cooling and o2 sensor issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ivorton74 · 07-07-2014, 02:27 PM

So I went and worked on my truck today. Got the maf sensor on and took it for a short drive. My temp gauge isn't working so my buddy hooked his scanner so I could monitor the temp while Im driving. After a bit the engine got hot..at about 230 degrees. So we checked the hoses and they're still cold...the radiator is full of coolant...took the top hose off and there is no coolant in there at all. Took the thermostat off and checked it and that turned out to be fine so we put it back on and vacuumed the system. Tried putting coolant back in and its not going in the motor...its in the radiator but not going in and circulating. Also there is a lopy idle...my buddy says the o2 sensors are not reading right...he says either they're faulty or they are not far down the exhaust. Beside those issues the truck pulls like a freakin train even with that 3.08 gear and its sounds even better now that all 8 cylinders are firing. I cant believe all that power I have now!!

Custom 68 · 07-07-2014, 02:49 PM

First off on the temperature, these ls motors are bad about air in the system. You will need to remove the upper radiator hose and dump your coolant into the hose into the motor. Just go slow and it will fill. That will take care of the cooling part.
Do you have exhaust? If not that could be your problem. Why does he say they are not working? A working O2 sensor acts or looks weird when scanning them They cycle from almost 0 to around 900, they just cycle like that until you go into open loop like at full throttle then they will go high and stay steady like around 825 or so.
Check for air leaks on your exhaust and vacuum leaks on your intake area including after your MAF.
good luck
David

ivorton74 · 07-07-2014, 03:41 PM

https://www.youtube.com/watch?v=4xjy...ature=youtu.be

heres a video of the truck driving today...the exhaust is on and there is no exhaust leaks at all. he said he had the scanner hooked up while the truck was running and its read weird. he's going to fiddle with it some more and figure out whats goin on

Custom 68 · 07-07-2014, 04:12 PM

Well looks like you figured out your overheating. I don't know what is "weird" about it based on what he has told you.

ivorton74 · 07-07-2014, 04:39 PM

I don't know either...he didn't really say what was weird about it but he'll figure it out I guess

BR3W CITY · 07-07-2014, 06:12 PM

Turn your maf so the dang harness isn't hanging straight down. It won't read correctly like that, or it will accumulate moisture and junk. You'll have MAF and IAT readings all over the place otherwise.

Get him to define "weird", and we can try to tell ya whats going on with her.

ivorton74 · 07-07-2014, 07:35 PM

we still have some neatening up to do so we'll get the maf wiring up and out of the way. I'll talk to him again and see what he's talking about. He didn't have much time to work on it today cuz he had other work to do in the shop but I keep bothering him to get it done so it'll be done soon hopefully.
He told me he organized a burnout contest and asked me to take part on the 26th. that made even more excited...my first burnout contest...cant wait.

07-07-2014, 02:27 PM	#1
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	cooling and o2 sensor issues So I went and worked on my truck today. Got the maf sensor on and took it for a short drive. My temp gauge isn't working so my buddy hooked his scanner so I could monitor the temp while Im driving. After a bit the engine got hot..at about 230 degrees. So we checked the hoses and they're still cold...the radiator is full of coolant...took the top hose off and there is no coolant in there at all. Took the thermostat off and checked it and that turned out to be fine so we put it back on and vacuumed the system. Tried putting coolant back in and its not going in the motor...its in the radiator but not going in and circulating. Also there is a lopy idle...my buddy says the o2 sensors are not reading right...he says either they're faulty or they are not far down the exhaust. Beside those issues the truck pulls like a freakin train even with that 3.08 gear and its sounds even better now that all 8 cylinders are firing. I cant believe all that power I have now!! Attached Images __________________ 1983 C10 Silverado 5.3 swap 1974 C10 lwb 5.3 swap(sold)...http://67-72chevytrucks.com/board/sh...d.php?t=614122 2001 BMW 530i 5 speed 2019 Nissan Titan SV Midnight 1979 Datsun 210 4 door 1980 Datsun 120y(back home in Trinidad)

