Question for the car experts..

[draggar]

My wife's mini van died.

They said that all the censors melted as well as the catalytic converter.

Any thoughts on what might have caused this?

[Evil Queen]

bwa.... what?? Is that possible?

(btw; I need your opinion on dog food for my dog, I have a thread started in the advice section)

[ravevolution]

Wow thats crazy!!!

Well I can only assume if things got melted like the sensors that there had to be some type of overheating. Issue could be with the cooling system, like a leak from somewhere.

What year is the van?

[draggar]

2004ish? It's out of warranty, we checked when the transmission went out.

[Evil Queen]

It's a 2004(ish) van and it has melted sensors already? I would expect that on something closer to 10-15 years.

I agree with Rave, it sounds like a problem with overheating. When was the last time the coolants were checked/changed? Does your wife remember the last time she noticed how hot the vehicle was running?

[ravevolution]

2004ish? It's out of warranty, we checked when the transmission went out.

Wow thats premature, even if it is out of manufacturer warranty. It's not a old van.

Then you had the transmission go out before?

Either the van is a lemon or (not pointing fingers, just from experience) that there wasn't proper maintenance done on the van. Was there ever a check engine light that came on?

Seems thought this vehicle has had it share of issues

[bean]

How many miles? What kind of van?

Which sensors "melted", and have they told you why the catalytic converter has gone bad? If it's clogged, that will cause poor performance and high temps. And you absolutely need a second, third, etc opinion if it'll start and run.

Symptoms, and what codes is the engine computer giving?

[Imprl59]

My wife's mini van died.

They said that all the censors melted as well as the catalytic converter.

Any thoughts on what might have caused this?

All of the sensors have not melted. If that is actually what the mechanic told you then you need to take it to another mechanic. Find out what sensors have melted and let us know. Has the van been running bad? Have you seen a flashing check engine light?

[Greenday]

Since it's not old, I'm going to say it had no coolant resulting in overheating. That or you must put a thousand miles a day on it or something

[draggar]

Then you had the transmission go out before?

Earlier this year the transmission went out and when they fixed that they noticed the (or a?) computer went bad. This place didn't know if the bad computer caused the transmission to fail or vice versa.

Either the van is a lemon or (not pointing fingers, just from experience) that there wasn't proper maintenance done on the van. Was there ever a check engine light that came on?

Don't worry, I wasn't responsible for the maintenance on this, I couldn't even drive it (modified for my wife plus the crates forced the seat to be all the way to the front).

It wouldn't surprise me if it turns out poor maintenance. She claims she didn't need to get oil changes until around 15,000 miles because she uses full synthetic. Honestly, I think it's been a lot longer 9and this angers me because I paid for a batch of FREE oil changes last year and they're still good!!).

How many miles? What kind of van?

70,000? Dodge Caravan

Which sensors "melted", and have they told you why the catalytic converter has gone bad? If it's clogged, that will cause poor performance and high temps. And you absolutely need a second, third, etc opinion if it'll start and run.

Symptoms, and what codes is the engine computer giving?

All of the sensors have not melted. If that is actually what the mechanic told you then you need to take it to another mechanic. Find out what sensors have melted and let us know. Has the van been running bad? Have you seen a flashing check engine light?

My wife read off the list, they didn't say what I said exactly, I just don't remember which ones. I know one was the cooling / overheating sensor.

Symptoms - it wouldn't go over 50 on the highway and had little to no power.

I don't know about the check engine light but it wouldn't surprise me if she ignored it.

We had a good mechanic but last time it broke down the AAA tow truck driver "recommended" a "really good place" nearby because he had heard a lot of bad things about where we've been going to (oddly, one of my neighbors has been going to them for years with no issues). She was (choose your adjective) enough to follow the driver's advice.

Thy put in a reconditioned catalytic converter for something like $450 (this was a few months ago).

[bean]

Earlier this year the transmission went out and when they fixed that they noticed the (or a?) computer went bad. This place didn't know if the bad computer caused the transmission to fail or vice versa.

Don't worry, I wasn't responsible for the maintenance on this, I couldn't even drive it (modified for my wife plus the crates forced the seat to be all the way to the front).

It wouldn't surprise me if it turns out poor maintenance. She claims she didn't need to get oil changes until around 15,000 miles because she uses full synthetic. Honestly, I think it's been a lot longer 9and this angers me because I paid for a batch of FREE oil changes last year and they're still good!!).

70,000? Dodge Caravan

My wife read off the list, they didn't say what I said exactly, I just don't remember which ones. I know one was the cooling / overheating sensor.

Symptoms - it wouldn't go over 50 on the highway and had little to no power.

I don't know about the check engine light but it wouldn't surprise me if she ignored it.

We had a good mechanic but last time it broke down the AAA tow truck driver "recommended" a "really good place" nearby because he had heard a lot of bad things about where we've been going to (oddly, one of my neighbors has been going to them for years with no issues). She was (choose your adjective) enough to follow the driver's advice.

Thy put in a reconditioned catalytic converter for something like $450 (this was a few months ago).

How do you recondition something that's function is to basically act as, well, a catalyst (i.e. it's there to promote combustion and mostly fuels itself)? Also, next time go to any old exhaust shop, a brand new cat shouldn't be more than $150 installed. Unless you're in California. I really, really doubt the cat has actually been replaced (and they can't be "reconditioned" anyway, they're either new or used).

