Rx450H Exhaust - Achilles Heel?

[motowpk]

As a result of a high temp alarm our 2010 RX450h was towed to the dealer. Inspection revealed some road debris had hit the heat exchanger in the exhaust, a new feature beginning with the RX450h to more quickly bring the engine up to temperature.

As to what specifically hit the heat exchanger is unknown, probably a rock, and while the damage is apparent, the magniture of the hit was small enough that neither the driver or passenger noticed anything unusual, even though the heat exchanger is directly under the front passenger seat.

While you'd think one would simply have the heat exchanger replaced, Lexus has chosen to make it part of an assembly that includes the catalytic converter and muffler - a $4200 part. A few other bits and pieces raises the parts total to $4400 and with $300 in labor the total is $4700 to repair.

While Lexus can't control damage from road debris, they could have added two more pairs of flanges in the exhaust system (an insignificant cost) allowing the heat exchanger to be replaced individually instead of having to replace every major component in the exhaust pipe, dramatically reducing the cost of repair.

With having designed and built the exhaust system the way they did, they have provided insufficient protection to an extremely expensive assembly that is located in an inherently vulnerable location. After all, this is the underside of the car and debris will strike it in normal operation.

Frankly I consider this an unacceptable vulnerability entailing excessive risk of expensive repairs and have to wonder if it's worthwhile to keep the vehicle.

[lemon]

Is that something insurance would cover? What about approaching Toyota for some goodwill service, since it's not a defect but maybe bad design with the heat exchanger hanging down vulnerable to impact damage? Otherwise, see if you can find a wrecked RX450h, pull that part out and go to a custom exhuaust shop and have it welded in? By the way, any pics? I'm curious to see this part.

Just did a quick search and I found it cheaper online by about 3 or 4 hundred bucks...Still freaking expensive. One place wanted over $8000 bucks...insane....must be a mistake I'm thinking..

[James Horning]

This is not lexus's fault or yours. I would agree that insurance should get involved. This is not poor design, it is a unfortunate accident, a 450h is rolling high technology at its best, and at a price point that is for a qualified buyer. This system allows faster coolant warm up so the ECM can enter closed loop faster.. This with many other things combined helps fuel economy and emissions. You just hit he wrong thing it could of been a tire , or worse .

[BobBass]

There's some other (or maybe the same) component on the RX hybrids that have suffered failure from road debris that has been mentioned before.

You're right, there should be some sort of shield or something, but the bean counters probably decided it wasn't worth the extra cost to include.

I agree with the others; contact your insurance company.

[lemon]

I don't think the OP is so much complaining about the fact that it got damaged - it's more that the heat exchanger was not designed to be replaced as an individual component, necessitating the replacement of the perfectly fine cat and muffler and thus unneccessary expense.

[RX400h]

Is it possible to have a muffler/exhaust shop install a shield. Many of those shops do custom exhaust work all the time. Sheetmetal, even stainless steel sheetmetal is not very expensive. If I had the 450h, I'd be trying to conjure up a shield design, have a sheetmetal shop make it and either a shop or I would install it.

[MeryLexmas]

Or you could possibly bypass it altogether. I have no idea what one looks like or if it has sensors running to it which would throw a CEL if the component is not present. Seems ridiculous to have to replace the entire assembly. I would do as stated earlier and try to find one off a wreck and have an exhaust shop fab it in. That is if I couldn't easily bypass it.

[BobBass]

I'll bet if you had some sort of custom shield installed and the part failed they'd blame it on the modification.

[motowpk]

Update -

Below is a photo (at least I hope it appears, this is the first time I've attempted including a photo in a post) showing the damage to the cooling tube that connects to the right side of the heat exchanger. The tube is crushed where it connects to the nozzle on the heat exchanger, which has been bent back with its connection to the heat exchanger housing cracked. The protruding valve actuator (that controls coolant flow to the heat exchanger), to the left in this view, was also damaged.

Of note, while the housing of the heat exchanger is abraded (by what I think was a rock), it is not dented nor is there any damage to the exhaust pipe. In this view the catalytic converter is to the right and the muffler to the left.

I find Lexus failing in the following areas:

1) The tube and valve actuator are clearly less robust than the heat exchanger itself or the nearby catalytic converter, muffler or the exhaust pipe. Being located in an are that will inherently be struck by debris in normal operation, a shield should be provided to protect these components (interestingly, shields are provided immediately ahead of this area to the left and right of the exhaust).

