98,000 1995 MAzda MX-3 IDLE Problem!

[vegetoking]

Hey guys... I know you like the low milage =)
I just bought this mx-3 for my brother. The car is a 1995 Mazda mx-3 rs, 5 speed manual. Great condition. I have the receipts for everything... Here is a run down:
@50k
brakepads and front rotors replaced
Muffler, exhaust pipe and clamp replaced.
PCV valve replaced
Radiator purge valve replaced
half cv axle replaced ( thats what the receipt said)
Entire A/C system replaced (over 300 bucks)
@77k
4 wheel aligment
Tire balanced and rotate (2 new front tires)
New sparkplug wires (BOSCH) Lifetime warranty
SPArk plugs platinum ( BOSCH 60k warranty)
Cheap *** Purolator air filter
purolator fuel filter
Fuel injector cleaner liquid
distributor cap and rotor
Replaced alternator belt
Radiator flushed with orage prestone high milage
Tranny fluid replaced havoline non-synthetic
Alternator belt replaced
Replaced R and left front hub bearings.
Duralast 69.99 battery GOLD.

Now, im trying to contact him cuz what worries me the most is that the timing belt doesnt seem to have been replaced, also the 02 sensor and the thermostat.

Its been almost 45k since the pcv valve has been replaced, so thats next for me to buy and also ill go ahead and buy a k&N air filter.

Is there anything at all you guys see that im missing? anything I should buy for the car? I just bought the car 2 days ago and I got the ANNOYING idle stumbeling feel... IS not bad at all, is just barely there it seems to be idleing at 650 or 700. SOmeone told me to maybe buy a new air hose from the dealership? maybe it got cracked or is too old. Also is it normal for teh car to stuble around 2000 rpms when u upshift or doenshift? like when im driving and i upshist at 2500 or so the next gear will seem to stumble just a bit. well maybe is the lack of torque lol
THANX AGAIN GUYS... IM SO JEALOUS of my bros car but i hope it was a good find.

[perhapsadingo8yerbaby]

Yeah, I have a 95 RS as well and like it very much. Reviewing your maintenance list, the cap & rotor and air filter have 21,000 miles on em. I usually replace my cap/rotor around 12-15K. 21K is a fairly high amt. of wear for those parts & replacing them might help the "stumbling" problem at both low and mid rpm ranges.

Same applies to replacing that old air filter.
Regarding the mid rpm stumble... when I had an oem type filter, the car didn't stumble but did seem to not produce much torque from around 2800 4500+ rpm. Then I went with a custom fabricated foam filter in the stock airbox (your new K&N should produce similar results) and was pleasantly surprised at the improved throttle response from idle/low rpms and really surprised at the "new" power band from 2800 - 4500+ rpm. Before the more free flowing filter was installed, and even with a new paper type filter, that motor was clearly getting starved for air when ya tried to punch it a little in mid-upper rpm range. Now it just begs to run in those rpm ranges and so... I must and just oblige...

[perhapsadingo8yerbaby]

Couple more thoughts...

I wouldn't see a need to replace that ribbed air intake hose unless you actually detect cracks. A new replacement hose from Mazda runs a list price close to $115 if memory serves & I recall *****in & moanin enough at my local dealership that the Mazda parts guy finally sold it to me for $87 just to get me outta there I think. If the old hose is intact, keep it and give it a wipe-down on the outside w/WD40 to keep the rubber from drying/cracking later on.

Your bro's car is due/overdue for that timing belt replacement and part of that job should include replacing the t-belt tensioner & idler pulley as well. Some places sell all these together as a "timing belt kit". Anyway, those parts together shouldn't run much more than around a $100 for just the parts unless you decide to get raped at the dealership for em. Makes sense to replace the H20 pump whenever the t-belt gets replaced and probably just do the thermo at that time as well unless you're having probs overheating now. BTW, the 1.6 DOHC motor is "non-interference" type design so a broken timing belt would suck, but at least should not cause damage to the valves should the t-belt ever break/strip.

