Completely Stumped with my 2003 P5

FEGUA250

Member
Hey all, been lurking here on and off whenever an issue has come up with my little Suzu, but finally hit a point where i'm completely stumped as to what's affecting my car. Going to give the best play by play as I can and maybe someone's had similar issues and can help.

My car is just over 140k, bought her in 2016 with 100k.

I was driving home earlier this month and my CEL came on, then went back off later in the day. After it went off, I started having a rough idle where the revs would just randomly drop like the car wanted to die, then it would catch. then started having mild hesitation when accelerating until I get over about 1500-2000RPM, so stopped driving it till I could get it to my shop. They took a look at it and the computer threw them a code about the Intake Manifold Runner Solenoid being faulty, which they replaced, and the car still idled rough and had hesitation again. Brought it back again, this whole time thinking it was the coils, and got a CEL which when they read the code this time did come up as a misfire. Diagnosis this time was oil in the spark plug wells, they didn't charge me for the work to clean it up and gave the car back to me since they weren't 100% is was a leaking gasket, and I will be bringing the car back in a couple of weeks for a "check up" to see if that's the case (I'm not very mechanically inclined). Car runs better after the cleanout, but still occasionally drops the RPM, usually when the wheel is turned, and has a bit of hesitation when accelerating unless I barely tap the accelerator, but runs fine over 1500RPM. The idle in drive (It's an automatic) also seems lower then usual to me, but I also might just be paranoid.

I love this car and it's slowly starting to drive me crazy!! Really hoping someone out there knows what my issue might be.
 
there's an issue with the intake manifold flaps letting loose and pinging around on top of the cylinder. I'd pull the intake manifold and see if the butterfly valves are together or not. and make sure all screws are attached- if not- they're on the piston.
 
Failed VSV's are quite common. IT's an old car and they go bad. Fortunately they're cheap and easy to replace.


I'd start by doing a general tune-up. New spark plugs (use NGK plugs), air filter, oil change, etc. While the spark plugs are out, I always like to do a compression test, not that I think anything is wrong with compression, but I like to know where it's at. And it gives a good indication of engine health. It should be around 200psi across all 4 cylinders.

I would also remove and thoroughly clean out the throttle body and idle air control (IAC) valve. Disconnect the negative battery terminal for a few minutes to reset the computer after the valve is cleaned, it will take a hundred miles or so of driving to "relearn" the new idle settings, but it is absolutely necessary after cleaning/replacing throttle body or IAC. The computer "learns" how to idle with a dirty TB or IAC and compensates for the buildup. Then once you clean it all out, it can go kinda crazy and have a high or erratic idle. Resetting the computer solves that.

While the airbox and intake hose is removed to access the throttle body, the hose needs to be inspected for cracks/tears. Cracked intake hose is super common and a new one is not very expensive. This can also cause a poor idle because the engine is sucking in air that has not been metered by the air flow sensor.



I'd start simple with the easy (cheap/free) stuff before assuming the worst and tearing into the engine looking for loose screws and broken stuff.
 
Failed VSV's are quite common. IT's an old car and they go bad. Fortunately they're cheap and easy to replace.


I'd start by doing a general tune-up. New spark plugs (use NGK plugs), air filter, oil change, etc. While the spark plugs are out, I always like to do a compression test, not that I think anything is wrong with compression, but I like to know where it's at. And it gives a good indication of engine health. It should be around 200psi across all 4 cylinders.

I would also remove and thoroughly clean out the throttle body and idle air control (IAC) valve. Disconnect the negative battery terminal for a few minutes to reset the computer after the valve is cleaned, it will take a hundred miles or so of driving to "relearn" the new idle settings, but it is absolutely necessary after cleaning/replacing throttle body or IAC. The computer "learns" how to idle with a dirty TB or IAC and compensates for the buildup. Then once you clean it all out, it can go kinda crazy and have a high or erratic idle. Resetting the computer solves that.

