Throttle body failure - not covered by warranty?!

[Snagjim]

Had my 2007 M5GT towed to the dealer today. :'( Sunday afternoon I started it and the CEL was on. It idled fine, but almost no throttle response. If I floored it, it would slowly rev to about 3000rpm, then stumble. Restarted half a dozen times - no change.

Dealer says it needs a new TB - no other explanation. Also says that the TB is NOT covered by the powertrain warranty! (Car has 65,000 km and is 3-1/2 years old.) I had expected the powertrain warranty would cover it, but apparently Mazda Canada doesn't consider the TB (or any other external parts) to be part of the powertrain! I argued to no avail (so far - I'm not done...).:mad:

Anyone else had their TB fail so early?
Anyone else in Canada had such a lousy response on the warranty?
How hard is it to change the TB - is this a potential DIY? I am trying to sell this car, and really don't want to sink $400+ into it...

 

[chromal]

This is outside my experience, but I think I've seen a few threads here or maybe elsewhere that suggest it might be your MAF sensor, which is integral to the TB. Some folks with CAIs apparently have had issues with their MAF sensors getting dirty and malfunctioning and causing similar symptoms. But. I'm not really sure.

Pursue non-dealer/mechanic solutions at your own risk, but you might want to read this: http://www.ehow.com/how_5074698_clean-air-flow-sensor-mazda.html

 

[skyhawk]

This is outside my experience, but I think I've seen a few threads here or maybe elsewhere that suggest it might be your MAF sensor, which is integral to the TB. Some folks with CAIs apparently have had issues with their MAF sensors getting dirty and malfunctioning and causing similar symptoms. But. I'm not really sure.

Pursue non-dealer/mechanic solutions at your own risk, but you might want to read this: http://www.ehow.com/how_5074698_clean-air-flow-sensor-mazda.html

What was the CEL code?

 

[Snagjim]

I don't have it ... how would I get it?

 

[Tsuru]

You'd need an OBD-II scanner. Chances are that the code has already been cleared. If your Check Engine Light (CEL) is still on then either get yourself a scan tool (doesn't need to be anything fancy), borrow one or get a garage to check the code for you. I'd recommend getting the tool unless you really don't want to work on your car at all or if you can find a garage that will check for free.

 

[Sean2010]

A throttle body is probably pretty easy to change out. A couple wires and maybe 4 bolts holding it on? Correct me if I am wrong

 

[jimp]

A throttle body is probably pretty easy to change out. A couple wires and maybe 4 bolts holding it on? Correct me if I am wrong

close, but believe there is the TB coolant/heater hose line as well, which when removed will cause some antifreeze to leak out. Might try cleaning the TB and MAF with stuff from a parts store to see if that clears up the issue. use the right stuff to clean the MAF or you'll ruin it. Several threads on the right stuff to use

Autozone will read the codes for free I believe.

 

[Robotazky]

No way would I let a dealer just start replacing parts like a TB without more investigation. First of all, I've never heard of a TB problem that can't be fixed with cleaning. Just hearing this ticks me off at dealers. Clean the MAF sensor and the TB butterfly valve.

 

[skyhawk]

And one of the possible causes listed for such symptoms is 'bad fuel'.

 

[Robotazky]

And one of the possible causes listed for such symptoms is 'bad fuel'.

Yes, exactly. There are lots of places to start other than replacing the TB. I was thinking earlier about what problems replacing a TB would fix. I can't think of a single situation other than if it was cracked. Any other issue can be fixed fairly easily.

 

[KBrian]

Airflow into the engine could cause the symptoms you describe. I would check the filter and intake tube for some kind of blockage (animal, vegetable, mineral) before handing it to a dealer.

 

[AIMWO4]

TB replace is EZ... It's probably the TPS (Throttle Position Sensor) if it's anything like every other car with a TB. I have swapped these out in minutes on Saabs. There is a way to reset the TPS on most cars. On Saabs, it's called "Limp Home Mode". Just reset the TPS and you are usually good for many more miles. If I had time, I'd look to see how similar the Mazdas are.

A bad (or dirty) Crankshaft Position Sensor can also cause similar symptoms.

 

[codeyell0]

is the TB drive by wire or cable?

I have not looked

 

[flcruising]

Wire in the '08, no cable.

Not sure about the 05-07 as the service manual I have for the 05 doesn't mention the electric throttle.

 

[skyhawk]

Wire in the '08, no cable.

Not sure about the 05-07 as the service manual I have for the 05 doesn't mention the electric throttle.

I have the Workshop Diagram (Printed copy) for the 2006. The part number is in the owner's handbook. Compared to the 2005 pdf manual that you and I got from the net, One difference is the addition of CEL codes for Throttle Actuator, and Accelerator pedal position. These two components are 'monitored' by the system.. Low or high current going to the Throttle actuator for example.

Attachment 1: Shows CEL codes for throttle actuator, and Accelerator pedal.
(quite a task just to replace that piece of steel cable).

Attachment 2: shows the CEL codes for the TPS (Trottle position sensor) that is also common for the old 2005 cable driven throttle plate.

Attachment 3: is also for throttle actuator..

I guess if any of these CEL codes are seen by the dealer tech, the easiest and fastest way to troubleshoot is for them to get that spare throttle body in their stock and shove it into the Mazda5. Problem solve.

But the detailed troubleshooting include checking the wires and connectors etc...

 

[timoboy]

I had the same problem with mine..car first needed to be floored to move, then straight up wouldn't start at all. pathetic for 1st of all the TPS to be integral to the TB, and 2nd for the DARN THING TO FAIL AT 37K!! Anyhow, what fails is the black plastic cap thing that covers the gear drive for the butterfly. That is where all the electronics for it are actually housed, but it is fused sealed together so it is not repairable, or available on its own, you have to buy a whole new throttle body. After looking at my options of a $300++ from mazda, I went with a used one with 100k and a lifetime warranty for $100. Figure if it ain't failed by 100k, it's prolly not going to.

So to recap: cleaning the butterfly WILL NOT FIX THIS ISSUE. Changing/Cleaning the MAF WILL NOT FIX THIS ISSUE. The TB needs to be replaced. Easy job, but costly if you didn't know better and had to write the dealer a check for $600++ with labor and diagnostic.

Also mazdaspeed and others apparently made and "earthing" kit for these TB's because they have really terrible grounds. It is essentially a large diameter grounding strap that is bolted to the TB and the engine block, easy to make and might help prevent this problem.