As far as the O2 sensor goes, I have 135K on my engine & am still running the original O2 sensor. I checked into replacing it as maintenance item when I bought my 95 RS (w/101K). That is, until NAPA autoparts quoted me a price of $140... then, they checked further and said they couldn't order it after all... told me to go to the dealer... NOT an option to my way of thinking until my current O2 sensor goes bad and then I'll research universal replacements before going to the dealer.

<small>[ July 12, 2004, 12:05 PM: Message edited by: perhapsadingo8yerbaby ]</small>

[vegetoking]

IM impressed with the courtesy and friendliness this forum offers. Im a fellow owner of a mazda rx-7 and let me tell u the rx7club is not as nice.

Back to business... I just read all the replies and it seems that my next steps to follow are Checking and cleaning the air hose, getting the air filter, distributor cap and rotor all replaced. About the timing belt accesories i can get them probably from mazdaformance. The waterpump and thermostat will go last ill wait on those since i dont see any overheating and I know my bro wont have any money left.

To quote the mazda dealership here in Daytona BEach, FL " The air intake hose is 77.94 but your problem might be the "BY PASS AIR VALVE", I have seen many go out in that type of cars around 60 to 90k miles and they are 500 dollars or so". He even printed a nice picture for me.

What is this by pass air valve? and was he full of SHIZZNET? thank you again guys.!

[vegetoking]

also what about the PCV valve?

[perhapsadingo8yerbaby]

Oh yeah, def time to replace the PCV valve. That's why I didn't comment on it because you already caight it. A clogged sticky PCV could be affecting engine performance as well.

As for the bypass air control (BAC) valve, it's part of the idle air control (IAC) system located under the throttle body and can be expensive if replacement is needed. (If you go w/a new dealership part at least.) I'm not personally aware of chronic probs on this that are somehow typical of 1.6 DOHC motors but maybe that's because mine seems to be functioning fine? Anyway, if you'll look a few inches up from the end of the large ribbed air intake hose near the air intake box, you'll notice a smaller right-angle hose leading from it, sectioned and routed to the IAC/BAC under the throttle body. Check to make sure that smaller hose(s) is not damaged and that it is connected. The IAC system functions to improve idle smoothness by regulating the amount of intake bypass air that passes thru the throttle valve/body. It consists of an air valve that functions only when the engine is cold and an IAC valve that works throughout the entire rpm range.

IMO, replacing the air filter, cap/rotor & PCV valve are the simplest & cheapest things that need to be done anyway, and that might also help the idle & throttle response. If idle & throttle response don't clear up with those things done, it's easy enough to test the idle air control system for correct function.

[vegetoking]

Well thank you again sir. Since u seem to be the only good soul in here. lol...

Like i said earlier, I called the other owner and he told me he had no record of the timing belt ever being replaced at all. Know knowing this I have to set it aside since i have no money to get it replaced since labor is going be crazy at any mechanic. (However I will try my hardest to see if he can get it done before the end of the year).

Now I woke up early today to checked some stuff on the car. I checked the air filter... and it seemed pretty darn good, no build up or black grit... however i will still get it replaced. after retighten the main big fat air intake hose I saw a lil tiny hose coming from the bottom left side of the airbox (IS THIS WHAT U ARE REFERRING TOO). I drew a picture see:

<img src="http://www.imagestation.com/picture/sra ... ddfcba.jpg" alt=" - " />

that liltle tiny hose is what seems like broken off, is not even tightly in there ( its just hanging there)... I can use some gasket sealer around it if its suppose to be tight in there. Is it suppose to be tight?

