GM LS Gurus - sludge opinions!

[WAAZ]

Fixed it

What’s a good cam for the 6.0 in a 2500 if you want to keep using it as a truck. I’d really like to get more “grunt” out of it. It struggles pulling a light trailer (1500lbs) up a modest grade - dropping to 2nd gear to maintain 55 at times.

 

[Bigbore500r]

No joy on the OBD2 and app. Works fine but the oil pressure is not available. But several other sensors are showing me how much the gauges are off so that’s interesting. I also won’t have to go to the store to read error codes anymore.

That's wierd, because the info goes "in" to the ecm for sure......must be a thing with the specific operating system your year truck is programmed with.

 

[Bigbore500r]

What’s a good cam for the 6.0 in a 2500 if you want to keep using it as a truck. I’d really like to get more “grunt” out of it. It struggles pulling a light trailer (1500lbs) up a modest grade - dropping to 2nd gear to maintain 55 at times.

That is bizzare. What size tires are you running, and what rear gear?

If that's happening you have another issue, it should yank a baby trailer light that in overdrive, or 3rd up a steep grade....

 

[LargeOrangeFont]

That's wierd, because the info goes "in" to the ecm for sure......must be a thing with the specific operating system your year truck is programmed with.

That is what I remember with a lot of the ECUs in the early years. But again.. I don’t know where the crossovers were in different models.

 

[DarkHorseRacing]

What’s a good cam for the 6.0 in a 2500 if you want to keep using it as a truck. I’d really like to get more “grunt” out of it. It struggles pulling a light trailer (1500lbs) up a modest grade - dropping to 2nd gear to maintain 55 at times.

Would it be preferable to simply advance the cam timing a few degrees (like 2 to start) and see if that helps? Supposed to peak the torque curve like 200 rpm’s sooner and increase low end power.

Obviously caveats are making sure you don’t hit a valve with the piston by changing this.

 

[WAAZ]

That is bizzare. What size tires are you running, and what rear gear?

If that's happening you have another issue, it should yank a baby trailer light that in overdrive, or 3rd up a steep grade....

Truck is rock stock - wheels/tires too - 190k. Haven’t checked the ratio - guessing 3.42 ish. Bought it with 130k - always ran the same.

 

[mesquito_creek]

Mine has the factory 4:10 gear option… makes overdrive and 3rd much more effective

If you have a 3:42 I can imagine it giving up overdrive pretty easy

Most were 3:73 and even then I think they would down shift under a light load.

 

[Bigbore500r]

Truck is rock stock - wheels/tires too - 190k. Haven’t checked the ratio - guessing 3.42 ish. Bought it with 130k - always ran the same.

What year?

For reference - my stock 2003, and 2007 2500HD 6.0 truck's both pulled my 10k toy hauler up mild hills in 3rd, steep hills in 2nd. Id let it use overdrive (4th) on flat ground, over 60mph. Trucks both impressed me how well they pulled for being a relatively small gasser. And that was with 33" tires.....

Most 2500HD's come equiped with 4.10 rear gears.

Matter of fact..... @HOOTER SLED still has my old truck i think!


Towing my 28' boat - 8k (estimated)

Towing 10k plus.....26' toy hauler, XP41K rzr inside, 2 quads, 100 gallons fresh water + gear

 

[Sharky]

The Torque App with a $20 Bluetooth OBD dongle will read the oil pressure..

But I do not remember if the actual oil pressure was read by the ECU in 2005, or it was just the functionality of the sensor itself.

Bet it don't

Tech2 (factory GM scan tool) only shows voltage from the sensor. Mode$06 and SI I believe gives a cross reference voltage to pressure.

I can dig through some old Mode$06 info on the LQ4 and see what the cross reference is. Have to find it buried in my stack.