70k? Serious? I know Dodge has some really crappy transmissions in those things, but not that horrible. Can't be too terrible since they're rebadging them as VW Routan's now (built in the US by Chrysler for VW. Even if your wife is like most people in the US, it should go 100k+ on the original transmission and transmission fluid (not saying you should do this, it's terrible for the car, but most people ignore the transmission until it breaks).

If it's new enough to have a computer controlling the transmission (late 80s and newer), they should have the equipment to talk to it. 96+ can have even AutoZone read the engine computer to tell you what's failing. 95 and older usually has a light on the transmission control unit (TCU) that's capable of flashing out error codes. Or they can sometimes do it via the overdrive light or drive light on the dash. Also, if the TCU was bad, there should have been an additional light lit up and/or flashing in addition to the check engine light, and it would have likely gotten stuck in 2nd gear going forward and wouldn't shift any higher. To be honest, I doubt your original transmission was even bad unless she was pulling an 18 wheeler uphill behind it for a few months.

Once I've found a good shop I stick with them for years, I've been using my current shop since they opened 13 years ago. Looks like I'll have to find a new one though, my current one only works on Honda/Acura and I'm pretty set on getting a Volvo this time. Mom's hellbent on using the dealer for everything even though they've scammed her really bad from day 1 on her Toyota (going as far as selling her fully loaded, leather, navigation, etc car out from under her and trying to give her a base model for the same price) and she's long out of warranty..

Admittedly, I'm bad about oil changes - usually pushing them to 5,000 miles on my last car, but it used almost zero oil between changes (never had to top it off) and an oil analysis said it was like new inside of the engine. But I actually did stuff like check the oil. And a lot of car makers actually recommend 10k+ on synthetic now. But one look at BMW and Toyota's policy on that vs engine failures in relation to oil sludging, well....

There's several sensors related to the cooling system and "overheating" - one of which is related to the gauge/lights on the dash, the rest of them tell the engine computer how hot the engine is so it can modify how much fuel the engine is getting, what RPMs to shift at, what RPM to idle at, decide when to cycle the cooling fans... you get the idea. There's tons of stuff related to engine temp with the computer(s).

Since it sounds like the van still drives (just really badly), either drive it to another shop or have it towed. You need at least 1 more opinion on it, it sounds like it's got a lot of issues in addition to being very poorly maintained.

[Seshat]

She claims she didn't need to get oil changes until around 15,000 miles because she uses full synthetic.

I laugh. Ha ha ha.


Check the oil. If it's not a lovely shade of brown, it needs changing. If it's not between 'empty' and 'full' on the dipstick when the car is cold, it needs topping up (or - much less likely - some oil removed).

But definitely not 15 thousand miles between changes!

[Mr. Rager!]

I laugh. Ha ha ha.


Check the oil. If it's not a lovely shade of brown, it needs changing. If it's not between 'empty' and 'full' on the dipstick when the car is cold, it needs topping up (or - much less likely - some oil removed).

But definitely not 15 thousand miles between changes!

Depending on your driving conditions, you can go up to 15,000 miles on fully synthetic. If you're mainly driving in the city, doing a lot of hard driving (stop-n-go) then you would want to change it sooner. My BMW will tell you when the oil needs changing, it's been doing a lot of back and forth from Minnesota to Idaho lately... it's on 12,000 miles with no oil change and the oil still looks great. My little VW is on 6,000 miles with no oil change and the oil looks brand new. So laughing, meh. Unnecessary.

[wolfie]

If the cat melted down, it could very easily take the oxygen sensors with it. Common cause for an overheated cat is an overly rich mixture (unburned hydrocarbons to dispose of), or it's missing on one or more cylinders (both the fuel and oxygen that should have burned in the affected cylinder are burning in the cat).

But definitely not 15 thousand miles between changes!

I routinely go 15 thousand miles between changes (regular mineral oil, 15W40). Of course, that's with mostly highway driving, and it takes 10 gallons to fill the crankcase. That's the standard oil change interval on a Series 60 Detroit, and it's typical of engines in class 8 trucks.

[Mr. Rager!]

If the cat melted down, it could very easily take the oxygen sensors with it. Common cause for an overheated cat is an overly rich mixture (unburned hydrocarbons to dispose of), or it's missing on one or more cylinders (both the fuel and oxygen that should have burned in the affected cylinder are burning in the cat).



I routinely go 15 thousand miles between changes (regular mineral oil, 15W40). Of course, that's with mostly highway driving, and it takes 10 gallons to fill the crankcase. That's the standard oil change interval on a Series 60 Detroit, and it's typical of engines in class 8 trucks.

You're definitely right about the O2 sensors causing issues with the cat.

With a 10 gallon oil capacity, I would think you'd be able to go longer between oil changes. (I actually looked it up and a for your engine, you should be able to go up to 30,000 miles long haul between oil changes. The only reason I researched it is because my dad does long haul driving and at a rate of 15,000 miles, he'd be changing his oil once a month or so) Have you considered getting your used oil tested? I had the BMW tested after changing at 8k miles, they suggested waiting until 9500 miles before the next change, but with all the highway driving, it still looks good.