Hitch causing trim to melt?

Hmm..can you take a picture?

I have the coastal tech hitch and it comes with an O-ring to push "up" the exhaust to provide greater clearance...but this clearance actually brought my muffler closer to the bumper, but hasn't melted it.

You might be able to do just the opposite maybe. Buy a larger rubber ring and let the exhaust drop a bit? Not too sure, maybe i'm wrong on this one.

 

Heat rises, and metal retains heat.

 

on the second picture which I assume is reversed, you can't have the tail pipe direct the exhaust on the hitch cross bar. Do some thing to lower it so the exhaust exits below the cross bar.

 

Oh man... this could be me typing exactly! I just came here to ask the same question.

Just this evening returned from a VERY hot 300 mile drive, and found the same thing you did. I thought somebody had backed into me, and eventually realized that the part had melted and that it must have been from the exhaust. I'm heading out again tomorrow, and am a bit worried about making it worse. The solution is somewhat simple for anybody with an A/O torch (or a muffler shop with same). Just heat the tail pipe and bend it down a few more degrees until it is definitely below the cross-bar. I'm quite amazed that enough of the heat splashed up to create this deformation. I'm also surprised that right now, just after it happening to me - is the first I've heard of the problem Yikes, this is ugly. I wonder what Curt will have to say about it.

And no, the second photo above is not reversed. Looks like it is taken from the driver side looking toward the passenger side.

Let's keep in touch on getting this fixed. Need to find the part number for that plastic trim (a bit of my painted bumper is a bit deformed too, I think).

Here are my images:



I have contacted Curt at www.curtmfg.com

 

Just put an extension on the tailpipe so the exhaust exits past the hitch. They sell style exhaust tips at Pep Boys etc. just buy one, put it on ( easy, one set screw ), paint it black to make it invisible.

 

Even if you add a tailpipe extender, if the extender touches the hitch there still might be enough heat to keep melting new plastic.

You might need to clip the old tailpipe and have it re-routed around the hitch in a way that limits any contact.

We had plastic tubes on a set of Sears air shocks back 30-odd years ago, and we thought they were far enough away from the tailpipe to not melt. We were wrong...

 

<div class='quotetop'>QUOTE(darelldd @ Jun 27 2006, 02:28 AM) [snapback]277254[/snapback]</div>

From the second picture it looks like the exhaust is directed right at the lip of the hitch bar; about half of the exhaust goes down below, but half would get caught by the bar, and because if its "L" shape, would be deflected upwards, right at the plastic moulding.

Bummer...

*contemplates hitch options, having almost bought a rear bike carrier this past weekend*

Update: Sorry, based on a subsequent pic the crossbar is *not* L-shaped, but apparently hot gases are being directed upward enough anyway. <ET>

 

Very hard to get the proper picture agle. As Climateguy says, I *KNEW* the exhaust would hit the bar slightly, but figured the bulk of it would go under. Of course we don't know what the air does under there when under way (well, we do now, that's for sure). Here is another picture, though it still makes it look like the pipe is directly pointed at the cross bar, which it isn't. I'm interested in what that grey plastic tab directly above the pipe was supposed to do???



And here is my temporary fix for today's trip until I can do it properly. I really don't think that heating the cross bar is causing the problem (but hell, I've sure been wrong before!) I think it is the hot gasses splashing against the square tube and heading up in to the bumper recess. This should direct it all down below the bar. See???? This is yet another reason to hate anything with exhaust!



Nice to have somebody to commiserate with at least, Climateguy! I'll surely poste what Curt has to say, though I recommend that you report the problem as well. They could easily design this slightly differently (put a solid flat bar high across this area instead of the square tube). They need to know the problem for sure.

 

I should have my lower spoiler removed in a few weeks to replace it with colored version. If anyone is interested in it I would be willing to part with it for $150 plus shipping or best offer.

