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DebiA · 10-27-2021, 08:42 AM

Hello,
Hoping someone can help me with an issue.
I have a Cat 3126 engine. After a storm the ECM was knocked out. Had that replaced. It started right up, but now my oil gauge has not moved, and oil light is on. All other gauges are fine.
Help?

PABO05 · 10-27-2021, 10:02 AM

Have you check your oil?

Also check your fuses.

There are many knowledgeable people here.

Someone will help if my suggestions did not solve your problems.

MSHappyCampers · 10-27-2021, 10:38 AM

Hi ! Welcome to IRV2! We're sure glad you joined us!

Good luck, happy trails, and God bless!

hex nut · 10-28-2021, 08:21 AM

The CAT 3126 is a HEUI motor that uses the engine oil to fire the injectors. It will not run at all without oil pressure. It sounds like you have lost connection to the oil pressure sending unit. The sending unit is close to the ECM. The connection may have been knocked loose (or left off) while replacing the ECM. Good luck.
Richard

CountryB · 10-28-2021, 09:12 AM

Quote:

Originally Posted by DebiA

Hello,
Hoping someone can help me with an issue.
I have a Cat 3126 engine. After a storm the ECM was knocked out. Had that replaced. It started right up, but now my oil gauge has not moved, and oil light is on. All other gauges are fine.
Help?

I assume you are using the dash gauges. The Dash gauges have their own oil pressure sending unit (separate form the one the CAT ECM uses). It may have been damaged or disconnected when the ECM was replaced. I believe it is located on the same side of engine as the ECM.

The dash gauges in our Coaches are known to be inaccurate. The best way to monitor engine parameters is use a "display" (scan tool) that plugs into the computer data port. Usually there is a data port under the dash (and one near the engine). Look for a round 6-pin or 9-pin connector (the J1708 or J1939 connector).

I use the ScanGuage D, which runs around $150. https://www.scangauge.com/products/scangauge-d/ There are other choices. These type of displays give you accurate engine readings (water temp, oil press, etc.) as they read data from the sensors that come on the engine (form CAT) and not the add-on sensors the Coach manufacture installs for the dash gauges.

Skip426 · 10-28-2021, 07:31 PM

Welcome to iRV2.

Your Cat 3126 E has the oil pressure sensor on the passenger side of the engine block , as per diagram .
First thing to do is check that there is a good connection at the sensor .

As mentioned your engine will not run with no oil pressure . Your HEUI system requires oil pressure ; boosted ; to fire the fuel injectors .

Please add info about your chassis manufacturer to your post , as Freightliner chassis may require special methods to test the gauge operation.

DebiA · 10-29-2021, 11:30 AM

thank you for the reply. i have checked all connections and everything seems to be ok. unfortunately Cat here in Gulfport does not have a mobile service and i was afraid to drive it not knowing if my engine is getting oil.

DebiA · 10-29-2021, 11:46 AM

Hi Skip,
prior to storm knocking out ecm, all gauges worked fine. I am afraid to drive it to cat dealer with oil light on and gauge not responding. the engine sounded good once i started it.
FYI i ordered the ecm and after weeks of waiting it came in. they flashed it at cat, i picked up and installed at my property. I had been informed that the check engine light would come on ,and I was to bring it to cat once I got it started so they could time it and finish the computer flash (not sure the technical term) I have no way of knowing if oil is flowing or if light and gauge not working due to not being flashed on the motor.
had 44000 miles on it but now 00000 reading. was told they could correct that once i get it to Cat .
P.S. i have no idea how to get around this forum

Ljwt330 · 10-29-2021, 12:12 PM

Quote:

Originally Posted by DebiA

Hi Skip,
prior to storm knocking out ecm, all gauges worked fine. I am afraid to drive it to cat dealer with oil light on and gauge not responding. the engine sounded good once i started it.
FYI i ordered the ecm and after weeks of waiting it came in. they flashed it at cat, i picked up and installed at my property. I had been informed that the check engine light would come on ,and I was to bring it to cat once I got it started so they could time it and finish the computer flash (not sure the technical term) I have no way of knowing if oil is flowing or if light and gauge not working due to not being flashed on the motor.
had 44000 miles on it but now 00000 reading. was told they could correct that once i get it to Cat .
P.S. i have no idea how to get around this forum

You may wish to call the Cat location where you would need to take it and ask their advice. Others have already stated the engine will not run without oil pressure but for peace of mind, a call to Cat may help. They may also confirm that the oil warning may be a function of the new ECM not being fully programmed.

I am not familiar with Cat engines, but you may be able to put a mechanical pressure gauge into the sensor port, or the inlet to the oil filter, and get a reading on the dial. At least then you would know you had proper pressure.

C9marine · 11-07-2021, 06:27 PM

You should have 1 or 2 access ports for a mechanical oil gauge, on my C9 there is 1 above and 1 below the oil pressure sender. It's just a bolt to remove and then thread in your mechanical gauge. Best to do it on a cold engine as oil will pour out of a warm engine since oil is in your head rail and gravity will cause it to pour out. If you're are fast enough not too big of a mess.