Warning beeps when stopping, goes away at aceleration

[GoDaddyO]

Hello All! I’ve got a new issue with my Cummins 6CTA powered Intrigue yesterday. The warning beeps go off rapidly just before coming to a stop light, and occasionally will stall. Starts right up & alarm beeps stop as I accelerate. No warning lights or low coolant lights come on.

Thought it was a coolant issue as I was driving earlier about 10 miles for fuel. I added about 1/3 gal of coolant & issue stopped for about 5 miles, then started again. Got to my destination about 15 miles, checked coolant & was full.

I thought maybe a burnt out bulb from a dash low coolant warning light I may not be seeing but having full coolant reservoir after short trip must mean it’s some other issue.

Not sure if it’s a Cummins issue or a CC issue.

Any thoughts would be greatly appreciated.

[hkuhnert]

Could it be the oil level? If the pick up tube is in the back of the oil pan...when you brake the oil moves forward and the oil might be sucking air and you are losing oil pressure.
Also, when you turn your ignition on don't all the lights turn on?

Moot

[deandec]

It sounds like your coolant sensor in the tank is becoming uncovered when stopping and gets covered when starting and running level.

Coolant may be just a little bit low?

We used to get get warnings or shutdown on cloverleaf turns for the same reason.

Our sensor is near the middle passenger side of the coolant surge tank.

[wolfe10]

Originally Posted by hkuhnert

Could it be the oil level? If the pick up tube is in the back of the oil pan...when you brake the oil moves forward and the oil might be sucking air and you are losing oil pressure.
Also, when you turn your ignition on don't all the lights turn on?

Moot

Not aware of an oil level sensor on the Cummins 8.3/C engine.


Oil PRESSURE yes, but oil level would have to be extremely low for this to occur.

[hkuhnert]

You are right...there is not an oil sensor in the pan. This is why I said if/when he is using the brakes the oil pick up tube is no longer reaches the oil because the oil shifts forward...thus the pump is sucking air...which will lower the oil pressure to almost zero causing the engine to shutdown.

[Skip426]

Cummins engines with the P-7100 injection pump have a manual idle speed adjustment . Low idle speed in gear with dash A/C compressor running could be the cause of the stall ; throw in A POSSIBLE low voltage warning to explain the alarm .

What is the engine rpm at idle in gear , with the dash A/C on ?

[GoDaddyO]

Originally Posted by wolfe10

Not aware of an oil level sensor on the Cummins 8.3/C engine.


Oil PRESSURE yes, but oil level would have to be extremely low for this to occur.

My oil level was a quart low but the add point on the dipstick takes about a full gallon, however on my trip yesterday evening back to Merritt Island the beep beep warning went off once on my 1.5 mile trek to the FL turnpike, then no further issues even at the stop light light when exiting 528 into Merritt Island. I did pay close attention to oil pressure which shows 40-50 psi while driving but drops to about 9-10 when at a stop light. I wonder if a possible screen may be slightly gummed up.

[GoDaddyO]

Originally Posted by hkuhnert

Could it be the oil level? If the pick up tube is in the back of the oil pan...when you brake the oil moves forward and the oil might be sucking air and you are losing oil pressure.
Also, when you turn your ignition on don't all the lights turn on?

Moot

The only lights than come on are, WAIT TO START, DO NOT SHIFT, & EXHAUST BRAKE.
I don’t ever recall any others coming on prior to starting. I did need about a 1/3 of a gallon again this morning after checking all my fluids. But the warning didn’t come on when I reached my destination last night… I guess it is an Intermittent problem, which are the worst to diagnose for a mechanic.

[Jim_HiTek]

Could it be the slide/jacks low oil alarm? Those can sound off intermittently while coming to a stop if low on oil too. At least my old Power Gear system did. Took a while to figure out what it was as I didn't expect it to sound off while driving.

[GoDaddyO]

Originally Posted by Skip426

Cummins engines with the P-7100 injection pump have a manual idle speed adjustment . Low idle speed in gear with dash A/C compressor running could be the cause of the stall ; throw in A POSSIBLE low voltage warning to explain the alarm .

What is the engine rpm at idle in gear , with the dash A/C on ?

