GMT800 5.3 was struggling up the grapevine (CA)

[Mark-23]

So I was taking my 04 Yukon XL 1500 across the grapevine from LA to SF with no trailer just the 4 of us and our sleeping bags ect.

 

I thought it would be an easy trek for my GMT800 but nope! I was struggling going up the interstate 5. I mean I had small cars and mid sized so called SUVs pass by me like it was nothing....

 

 

Can someone please explain why my car was so damn weak going up the mountains?

[jzaldivar]

Your rear end might be going out.

 

Those trucks are pretty ballsy.

Change all fluids and check that rear end.

 

Also when was your last tune up. Might be running rich and wasting horsepower.

 

 

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[jzaldivar]

Your truck is already heavy though. Depending on weight of passengers and tire size might affect it to.

 

 

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Too.

 

 

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[Chris]

So I was taking my 04 Yukon XL 1500 across the grapevine from LA to SF with no trailer just the 4 of us and our sleeping bags ect.

 

I thought it would be an easy trek for my GMT800 but nope! I was struggling going up the interstate 5. I mean I had small cars and mid sized so called SUVs pass by me like it was nothing....

 

 

Can someone please explain why my car was so damn weak going up the mountains?

Ok so you were going the other way. Bakersfield to LA seems tougher, but my truck normally stays in third gear when climbing. If it tried hunting then I put it in third. But also some people drive like dickheads through there. Your Yukon may just need a tune up. Plugs, wires, clean the throttle body.

[Mark-23]

Your rear end might be going out.

 

Those trucks are pretty ballsy.

Change all fluids and check that rear end.

 

Also when was your last tune up. Might be running rich and wasting horsepower.

 

 

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My rear end? I don't know anything about that. But my last tune up was a year ago...

 

What should I do before this worsens? And yes it's ballsy as F!

[Mark-23]

Ok so you were going the other way. Bakersfield to LA seems tougher, but my truck normally stays in third gear when climbing. If it tried hunting then I put it in third. But also some people drive like dickheads through there. Your Yukon may just need a tune up. Plugs, wires, clean the throttle body.

I drove from OC to SF and I just got back home to OC. I wanted to know why it happened because both ways I struggled, both ways. I'm scared cause I didn't a tune up a year ago.

[Chris]

Does the engine still run smooth? Might be time for fluids in the transmission and axles. With the age, the transmission could be starting to let go. I got mine from pickup salvage in Bakersfield for $1000. So that would probably be the biggest expense if something is letting go

[Mark-23]

Does the engine still run smooth? Might be time for fluids in the transmission and axles. With the age, the transmission could be starting to let go. I got mine from pickup salvage in Bakersfield for $1000. So that would probably be the biggest expense if something is letting go

The engine runs very very smooth. On the ground and the city... but god did I struggle pushing this thing up the grapevine.

[Chris]

That isn't a light grade. I guess this is not the first trip with it. Might be time to go through everything on it to make sure all is good

[Mark-23]

That isn't a light grade. I guess this is not the first trip with it. Might be time to go through everything on it to make sure all is good

I'll have to take it to get it looked at. But I'm definitely in no position to get another car no bueno. I'm hoping it's a solvable thing...

 

What are you guys thinking it is?

 

And what do you think I should do?

[Chris]

Get it looked at. Small diagnostic fee would be worth it. Then go from there

[Mark-23]

Get it looked at. Small diagnostic fee would be worth it. Then go from there

What do you think is wrong with the car? I really don't have the funds to get this thing even fixed... I'm a full time student

[Chris]

No clue. Spend the $100 to have someone look at it and go from there

[Colossus]

Agreed, have it diagnosed instead of throwing money at it trying to guess. But don't cheap out on a diagnosis. Take it to a good independent facility that knows GM trucks and has a good reputation and good customer feedback. You might plan on spending $130-200+ just to have it diagnosed depending on how complex the issue is.

[r1byker]

I have an '05 Suburban and done that drive many times. What's the axle ratio on your Yukon? That will have a huge effect on how it pulls the Grapevine. I have a 3.42 and the motor's working hard over that pass to maintain 65-70. I kinda doubt anything's wrong if you're not hearing any funny noises, but what do I know? Just expect it to downshift lots, even to second gear, if you're trying to go over 65.