 

[mesquito_creek]

My stock 2005 6L gas had pulled a 10k boat 40 ish miles to and from the lake up some decent grade’s without issue. I shift it out of overdrive and let it rev 4k on the hills…

My only point about the gearing is the it likes to down shift and run high rpm’s so don’t worry about it.

 

[LargeOrangeFont]

Bet it don't

Tech2 (factory GM scan tool) only shows voltage from the sensor. Mode$06 and SI I believe gives a cross reference voltage to pressure.

I can dig through some old Mode$06 info on the LQ4 and see what the cross reference is. Have to find it buried in my stack.

View attachment 1239794

I meant it will read the oil pressure if it is sent to the ECU and there is a PID for it. On 20 year old GMs, there isn’t, as you noted.

 

[mesquito_creek]

My window sticker shows 4:10 under options Fyi but lots of them have it. I also paid $28,286 not sticker! Haha

 

[Bigbore500r]

Bet it don't

Tech2 (factory GM scan tool) only shows voltage from the sensor. Mode$06 and SI I believe gives a cross reference voltage to pressure.

I can dig through some old Mode$06 info on the LQ4 and see what the cross reference is. Have to find it buried in my stack.

View attachment 1239794

Might be able to work with that...

Here's a chart for the stock sensor, typical to most used by GM those years. 3 pin, 0-130 PSI range, 0-5V

@mesquito_creek if we can find a way to read the "raw" voltage coming from the sensor wire, it can be tied out to the chart below.

Then again - we don't really need to know WHAT the pressure is exactly, more so to see if it is fluctuating, like what your seeing on your dash gauge....
The chart below isn't linear, but in the typical pressure ranges you would see holding the motor at 2,000 rpm, - 0.33 V change = 9PSI .

So either chase this rabbit hole further.....or put a mechanical oil pressure adapter on it and read the mechanical gauge......
If you go that route, There's 2 spots to tap a gauge in -

#1 - At stock sender location (behind intake manifold, a PITA to get to with intake in place) -
This one comes with the 16mm adapter, which many (including the harbor freight kit) DONT have....

https://www.amazon.com/Pressure-Tester-Gauge-Diagnostic-Engine/dp/B0BBGG72JN/ref=asc_df_B0BBGG72JN/?tag=hyprod-20&linkCode=df0&hvadid=652455257749&hvpos=&hvnetw=g&hvrand=9215643192811207529&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031150&hvtargid=pla-1888426739933&psc=1&gclid=CjwKCAjw-IWkBhBTEiwA2exyOxSyRN81Fwj9Vpqt8w-XKrHXgpOkddfnShxUgIu43UvaxR6RajDc5xoCcd8QAvD_BwE

#2 -OR - Down by the oil filter...easiest, requires temporary removal of the oil filter

https://www.amazon.com/Bestong-EN-47971-Pressure-Adapter-Generation/dp/B082M8SQMM/ref=sxin_17_pa_sp_search_thematic_sspa?content-id=amzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6%3Aamzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&crid=3GGS73ST2HT4J&cv_ct_cx=oil+pressure+test+filter&keywords=oil+pressure+test+filter&pd_rd_i=B082M8SQMM&pd_rd_r=b0fcb750-5a62-42d3-900c-2054b9d82c2c&pd_rd_w=nAXve&pd_rd_wg=PApVE&pf_rd_p=d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&pf_rd_r=ZH4HKS5NTCHNK6BK5XVJ&qid=1686264654&s=automotive&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=oil+pressure+test+filte%2Cautomotive%2C129&sr=1-1-2b34d040-5c83-4b7f-ba01-15975dfb8828-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyNlJYRkFROVM4V0ZXJmVuY3J5cHRlZElkPUEwMTMzMzE3MlNWVU5UREZFRk0yMSZlbmNyeXB0ZWRBZElkPUEwMzgzNDIxM01GQlVPSVZMUjhFQSZ3aWRnZXROYW1lPXNwX3NlYXJjaF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

I'm a glutton for punishment so i'd probably figure out a way to either get the raw voltage data from the OBD II port or see if I could throw a low-voltage meter on the signal wire and set it to read in the range of the 0-5V sensor, and refernce the chart. Again....looking to confirm the fluctuation of 10psi, not so much to read the actual pressure value exact

 

[mesquito_creek]

Might be able to work with that...