I also saw that the head of a bolt that tightens the head of the engine to the lower section was completly gone... only half of the bolt remained there and right under it there seemed to be some dried oil. here is a picture

<img src="http://www.imagestation.com/picture/sra ... ddfcb8.jpg" alt=" - " />

So now I know I have to replace the head gasket as well. I turned the car on and let it idle... i didnt see any oil coming from it though... But im still shaky and what do u guys reccomend i shoudl do about this? Can I replace teh head gasket myself?

ANyways, while the car was idleing, i heard a ticking noise coming from where the spark plug wires connect to on the right side of the engine...( if you were looking at it from the front bumper side) it was a weird ticking noise, like a spark noise.Could he have connected teh aprk plus wires wrong? this is how it was when i saw it this morning.

<img src="http://www.imagestation.com/picture/sra ... ddfcbb.jpg" alt=" - " />

then that noise became less and less frequent but it was still there then i started to hear this like BOV turbo sound like pshh pshh pssh
coming from the engine it wasent bad, but it seemed liek a suction of air or something I have no clue. and it wasent high pitched either it was like a deep suction.( the idle however was steady at 620-650 rpms, but the cabin was alil shaky still)

Keep in mind im trying to describe every single thing i heard and saw when the car was cold and hadent been started since last night.

<small>[ July 13, 2004, 09:07 AM: Message edited by: vegetoking ]</small>

[lycanthrope]

replacing the cap and rotor would be good, just clean your pcv valve with some gumout, it's one of simplest check valves you'll ever see, as for the stumbling, plug wires can be very deceiving, i believe you have a bad spark plug wire, sounds as if your spark is jumping to your head somewhere, a darkened garage can find this blueish orange arc coming off one of the wires (at the troubled rpm range), if you can't hear the arc making it's popping noise, and if they are free replacement, dont even test them, just replace them, happened to me once, car would idle fine, however when parked & slowly reving across my tach (after warmed up, it should be a very smooth incline to red), it would stumble between 2300-3000k then relatively get back on track up to redline, i change my wires every year to keep that from happening (free replacement), they aren't really protected on the 1.6 sohc, they hover over the exhaust manifold, clipped to the valve cover, oh yeah if you handle the wires when the car is running, be carefull, a wire that jumps spark can really bite you, never hurts to peak at your plugs as well, hope this helps

[vegetoking]

"it should be a very smooth incline to red), it would stumble between 2300-3000k then relatively get back on track up to redline"

Thats exactly what happens or did anyways... I think i still have the warranty teh othe rowner had from the plugs ( even though i have a DOCH)... Ill go ahead and change them right away and buy the oem ngk sparkplug wires from mazdafromance.

[perhapsadingo8yerbaby]

Originally posted by vegetoking:
(1) after retighten the main big fat air intake hose I saw a lil tiny hose coming from the bottom left side of the airbox (IS THIS WHAT U ARE REFERRING TOO). that liltle tiny hose is what seems like broken off, is not even tightly in there ( its just hanging there)... I can use some gasket sealer around it if its suppose to be tight in there. Is it suppose to be tight?

(2) I also saw that the head of a bolt that tightens the head of the engine to the lower section was completly gone... only half of the bolt remained there and right under it there seemed to be some dried oil. here is a picture
So now I know I have to replace the head gasket as well. I turned the car on and let it idle... i didnt see any oil coming from it though... But im still shaky and what do u guys reccomend i shoudl do about this? Can I replace teh head gasket myself?

(3) ANyways, while the car was idleing, i heard a ticking noise coming from where the spark plug wires connect to on the right side of the engine...( if you were looking at it from the front bumper side) it was a weird ticking noise, like a spark noise.Could he have connected teh aprk plus wires wrong? this is how it was when i saw it this morning. then that noise became less and less frequent.

Taking your main points in 1,2,3 order...

