alpha_omega
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Front Driveshaft arrived this morning. Even had this fancy clip to keep the caps together during transit.
What did you do to your NNBS GMT900 Tahoe/Yukon Today?
- Thread starter phattyford
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mikez71
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hope it isnt the heater core, seems like i only smell it inside, but some drip stains look like it maybe radiator. didnt see any evidence by heater t's, dont smell it in engine compartment, will crawl under and check soon.
alternator voltage programmed with hptuners.
alternator voltage programmed with hptuners.
mikez71
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cant find the leak! see one, it looks like it maybe motor mount? heater tees look dry, radiator, hoses, rear heater lines all look dry.. didnt smell any coolant underneath. only when my nose was by the coolant tank. turned heater on, didnt smell coolant. wonder if its leaking headgasket. i thought my coolant level was right on the cold full line, looks about .5" low.. unless there is a freeze plug right above driver side motor mount..
that's definetly a blown out motor mount, the fix is to use the hummer mount.
places to look for a coolant leak are
under water pump (use a telescoping mirror and flashlight)
all 6 sides of radiator (unbolt fan shroud and tilt it back to see inside edges), look down both sides, front and underneath with a flashlight
heater hoses, especially around the "t"'s at firewall and where it splits from water pump to reseveroir
crossover steam pipe/seals
reservoir tank
where ever it is leaking it will flow down so best to look up from under the vehicle with a flashlight
if you still can't find anything mark the coolant level on the reservoir tank while cool and on a level surface and check the level mark weekly (while cool and level) to confirm there is a leak or not.
and after the daily routine park it on a level surface and place a large piece of clean cardboard under the entire engine area and check it in the morning for a wet spot and look directly up from there.
mikez71
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Thanks! Right on, good knowing the leak is motor mount. Will check the spots you mentioned closer. really dont smell it outside which has me worried. Seem to smell it in the morning on or before first startup.
my coldcase I had for about 30 days started leaking I would only catch a faint whiff of it by the drivers door, after a lot of searching I found the tiniest leak in the upper left hand corner inside edge of the radiator leak was so small it just left a red smudge mark because it would dry out while driving
Tonyrodz
Resident Resident
Does the system pressurize once the thermostat opens? I had a radiator cap go bad on me once. System wouldn't pressurize and I'd smell a faint smell of coolant.Speaking of radiators, I have smelled coolant when getting in the truck past few days.. Have a feeling it maybe the heater core.. wish it was the radiator
Changed my charging voltages for AGM batteries. I noticed while driving the voltage was at 12.7V.
I raised the minimum to 13.5V and lowered the maximum to 15V.
That is based on what I can find about maximum and minimum voltages for AGM's.. but that doesn't mean the charging cycles are optimized.
I have had that happen as well, my last cap in fact simply fell apart when I took it off and part of it was stuck in the reservoir tank, I said screw it and just bought a whole new tank
Sparksalot
Elite Member
I’ve had that happen to thecopcar also.
mikez71
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Thanks, will check cap too! Temp has stayed steady, hopefully it is a tiny leak somewhere not on the heater core and I can replace a maintenance item while Im at it. Cursory look around Tees, radiator and water pump looked dry. Will dig in deeper next day or two.
iamdub
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Right, gray is for daily drivers and black is used on sports/performance vehicles - Thought this was common knowledge!
Gray/silver is for body panels that will be seen. Duuuuh!
Back around '92, I had a few rounds of Buttery Nipples with some GM injuneers. Two of the secrets they slipped was that (1) black duct tape doesn't say "duct tape". It says "proprietary flexible attachment wrap". Given the world we live in today, they were ahead of their time. It's not what it is, it's what it's known as that we accept. (2) It's a genius marketing angle. Instead of engineering everything to be blatantly proprietary, they make it appear easily substituted, but with their own alternatives. This applies to many instances, but lets "stick" to the duct tape analogy: End users will either be repulsed by the idea of installing what they smugly call "duct tape" and they'll purchase a whole new replacement part, or, feeling like they're cheating the system with a hack, they'll purchase the "proprietary flexible attachment wrap" to repair their existing part. The GM parts department wins either way.
if you can buy a radiator pressure tester it will be your best friend finding leaks. most stores loan them too. pump it up a bit and wait.. you'll see it if it's there. except maybe the pump, those leak kinda weirdly.
