Toyota Sienna Forum - siennachat.com banner

61 - 80 of 114 Posts

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

Zero260 said:
brian_bp said:
The hitch does not need to be Class 3, but does need to be 2" if a WD system is to be used.
This is not quite correct... To use a WDH the hitch does not necessarily need to be a Class 3 hitch nor have a 2" receiver opening, but it must be rated for a WD system.
Yes, it must be rated for WD use (which is a good point, along with the rest of Brad's information), but in practice WD systems are only available for 2" receiver boxes, and that's why the receiver must be 2".

While none of the hitches currently available for the Sienna have a 2" opening and only a Class 2 (3500 lb) rating, such combinations have been available for other vehicles, and could appear for the Sienna. A Sienna hitch does not need to be Class 3, because that means trailer capacity over 3500 lb (up to 5000 lb), and the Sienna's rated limit is only 3500 lb.
 

·
Registered
Joined
·
109 Posts
Re: Sienna Gen-II Towing Capacity.

Wow, I'm officially sick to my stomach after reading this highly technical, vague, yet detailed post. One thing is for sure, never trust a salesman to tell you something technical (which I didn't, btw).

1200lb towing, with a 265hp engine, basically because it can get too hot for it's own good. Is this correct?
 

·
Registered
Joined
·
617 Posts
Re: Sienna Gen-II Towing Capacity.

In theory.

You would really need to push the engine to extremes to have a problem. High ambient temperature, little airflow, extreme grades, heavily loaded and you keeping the throttle buried might...and I say might....cause a problem. The 3.5 is not known for having overheating or sludging issues. It's very robust and used in many applications. If it were me, I'd run a quality synthetic oil, (amsoil maybe), get the trailer you want and go camping.

wegngis said:
Wow, I'm officially sick to my stomach after reading this highly technical, vague, yet detailed post. One thing is for sure, never trust a salesman to tell you something technical (which I didn't, btw).

1200lb towing, with a 265hp engine, basically because it can get too hot for it's own good. Is this correct?
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

wegngis said:
1200lb towing, with a 265hp engine, basically because it can get too hot for it's own good. Is this correct?
Yes, like every other passenger vehicle, it is not intended to use all that power for extended periods; a 500 hp Ferrari can't tow much, either. Fortunately, the OEM engine oil cooler is all that's needed, so there's no problem with correctly ordered vehicles. It is unfortunate for those who tow that most minivan owners never tow, and thus the oil cooler is not standard equipment in the U.S.

As already mentioned, the 1200 lb rating may be conservative to allow for extreme conditions, but I personally would not fault Toyota for being conservative in this instance, as it seems more prudent than being optimistic about operating conditions.

wegngis said:
One thing is for sure, never trust a salesman to tell you something technical
So true!
 

·
Registered
Joined
·
109 Posts
Re: Sienna Gen-II Towing Capacity.

One other thing to remember, the manual states that your GCWR is only 6200 without the tow package. So if you're carrying a theoretical maximum payload of 1420lbs, thus reaching your GVWR of 5690, you've only got 510 left for a trailer. Yikes.

Any thought of using an aftermarket oil cooler?
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

wegngis said:
... the manual states that your GCWR is only 6200 without the tow package.
Right, that's the same response to the possible condition of sustained operation under high load as the trailer rating, and the same comments about operation under less extreme conditions apply.

wegngis said:
Any thought of using an aftermarket oil cooler?
I think that would be tough to set up. Aftermarket engine oil cooler setups normally depend on intercepting the oil flow between engine and filter with an adapter sandwiched between the spin-on filter and the engine, but the 2GR-FE uses a cartridge filter which apparently would not accommodate this approach. Since there is no other point that engine oil flow is available at an external port or hose, I don't know how an aftermarket cooler would be plumbed in.

It is unfortunate that the very nicely designed OEM oil cooler is not on every Sienna, as it is a much tidier solution that anything that is likely to be added later.
 

·
Registered
Joined
·
109 Posts
Re: Sienna Gen-II Towing Capacity.

brian_bp said:
It is unfortunate that the very nicely designed OEM oil cooler is not on every Sienna, as it is a much tidier solution that anything that is likely to be added later.
Amen to that.
 

·
Registered
Joined
·
109 Posts
Re: Sienna Gen-II Towing Capacity.

Not to double post, but I've been thinking about this a lot. What about installing an oil temperature gauge? At least that way you could lay off the gas (or know when NOT to travel, e.g. the heat of the day) and instead of just hoping you're staying cool, knowing a little more. I don't tow a lot, maybe 3-4 times per year, and typically not super far either.
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

wegngis said:
What about installing an oil temperature gauge? At least that way you could lay off the gas (or know when NOT to travel, e.g. the heat of the day) and instead of just hoping you're staying cool, knowing a little more.
This makes sense to me.
 

·
Registered
Joined
·
109 Posts
Re: Sienna Gen-II Towing Capacity.

Now the hard part. Finding out where to install the sensor. Any ideas? Maybe I'll post this as a separate topic.
 

·
Registered
Joined
·
43 Posts
Re: Sienna Gen-II Towing Capacity.

Hi guys-Even after reading this entire thread I'm still confused (Probably my fault!)

I have a 2006 Sienna XLE Limited. Does it have a Transmission Cooler? and/or an Engine Oil Cooler?

Can anyone clear that up?

Cheers,

Jay

Edit: I have a friend who runs the parts dept at our local Toyota dealership-His response to the same question:

"Oh, okay, well it appears that the 2006 models (unlike the 2005) have the upgraded towing fans and fan motors used in the '05 w/ towing. The radiator is unique to the 2006 with no difference between towing and non-tow package......In other words in 2006 Toyota did not offer a Sienna as with tow package or without. Educated guess says since the identifiable parts are used for tow package in prior year, you have a tow prep package."

