Saginaw Michigan - Service a 2008 Hybrid Yukon?

[Zylin]

My daughter just went to Saginaw, Michigan due to a death on her Bo's side of the family. Our 2008 GMC Yukon Hybrid was losing oil, so I just had her leave the truck ( she has already flown home with her very young son ).

I started calling around and I cannot find anyone that will touch the Hybrid. Personally, if it's losing oil, I wouldn't think it would have anything to do with the hybrid; however, I also know the high voltage is an issue if you are unfamiliar with what's in bounds vs. out of bounds. And out of bounds comes with a very nasty bite.

My ask of the forum, does anyone know a trusted shop anywhere near Saginaw that could take a look at the truck?

 

[j91z28d1]

sorry I don't know anything about the area but I can tell you there's nothing special about the hybrid tahoe oil system as are where it can leak from. short of maybe a rear main seal that they need to pull the tranny for. then it's one plug on the hybrid battery, wait a few mins, check for volume across the wires, there never is. the safety plug removes the battery completely from the circuit. then unbolt the orange cables on the tranny. rest is normal.

but unless it's just a slow leak, it's very rare for a rear main to just start pouring out oil, short of a boosted race motor that builds to much crank case pressure and blows it out, I've literally never heard of anything but slow leak that slowly get worse from a rear main.

if I had to guess, without being there. for all of a sudden losing a lot of oil there's a oil cooler bypass block off plate above the oil filter that can leak pretty good sometimes, or the top back of the motor behind the intake manifold, there's the oil pressure sensor. sometimes they get old, or are replaced with non oem gm sensors and they can pop the plastic top and start leaking.

did she give you any details of the location and amount of oil? if it's just a few drops, might be OK to just top off the oil and drive it home to deal with yourself?

 

[Zylin]

No details and I didn't ask for more details. She's the type of person when asked what kind of car she would like her answer would be "white".

I'm getting ready to fly up to retrieve the truck. Was just hoping to get lucky and know the extent and timeframe for fix before heading up.

Many thanks for the details...

 

[j91z28d1]

good luck with it.. I totally get just get her home and I'll deal with it.

let us know how it goes. Hopefully you find a good shop.

 

[Tonyv__]

Have you tried any actual GM dealers? Dealership is usually my last stop but I imagine they’d have to service something they once sold.

 

[petethepug]

Is there a puddle of oil under the truck or is the dip stick measuring the loss? Is it a low oil press warning light?

Fortunately the 6.0L motor is common GM territory until you get into the hybrid system. Just need a little more info

 

[Zylin]

Update. Found a shop and have the truck there - Redmond's in Saginaw. They say the engine is making a noise and is not holding oil pressure. It's not a bad indicator. Waiting for an estimate to tear the truck apart. I'll get more details soon.

Trying to decide if I should just sell it for parts or invest in getting back on the road. More to follow.

 

[Zylin]

Holy cow, they want $1,000 just to Remove Cylinder Head To Check Valves and Springs (One Side).

What would be the cost if it's a bad valve or spring?

 

[j91z28d1]

well pulling heads off the truck is a lot of work, but why are they pulling heads.


valve springs only require them to pull the valve cover to inspect for a broken one. it's not a common thing seen posted here. but it has happened. that doesn't involve oil pressure at all thou and a tick on these ls engines can be anything front a broken exhaust manifold bolt, not big deal to drive home. to a lifter failing and will be very bad to drive on.

did they talk about replacing the oil pressure sensor and the small screen under it? that's usually the first thing to test.

did you see any oil leaking?

 

[j91z28d1]

oh, just incase they bring it up, these ls engines have 2 style heads, one called rectangle port and one called Cathedral port.

the rectangle has a bit of a history of dropping a valve seat, that would require pulling the head to see, but your hybrid 6.0 does not have that kinda of head. you have cathedral port heads, as far as I know I've never seen anyone report dropping valve seats out of a cathedral port head.

I don't see any reason they need to pull a head to inspect anything, they can diagnose a failed lifter or a broken valve spring from removing the valve cover on the top of the head.