Here's a chart for the stock sensor, typical to most used by GM those years. 3 pin, 0-130 PSI range, 0-5V

@mesquito_creek if we can find a way to read the "raw" voltage coming from the sensor wire, it can be tied out to the chart below.

Then again - we don't really need to know WHAT the pressure is exactly, more so to see if it is fluctuating, like what your seeing on your dash gauge....
The chart below isn't linear, but in the typical pressure ranges you would see holding the motor at 2,000 rpm, - 0.33 V change = 9PSI .

So either chase this rabbit hole further.....or put a mechanical oil pressure adapter on it and read the mechanical gauge......
If you go that route, There's 2 spots to tap a gauge in -

#1 - At stock sender location (behind intake manifold, a PITA to get to with intake in place) -
This one comes with the 16mm adapter, which many (including the harbor freight kit) DONT have....

https://www.amazon.com/Pressure-Tester-Gauge-Diagnostic-Engine/dp/B0BBGG72JN/ref=asc_df_B0BBGG72JN/?tag=hyprod-20&linkCode=df0&hvadid=652455257749&hvpos=&hvnetw=g&hvrand=9215643192811207529&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031150&hvtargid=pla-1888426739933&psc=1&gclid=CjwKCAjw-IWkBhBTEiwA2exyOxSyRN81Fwj9Vpqt8w-XKrHXgpOkddfnShxUgIu43UvaxR6RajDc5xoCcd8QAvD_BwE

#2 -OR - Down by the oil filter...easiest, requires temporary removal of the oil filter

https://www.amazon.com/Bestong-EN-47971-Pressure-Adapter-Generation/dp/B082M8SQMM/ref=sxin_17_pa_sp_search_thematic_sspa?content-id=amzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6%3Aamzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&crid=3GGS73ST2HT4J&cv_ct_cx=oil+pressure+test+filter&keywords=oil+pressure+test+filter&pd_rd_i=B082M8SQMM&pd_rd_r=b0fcb750-5a62-42d3-900c-2054b9d82c2c&pd_rd_w=nAXve&pd_rd_wg=PApVE&pf_rd_p=d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&pf_rd_r=ZH4HKS5NTCHNK6BK5XVJ&qid=1686264654&s=automotive&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=oil+pressure+test+filte%2Cautomotive%2C129&sr=1-1-2b34d040-5c83-4b7f-ba01-15975dfb8828-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyNlJYRkFROVM4V0ZXJmVuY3J5cHRlZElkPUEwMTMzMzE3MlNWVU5UREZFRk0yMSZlbmNyeXB0ZWRBZElkPUEwMzgzNDIxM01GQlVPSVZMUjhFQSZ3aWRnZXROYW1lPXNwX3NlYXJjaF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

I'm a glutton for punishment so i'd probably figure out a way to either get the raw voltage data from the OBD II port or see if I could throw a low-voltage meter on the signal wire and set it to read in the range of the 0-5V sensor, and refernce the chart. Again....looking to confirm the fluctuation of 10psi, not so much to read the actual pressure value exact

I had to leave town for the weekend so I will attack it again next week. Thanks for all the help!

 

[Bigbore500r]

I had to leave town for the weekend so I will attack it again next week. Thanks for all the help!