2) The cost of the repair is hugely increased by the fact that flanges have not been included in the exhaust pipe between the catalytic converter and the heat exchanger and between the heat exchanger and the muffler. Instead, Lexus has chosen to include flanges only ahead of the catalytic converter and after the muffler, and only offers the entire assembly consisting of these three components at a price of a bit less than $4600. (If they would sell only the heat exchanger there would be no problem having an exhaust system shop installing it - but just the heat exchanger is not available).

3) Lexus' pricing of this assembly, since they are the sole source, appears to be 'whatever the market will bear'. One can readily source, for example, a catalytic converter for a 2010 ES350 from a third party supplier for less than $350. Even if we accept that all three components (converter, heat exchanger, muffler) must be purchased and we multiply this price by three or so, it is still a fraction of the $4600 Lexus charges for this assembly, a pricing policy I can only describe as predatory.

Along with about $100 for some hardware and coolant, $75 in 'disposal fees', about $300 in labor and a similar amount in sales tax, the total is a jaw dropping $5400.

I have expressed the above to Lexus and proposed that as I only need to replace the heat exchanger and not the perfectly good catalytic converter and muffler they provide a 2/3 discount on the $4600 part. While expressing sympathy with the situation, they have declined this or any assistance.

At this point my wife have been soured on the Lexus ownership experience and plan on selling our RX450h.

The quantitative part of the decision is that there is no way to avoid this from reoccuring. It has nothing to do with a mistake by the driver or how the car is used (any more than a rock hitting the windshield does) so that continuing to drive our RX450h means exposing ourselves to the constant risk of a $5400 repair.

The qualitative aspect of this is Lexus' making available replacements only as an assembly that consistents of almost the entire exhaust system (after the headers) coupled with an absurd price. When one purchases a car you are placing trust in the manufacturer that the pricing of maintenance and repair will be somewhat reasonable. With Lexus' approach on this they have, in my view, violated that trust and as a result I no longer wish to do business with them, and continuing to own this vehicle would mean doing so.

Hopefully I am not unduly burdening the forum with this lengthly posting, but I felt it important to make existing and prospective RX450h owners aware of this. While this specific case involves the heat exchanger, a hybrid specific part, the same repair cost would be incurred if either the catalytic converter or the muffler required replacement. This is unprecedented and any owner would be shocked to find that replacing the muffler, a replacement they would expect to cost a few to several hundred dollars, is going to cost them $5400.

[lemon]

Good lord...that's an insane price, and a ridiculous design. You've just been a beta tester for Lexus, and I bet in newer models that system will either be protected by a skid plate or redesigned. I'm surprised there haven't been more reports of this, especially for those that live in snowy areas and may be driving over a snow drift or two.

This reminds me of the first couple years of the last generation Honda Odyssey (I had a 2006). Many owner's suffered holes in the radiator or A/C condensor from rocks flying through the enormous lower grill opening. Crafty owner's installed "gutter guard" mesh in that hole to protect the rad/condensor. Sure enough the 2008 models onwards came from the factory with mesh in the lower grill, just like gutter guard.

[RX400h]

Moto,

Have you contacted the Lexus corporate folks?

I would not accept an answer such as that the dealership gave you when the design is clearly flawed.

Don't give in! Go higher up the ladder until you obtain satisfaction.

[motowpk]

lemon, 'insane' is a good description, though you'll appreciate I've thought of even more descriptive words.

You're point about a beta tester are interesting and I do wonder if a skid plate has been added. It's obvious to me that the ~1" cooling tube and nozzle are not nearly as robust as the heat exchanger itself or the catalytic converter or muffler or the exhaust pipe (and I say this with the background of being a mechanical engineer whose experience includes having designed engine exhaust and cooling systems - not automotive, rather heavy diesel, but the principals are the same). While we have decades of experience as to the durabiity of catalytic converters, mufflers and exhaust pipes relative to the strikes they will inevitably take being located where they are, this cooling tube and exposed valve actuator simply does not measure up to that experience and some sort of protection not being provided is, in my view, a clear design flaw. This was most certainly caused by a rock, but, yes, I'm convinced a check of ice could do the same.