So-for the 2006 anyway, the answer is Yes, a Transmission Cooler was Standard.
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

Oilman said:
I have a 2006 Sienna XLE Limited. Does it have a Transmission Cooler? and/or an Engine Oil Cooler?
A 2006 is the early second-generation, so it has the 3.3 L 3MZ-FE engine, which does not get an engine oil cooler (towing prep package or not). It does have a transmission oil cooler, because they all do. It presumably has the towing prep package, which includes increased cooling capacity, because the consensus seems to be that they all got it... but I wouldn't bet on that.

The trim level (XLE Limited) doesn't make any difference, unless one of the U.S. distributors decided to order the towing prep package with all Siennas of one trim level and not another - as far as Toyota itself is concerned the towing prep package is unrelated to trim level.
 

·
Registered
Joined
·
43 Posts
Re: Sienna Gen-II Towing Capacity.

Just to remove any doubt-how would I visually check for the presence of the Transmission Cooler?
 

·
Registered
Joined
·
617 Posts
Re: Sienna Gen-II Towing Capacity.

The stock cooler is integrated into the radiator. In addition to the large coolant hoses, there are two other smaller (maybe 1/2") pipes/hoses that go to the radiator. If you follow them back they go to the transmission. That's the cooler. Just be careful you don't confuse them with the AC hoses. Those go to a separate radiator(condenser) that sits in front of the main radiator.

Oilman said:
Just to remove any doubt-how would I visually check for the presence of the Transmission Cooler?
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

tcp said:
The stock cooler is integrated into the radiator...
... and so is the upgraded (higher capacity) cooler of the towing prep package. If my understanding of the non-towing configuration is correct, there is still a transmission oil cooler integrated with the radiator. You can find the cooling lines, but that still doesn't tell you whether it is the base level of equipment or the higher capacity level of the towing prep package.
 

·
Registered
Joined
·
617 Posts
Re: Sienna Gen-II Towing Capacity.

Sorry, when I wrote "stock", I meant stock towing prep. Does the non-towing equipped 2004-2006 even have a transmission cooler?

brian_bp said:
tcp said:
The stock cooler is integrated into the radiator...
... and so is the upgraded (higher capacity) cooler of the towing prep package. If my understanding of the non-towing configuration is correct, there is still a transmission oil cooler integrated with the radiator. You can find the cooling lines, but that still doesn't tell you whether it is the base level of equipment or the higher capacity level of the towing prep package.
 

·
Premium Member
Joined
·
2,923 Posts
Re: Sienna Gen-II Towing Capacity.

tcp said:
Does the non-towing equipped 2004-2006 even have a transmission cooler?
I believe so. It think it would be hard to find a 200hp+ modern vehicle with an automatic transmission and no transmission fluid cooler, but that is only my impression.
 

·
Registered
Joined
·
43 Posts
Re: Sienna Gen-II Towing Capacity.

Visual inspection confirms the presence of a Transmission Cooler in my 2006 w/o Tow Prep

Thanks
 

·
Registered
Joined
·
2 Posts
Re: Sienna Gen-II Towing Capacity.

Note: The moderator closed my other topic, so I am reposting here as he/she suggested.)

This is mostly intended for those towing with a 2nd generation Toyota Sienna (2007 thru 2010) with or without a tow prep package, but anyone else who wants to weigh-in is welcome to.

I have a 2008 Sienna Limited AWD that I bought without the tow prep package since I had no intention of towing. Then last year we bought our R-POD travel trailer. The 2008 Sienna sales brochure as well as the local dealer told me that the tow prep package consisted of a heavy-duty (HD) radiator, HD fan, 150-amp alternator, and a power steering cooler. Further discussions with the parts and service folks at the dealer determined that all 2008 Siennas came with these items – whether or not they had the “tow prep package”. This package was a $220 factory option, and no one could tell me why Toyota was charging $220 for items that were standard on the vehicle. The service manager said he thought I would be good-to-go if I added an auxiliary transmission oil cooler, which I did.

It never set right with me that my Sienna was officially rated (according to a VIN lookup) to tow only 1200 pounds, but apparently had everything it needed to tow 3500 pounds. So about 6 months ago, I e-mailed Toyota corporate (numerous times) asking about this discrepancy. They kept sending me replies apologizing for the delay in getting me an answer, and I had to keep e-mailing them over and over. Finally yesterday I get an answer from Toyota corporate. Yes, the four items previously identified as being part of the tow prep package were standard on all 2008 Siennas. And the e-mail said the tow prep package consisted of only an engine oil cooler.

I called a local Toyota dealership, and the parts person thought that all 2008 Siennas came with an engine oil cooler, so he speculated that the one in the tow prep package must be heavier duty. The parts person also said that he could find two engine oil coolers for my vehicle, and one of the two was described as being for the 3500 pound towing prep package. However, both of the engine oil coolers had the same Toyota part number. He is going to contact his district manager for help in sorting this out.

I have also found comments on forums saying that you probably don’t need the engine oil cooler if you don’t tow at high speeds on level highways or tow up hills with the metal –to-the-petal. (The theory being that the engine would only produce excessive oil temps if you were at 80% or more of the rated HP.)

Other posts speculated that one could run with a full synthetic engine oil in lieu of an engine oil cooler since engines run cooler on synthetic oil, and the oil doesn’t breakdown at high temps. (I do this now.)
If you have a 2008 Sienna with a tow prep package, and know for sure what it consisted of, please let me know. Or if you can shed any light on this fiasco, please do.

Thanks
 
61 - 80 of 114 Posts
Top