Ism oil pressure

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Ism oil pressure

October 08, 2020, 01:46:22 pm

During the past 2k miles I've noticed that during stopping and prompt restarting for a instant I get a low oil indication. Suspecting a cracked pick up tube or improper tube or missing Baffles. Added a additional gallon of oil which reduced the frequency but still happens oil level on the stick is now at the O in overfill. I will operate home but was wondering if anyone else sees this in operating the ISM engine. Will pull oil pan when I get home if I'm the only one with this issue. Thanks
Scott

Re: Ism oil pressure

Reply #1 – October 08, 2020, 01:59:59 pm

I don't get a low oil pressure indication but idle oil pressure is low on these engines and 35 is normal operating pressure.

Re: Ism oil pressure

Reply #2 – October 08, 2020, 02:36:04 pm

Craneman mine runs the same. Don't like getting that momentarily caution indication during stoping starting. If you transition slower it doesn't happen
Scott

Re: Ism oil pressure

Reply #3 – October 08, 2020, 04:25:13 pm

Read a gauge, either on an electronic readout or mechanical gauge on a non-computer engine. You want to know what pressure the warning light will start to flicker. Find out from Cummins what idle as well as highway pressures are within limits before pulling the pan. Some oil filters have a check valve that may not seat all the way and cause lower pressure at slow engine speeds. Changing filters is cheap, fast and may solve a problem if there is one.

Pierce

Re: Ism oil pressure

Reply #4 – October 08, 2020, 04:59:10 pm

Quote from: dsd – October 08, 2020, 01:46:22 pm

Added a additional gallon of oil which reduced the frequency but still happens oil level on the stick is now at the O in overfill.
Scott

Be careful about over filling the crankcase. An extra gallon in an ISM may not be a problem, but high oil level can cause windage and aerate the oil enough to cause a loss of pressure and volume. As Pierce says, use the gauge as your primary indicator of oil pressure. The "dummy light" should be considered an attention getting backup, and the switch that operates that light may be inaccurate.

Greg

Re: Ism oil pressure

Reply #5 – October 08, 2020, 06:04:11 pm

This only happens when coming to a stop at idle then accelerating away and not ever at the stop. Slow stops never happens. Just as it starts to (above idle) accelerate it dips for a slight moment. Gauge drops, warning horn and light blink then gone. Like oil has no baffles and rushes away from pickup or air leak in pick up tube. I've first hand seen pick up tubes too short for the pan yes over servicing can cause many problems but better than continuous air leak in pick up. Oil pan will get dropped when I get home. Was just curious if this happens to other ISM operators I'm confident gauge is working correct and giving me a correct indication
It's Tolerable by knowing to stop slow and accelerate slowly
Scott

Re: Ism oil pressure

Reply #6 – October 08, 2020, 06:24:31 pm

No lights ever. STD oil level. Drove 279 miles today, 34-35 psi. 8.3 mpg for last 600 miles at 65 towing. Gentle long mild slopes. Little wind. 36k combined

Re: Ism oil pressure

Reply #7 – October 08, 2020, 09:28:05 pm

ISM11 oil pressure at operating temps will drop to 20 psi or so when you come to a stop and the engine is idling. At normal speeds the oil pressure will be about 35 as Craneman suggests. If you are using VMSpc set the yellow lower limit to what you see, 18 or 19 psi. Set the red lower limit a couple psi below that.

Bob's experience is not common. I never see any dash indications of low oil pressure if that is what he is referring to. You can set VMSpc to anything you want for a low pressure level. There is no standard and specifying an engine type makes no difference.

Re: Ism oil pressure

Reply #8 – October 08, 2020, 10:43:39 pm

@ dsd ,

We've had no oiling issues with our ISM. Your plan of dropping the pan for a looksee makes sense, and shouldn't be too bad a job. Just took a look at Cummins Quick Serve, and the pickup tube is fairly long; maybe the attaching screw came loose? Regardless, hope it's an easy fix for you.

Greg

Re: Ism oil pressure

Reply #9 – October 08, 2020, 11:01:25 pm

My oil pressure quote should have been fairly obvious that it was a 1300-1500 rpm. 20 at idle. You really thought my 34 was at idle? I guess I need to explain every detail versus someone not understand my comments. Back to 101 I see.

Re: Ism oil pressure

Reply #10 – January 23, 2021, 09:22:44 pm

So I had ordered a new oil pressure /temperature sender. Was getting frustrated with current welding project and decided to take a break from it and put sensor in. This is the one behind the air conditioner compressor and above the air pump drive.

So the sensor is a 1 1/4 nut. There is minimum clearance and you cannot put a socket on it. I cut a 12 point socket down to about 3/4 of a inch and welded to a 3/8 x 8 inch extension. No joy still too big to fit. Relieved down to 5/16 inch. Was able to snake in there then. Tighten up sensor and with the new indexing of the new sensor the clip for the plug was positioned so as you could not remove wrench. Loosed up and removed wrench. Cut center flat out and reinstalled and torqued. Removed wrench but new problem is the connector release clip is against the engine gear drive housing. Don't know if I ever have to remove that I would be able to. In a leap of faith I plugged the connector on and heard it lock. Went up in the coach and started it up. NO OIL PRESSURE!
Reinstalled original sensor. Same indications as before, but somehow I feel better about it now since the two hour long beating. I was able to get the plug to release easier that I thought, only saving grace. Think I'll call it a day.
Scott

Re: Ism oil pressure

Reply #11 – January 24, 2021, 03:48:35 pm

Scott,

Did you pull the 2 5/16" bolts out? One is forward and one is facing back. If you understand where I am talking about.