I guess these motor mounts have that oil stuff inside them too? I tore a c6 mount last mountain trip.. made an absolute mess under the car. like old cars with stright rusty water in the radiator haha.
I wonder if my hp adjusts battery voltage. probably not, probably bcm, but I might look I put an agm in it last time. dash always shows 14 or 15 when I've checked. even thou with a meter on the battery it was a bit less for some reason.
I've looked before but didn't find a good answer. what is the proper voltage for a non optima agm when just being maintained by the alt, not while charging after cranking, kinda the 100% float charge v?
I guess these motor mounts have that oil stuff inside them too? I tore a c6 mount last mountain trip.. made an absolute mess under the car. like old cars with stright rusty water in the radiator haha.
I wonder if my hp adjusts battery voltage. probably not, probably bcm, but I might look I put an agm in it last time. dash always shows 14 or 15 when I've checked. even thou with a meter on the battery it was a bit less for some reason.
I've looked before but didn't find a good answer. what is the proper voltage for a non optima agm when just being maintained by the alt, not while charging after cranking, kinda the 100% float charge v?
If it's the heater core, you will generally get condensation on the windshield when using defrost, so try that.
Double check the coolant T, make sure there's not a small leak that allows coolant to drain down the outside of the hose back into your evaporator box....if the seal is bad where the hose enters the firewall.
Could be just the odor is making it's way into your fresh air intake for the cabin, and hopefully not the heater core.
George B
¯\_(ツ)_/¯
What part number and suspension code?
Front GM# is 19420494.
Rear Arnott is 2708, my gut tells me that even though the 2708 is a factory replacement, that the OE BDI might be just a tad softer....not sure though.
My RPO codes are Z55, 6XA, 7XA
mikez71
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Think I will try that pressure tester if I don't find it soon. Radiator looks good from what I can tell, coolant tank cap as well. I'm hoping it's the heater T's and I just can't see it. Will feel around there..
As far as AGM battery voltages, internet shows 14.4-15V for charging (some places say 14.4-14.8V)
and for float charge I see 13.2-13.8V.
No need to buy a cooling system pressure tester. Most decent parts stores will rent you one: you pay for it with a credit card, take it home and use it, and return it within the specified period to get your account credited. If you don't take it back, you bought it.
Added wireless charging to the 2500 today; install was very straightforward and I only made one modification.
In the second picture I cut out a small indent for the wiring to pass forward, otherwise the trim panel which holds the HVAC for the rear will not seat like it did prior. It will seat enough to not really notice but my OCD self can definitely tell that it's not OEM as there is a small break where the rear trim panel connects to the center console as seen in the fourth picture.
This is the kit: https://boostautoparts.com/products/07-14-gm-charging
Install video:
Now I just need for Dynavin to release the version 8 of the N7-GM2007 Pro and I'll have a navigation unit with wireless apple car play.
Last pic because the LED lights look so good. They are GTR Lighting LEDs from headlight revolution.
In the second picture I cut out a small indent for the wiring to pass forward, otherwise the trim panel which holds the HVAC for the rear will not seat like it did prior. It will seat enough to not really notice but my OCD self can definitely tell that it's not OEM as there is a small break where the rear trim panel connects to the center console as seen in the fourth picture.
This is the kit: https://boostautoparts.com/products/07-14-gm-charging
Install video:
Now I just need for Dynavin to release the version 8 of the N7-GM2007 Pro and I'll have a navigation unit with wireless apple car play.
Last pic because the LED lights look so good. They are GTR Lighting LEDs from headlight revolution.
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ya I was going to ask you if the hp tuners let you set it for like 14.5+ all the time like (min 14.5-15.5 max or no max)
my mechman seems to hang around 14.2 a lot with the ac on since it stays on here 24/7 from april until nov so it's one fix for me lol
