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

[alpha_omega]

Front Driveshaft arrived this morning. Even had this fancy clip to keep the caps together during transit.

 

[mikez71]

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.

 

[mikez71]

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..

 

[Doubeleive]

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..
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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]

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.

 

[Doubeleive]

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]

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.

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.

 

[Doubeleive]

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.

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]

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

I’ve had that happen to thecopcar also.

 

[mikez71]

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.

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.