What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[j91z28d1]

yeah the older hybrids had a cross mounted muffler where the spare would be. I don't know what year, but at some point they put a normal muffler on it. must have put this valve in it around then. I've asked other hybrid owners if they they have it. but most people that have hybrids aren't big on working on cars haha. so no one has looked.


I've held it open while idling and it is definitely louder while open. I had thought it was to make it quiet since it's very quiet for a V8 but v4 makes sense. I meant to test the sound with it open and totally about it till now. it's pretty stiff to turn all the way.

 

[Doubeleive]

yeah the older hybrids had a cross mounted muffler where the spare would be. I don't know what year, but at some point they put a normal muffler on it. must have put this valve in it around then. I've asked other hybrid owners if they they have it. but most people that have hybrids aren't big on working on cars haha. so no one has looked.


I've held it open while idling and it is definitely louder while open. I had thought it was to make it quiet since it's very quiet for a V8 but v4 makes sense. I meant to test the sound with it open and totally about it till now. it's pretty stiff to turn all the way.

when I bought my silverado it had a catback on it already so the flap was gone, but no tune or anything turned off and when it went to v4 mode it sounded like cr*p like a lawnmower lol
that's why they put those flaps on them in v4 mode it pretty much stays closed and masks the v4 sound.
for whatever reason you didn't really hear it on the gmt900's but you can feel it when driving at least I can, annoying as hell
the k2's are slightly better "feel" wise but it's still there

 

[j91z28d1]

huh. I only drove mine around a day or 2 with it enabled. I honestly couldn't tell at all. only knew because the dash saying it. but then again the literature says the battery assist allowed it to be in v4 longer and more often than normal trucks. maybe it hid it some.

I'm definitely going to bring home some wire and see if I can't wire it open.

 

[Doubeleive]

huh. I only drove mine around a day or 2 with it enabled. I honestly couldn't tell at all. only knew because the dash saying it. but then again the literature says the battery assist allowed it to be in v4 longer and more often than normal trucks. maybe it hid it some.

I'm definitely going to bring home some wire and see if I can't wire it open.

bailing wire will work, I would wrap it around the knob part, hold it open tight and then go in a X pattern around the pipe,

 

[j91z28d1]

exhaust mods lol.

don't know if changed anything yet. Will have to get up to temp and some logs. it is louder thou. the completely silent feeling is gone haha.

 

[Doubeleive]

didn't work on mine but the neighbor asked me last week if I would change the strut on his Tacoma so did that, took 2 hours only because his stupid wheels required a 21mm thin wall deep socket so after searching for one I just went and bought one, got 4 off and surprise the last 2 are 19mm lol
then the strut bolts on the old one and new one were different sizes so i'm runing back and forth between my house and his grabbing different tools.
so probably really only took about 40 minutes. he gave me $70 easy money.

 

[Grady_Wilson]

After reading a few past threads about block heaters and the codes that can be thrown when the temps are not cold enough for the ECU programming, I am debating about installing the OEM block heater and just getting one of those adhesive squares to heat up the oil pan when it gets really cold out here.
There is a convenient electrical outlet on an outside wall right near the driveway so I can plug in whatever I decide to use.

 

[Geotrash]

After reading a few past threads about block heaters and the codes that can be thrown when the temps are not cold enough for the ECU programming, I am debating about installing the OEM block heater and just getting one of those adhesive squares to heat up the oil pan when it gets really cold out here.
There is a convenient electrical outlet on an outside wall right near the driveway so I can plug in whatever I decide to use.

An oil pan heater is only half of the solution and creates other problems. As soon as that heated oil starts to circulate, it will be instantly cooled to the temp of the block anyway. Worse, heating just the oil creates a warm condensing environment inside the engine where the moisture in the oil is liberated and deposited on the cold bare surfaces. I ran into a real problem with this in an aircraft engine several years ago. There was rust forming on the cam, pushrods and inside the magnetos of a Continental O-470 from the use of an oil pan heater in the winter.

You're better off heating the entire block with a factory style heater, and you can add an oil pan heater as well, if you wish, and avoid the condensation problems.

 

[Grady_Wilson]

An oil pan heater is only half of the solution and creates other problems. As soon as that heated oil starts to circulate, it will be instantly cooled to the temp of the block anyway. Worse, heating just the oil creates a warm condensing environment inside the engine where the moisture in the oil is liberated and deposited on the cold bare surfaces. I ran into a real problem with this in an aircraft engine several years ago. There was rust forming on the cam, pushrods and inside the magnetos of a Continental O-470 from the use of an oil pan heater in the winter.

You're better off heating the entire block with a factory style heater, and you can add an oil pan heater as well, if you wish, and avoid the condensation problems.

Thanks for the insight.
Guess I'll go ahead and install the factory coolant heater, see how that goes and add the oil pan heater if need be.

 

[Geotrash]

Thanks for the insight.
Guess I'll go ahead and install the factory coolant heater, see how that goes and add the oil pan heater if need be.

That's what I have always done and it works well. Spent several winters in Wyoming, Montana and North Dakota chasing drilling rigs and a block heater always did me right when I couldn't leave the engine running all night. One other little tidbit: get yourself a cord designed for cold weather. I came out to my car one real cold morning in Dickinson, ND and went to wrap up the orange power cord I was using for my block heater. The insulation jacket shattered into pieces all over the ground. A guy a couple cars away started laughing and told me to get myself a blue one rated for cold weather over at the hardware store. Good advice. I still have that cord.