07-07-2014, 02:49 PM	#2
Custom 68 Registered User Join Date: Nov 2001 Location: Springfield, MO Posts: 2,928	Re: cooling and o2 sensor issues First off on the temperature, these ls motors are bad about air in the system. You will need to remove the upper radiator hose and dump your coolant into the hose into the motor. Just go slow and it will fill. That will take care of the cooling part. Do you have exhaust? If not that could be your problem. Why does he say they are not working? A working O2 sensor acts or looks weird when scanning them They cycle from almost 0 to around 900, they just cycle like that until you go into open loop like at full throttle then they will go high and stay steady like around 825 or so. Check for air leaks on your exhaust and vacuum leaks on your intake area including after your MAF. good luck David __________________ Dave 1968 Custom Chevy with turbo charged 5.3 gen III 4l80e swap 1967-71 GMC 3/4 ton long step 4x4 (not sure what year exactly?) "A good friend will bail you out of jail...but a true friend will be sitting next to you saying "that was frekin awesome". "If it doesn't fit force it...If it breaks then it needed to be replaced anyway!"

07-07-2014, 03:41 PM	#3
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: cooling and o2 sensor issues https://www.youtube.com/watch?v=4xjy...ature=youtu.be heres a video of the truck driving today...the exhaust is on and there is no exhaust leaks at all. he said he had the scanner hooked up while the truck was running and its read weird. he's going to fiddle with it some more and figure out whats goin on __________________ 1983 C10 Silverado 5.3 swap 1974 C10 lwb 5.3 swap(sold)...http://67-72chevytrucks.com/board/sh...d.php?t=614122 2001 BMW 530i 5 speed 2019 Nissan Titan SV Midnight 1979 Datsun 210 4 door 1980 Datsun 120y(back home in Trinidad)

07-07-2014, 04:12 PM	#4
Custom 68 Registered User Join Date: Nov 2001 Location: Springfield, MO Posts: 2,928	Re: cooling and o2 sensor issues Well looks like you figured out your overheating. I don't know what is "weird" about it based on what he has told you. __________________ Dave 1968 Custom Chevy with turbo charged 5.3 gen III 4l80e swap 1967-71 GMC 3/4 ton long step 4x4 (not sure what year exactly?) "A good friend will bail you out of jail...but a true friend will be sitting next to you saying "that was frekin awesome". "If it doesn't fit force it...If it breaks then it needed to be replaced anyway!"

07-07-2014, 04:39 PM	#5
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: cooling and o2 sensor issues I don't know either...he didn't really say what was weird about it but he'll figure it out I guess __________________ 1983 C10 Silverado 5.3 swap 1974 C10 lwb 5.3 swap(sold)...http://67-72chevytrucks.com/board/sh...d.php?t=614122 2001 BMW 530i 5 speed 2019 Nissan Titan SV Midnight 1979 Datsun 210 4 door 1980 Datsun 120y(back home in Trinidad)

07-07-2014, 06:12 PM	#6
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: cooling and o2 sensor issues Turn your maf so the dang harness isn't hanging straight down. It won't read correctly like that, or it will accumulate moisture and junk. You'll have MAF and IAT readings all over the place otherwise. Get him to define "weird", and we can try to tell ya whats going on with her. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

07-07-2014, 07:35 PM	#7
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: cooling and o2 sensor issues we still have some neatening up to do so we'll get the maf wiring up and out of the way. I'll talk to him again and see what he's talking about. He didn't have much time to work on it today cuz he had other work to do in the shop but I keep bothering him to get it done so it'll be done soon hopefully. He told me he organized a burnout contest and asked me to take part on the 26th. that made even more excited...my first burnout contest...cant wait. __________________ 1983 C10 Silverado 5.3 swap 1974 C10 lwb 5.3 swap(sold)...http://67-72chevytrucks.com/board/sh...d.php?t=614122 2001 BMW 530i 5 speed 2019 Nissan Titan SV Midnight 1979 Datsun 210 4 door 1980 Datsun 120y(back home in Trinidad)



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