Also, if there's a misfire, wouldn't the mpg be fairly bad on top of an engine light?
I'm getting 13 to 14 mpg combined. I get about 17mpg @ 65mph. 22ish @ 45mph.

 

I get 12mpg average. 05 H2 102k miles.

The only thing that has been wrong with mine since 95k (when I bought it) was front wheel bearing hub. No offroading ever.

If yours is needing all that you are saying I would suspect that it has more miles than what is showing. How long have you had it and did all this go wrong while you had it? Off road a lot?

It is really hard to tell whats wrong over the internet. If you are in the Houston area I will help you look at it.

Can you post a video of it with sound?

 

Thanks. The 08/09s have different power trains, so it's hard to compare.
I had an 03 H2, so I know the difference. That one was solid & the only issues were the fuel pump going out twice & some leaking, which was really due to safelite.

I've this one just about one year. It had 106k when I got it & just broke 119k this month. I've done no offroading other than grasssy areas & a piece of property I have that throws it around a good bit, but nothing crazy.

I have a feeling that the previous owner off-roaded this thing really hard. Everything's shot on it, suspension-wise. That's why I kept leaning towards mounts, bolts, etc. But, now I'm not sure.

To be honest, I've been working on this over the course of a year & at this point, it's hard to recall what was suspension related & what would be engine related, as strange as that sounds. I could feel every pebble in the road at first. Originally, anything shaking or any bad road conditions literally resonated through the vehicle. Considering it had bad engine mounts, that make the situation worse.

I live about 6 hours east of you, so that's quite a drive, but i appreciate the help none the less.

I'll see what I can do about the video.


From what other 08/09 owners have said, my mpg seems to be normal & was when I got it. I haven't seen a change. I don't have any way to check the suction with a vacuum gauge.


I'm considering ordering an OBD2 dongle to use with torque to see if anything looks odd.

 

Not sure if this is correct, but I had someone tell me to check the throttle body b/c his vehicle shakes like mine when it's dirty. I've never heard of it, but figured I'd check it out. Mine's dirty...




Too late to do anything else. I'll put it back together tomorrow & see if that helps or not. At least it's clean.

 

Dirty throttle body should not make it vibrate. It could make the idle too low and cause stalling at stop lights. It's good that you cleaned it.

 

I took it to the mechanic I know & drove it around.
Strangely enough, there is something going on with the power steering that increases the vibration when turning the wheel. He's getting a look at it to tell me what he thinks. Even he said that shouldn't make the vehicle shake while driving straight down a road, but who knows... I've had weird problems come up before.

 

Not to scare you, but I had a flex plate lose a balance weight once. Thing shook like crazy, but was worse at certain rpm's and speeds. Could even get it almost smooth at around 40 mph, but any other time was shaky, including idling in park. It caused bolts to loosen up, tranny mount bolts, even the bolt holding the fuel pump eccentric to the camshaft. That one came out on the interstate 20 miles from destination on a weekend road trip. Your symptoms sound REAL familiar.

 

I have a small update.
The vibration changes in park as I turn the wheel from straight all the way to full lock.
The mechanic I know doesn't seem to think it's the power steering, strangely enough. I know that would be a really weird reason to cause all of this vibration. He really doesn't know.

Compared to my 03 H2, this thing is a rattling tin can. I felt nothing in the 03 (especially the steering wheel) & I can't recall feeling anything in the steering wheel in the 09 until recently.

The steering column cover doesn't shake or transfer any shake.
Could this be related to steering entirely? Bad idler arm support? Bad steering column? Even the steering box?

 

Well, I feel ignorant. Flex plate? What's that?
I can google, but since you're online, I might as well ask while looking.
I'm up for any ideas.

Edit:
I see what it is... damn.
I've never heard of this. I wonder how hard it is to get to it.
This is going to be interesting. I really hope this is it. Whatever is going on shook loose the bolt on my differential crossmember once.

You know, my motor mounts were bad (one was pancaked an entire inch), so maybe my flexplate is warped or cracked.

 

The flexplate is what the starter engages and also serves as the connection between the crank and torque converter.....ie the converter bolts to flexplate. It also helps balance the rotating assembly (engine). When and engine is balanced, it is a combination of weights or lack of weight in spots on the crank, rods, pistons, harmonic balancer (front of crankshaft)and flexplate (rear of crankshaft).

I might suggest that you remove the serpentine belt briefly and see what happens to the vibration. This will eliminate power steering and a/c. Don't drive it, just remove the belt and see what happens. There is a tension and idler pulley that if they were to go bad could cause this issue too.

I have added a generic pic to help explain:

TH