RX400h, I have contacted Lexus customer service and as mentioned in my previous post that lead nowhere. Are you suggesting going up the ladder within customer service? I don't mind putting more time into this if I thought it had a chance of producing some results. Is there experience dealing with higher levels of Lexus customer service that indicate they may reverse a lower level decision instead of simply confirming it? I have filed a comprehensive damage claim with my insurance company, so the bulk of the cost will be borne by them, but that in no way reduces my opinion of Lexus' failures in this incident.

[RX400h]

Moto,

I have not had to do this, personally but I would try my hardest to find a "higher level" person with whom to speak.

I recall reading about a Lotus Elise owner who ran over a small object on the highway. It tore up his floor board very badly, costing his insurance company many thousands of dollars. Certainly, undercar components do get damaged, occasionally, but for the repair to cost the owner that much is downright rediculous.

[motowpk]

Another update -

Repair completed last Thursday and wanted to share a couple of pictures of what it's supposed to look like.

Work order refers to this as the 'gas control actuator', pictured below:

The actuator is the horizontal cylinder mounted mid-length to a bracket connected to the heat exchanger body. On the left end of this cylinder you can see a rod that is connected to the valve, to the left, that controls engine coolant flow to the heat exchanger.

Coolant in the tube on the right (passing under the exhaust pipe) travels through the right half of the actuator and to the heat exchanger (via a short connection hidden in this view by the body of the actuator). I expect this is much like the thermostat in the engine, whose actuator is immersed in the engine coolant and moves a valve disc according to that temperature thus controlling the coolant flow to the radiator and therefore the engine temperature. In this case the thermostatic element moves the valve that controls coolant flow through the heat exchanger.

The second picture is taken nearly horizontal looking under the vehicle.

As is apparent in this view, the actuator and associated coolant tube are the lowest point of the vehicle in this area, well below the catalytic converter, heat exchanger body and the muffler.

Now this is certainly an opinion, but to my mind this is placed in an extremely vulnerable position and should be equipped with a reasonable guard to deflect the inevitable contact from debris - especially considering the outrageous $4600 cost of the replacement part, which as previously explained, is the entire exhaust system from the catalytic converter through the muffler (and as one can see in the first photo, there is certainly room for a couple of pairs of connecting flanges before and after the heat exchanger to have allowed this component to be replaced individually).

A sad design aspect to an otherwise well engineered vehice, one that places any ower/operator at risk of expensive damage from normal usage.

[lemon]

I'm not an engineer, but that looks like a very poor design. Your pictures really show how low that sucker hangs down. The other thing I'd worry about (living in an area where the road get salted to death at the first sign of a snowflake - truly it's ridiculous) is how well that actuator is going to work after four or five winters. I can see that rod rusting and seizing.

Just as an aside, I had a closer look at your first pic with the damaged heat exchanger and I see what looks like plant debris (dandelion maybe) on the rubber exhaust hanger. Are you sure someone else (wife / kids etc.) wasn't driving and tried driving over a curb or something?

[anasazi]

It is ridiculous for Lexus to try to charge you such an exorbitant price to replace so many parts when only a couple minor sub-components are damaged! You need to chase this all the way up the Lexus organization, then threaten with "I'm calling my lawyer" if you get no satisfaction.

Be sure to log every phone call you have, cover with a written letter and save every bit of correspondence.

Also be sure to mention that you have posted this on the Lexus Club forum and that, absent satisfactory response from Lexus, you will be notifying Consumer Reports, etc. about a) the far too fragile design of these components and B) Lexus' unacceptable expectation and pricing re: rectifying this situation.

[motowpk]

Good eye lemon but, yes, I'm sure the car wasn't being driver over a curb or anything other than the road. Besides what the driver told me, we have a good indication of when this happened. While stopped at the light at the end of the off ramp exiting the interstate a driver in the lane to right caught the driver and passenger's attention and said liquid was leaking. I inspected the vehicle just before it was loaded onto the tow truck and about 20 minutes of driving from the aforementioned notice from the other vehicle, and at that time there was plenty of coolant in the expansion tank and there was not coolant leaking from the damaged heat exchange and connecting line at that time. This confirms that the engine cooling circuit was not open and able to drain, due certainly to the valve that admits coolant to the heat exchanger being closed as the engine was at operating temperature (the point of the heat exchanger is to bring a cold engine up to temperature more quickly so coolant is only circulated to it when the engine is cold). Accordingly, the volume of liquid available to leak out is limited to the volume of the heat exchanger which is a small fraction of the engine cooling system. That places the time this damage occured almost certainly during the few miles the vehicle was on the interstate - there are no curbs to run over or off roading to be had then.