1) No that little hose from the airbox was not what I was referring to and yes absolutely!, it should be firmly connected to the airbox. It works to control your Exhaust Gas Recirculation (EGR) valve and re-attaching it might well clear up your idle & rpm "stumble" problem. If the hose has enough length, just trim a fresh end on that hose and it should fit snugly to the airbox. The other IAC/BAC hose I was referring to attaches directly to the large ribbed intake hose - check that it hasn't pulled loose anywhere. For a visual, just follow the large ribbed air intake hose starting near the airbox. A few inches up the lg. ribbed hose (toward the engine side of the ribbed hose), you'll see a smaller hose (size of your thumb) connected into it at a right angle.

2) That broken bolt is a valve cover bolt, not a head bolt. Huge difference. Your head bolts are hidden from view underneath the valve cover - no worries there - based on what you described, it is highly unlikely you have head gasket issues. Soundls like the broken valve cover bolt allowed some previous oil seepage around the valve cover gasket. If it's not leaking now, you can take care of replacing it later at which time you would put on a new valve cover gasket. Not a major job like a head gasket.

3) That ticking noise sounds like a valvetrain "tick" that diminished as engine oil circulated and the internals heated to operating temperature. Doesn't sound critical to me & I'd worry about it later as it's not related to your idle/stumble etc. Just be sure your oil is in good shape and at a proper fill level.

Your sparkplug wires are routed correctly according to your diagram. Also, unless the Bosch plug wires have been abused/mishandled, it's doubtful that you need to replace them. They only have 21K on em and plug wires generally hold up just fine for 50K+ miles.

So, fix that little EGR hose to the air intake box, make sure the IAC/BAC hose is attached to the large ribbed intake hose, and let us know how things are working.

[lycanthrope]

that's some funny ****, we posted the message at the same time, except it was nine o clock here, im in texas, yeah plug wires are very delicate, yeah, you can probably ride with the cap and rotor a while before having to change them, if you have the cash, just change them, O2 sensor will help on gas milage, and can improve idle being that you're nearing 100k, im getting ready to buy one today from autozone for 24 bucks(US), it's a universal that fits right on my 1.6, dont know about your dohc, wouldnt hurt to search/ask around the forum, sensors from the dealer are rediculously priced, and if i take my time i change mine in about 15 minutes (i only have one), if you do buy one from the parts house, get the tool to remove/install it, it's relatively cheap as well, and will prevent you from damaging the sensor on install, yeah, you'll be up and running in no time...
good luck

[lycanthrope]

to reiterate/add what perhapsadingo8yerbaby said about on the valve cover bolt, just make sure you arent seeing any new oil leak out of there, this could lead to a loss of vacuum, in turn, poor positive crankcase ventilation, what your pcv valve does...

[RoundTop]

about point 1, that hose. It controls the amount of gas your engine puts in for air. So it wouldn't really cause a rough idle as at low rpms the reading is about right, however as you put more RPMs in, you will dump more fuel in without enough air, causing some black smoke out the back (running rich).

If the mount point on the airbox has broken, a replacement part only costs about $70CDN from a dealership. Of course...when I got my replacement one it was the last v6 airbox top in north america brand new according to the dealership (others would have to come from japan)

[vegetoking]

thanx guys.

The distributor cap and rotor, and a oem mazda oil filter have all been ordered from Mazdaformance. I should be getting them by the end of the week or so.

After talking with the previous owner about the spark plug wires, he said even though they only had 21k miles, he said the car wasent driven often and that it had been almost 3 years since he replaced all that stuff, Anyways he had a lifetime warranty on the BOSCH 7mm SPark plug wires so im sending them back to him so I can get a brand new set.

I will try some gasket sealer on that tiny hose that attaches to the air box, about all the other air connections they seem fine and tight.

what can i use to clean my pcv valve? and would 10W-30 castrol gtx high milage oil do? thanx again guys. ill keep u updated by end of this week

[lycanthrope]

just clean your pcv valve with some Gumout (throttle body, carb, choke, and linkage cleaner), works just fine, you can also spray some in your throttle body (remove your large air hose to expose your t.b.'s port), to help clean any oil residue up that may have accumulated, should tell you instructs on the can...