expect low boost as well, as a symptom but not necessarily a cause, if that makes sense.
Of course any time one is working in the engine bay there is the chance something else got knocked out of whack.

[Phaeton04]

Thanks Jon C and Bigb56,
I will check for leaks around intercooler and boots as well look to see if something could be loose or disconnected..
Didn't think about those things.

[desertdd]

The correct way to check boost pressure is to have someone pressurize the intake system.

[JPO1980]

Dont want to hijack thread, but as for the air filter reset I read on a different forum/thread that it's a good idea to reset the air filter every so often.

There have been instances of a torn air filter. One way to check is to reset the indicator, drive the coach, and confirm the indicator moved. If it didn't move you should replace filter.

I've never had a torn filter so maybe it is OCDish, ymmv, but for me it is simple and may prevent me from unknowingly dusting my C7.

Safe travels

[bcbrowne]

Just a thought, I have a 3126 in my freightliner chassis for 11 years. the 1st year I had freightliner do oil and filter service and since had done myself with the filters replace with same numbers from the first service. About 3 years ago I started it in the spring to warm it up and found fuel leak. I found out I had a second filter up under the front of the bed under the floor that you have to service from the bed opening as it sits over the transmission/ engine area. I had never changed it in 7 or 8 years with knowledge of having it. I assume freightliner was not aware either. It had enough water that it froze and blew out the rubber gasket.

[Buly]

Originally Posted by bcbrowne

Just a thought, I have a 3126 in my freightliner chassis for 11 years. the 1st year I had freightliner do oil and filter service and since had done myself with the filters replace with same numbers from the first service. About 3 years ago I started it in the spring to warm it up and found fuel leak. I found out I had a second filter up under the front of the bed under the floor that you have to service from the bed opening as it sits over the transmission/ engine area. I had never changed it in 7 or 8 years with knowledge of having it. I assume freightliner was not aware either. It had enough water that it froze and blew out the rubber gasket.

You are right. Diesels have two filters. First one is the water separator, and very fine filter before the high pressure injection pump. When was last time you changed the fine filter?

[Goodtimes 2]

I had the cat c7 3126 engine it has 1 fuel filter on the engine and does have a manual priming pump. The water separator at the rear is just to remove water from the fuel. Fuel filter is a 10 micron that is reached/changed thru the metal cover panel under the bed. I always changed at the same time. The fuel filter on the engine can't be seen from the rear due to radiator. Consider looking on engine for the filter and change it.

[Npkp]

I too have a 3126, in a 2003 phaeton. CAT dealer in Stockton says there’s only one filter/separator so I’ve only changed one in the 5 years we’ve owned it. Am I just lucky or blind?

[Goodtimes 2]

The fuel water separator is easy to see but the fuel filter is not, must remove the cover panel over the engine inside the coach, service dealer maybe too lazy to open up the panel.

[Goodtimes 2]

I don't know how to post photo . I have photo that shows priming pump and fuel filter on the engine with the radiator removed.
Phaeton 04, if you provide email I will send the photo to you, if it will help you. Or someone teach photo posting.

[rgrpm]

Not All Freightliner’s had 2 filters or primer pumps, my 2004 3126 does Not, Call Freightliner with your serial # and they can tell you for sure