As to the plant debris, it could have been attached to the rock (my assessment of what hit the heat exchanger) or just as likely the plant debris could have been picked up at some other time (plant material blows across roads regularly, of course).

I recall some time ago noting how low the exhaust pipe goes as it passes under the rear differential since that can be easily seen from the rear of the vehical. I had not, however, ever noticed this actuator as you'd have to crouch down to see it, being under the front seats just to the right of centerline. When I did inspect I was shocked. It is clearly the lowest point on the car in this area and, indeed, provides noticealy less ground clearance than one would think by looking at the sides of the car. And, yes lemon, you're correct, it's not just damage from an impact, but this actuator and its connection to the valve is a linkage that looks ill suited to be in this environment.

Again, my primary reason for posting this experience is that I'm sure that most or almost all RX450h owners have no idea how vulnerable this component is and certainly no idea it will cost $5300 to fix, not to mention that's the price you'll pay if you happen to need to replace the catalytic converter or muffler.

As for me, as of today I am no longer an RX450h owner, having traded the vehicle in, this experience having soured me on the Lexus RX450h owner experience.

[MeryLexmas]

Damn, that really does hang down low. I would have asked for my old parts back. You could get a few hundred for the CAT alone. I'm sure the dealer did.

[lenore]

Wow, picture tells everything...I guess until that is fixed no RX450h in my future....

[Cruiter]

Update -

Below is a photo (at least I hope it appears, this is the first time I've attempted including a photo in a post) showing the damage to the cooling tube that connects to the right side of the heat exchanger. The tube is crushed where it connects to the nozzle on the heat exchanger, which has been bent back with its connection to the heat exchanger housing cracked. The protruding valve actuator (that controls coolant flow to the heat exchanger), to the left in this view, was also damaged.

Of note, while the housing of the heat exchanger is abraded (by what I think was a rock), it is not dented nor is there any damage to the exhaust pipe. In this view the catalytic converter is to the right and the muffler to the left.

I find Lexus failing in the following areas:

1) The tube and valve actuator are clearly less robust than the heat exchanger itself or the nearby catalytic converter, muffler or the exhaust pipe. Being located in an are that will inherently be struck by debris in normal operation, a shield should be provided to protect these components (interestingly, shields are provided immediately ahead of this area to the left and right of the exhaust).

After reading your post, I got under mine and compared with a photo I just took. I just don't see how a rock (or anything else) big enough to do that kind of damage got that far under the car and you didn't see it. It appears between your underside and mine that you've been off road with it and may have drug it over a large rock or obsticle. I have 42,000 miles on mine and it looks nothing like yours for wear. Also if you have read the manual it specifically states NOT to take the 450h off road even if it's AWD. It's not an offroad vehicle. If in fact you did, then you accepted what ever danger you might incur. I'm not saying you did, it just appears that you may have.

Jim M.

[lenore]

after seeing this I do believe a heat shield would have been installed for protection...That kind of hardware hanging under the car is not a great thing....

[motowpk]

Update -

Below is a photo (at least I hope it appears, this is the first time I've attempted including a photo in a post) showing the damage to the cooling tube that connects to the right side of the heat exchanger. The tube is crushed where it connects to the nozzle on the heat exchanger, which has been bent back with its connection to the heat exchanger housing cracked. The protruding valve actuator (that controls coolant flow to the heat exchanger), to the left in this view, was also damaged.

Of note, while the housing of the heat exchanger is abraded (by what I think was a rock), it is not dented nor is there any damage to the exhaust pipe. In this view the catalytic converter is to the right and the muffler to the left.

I find Lexus failing in the following areas:

1) The tube and valve actuator are clearly less robust than the heat exchanger itself or the nearby catalytic converter, muffler or the exhaust pipe. Being located in an are that will inherently be struck by debris in normal operation, a shield should be provided to protect these components (interestingly, shields are provided immediately ahead of this area to the left and right of the exhaust).