My tach has never worked since I had a alternator repair in New York State 3 yrs ago so I don’t have an accurate answer. I don’t have a working AC so the AC compressor wasn’t engaged, only the fan. My currant alternator occasionally throws a red warning light on the voltage gauge, but that wasn’t indicated at this particular occurrence of the stall. I could see the injection pump causing issues. I have purchased a ScanGauge to get a tach signal but have not located a port to attach it to. The only port I can find is under the Allison transmission panel.

[Skip426]

Originally Posted by GoDaddyO

I have purchased a ScanGauge to get a tach signal but have not located a port to attach it to. The only port I can find is under the Allison transmission panel.

Scan Gauge would communicate with a Cummins ECM , that your mechanical engine doesn't have , so no connection will be found.

No tach for three years ; I think the alternator installed wasn't 100% correct for your application .

[OldWEB]

Originally Posted by GoDaddyO

The only lights than come on are, WAIT TO START, DO NOT SHIFT, & EXHAUST BRAKE.
I don’t ever recall any others coming on prior to starting. I did need about a 1/3 of a gallon again this morning after checking all my fluids. But the warning didn’t come on when I reached my destination last night… I guess it is an Intermittent problem, which are the worst to diagnose for a mechanic.

When the key is turned to "ON", ALL instrument warning lights that are applicable to your unit should light up, then some will go out as they are not in 'alarm mode', this is a lamp test for the instrument lamps. i.e. the oil pressure light will continue to burn whereas the coolant temp light will extinguish if the temp is not in alarm mode. The chassis manual should have a instrument light layout explaining each.

[GoDaddyO]

Thank you all for your comments & suggestions. Sorry that I answered several post out of order today.. I know I have multiple issues going on that could individually cause the warning to go off and being intermittent complicates the diagnostic process..
Possible injection pump, possible low coolant bulb burnt out, low oil pressure at idle, etc.

When I left Clermont yesterday, the warning came on once in the 1.5 mile trek to the FL turnpike at a stop light. Then never again, even at the stop light off 528 onto Merritt Island. I idled with no issues disconnecting the Jeep at the Moose Lodge. I check fluids this morning & needed again about 1/3 gal of coolant and 1 quart of oil, no where near the add line of the dipstick.

On my last journey to FL from KS, 3 weeks ago, I did have a coolant pump hose that needed replacing, which happened just as I was pulling into a Love travel center and the low coolant warning did work then as well as the engine stalling just 100 yards from the repair shop.It took about 3 hrs to repair & 3 gallons to fill the system. My next stop for the evening the low coolant warning went off again. I checked the hose repair & the hose clamps did need additional tightening. I thought that was the reason for the loss of coolant for only a 2 hour trip before stopping for the night. There is one other short, L shaped coolant hose off the coolant pump which may be going bad too so I’ll have to check that & maybe just replace it for good measure.

Just crawled under the Coach & a 2’ coolant hose off the engine which connects to the other L shaped hose is loose to the point I can wiggle the hose at the engine connection. I’ll have to pull the mattress to access the hose clamps. Hopefully that will explain the needed 1/3 gallon of coolant after each short trip. A burnt out bulb would explain why no visible dash warning only audible beep beep beep.

When I bought the coach 4.5 yrs ago, the seller did replace an oil sensor/ sending unit before I drove it back from TX. I don’t know if that may be at issue with such a low oil pressure at idle. I not sure what’s normal.

Several issue going on and know a properly working tach is essential for further western mountain journeys..not really sure where to turn for that. My RV/ engine tech has tried twice to get it working and it’s intermittent as well. At least this recent trip the needle is working but not calibrated. At 64-66 mph it’s reading 25-2600 rpm & I believe the first year before that alternator repair 1900-2000 was normal cruising rpm.

Thanks again for all the comments, suggestions and experience from RV veterans! An older coach is not only a project but an ongoing challenge at the very least!

[hkuhnert]

My 99 Allure needed and ALDL adapter to work with the ScanGauge D. See if you have that connecter on the footboard under the dash. Here is the cable adapter I purchased to use the ScanGauge D on my rig:
OBD Diagnostics, Inc. - OBD2 All-In-One Scan Tool w/ USB

Moot