It's my pleasure, I love this shit

 

[Sharky]

#2 -OR - Down by the oil filter...easiest, requires temporary removal of the oil filter

https://www.amazon.com/Bestong-EN-47971-Pressure-Adapter-Generation/dp/B082M8SQMM/ref=sxin_17_pa_sp_search_thematic_sspa?content-id=amzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6%3Aamzn1.sym.d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&crid=3GGS73ST2HT4J&cv_ct_cx=oil+pressure+test+filter&keywords=oil+pressure+test+filter&pd_rd_i=B082M8SQMM&pd_rd_r=b0fcb750-5a62-42d3-900c-2054b9d82c2c&pd_rd_w=nAXve&pd_rd_wg=PApVE&pf_rd_p=d4a38ec2-b247-4e89-866a-4c0fd8a4dfa6&pf_rd_r=ZH4HKS5NTCHNK6BK5XVJ&qid=1686264654&s=automotive&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=oil+pressure+test+filte%2Cautomotive%2C129&sr=1-1-2b34d040-5c83-4b7f-ba01-15975dfb8828-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyNlJYRkFROVM4V0ZXJmVuY3J5cHRlZElkPUEwMTMzMzE3MlNWVU5UREZFRk0yMSZlbmNyeXB0ZWRBZElkPUEwMzgzNDIxM01GQlVPSVZMUjhFQSZ3aWRnZXROYW1lPXNwX3NlYXJjaF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

That's almost the exact same Kent Moore adapter that cost about $300 at the dealer and was required to purchase for special tools. The second guy in the shop to use it stuck it in his tool box and it disappeared from the tool room

I just took a PF46 and brazed an adapter in for my manual gauge. That lived in my box.

 

[mesquito_creek]

What is the Allen head set screw in the side of the oil filter adapter for?

 

[Bajastu]

What is the Allen head set screw in the side of the oil filter adapter for?

Temp or pressure sensor hole.

 

[mesquito_creek]

I had to return the oil filter adapter because it was the wrong size, but I was able to use the amazon oil pressure gauge at the oil pressure sensor hole located in the rear of the motor up top.

I am seeing about 28-30 psi at idle. Oil pressure jumps up to 40 almost as soon as you get on the gas.... Cruise control set at 2500 rpm/70 mph I see 42-44 without as much variation as the gauge would read, but I can't compare side by side with the analog gauge using the sensor hole.

 

[77charger]

What’s a good cam for the 6.0 in a 2500 if you want to keep using it as a truck. I’d really like to get more “grunt” out of it. It struggles pulling a light trailer (1500lbs) up a modest grade - dropping to 2nd gear to maintain 55 at times.

Ill tell you that a tuned ecu like a black bear does pretty good.I have an 04 hd and i got a new ecu last year it did enough to notice the gain for sure.I also told an uncle who has a small motorhome he wanted more power too and got one since he had a 6.0 in it.He drove it last week and it was just what he needed he said.

 

[Bigbore500r]

I had to return the oil filter adapter because it was the wrong size, but I was able to use the amazon oil pressure gauge at the oil pressure sensor hole located in the rear of the motor up top.

I am seeing about 28-30 psi at idle. Oil pressure jumps up to 40 almost as soon as you get on the gas.... Cruise control set at 2500 rpm/70 mph I see 42-44 without as much variation as the gauge would read, but I can't compare side by side with the analog gauge using the sensor hole.

So, at 2500 rpm is the pressure holding steady or is the needle "hopping" around at all on the mechanical gauge?

Pressure range sounds normal, it's on the lower end of the spectrum but it is a high mileage motor. I would look to run thicker oil to bump the oil pressure up a bit, 10w40 or 15w40 would be a good choice.

 

[mesquito_creek]

So, at 2500 rpm is the pressure holding steady or is the needle "hopping" around at all on the mechanical gauge?

Pressure range sounds normal, it's on the lower end of the spectrum but it is a high mileage motor. I would look to run thicker oil to bump the oil pressure up a bit, 10w40 or 15w40 would be a good choice.

At 2500 the needle was pretty stable +- 2 psi and not jumping, just responding to the terrain.

