According to this website, they have a slightly different final drive.


http://www.cargister.com/2007-toyota-highlander-v6-215-spec

http://www.cargister.com/2005-toyota-sienna-xle-limited-230-spec

Sometimes two similar vehicles will be different. Like when I had two Fords back in the 80's. One was a piece of sh%t and the other was a f%ckin piece of sh%t.

 

Like when I had two Fords back in the 80's. One was a piece of sh%t and the other was a f%ckin piece of sh%t.

:rofl2:

 

:lol:

 

My Mustang II was a smoldering pile of ****. Probably a few points shy of your worst category....:crap-emoticon:

Oh, and I echo LOL...about spit out my tea....

 

I had a 1979 Pontiac Grand Prix sounds similar to the latter Ford truck. Despite meticulous care and maintenance it was junk that just fell apart... permanently cured me of ever owning another GM product.

 

Mine shifts pretty slow as well, I wish there was a way to firm it up a little...

 

another thing I noticed over the weekend after driving both the HL and Sienna.

at 65mph using CC, my 05 Sienna stated under 2000 RPM, probably 1900
at 65mph using CC, the 07 Highlander was above the 2000 RPM mark, probably 2050-2100 RPM

 

Seafoam it bro...

 

Not sure is by design or what. Both engine runs smooth and quiet so don't think Seafoam will make any different. You Seafoam your Camry, what year? how many miles?

 

transaxles between the HL/sienna could have different drive ratios :dunno:

 

I'm telling you, if you have 100,000 miles on it and haven't seafoamed it, seafoam will make a big improvement. Don't worry bro, we'll have your highlander sounding like a ferrari in no time...

 

The Highlander and Sienna may have the same basic engine block, but they could have different internal components... cam shafts, pistons, etc... I don't know for sure. The Highlander is probably tuned more for towing and offroading, while the Sienna is more for of a basic van. The other thing that would help with engine noise is to install an engine grounding kit. I put one on my truck and it made the engine so quiet and smooth... (it was on a Ford though, it should help on a Toyota too though).. You can find them for $20-25 on ebay. Not hard to install, you just attach the adapter to your negative battery terminal and run thicker grounding wires to different parts of you engine. You should be able to get a little better gas mileage too with those. Anyways, try the seafoam first, it really quieted down our camry... The idle rpms went from about 2000 to 1000 after the seafoam. It burns out all the carbon deposits in your engine. Watch some youtube videos on how to do it, you have to find the breather line in your engine bay and us it like a straw to get the seafoam into the engine.