Need advice. Going nuts, seriously rough idle on start

[CheeseHelmet]

^Oh damn, that looks nice. But yeah, expensive...

If you have a Harbor Freight near you, I'd recommend going there to get a cheap metric 1/4" set.

 

[Jackie chan]

Craftsman stuff is pretty nice. I've got a pretty big collection of craftsman stuff. But if you're not goin to be usin' it much, might as well get a cheap one from HF or the local auto parts store. Wear gloves and DONT drop the gasket. That sucked diggin' that out. Tip... Put a little grease on the gasket so it sticks to the valve itself, then it wont slide off while you're positioning it.

 

[wolleymp5]

Hi guys i was able to get my hand on a 1/4" inch ratchet and used a 1/2" socket for the screw. Took about 45 minutes, however I think i put the gasket on wrong as the car idles worse when turning on during the hotter times of the day and idles beautifully at night. The gasket has a triangular part and a round one I believe i put the triangular part over the aluminum cover the EGR has in the middle making the gasket be uneven and leaking air. I'm going to take it out and change it but haven't had a chance since its been raining a lot and I don't have a garage. I'll post back on when i do re-install it.

BTW the old EGR looks rusted in the middle and pretty old, the screws are very hard to take off so i did not look inside but i am certain the mechanic did not clean out this valve or the screws wouldn't be so set in.

 

[RicoP5]

check your vac hoses our cars seem to have plenty of those lol. i had one on mines off on top of the im that looks to come off the fuel sensor line and it was making my idle act up a bit before.

 

[CheeseHelmet]

I agree with Rico, before wasting time pulling the EGR valve check the accordion-shaped tube that goes from the air box to the throttle body. It's very common for that rubber to become brittle and crack.

 

[RicoP5]

wait which tube is that? got a pic? idk y my idle has been a little bouncy the past 2 days after reading all these idle threads lol. like it started hunting me down smh lol

 

[us3r]

Got the EGR pretty fast. Ordered Friday morning and got it today. I'll attempt installing it later in the week, never thought i'd end up enjoying some of this mechanic work lol.

does the new egr come with the 2 bolts? I'm missing one.

 

[CheeseHelmet]

wait which tube is that? got a pic? idk y my idle has been a little bouncy the past 2 days after reading all these idle threads lol. like it started hunting me down smh lol

It's the biggest one

does the new egr come with the 2 bolts? I'm missing one.

Nope, you'll have to get a new one from Mazda.

 

[wolleymp5]

yeah the EGR doesn't come with the bolts. On a side note before pulling the EGR and since its rainy season aka summer here I just remembered I forgot to reset the ecu after the install. I did the reset and now the car almost*** doesn't do the hard idle it feels almost like new. But there's still times when the rpm will just dip and go back up or that it will sound like a loud v8 engine when turning it on and revving it to stop the idle issue(warming it up).

I will check the air hoses tomorrow. I was thinking of just getting a SRI instead of replacing OEM air hoses but don't want the loudness with the SRI.

Also found my coolant reservoir cracked on the top side wall and my cars been loosing coolant. Not a serious loss but i gotta check it every 4-5 days. Looked up the OEM reservoir and its about $48-$56!!! can't believe its so freaking expensive. Anyone know where i can get a cheaper one? maybe that looks like the stock one?

 

[BinoMP5]

i am having the same exact problem as the OP, but my MP5 is an auto. I was told it was the VC gasket, which i replaced, and the issue came back to day. When i turned the car on, it flashed the CEL several times before staying on, but i just let it rest for a bit and it went away. This is the only time it has happened since i changed the VCG since Sunday.

but since he has a MTX, and i have ATX, i'm saying it is safe to assume it isn't a transmission problem. My EGR was welded to my header, so i do not know how well i will be able to clean it. i have seen people disregard the EGR and completely remove it

 

[CheeseHelmet]

i am having the same exact problem as the OP, but my MP5 is an auto. I was told it was the VC gasket, which i replaced, and the issue came back to day. When i turned the car on, it flashed the CEL several times before staying on, but i just let it rest for a bit and it went away. This is the only time it has happened since i changed the VCG since Sunday.

Get to an autozone and have them read the current and pending codes, that'll will give you a good idea of what's going on. A blinking CEL is never a good sign.

