[j cat]

when the extreme cold hit I got the CEL, found that the lean codes 171-174 fuel trims 25 max...

what I found was cold air is more dense , so any very small leaks will cause this . upper intake manifold gasket is going on 18 yrs old so I am sure that is the problem . could not locate leaks so most likely inside the KS area of the upper intake ..

found rock auto has the felpro gasket set/kit .. I need the EGR gaskets on the 2000 5.3L this kit has them .. newer engines not a need/ issue . cost $56 ... much cheaper than auto store $80..............

I also found that GM used materials not compatible with alcohol fuels so these gaskets OEM fail ..
felpro reviews state very robust high quality never had to replace again..

 

[silverado002]

You are correct about GM's gasket as there was a TSB on them. Just curious Jcat. Do you have a rough idle when cold?

 

[bazar01]

Same here, did it affect the drivability or it just triggered the CEL?

 

[j cat]

You are correct about GM's gasket as there was a TSB on them. Just curious Jcat. Do you have a rough idle when cold?

after the engine started took 10 seconds for it to idle normally .. after that ran great . pedal to metal no problems engine power great .. on hywy doing 80 MPH floored it normal great power smooth idle after the 10 sec cold start.. so when I increase the idle speed to 2K the trims drop to a normal range.. @600 rpm stft and ltft pop up... so a small intake leak is the problem ..

so when the warmer weather arrives I will do the gasket . check out the KS connections and then seal up those with perfect sealer and also use RTV high temp on the foam GM crap at the ends to keep out the water/dirt etc..

 

[silverado002]

That sounds like a plan. Hope your foam gasket is in better shape than mine was as it crumbled.

 

[j cat]

That sounds like a plan. Hope your foam gasket is in better shape than mine was as it crumbled.

foam rubber is available cut to fit the hole then squeeze into the foam the RTV let it set up an hour or so then put in in...

rodents don't like the RTV ..

 

[xPosTech]

Intake vacuum is highest at idle. That's why a small leak sticks it's head up at idle.

Ted

 

[j cat]

so today air temp 42F. took for a 40 mile run to drop off some equipment for a guy I know. fuel trims did not max out a bit high at idle but not at the max... short trims below 5 ..

sure must be very small leaks .. got the gasket kit felpro $56 ... when spring arrives I will do the work..

 

[jasons99hoe]

im not up on abbreviations but what is the KS side of intake? and what is TSB? im young but i dont stay up with any new things as i am stuck in the 90's and i just found out what smh meant. sorry for lack of knowledge but i dont pay any mind to anything other than my family and vehicles

 

[silverado002]

KS usually stands for knock sensor and is in the very middle of the engine under the intake manifold. They are subject to water intrusion/destruction if the rubber flange seals get hard or deformed due to the heat in the middle of the engine. GM used a foam block in the front of the intake manifold are to help prevent water and dirt traveling to these sensor but after a few years the foam block turns into a crumbling block of flakes when disturbed. I always seal the KS rubber flanges with hi-temp RTV. No issues after that.
TSB stands for technical service bulletin which is issued by GM to the service techs to adhere to when a somewhat know problem/condition pops up in the servicing of a vehicle. Some techs are unaware of them because they may not check in the GM service database.

 

[j cat]

im not up on abbreviations but what is the KS side of intake? and what is TSB? im young but i dont stay up with any new things as i am stuck in the 90's and i just found out what smh meant. sorry for lack of knowledge but i dont pay any mind to anything other than my family and vehicles

KS is Knock Sensor ..KS engine has 2 . both in the middle of engine on top of the lower intake manifold. under the upper intake manifold.

TSB is not new . this is a tech service bulletin .. GM will not send these to the owners or repair shops to inform us of GM failures .. GM has created these to ONLY help dealerships . some people do post these warning failure bulletins.. the big one that should have been exposed was the defective DEXRON III.. 2006 this TSB was sent out .. caused millions of $$$ damage .. put GM into bankruptcy ..

 

[jasons99hoe]

KS usually stands for knock sensor and is in the very middle of the engine under the intake manifold. They are subject to water intrusion/destruction if the rubber flange seals get hard or deformed due to the heat in the middle of the engine. GM used a foam block in the front of the intake manifold are to help prevent water and dirt traveling to these sensor but after a few years the foam block turns into a crumbling block of flakes when disturbed. I always seal the KS rubber flanges with hi-temp RTV. No issues after that.
TSB stands for technical service bulletin which is issued by GM to the service techs to adhere to when a somewhat know problem/condition pops up in the servicing of a vehicle. Some techs are unaware of them because they may not check in the GM service database.

I got ya. I understand the terms just not the abbreviations. thanks man

 

[jasons99hoe]

KS is Knock Sensor ..KS engine has 2 . both in the middle of engine on top of the lower intake manifold. under the upper intake manifold.

TSB is not new . this is a tech service bulletin .. GM will not send these to the owners or repair shops to inform us of GM failures .. GM has created these to ONLY help dealerships . some people do post these warning failure bulletins.. the big one that should have been exposed was the defective DEXRON III.. 2006 this TSB was sent out .. caused millions of $$$ damage .. put GM into bankruptcy ..

I know the terms aren't new but its a "new" thing for people to abbreviate terms and words on social media. I appreciate the feed back. I only started doing social media about a year ago so I see a lot of stuff I don't understand and believe it or not I do NOT own a cell phone. I'm 33 but you would think I'm 80 by the way I live

 

[j cat]

I know the terms aren't new but its a "new" thing for people to abbreviate terms and words on social media. I appreciate the feed back. I only started doing social media about a year ago so I see a lot of stuff I don't understand and believe it or not I do NOT own a cell phone. I'm 33 but you would think I'm 80 by the way I live

if you type GM TSB on search , you will get a load of info .. some will charge you , if your looking for a specific TSB about your ride. Forums help many on this , GM not much , but possible your dealership will give you TSB data on your ride..

I was hoping for a method that an owner of a vehicle could enter his vin# and then have the TSB downloaded from the manufacturer to help keep the vehicle safe and properly maintained .. It may happen maybe..also helps auto repair shops from making expensive errors.

 

[thegawd]

Me too.

I know the terms aren't new but its a "new" thing for people to abbreviate terms and words on social media. I appreciate the feed back. I only started doing social media about a year ago so I see a lot of stuff I don't understand and believe it or not I do NOT own a cell phone. I'm 33 but you would think I'm 80 by the way I live