After reading your post, I got under mine and compared with a photo I just took. I just don't see how a rock (or anything else) big enough to do that kind of damage got that far under the car and you didn't see it. It appears between your underside and mine that you've been off road with it and may have drug it over a large rock or obsticle. I have 42,000 miles on mine and it looks nothing like yours for wear. Also if you have read the manual it specifically states NOT to take the 450h off road even if it's AWD. It's not an offroad vehicle. If in fact you did, then you accepted what ever danger you might incur. I'm not saying you did, it just appears that you may have.

The vehicle has never been taken off road.

As far as something having 'gotten that far under the car' without seeing it, neither the driver nor the passenger (who also has 20+ years of driving experience) saw anything, leading to the conclusion that a rock (or similar hard object) was kicked into their path by another vehicle so that it wasn't something lying in their path with an opportunity to avoid it. Also, at 65 mph (the normal speed on the highway they were traveling), it wouldn't take a particularly big rock to have sufficient momentum to cause this damage. One of my observations is just how much less robust the coolant tube and actuator are compared to, say, the heat exchanger body or catalytic converter or muffler. To me it's one of the reasons Lexus should have fitted a guard to protect these components in an area with inherently high risk of impact in normal operation.

As far as yours looking nothing like ours for 'wear', I'm not sure what you're referring to, but if it's the abrasion marks on the heat exchanger (in my first photo), that's not wear, but clearly from the impact that caused the damage. The other marks one may think are 'wear' are coolant discharged from the broken cooling line that then dried on the underside of the vehicle. Aside from the immediate area of damage there was no damage or, for that matter, obvious signs of wear anywhere else under the vehicle.

Again, to summarize, I see Lexus' failings here multiple. First, the coolant tube and actuator are located in an especially exposed fashion; see my last photo illustrating how far below the rest of the vehicle they are situated. Secondly, they are not as robust as other exhaust system components and, particularly in conjunction with where they decided to locate them, should have had some sort of guard to protect against the inevitable impacts that will occur during normal operation to the underside of the vehicle (indeed, other areas under the vehicle close by have guards). Then they fail to fit flanges before and after the heat exchanger and make available a replacement heat exchanger only as part of an assembly that runs from the catalytic converter through the muffler. To my experience it is unheard of that you cannot purchase a muffler or catalytic converter, or in the case of this hybrid specific component, the heat exchanger, as an individual component. Finally, to add insult to injury, they price this assembly at $4700. You can buy catalytic converters for other model Lexus' for $350 and less, so I can only understand the pricing of this assembly (roughly three times a catalytic converter) to be the result of Lexus being sole source for the assembly and charging whatever they feel the market will bear. As stated before, while my experience was with the hybrid specific heat exchanger, any owner would face the same situation and costs ($5300 with installation and taxes) to replace the muffler or catalytic converter. I am willing to bet that no one purchasing an X450h expects a replacement muffler will cost $5300.

In conclusion, I find the design failure of this vehicle from the standpoint of vulnerability and serviceability, in conjunction with Lexus' replacement part and pricing practise, to be unacceptable and do not want to do business with Lexus any longer. We sold the RX450h immediately after having the repair completed and would not consider a Lexus vehicle in the future.

[Cruiter]

Motowpk, of course I wasn't there when the incident (whatever it was) happened. One of my retirements is from the car business and this is not my 1st Lexus. Looking at your photo caused me to check the feeling of durability and mounting when I was under the car. I've got to tell you that it's high enough and sturdy enough that nothing you should encounter in the road (that you wouldn't see on the road or feel when you hit it) should do the damage done to yours that wouldn't have been noticed inside while driving. We both bought a Luxury SUV not designed for off road driving. As a moderator on the Club Lexus board I've not seen a single post with damage of this type from any of our many members. For paved road only use I'd say the car was very well designed. If you hit something on the road big enough to do that, you should have an insurance claim.

Now I will admit the lower grill opening is big enough for something to enter and damage the A/C condensor and has for one or two drivers. I used black vinyl gutter guard and platic ties to correct that and it can't be seen unless you get below the bumper to look. Nothing will get through the gutter guard.

[RX400h]

I am hoping that aftermarket manufacturers like Walker, Magnaflow, etc step up and make individual replacement parts. Sometimes it takes a few years after a new model has been introduced.

[lemon]

For that amount of damage, one would think the impact would have made a loud BANG of some sort. Did neither the driver or passenger hear anything.

The plant debris is still suspect in my mind - I doubt plant debris blowing across the highway would have lodged in there at that impact point. I'm still leaning to someone taking this thing where it shouldn't have been.