My EGR was welded to my header, so i do not know how well i will be able to clean it. i have seen people disregard the EGR and completely remove it

We're not talking about the EGR tube, we're talking about the valve which is mounted in a really awkward location under the throttle body.

 

[BinoMP5]

i threw the same codes you were, the p0300 and a "absent" downstream O2 sensor, but i have an aftermarket exhaust and the O2 sensor non fouler.

 

[wolleymp5]

Well here are the pictures for the old EGR. I'm waiting to get payed from my job to order a cheap SRI see if the tubing helps, and also found the reservoir in rockauto for 36$ cheapest price yet.

I will look up the how to's to check for a vacuum leak and then clean out the IACV if I can take it out and also re-install the EGR see if that helps. If not I will have to wait some time and go to a junk yard see if i can find the IACV from a 626 or millenia and try it on my car because brand new they run for 215 up to 300$(pissed).


On a side note, the symptoms i am now getting are like feeling a sudden drag force backwards when I let go of the gas. It shakes the people inside the car forward and backwards. When i press the gas pedal it doesn't feel like it accelerates immediately but instead goes slow feels sluggish. It was working fine for a few days after the ECU was reset and now it's slightly worse, i'm wondering if it could be a computer issue?

 

[wolleymp5]

1st pic) Another pic of the old EGR from top view.

2nd pic) The new EGR compared to old but in red I circled the NEW aluminum cover that goes in the middle which the old EGR did not have. Pardon my pre-school drawings but I am not great at 'MS paint' Effects lol.

The yellow is for the gasket shape and you can see where I think the sharp triangular top side of the gasket may be laying on top of the new rectangular aluminum cover, and maybe letting air in through there.

3) Gasket change?
Any one know when it's recommended to just change the EGR gasket?? I could get one from advanced auto for around round 6$.

 

[wolleymp5]

check your vac hoses our cars seem to have plenty of those lol. i had one on mines off on top of the im that looks to come off the fuel sensor line and it was making my idle act up a bit before.

Do you know where I can find a diagram or something which shows the complete VAC lines to check??

 

[wolleymp5]

i threw the same codes you were, the p0300 and a "absent" downstream O2 sensor, but i have an aftermarket exhaust and the O2 sensor non fouler.

Jus read your posts. I had the same problem. When it first started doing this I took it to the mechanic and he told me it was the valve cover gasket where 1 or 2 plugs were full of oil. He replaced it, and the p304 and p300 stopped coming back but the idle problem is still there.

Have you changed your coils, wires, and plugs? I got em changed and the idle got better but not resolved. From what I read some MP5's idle problems get solved with the coils. Each coil is about 25-30$ (need 2) in advanced, I would try these first and if it's not it you can return them. I have an aftermarket exhaust as well, don't know what brand because it came with the car when I bought it.

As an alternative it could also be the gaping of the spark plugs that's causing a misfire. Check around there's threads on that.

 

[wolleymp5]

re-installed EGR changed orientation of gasket, reset ecu, and it worked well for the first run but after that I parked and went on the highway couple hours later. It kind of did it but not as bad, i'm still waiting to see if the computer is trying to fix itself.

On a side note the NEW EGR looked like it had some rust around the holes now where the gasket covers so i suspect the gasket wasn't placed correctly like I mentioned and the humidity may have condensed and made water drops in there OR the throttle body is rusted. Lets see.

 

[wolleymp5]

Replaced the vacuum hose and air box with an SRI from ebay, I made sure there were no leaks. The car runs A LOT better however it still does the idle problems on start up, and I did reset the ECU.

One new thing I noticed is that its now making a rattling noise from under the hood. It sounds like if you have stones in a tin can and then ever so often another noise that sounds like something that flips open and close and gets stuck and eventually the unstuck sound.

I suspect it's the throttle body itself. I was planning on taking it out to clean it next week, but how common is it for the throttle body to require replacement ?? and are these sounds likely from the Throttle body?

Thanks.

 

[wolleymp5]

Changed the PCV valve, the old one was full of oil. Taking out the throttle body and IAC to clean them and also check the spark plugs to make sure they are not full of oil from the old PCV valve not working and spec gapping. Waiting on a security Torx TS25 socket to take IAC off.

Working a little better but still having idle problems on start up.