HELP - Rough Idle NOT egr valve...I think?

[tapiaa]

Hey guys. So I have a 1999 Mazda Protege ES 1.8L and it's been giving me nothing but problems. Right now, it's idling very rough. It sits at around 500-600 RPM and flutters up and down. Sometimes it drops very low to like the 200-300 RPM range and everything shakes tremendously. Everything shakes at 500-600 RPM and it drives me crazy, I just want smooth idling. Another thing I've noticed is that the air from the muffler isn't continuous? If that makes any sense? Like it goes "poof poof poof poof" - it doesn't sound to well.

Things I've done to try and fix the problem:
NEW motor mounts
Cleaned MAF sensor and got new one as well
Cleaned IAC valve
Cleaned EGR valve
Spark Plugs
Cleaned throttle body

I've taken it to the mechanic and nothing. No one knows what this is. There are NO check engine light codes. I've checked if there were any plugs out of place. No check engine light that comes on and off. I don't know what else to do. Love the car and all but this is just annoying. A temporary thing that I've done however is to raise the idle speed so it doesn't sit so low. It idles high now with no vibration but I just want to have smooth idle.

If anyone has any suggestions, please let me know! Thanks

 

[agr99]

Replace your coil packs

 

[tapiaa]

Replace your coil packs

You think that's what it could be? That was going to be my next thing to replace.


Sent from my iPhone using Tapatalk

 

[tapiaa]

So I just replaced the coil packs to OEM ones and still the problem persists. It stays idling to 300-500 and shakes. When I accelerate it's fine. When I stop at a traffic light it goes back to 300-500 but doesn't die.

Anyone have any other ideas?

Sent from my iPhone using Tapatalk

 

[31R]

exhaust leak?

 

[tapiaa]

Nope, no exhaust leaks. That wouldn't cause a low idle I don't think either.


Sent from my iPhone using Tapatalk

 

[hornsfan10609]

Replace the ignition wires and spark plugs as well if they are old. It definitely sounds like an exhaust leak and possibly a vacuum leak as well.

 

[tapiaa]

I'm gonna try and replace the ignition wires next and spark plugs.

I've checked for a vacuum leak and there are none. At least none that I can find. I have a SRI so it's not like the boot is broken or anything.

Also the egr and throttle body gaskets have been replaced so it's not that either.

I'll try checking to see if it's an exhaust leak cuz my car is pretty low and I bang the floor a lot lol.


Sent from my iPhone using Tapatalk

 

[tapiaa]

UPDATE: So found out there was a bolt broken from the CAT and fixed it by welding another.

Now the CAT is nice and secure. Changed both gaskets and problem still persists.

Any other ideas?


Sent from my iPhone using Tapatalk

 

[03protolx]

Sounds like you still need to complete your major tuneup. replace the wires going to the coil packs. also, check for signs of a leaking valve cover gasket. you may have a vacuum leak as well.

Its a typical protege problem honestly. I've owned several protos and except for my 2003 (idles very smoothly at 142k miles), they all idled rough. That was the difference between owning a civic vs protege.

clean your throttle body as well. a lot of gunk will cause the throttle plate to stick.

check your egr valve again.

Does it do it in Drive? What happens when its in Park? if it goes to normal in park, change your transmission fluid.

 

[tapiaa]

Sounds like you still need to complete your major tuneup. replace the wires going to the coil packs. also, check for signs of a leaking valve cover gasket. you may have a vacuum leak as well.

Its a typical protege problem honestly. I've owned several protos and except for my 2003 (idles very smoothly at 142k miles), they all idled rough. That was the difference between owning a civic vs protege.

clean your throttle body as well. a lot of gunk will cause the throttle plate to stick.

check your egr valve again.

Does it do it in Drive? What happens when its in Park? if it goes to normal in park, change your transmission fluid.

Well I've checked vacuum leaks all around the engine and can't find a single leak anywhere. I've always had this issue with the car ever since I bought it. So starting from the day that I bought it I've done:

-head gasket (Was idling poor before then too so I don't think this is the problem)
-throttle body gasket
-egr gasket
-replaced timing belt, water pump
-replaced coil pack
-replaced spark plugs
-replaced spark plug wires
-replaced motor mounts
-cleaned egr
-cleaned throttle body
-cleaned MAF
-cleaned iac
-fixed CAT issues
-new battery
-installed a SRI

I also replaced the throttle body and IAC from one I got at the junkyard and it was actually worse.