 

Hmmm.... Something to keep an eye on.
I put a Curt hitch on my 2005 right after I bought it. I've got 25,000 miles on the car now without anyth melting lower bumper hitch. It does get hot here in Colorado, so I don't know what's different here.

 

<div class='quotetop'>QUOTE(narf @ Jun 27 2006, 08:40 AM) [snapback]277377[/snapback]</div>

Well, have you ever driven 65mph in 104° heat for two hours with a fully-loaded cargo area, three people, plus all this crap on the roof? My guess is that the temp and the load had a bit to do with the problem.

 

Climateguy -

PLEASE report this to Curt. Here is the response I just recieved:

Darell,
I can see that you have had some issues with the heat generated by your exhaust. I can only say that we have sold hundreds of these hitches and this is the only case of this being reported. You could always alter the exhaust and lower it to give a more of a straight line for it to be directed. You must understand that this is an after market product and is altering the vehicle, and more directly the exhaust flow. By adding an after market product of any type to any vehicle you must expect that something could be affected. Again I must say that we haven't had even one other case of this being reported, but we appreciate you bringing it to our attention and we will watch to see if others begin to report problems.

As usual, I'm the first to report these things, and nobody has ever heard of a problem....

 

My hunch, although I have no education or experience to really back it up, is that the exhaust is actually being sucked through the gap between the hitch and the molding, rather than being blown there by the exhaust pressure. I would expect that a significant vacuum would exist behind the Prius when driving that would draw the exhaust up and over that hitch bar, even if the angle of the exhaust pipe would normally direct the exhaust mostly under the bar when the car is stopped.

Of course, I'm a programmer, not a fluid dynamics engineer, so I might be just making stuff up that sounds good.

 

<div class='quotetop'>QUOTE(Marlin @ Jun 27 2006, 09:51 AM) [snapback]277418[/snapback]</div>

Could very well be. And that little plastic "shield" above the tip might have had something to do with it... and the hitch came along and screwed it all up.

I am impressed that Curt got back to me so quickly, but I'm not so impressed with the actual response. I understand the whole "buyer beware" business, of course, but if I were Curt, I'd be plenty concerned to see this (I sent them my pictures).

 

I'd say this is an example of extremly poor engineering. Curt should have known where the exhaust is and made the hitch in a way to prevent the metal from being in the exhaust stream, or at least provided a way to safely divert the stream. The hitch from Coastal has the bar running under the tailpipe, though it requires a clamp on the rubber bracket to lift the pipe a fraction of an inch. I think the melting is a manufacturer's defect and should be corrected an Curt's expence. They had better to some redesign as well. Towing stuff or carrying loads always puts more stress on the engine then plain old driving, so there will be more exhaust heat. It will probably take longer for folks in the cooler areas of the country, but more and more are going to start showinf this deformation.

It would be interesting in the mean time, if any of you with the Curt hitches have a surface thermometer, to find out just how hot the hitch is getting on deformed and non deformed cars.



Darelldd:

Is that metal on your diverter in physical contact with the hitch? If so, it will still transfer the heat and will probably not alleviate the problem.



Edited because I didn't pay attention that it is Curt and not Kurt.

 

I agree with your assessment, and I've told them as much. I have also contacted the retail location where I purchased my hitch to let them know what is going on.

<div class='quotetop'>QUOTE(hawkjm73 @ Jun 27 2006, 10:06 AM) [snapback]277426[/snapback]</div>

The thin metal is now held off from the cross-bar by just a fraction of an inch. Even if touching, I think it will work fine for the short term. It is the hot exhaust that's causing the melting, not just the cross-bar getting hot. I think I could turn that cross bar red hot, and it wouldn't melt the facia. But blow the hot gas directly on the plastic, and we have a problem. I'm just diverting the exhaust to go down instead of up and over.

I suggested two fixes to Curt. Using a section of flat bar behind/above the exhaust tip, or adding a plate to the top of the cross bar that extends back and above the exhaust tip to keep the gasses from flowing over the tube. The first is probably more elegant.