Obviously when it was new I was running pure Dino oil, then years later the synthetic blends were coming online, now at this point pure synthetic is really the most available choice. Sometimes it the only choice. I have stuck with the oem 5-30.

I will try the 10-40 synthetics

 

[LargeOrangeFont]

So, at 2500 rpm is the pressure holding steady or is the needle "hopping" around at all on the mechanical gauge?

Pressure range sounds normal, it's on the lower end of the spectrum but it is a high mileage motor. I would look to run thicker oil to bump the oil pressure up a bit, 10w40 or 15w40 would be a good choice.

This. Thicker oil and run it.

At 2500 the needle was pretty stable +- 2 psi and not jumping, just responding to the terrain.

Obviously when it was new I was running pure Dino oil, then year later the synthetic blends were coming online, now at this point pure synthetic is really the most available choice. Sometimes it the only choice. I have stuck with the oem 5-30.

I will try the 10-40 synthetics

Walmart Mobile 1 10W40 or Kirkland 10W40 from Costco cheap and easy. Glad there was no engine problem.

 

[jetboatperformance]

Pro tip! whatever you do don't run an "engine cleaner" additive at this point , why ? because it will loosen up the existing deposits and recirculate them all at once , better to just let the oil detergents do their job ...

 

[Bigbore500r]

At 2500 the needle was pretty stable +- 2 psi and not jumping, just responding to the terrain.

Obviously when it was new I was running pure Dino oil, then years later the synthetic blends were coming online, now at this point pure synthetic is really the most available choice. Sometimes it the only choice. I have stuck with the oem 5-30.

I will try the 10-40 synthetics

This is your friend for the old girl......should bump your pressure 5-7 PSI across the board vs 5w30
Super budget friendly as well, and a good oil.

The higher "w" number (low end of spectrum) will help it hold pressure better when warm. All mult-weight oils use a friction modifier to achieve the higher viscosity number, but as the additive package is depleted they tend to sheer down faster and loose viscosity. Having the "bottom" number as a 15w instead of a 5w will help ensure pressure stays strong.

https://www.oreillyauto.com/detail/c/delo/oil--chemicals---fluids/motor-oil/motor-oil---heavy-duty-diesel/63c3f8dc6706/chevron-delo-conventional-heavy-duty-motor-oil-15w-40-1-gallon/chv1/40015401

 

[mesquito_creek]

This is your friend for the old girl......should bump your pressure 5-7 PSI across the board vs 5w30
Super budget friendly as well, and a good oil.

The higher "w" number (low end of spectrum) will help it hold pressure better when warm. All mult-weight oils use a friction modifier to achieve the higher viscosity number, but as the additive package is depleted they tend to sheer down faster and loose viscosity. Having the "bottom" number as a 15w instead of a 5w will help ensure pressure stays strong.

https://www.oreillyauto.com/detail/c/delo/oil--chemicals---fluids/motor-oil/motor-oil---heavy-duty-diesel/63c3f8dc6706/chevron-delo-conventional-heavy-duty-motor-oil-15w-40-1-gallon/chv1/40015401

 

[ElAzul]

This is your friend for the old girl......should bump your pressure 5-7 PSI across the board vs 5w30
Super budget friendly as well, and a good oil.

The higher "w" number (low end of spectrum) will help it hold pressure better when warm. All mult-weight oils use a friction modifier to achieve the higher viscosity number, but as the additive package is depleted they tend to sheer down faster and loose viscosity. Having the "bottom" number as a 15w instead of a 5w will help ensure pressure stays strong.

https://www.oreillyauto.com/detail/c/delo/oil--chemicals---fluids/motor-oil/motor-oil---heavy-duty-diesel/63c3f8dc6706/chevron-delo-conventional-heavy-duty-motor-oil-15w-40-1-gallon/chv1/40015401

No no and no LoL so much misinformation here

 

[Bigbore500r]

No no and no LoL so much misinformation here

Can't post that without bringing your info......

Enlighten me / us !