What's an idle speed motor (Honda)

I have a mechanic who just diagnosed my 98 Odyssey with a bad idle speed control motor.

What's that?

I am familiar with an IAC valve, but trying to figure out if he is just using some colorful descriptions, or if there is a different component I am not familiar with.

Thanks!

I also know what a fast idle thermo valve is...

I'm actually trying to figure out if I trust this mechanic (he's a friend who has always done good for me in the past).

As far as I know, there is no electric motor that controls the idle on a 1st gen Honda Odyssey. The IACV controls vacuum, and is activated by the ECM.

Am I wrong?

Well, I thought that a lot of the IAC valves use a stepper motor to vary the amount of air? Weird way to put it, but if asked, I'd guess he'd describe it as an IAC

Correct. It's a little motor that valves air around the throttle plate to regulate idle speed. On the K-series engines, it tends to stick often, requiring frequent cleaning.

+1, though I would say they have some tendency to stick on all '90's Hondas. Sometimes they can be cleaned, other times they must be replaced. They are expensive new, and sometimes questionably "remanufactured," so I typically hit the JY when I need one. The most common symptom is an idle that rhythmically surges, then drops back down, surges, then drops back down...

So, you are saying an "idle speed motor" is an alternate name for an "idle air control valve", right?

Honda calls it an IAC valve.

different words for the same thing... like a Bendix drive on a starter...

Here's my problem...

Testing an IAC valve is a simple matter of pulling the air intake and covering the vacuum ports to see if the IAC properly adjusts. If bad, a couple of bolts and it's simple to replace. also not too hard to clean. But this test would also tell if there are alternative vacuum leaks causing the problem.

When a guy tells me (without taking anything apart), "You need a new idle speed motor. Were are gonna have to remove the intake manifold to get to it. It will take $374 worth of parts (motor, intake gaskets, etc), and $280 in labor, $680 total with supplies", I think I'm being fed a heaping pile of horse E36 M3...

...especially when the part is properly called an IAC valve, and can be purchased retail for $168.

So, if there is something more significant, or some dark secret magic I am unaware of, I am willing to learn. If it's an IAC valve, I've got a friend who just lost my business.

I'd look up the procedure to R&R the valve before jumping to conclusions. If the upper plenum, or worse, the whole intake, does have to come off, on a modern FWD van I can totally believe that price. Is $168 how much the dealer gets for one, or the POS Chinese parts store one that has a propensity for failing? If its truly that much work to change, an honest mechanic is going to buy the best parts to prevent a comeback.

In reply to Kenny_McCormic:

Umm...it's a '98. I don't think I will be buying parts from the dealer (if they even stock stuff that old).

The POS Chinese E36 M3 is $68.

R&R procedure is not difficult for the IAC valve. The "idle speed motor" might be a little harder, since it is not listed in the shop manual.

your thinking too hard. take it to three other shops, one of which should be the dealer. compare notes of the four estimates and nomenclatures. decide then. done.

-J0N

SVreX wrote: In reply to Kenny_McCormic: Umm...it's a '98. I don't think I will be buying parts from the dealer (if they even stock stuff that old).

That makes no sense to me. Do you want it to be reliable and work well?

For certain parts, I am dealer only even on my 238k mile cars. Honda almost certainly has that part for you.

EDIT: Deleted because Bobzilla says everything I said, but better.

I agree that, especially with electrical parts, it is worth buying Honda over parts store crap. As I mentioned above, if money is tight or the car just isn't worth it, I would go get a junkyard part before I'd get one from autozone.

dculberson wrote:

SVreX wrote: In reply to Kenny_McCormic: Umm...it's a '98. I don't think I will be buying parts from the dealer (if they even stock stuff that old).

That makes no sense to me. Do you want it to be reliable and work well? For certain parts, I am dealer only even on my 238k mile cars. Honda almost certainly has that part for you.

This. The hondar's that I see with 300k+ miles have had OEM parts installed their entire life and are as reliable today as they were when they rolled off the lot new. The ones that are at 150 and complete junk are the ones that have had nothing but parts house crap thrown at them by hacks.

