Input needed: CEL Code - P1686 - Oil Metering Pump
 

Hi everyone,

My 8 started this morning with a solid CEL light. I drove it to the dealership but the car was not driving normally. The revs would move up very slowly and I could not even keep up with normal stop and go traffic.

Park Mazda ran a diagnostic and I got P1686, they concluded I needed a new metering pump.
It was 125 bucks for the diagnosis. Estimate for the repair was $1241 for the part and 1 hour labor(this don't seem right?)

Now I was a little worried b/c the tech could not even tell me what the part was for and more importantly whether it was covered under engine/powertrain warranty.

Phoned Weber Mazda and they informed me it was under powertrain warranty.

Car specs: 2004 RX-8 Auto GT, 49xxx kilometers, plugs/coils changed 7k ago.
The car was misfiring at high revs a couple weeks ago (flashing CEL happened a total of 3 times). I asked Park Mazda specifically to check for those codes as well and they did not get anything.

My questions are:
1) Should I go with Weber Mazda for the repair even though they are a 25 minute drive away? I don't know if I should be limping my car there.
2) What could cause the metering pump to go, and what consequences is there for other parts of my car, like the engine...? Are 2004 still covered under the PT warranty, I'm the 3rd owner...
3) Could this be the source of my misfire from a couple weeks ago?

From my experience it is likely that the Pump position sensor has unlearned the position of 0

If they want to replace it for free.........then I would go there and get it it done.....but if they are going to charge you...I would try and reset the sensor to see if it works.

You will need to be slightly mechanically inclined to do it...if you want to send me a PM and I'll help you

As for driving the car...it is in Limp Mode...so you won't be able to hurt it :) If you want..... add 8 oz of pre-mix to a full tank of gas to be sure

I'd have it towed to the dealer. Mazda roadside assistance might even do it for you.

Not sure why a metering pump would go bad, but you shouldn't drive the car if you are unsure if it is functioning or not (as dan mentioned it could be a sensor instead). I'd imagine a failed OMP would probably lead to excessive seal wear and ultimately a loss of compression/dead motor. No oil film on the rotor housing might also make it hard to start? I'm sure the people who actually re-build rotary engines can and will give you much better answers then I can.

Update: Picked it up and drove it home since I didn't feel like leaving it in the lot. The dealer must have cleared the CEL. So it was driving just fine coming home, the CEL never came back on. I'll take it to Weber on Monday if it is under warranty.

Frustrating situation, I've got no knowledge of this oil meter at all. The car has not been hard to start at all, its been down to -25C over here and the car gets going w/o being plugged in for over 6 hours.

may be an intermittent problem with the electrical sensors of the OMP system, which is why you have no symptoms before and once the code is cleared limp mode doesnt return. It'll only get worse with time most likely, I'd make sure the tech did a full wiring diagnostic before determining it to be specifically the pump, see if they'll tell you what exactly tested out bad with the pump aka a short, high resistance etc.

kevin.

^^ come on..you think they did anything BUT read the code and clear it ;)

the guy passed me the workshop manual on what he supposedly did. Said he did every step except replace the PCM.

yea but what step led him to believe it was bad is the key part. there's multiple ways it could fail.

kevin.

Teknics thanks for the help.

When I spoke with the technician about it, he said that he could not determine the problem specifically. He showed me the steps he performed, and concluded that the part needed to be replaced. Since the tech sounded like he didn't know what he was doing, I'm taking it to another dealership tomorrow.

Park Mazda is where I took it originally and they were being a real pain in the ass. Even though I was under powertrain warranty still, the car is originally American and seemed like they didn't want to work on it.
Pretending that they cannot find any recall info, or even if it was covered under warranty. I had to make calls to MazdaUSA myself. Real pain in the butt haha.

Sounds like the tech simply read the code and determined it meant that part needed replacing.

thats typical.

The OMP isnt a cheap part, at least not that i recall, but it's an important part of the engine so id imagine it should be covered under powertrain but i could be wrong.

kevin.

well shoot, you got an 04, rev the crap out of it and get a new motor...im kidding, dont do that.

take it to who ever is not going to charge you...and the first guy DEF should not charge since its an 04, your covered to 100k miles by mazda of NA for full engine replacement if neccessary.

Here's the thing....the OMP is a very simple stepper motor pump..and the only thing the PCM keeps track of is the position of the metering piston...it couldn't tell if the pump was actually working if it's life depended on it..it can only tell if it does what it expects from the positioning switch

If it gets confused about what zero/max are...then it says the pump isn't working....really the pump is likely fine and the switch is confused......That's why resetting the switch seems to work

It's about a 45 min job to remove the pump and reset the switch...or a $1200 part.......:)

Yeah I don't know if I should still be worried. Its been out of the shop and has 500 km put on it. no issues yet... I do have an appointment booked with another dealer in a couple weeks though. What are the chances that my problem has magically gone away?

If its bad it will through another cell code.

Want to be sfae, get the code read at the other dealership.

Bet they find nothing.

question for the USA guys. Is the OMP covered under powertrain warranty?
In Canada it is, but when I phoned MazdaUSA customer service told me it was not.
Seems like a silly part not to include...

Did anyone ever get an answer on this?? I am going through the exact same problem with my '04. My OMP is leaking and has damaged radiator hoses etc.

I never ended up replacing the OMP, after the CEL was cleared everything has returned to normal...

As far as the warranty is concerned. It is covered under the powertrain warranty for both MazdaUSA and MazdaCanada. I got different answers from MazdaUSA when I phoned them, it is best to have ur dealer e-mail them and they will get the right answer in writing.

If your out of warranty the part is ridiculously expensive 1200 bucks or something. I'd try to get the part from the net. I almost bought an OMP from a salvaged RX-8 off ebay for 150 bucks. Try ur local junkyards or around the net for a used part.

had the same problem... the guys helped... just look for the posts by me ... kamhus ... just took the OMP off rezeroed the OMP and put it back.. the CEL went away.... the problem had been created by leakge of coolant form a hose just above the OMP... somehow gave the OMP a bad signal.. it wa staken off for cleaning and put back again. and not rezeroed.

The replies to my post helped a lot... thanks Guys.

2005 rx-8 omp
 

Side Bar Question:
Is the gear cam portion of the omp (behind position sensor) supposed to be without oil?

Thanks

Yes.... it is dry in there.

The oil is in the internal passages and the stepper pistons

Reset oil step moter positioned to 0
 

[QUOTE=Pablo Pavon;4865115]

[QUOTE=Richie Coppola;4915278]Did you figure out how to reset to 0? I'm having p1688. Cheers

Before you mess around with the zero setting try the easier approach which is to clean the sensor terminals and check the coolant hose clamp above it for dripping coolant as this is possibly your problem. Clear code and you might be all fixed.
The 1686 code is for not enough oil flow so loosen but dont remove the 2 small bolts before moving the sensor a bit towards front of car. Tighten bolts then test.
I have been there and this has worked. Can only try and you should also search for MOP 1688. Good luck.

[QUOTE=Prasanth Sasikumar;4927335]In my case I replaced it since it had to be pulled. what I had to do was pull the step motor turn it I believe all the way counter clock wise an reinstall. It is tricky because you have to line up the the pump.. be careful the houses can be brittle and break. Also so bolts can snap very easily because they are hollow and expencive