Mike

Re: Ism oil pressure

Reply #12 – January 24, 2021, 11:51:09 pm

Scott....simple things first....what viscosity oil are you running?

Re: Ism oil pressure

Reply #13 – January 25, 2021, 12:03:48 am

Quote from: Pamela & Mike – January 24, 2021, 03:48:35 pm

Scott,

Did you pull the 2 5/16" bolts out? One is forward and one is facing back. If you understand where I am talking about.

Mike

I actually have no clue. There was no bolts around sensor? I also didn't remove ac Freon compressor or mount. The casting that was interfering was ahead of the gear box. The Cummins diagram showed two sensors and mine only has the rear one. (coach rear, engine forward)
No I didn't remove.
Scott

Re: Ism oil pressure

Reply #14 – January 25, 2021, 12:13:23 am

Quote from: Pyolet – January 24, 2021, 11:51:09 pm

Scott....simple things first....what viscosity oil are you running?

Chevron Delo 400 15W-40 Engine Oil

Re: Ism oil pressure

Reply #15 – January 25, 2021, 09:19:59 am

If the gauge is electric, then there could be a wiring problem(loose, or touching something). Mechanical gauges do not lie, tubing can have problems.

Re: Ism oil pressure

Reply #16 – January 25, 2021, 09:51:18 am

Pat it's a electrical and the sensor does both pressure and temperature. Gauge is reading 20 psi high all the time both Off , idle , and at full range operating pressure. When the new sensor was installed it stayed at 20 psi and never gave a Indication. Check engine and chime on. I haven't been concerned about the gauge reading off because the idiot light still was working. Temperature circuit is okay. The original complaint still existed the last time I drove. "Oil pressure warning would trigger during stop/start durning the moment the coach transition to moving forward" It still may be a sender, but I'm going to order a replacement gage once I figure out it's part number. Bluefire reads correct but does not show the low pressure blip during the stop/start sequence showing about 17psi minimum. Next step for me will be the gauge. Wiring could still be a issue also. I will also follow up with a direct reading gauge and physically verify pressure before removing oil pan searching for pickup tube leaks.
Scott

Re: Ism oil pressure

Reply #17 – January 25, 2021, 10:21:46 am

Your gauges are connected to a gray box as is the oli pressure sender. Reference voltage and return come and go from the gray box, something happens inside and a signal gets sent to the gauge. The gray boxes fail incrementally. Both air pressure gauges and the start battery voltage have failed on mine. It appeared that the air pressure senders were working OK but an internal failure made the gauges not work and low pressure dinger go off. I out an on/off switch on the dinger and replace the air gauges with mechanical ones. I replaced the bad voltmeter one with an air pressure gauge for the HWH tank.

Re: Ism oil pressure

Reply #18 – January 25, 2021, 10:43:07 am

Quote from: Roger & Susan in Home2 – January 25, 2021, 10:21:46 am

Your gauges are connected to a gray box as is the oli pressure sender. Reference voltage and return come and go from the gray box, something happens inside and a signal gets sent to the gauge. The gray boxes fail incrementally. Both air pressure gauges and the start battery voltage have failed on mine. It appeared that the air pressure senders were working OK but an internal failure made the gauges not work and low pressure dinger go off. I out an on/off switch on the dinger and replace the air gauges with mechanical ones. I replaced the bad voltmeter one with an air pressure gauge for the HWH tank.

Roger that very well could be the issue. Once I can verify that it's only a false indication I could easily at this level disregard the issue. I'm confident the gauge is bad because during prestart needle swing never goes below the 20 psi point. I would hate to have to do work around for all the gauges unless necessary. Somebody built that gray box, somebody can repair it.
Scott

Re: Ism oil pressure

Reply #19 – January 25, 2021, 11:08:13 am

Scott read reply #5 the box is no longer repairable or available. The color is blue but the same box.

"Blue Module" Failure

Re: Ism oil pressure

Reply #20 – January 25, 2021, 12:13:33 pm

Quote from: craneman – January 25, 2021, 11:08:13 am

Scott read reply #5 the box is no longer repairable or available. The color is blue but the same box.

"Blue Module" Failure

Yes I had read that several times in the past several years. Again someone built it, someone can fix it. Lol not me though

Re: Ism oil pressure

Reply #21 – January 25, 2021, 01:24:54 pm

Pulling the oil pan isn't hard but be prepared to possibly twist off a bolt where pan bolts to aluminum tranny housing. Had to pull mine as drain plug was stripped out and yes I twisted off one bolt at the tranny but enough was left to weld a nut on and get out. The machine shop installed the drain plug kit from cummins so all is good now.
My ISM runs low oil pressure also. It goes down when I turn the lights on also. Doesn't worry me since that is caused by voltage drop at the dash, haven't figured that one out yet.

Re: Ism oil pressure

Reply #22 – January 25, 2021, 10:01:47 pm

Quote from: Townrestor – January 25, 2021, 01:24:54 pm

Pulling the oil pan isn't hard but be prepared to possibly twist off a bolt where pan bolts to aluminum tranny housing. Had to pull mine as drain plug was stripped out and yes I twisted off one bolt at the tranny but enough was left to weld a nut on and get out. The machine shop installed the drain plug kit from cummins so all is good now.
My ISM runs low oil pressure also. It goes down when I turn the lights on also. Doesn't worry me since that is caused by voltage drop at the dash, haven't figured that one out yet.

Larry thanks that is good information. I was quite concerned about it but I don't think I'm As much. I would like to have a second mechanical gauge but Would have to find another place to tap into it. My Bluefire never shows anything that bothers me. I could also have a wiring issue or ground like yours. I've read several posts about solving weird stuff with proper grounds. As Roger mentioned could also be a failing converter box. Good fun either way.
Thanks Scott

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