There are PLENTY of online retailers that offer OEM parts at cheap E36 M3 prices. THIS ONE has them one day out for $164.07 for new OEM parts and unlike Majestic they don't charge a handling fee, just straight shipping costs.

And yes, Honda refers to them as "Rotary Air Valves" (control isn't always used) and can almost always be found in Throttle Body

EDIT: also note that when you find parts on hte honda catalog like this one, Number 8 comes with number 9, but 9 does not come with 8 if you select it individually. If it's connected by a line/bar, it's included with the top most number.

Umm... I never said I was buying E36 M3ty parts. I said probably not the dealer.

As Bobzilla has pointed out, there are plenty of places to buy OEM quality other than the dealer.

SVreX wrote: Umm... I never said I was buying E36 M3ty parts. I said probably not the dealer. As Bobzilla has pointed out, there are plenty of places to buy OEM quality other than the dealer.

Hint: These places ARE the dealer. At least in our case.

Right, like Bobzilla says, that is the dealer. When someone says they won't buy dealer parts I assume they mean aftermarket crap. Ordering from a Honda dealer online is still buying from "the dealer." Do that. Unless you don't care about reliability, or functionality, of course.

You guys are getting good at answering questions that were not asked.

I asked if there was a difference between an IAC valve and an idle speed motor.

I didn't ask if I could use cheap Chinese E36 M3 parts.

You also seemed to miss the part where he was charging me $374 for a part which retails $168 OEM.

If anyone has any relevant real info, that would be great (like, omg that job is a pita, or your gonna need a $60k specialized computer to tune it). Otherwise, thanks but no thanks. I share Margie's perspective on opinions.

In reply to SVreX:

OK, he is charging you that for the part(the full non competitive price), plus intake gaskets, plus whatever else.....Labor, that sounds like a 1.5-2hr job in their book.

If it's failed because the intake is gimmed up from oil/carbon, than the intake gaskets are so they can clean it out before installing a new one. The IAC is on the back of the intake, so it's facing teh firewall. Not as easy as replacing spark plugs in a SOHC Accent, but not as bad as doing head gaskets on a 5.7 Vortec.

It really depends on what all he's really doing. If he's removing the intake to clean it, that's all labor time.

Next time you want an opinion, but you don't want us to give you our opinions, don't ask to start with. Getting pissy because people tell you things you already know but don't want to think about when we're trying to help is counterproductive.

Don't misunderstand- I'm not "getting pissy". If anything I'm a little annoyed at myself (not y'all) for following the flounders into arguments about Chinese parts vs OEM.

I was looking for input from people who are familiar with Hondas. BZ: your last post is the first post in this thread where anyone got close to the actual process of R&R.

I agree with your assessment that the IAC is a little difficult because it faces the firewall. But it's a 4 cylinder, not a crammed modern 6. This shouldn't be that tough, and removal of the plenum and/or manifold is definitely not necessary. That is what I had hoped people more familiar with Hondas could have taught me.

I'm surprised that the Grassroots peanut gallery finds $680 acceptable for this type of work. Dealer, perhaps. Small time mechanic, not so much.

My expectation of a small time mechanic (especially a friend) is that he would suggest we pull it, check for vacuum, and try to clean it. If that didn't work, then replace.

What was the problem that made you bring the car to the dealership? What was the symptom?

I did this twice on a 2003 CRV. Not sure if its the same engine or similar at all. It was not difficult at all, just a little time consuming since I remove the throttle body. That meant the coolant had to be topped off/bled as the lines that go to the tb were disconnected.

IIRC, I bought new gaskets, but they were not paper. It uses o-rings that could have been reused. I bought everything from Majestic or Bernardi.

I would tackle it myself.

BTW, everytime this happened on the CRV, it would not idle. It would just shut off unless you kept your foot on the gas.

It was gummed up, I did not buy anything other than gaskets.

In reply to Slippery:

Rhythmic throttle surging both idling and in gear or accelerating. It was forceful- I couldn't hold it back with the brakes.

I disconnected the TPS to drive it to the shop (60 miles). I'd rather drive a car that wants to stall, then one that wants to drive through the car in front of me.

I am pretty sure it is the IAC. But I know how to test it to be sure.