I mean I've done literally everything possible so far. I don't have anything else I can think of. Unless the car's timing is wrong or something wrong with the car's computer. I'm going to have to take it to a local shop I guess to see if they can diagnose something on it.

To add: it does it while I'm in drive but when in Neutral, it does it less. So it does it while in Neutral but when I put it on drive, the rpms go really down. And also, it's not a constant thing. Sometimes it will idle fine but other times it won't. I'd say it idles good 2/10 times.

 

[tapiaa]

Just wanted to show how low it gets while in Drive.

Anyone have any other suggestions?


Sent from my iPhone using Tapatalk

 

[hornsfan10609]

That's normal for the idle to dip when the car is in drive. Replace your igntion setup if you want to fix the problem

 

[tradosaurus]

Good luck with the erratic idle. I've learned to live with it.
I've done everything you did except replace the IAC valve with a new one (~$200). I did find one in a junk yard but it didn't help.

 

[tapiaa]

Yeah **** this car. These cars are literally the worst. I'm about to get a new one, done trying to get it fixed and spending money on it to then have the car act up again smh

Worst car I've ever had.


Sent from my iPhone using Tapatalk

 

[03protolx]

It's an economy car. it isn't going to idle like a cadillac.

Ill buy your car. name the price, ill paypal you the money.

That idle is perfectly normal. on the 1.6 it will shake the car a little more than a higher displacement engine.

most of all jap 4 cylinders do it. both my honda d series, nissan sentra 1.8, and my protege 2.0 too.

EDIT: My 1997 protege with the 1.5 was BY FAR the WORST when it came to shaking at idle. just drive it. it wont hurt it. you've replaced a lot on the car.

if you do want to sell it though, i have cash. let me know.

 

[tapiaa]

It's an economy car. it isn't going to idle like a cadillac.

Ill buy your car. name the price, ill paypal you the money.

That idle is perfectly normal. on the 1.6 it will shake the car a little more than a higher displacement engine.

most of all jap 4 cylinders do it. both my honda d series, nissan sentra 1.8, and my protege 2.0 too.

EDIT: My 1997 protege with the 1.5 was BY FAR the WORST when it came to shaking at idle. just drive it. it wont hurt it. you've replaced a lot on the car.

if you do want to sell it though, i have cash. let me know.

It's not that it idles rough it's that it idles poorly. Meaning I'll be driving and will be fine but when I'm slowing down and coming to a stop, the RPM drop a bit and the car will surge almost die out and kick back again. The belt will also squeal slight and then you'll feel like the car kick again almost as if it wants to accelerate.

Then It'll be like kicking back and forth (not huge RPM drops but a little bit that it will be going up and down) -- if that makes any sense.

Also I've noticed that when I put the AC on, you'll hear the engine more and the car will shake much more vigorously. You will feel the engine much much more when I put the AC on -- if that makes any sense.

Anyways it may be hard to grasp what I'm trying to say so I'm gonna make a YouTube video and post the link up here to see if it'll help more.






Sent from my iPhone using Tapatalk

 

[samtak458]

Anyone figure this out cuz Im having the exact same issue. started with fouled spark plug #4 misfiring. Changed all spark plugs and wires. Drove fine for about 2 weeks then the idle issue as described above started. At stop light idle holds at 700 and dips to 400 or so and engine recovers this happens between 2-7 times. When coming to the stop rpm at 1000 and hops to 1200 then recovers to 1000 up and down up and down. Happens while car is warm.
Did the following in this order.
Changed coil packs
PCV valve
Changed upstream O2 ( got bank 1 cat below threshold code a few times)
Cleaned EGR and throttle body (idles smoother but still has flutter problem)
Changed air filter
Adjusted throttle position screw (I regret doing this I think I screwed up some settings)
Changed IAC ( read 11.6 ohms on the motor book said should be 7-9 ohms)
and I give up. Im guessing vacuum leak or tranny. The problem is way worse in gear.
I did a oil change recently and used Mobile 1 full synthetic 5W-30 which is different than the penzoil high mileage I usually used and just started noticing signs of leakage from valve cover gasket. any chance the oil is causing my problems?