While the airbox and intake hose is removed to access the throttle body, the hose needs to be inspected for cracks/tears. Cracked intake hose is super common and a new one is not very expensive. This can also cause a poor idle because the engine is sucking in air that has not been metered by the air flow sensor.



I'd start simple with the easy (cheap/free) stuff before assuming the worst and tearing into the engine looking for loose screws and broken stuff.


Have had the sparkplugs done, and just got an oil change. She was due when this all started anyway. Will definitely check.
 
Failed VSV's are quite common. IT's an old car and they go bad. Fortunately they're cheap and easy to replace.


I'd start by doing a general tune-up. New spark plugs (use NGK plugs), air filter, oil change, etc. While the spark plugs are out, I always like to do a compression test, not that I think anything is wrong with compression, but I like to know where it's at. And it gives a good indication of engine health. It should be around 200psi across all 4 cylinders.

I would also remove and thoroughly clean out the throttle body and idle air control (IAC) valve. Disconnect the negative battery terminal for a few minutes to reset the computer after the valve is cleaned, it will take a hundred miles or so of driving to "relearn" the new idle settings, but it is absolutely necessary after cleaning/replacing throttle body or IAC. The computer "learns" how to idle with a dirty TB or IAC and compensates for the buildup. Then once you clean it all out, it can go kinda crazy and have a high or erratic idle. Resetting the computer solves that.

While the airbox and intake hose is removed to access the throttle body, the hose needs to be inspected for cracks/tears. Cracked intake hose is super common and a new one is not very expensive. This can also cause a poor idle because the engine is sucking in air that has not been metered by the air flow sensor.



I'd start simple with the easy (cheap/free) stuff before assuming the worst and tearing into the engine looking for loose screws and broken stuff.

Smh.. ok then what do I know.(thought)
 
EGR VALVE! EGR clogs and sticks from carbon due to pig rich tune on these things. Pull the egr and clean it out. Do the IAC too while you're there if you haven't already. Canadian EGR valve is better about not doing this. Have cleaned mine once from this and probably need to again but won't mess with it until it acts up......only? @ 98k miles right now and no longer dd for last 8 yrs so might be a minute before it needs it. Guessing I did mine around 55-60k...been over decade since it was issue.
 
This is the "Canadian" EGR.



It's different in that it has coolant lines attached to it as well as vent tube.

Some guys had to clean their EGR every year.
They had much better luck with the improved EGR.

It's a bit of a chore to install though because it ties into the cooling system.


Canada was the first to have problems with the EGR due to our generally colder climate so it was introduced here first.

PS. It's not listed in the Protege 5 section at RockAuto but is in the Protege 2L section.
 
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Hmmm, IIRC, mine has coolant running thru it and I did bypass because warm climate................maybe, been long time since............
 
I'm not sure but I think the coolant is to warm up the EGR.
I figure a cold EGR would be more inclined to have dirty exhaust gas condense in it and foul it up, especially when the engine starts burning oil.
 
I'd have to go see if I ever even installed the bypass kit or not, lol..............
 
Hey all, thanks for the answers. Doing a bit of an update. Suzu goes back to the shop Friday to see if the gasket is bad.

Probably put about 150 miles at the most on the car and once again still runs fine aside from the very occasional dip in RPMs during idle which I'm noticing happens more when i'm doing freeway driving/it's hotter out then when i'm just cruising around on surface streets. Also completely random. Sometimes it has a hiccup while i'm at a light, sometimes it doesn't, sometimes there's a bit of hesitation accelerating, sometimes there isn't! The idle also seems really low to me. Only other time i've had a car behave like this was when I was at altitude, 7000+ Feet. Assuming it's the EGR being dirty or something related. I got the car secondhand the previous owner did not take care of it, great example being the only brake work between 2003 and when I bought it in 2016 was new pads...either will say something to the shop about the EGR (I'm not very mechanically inclined) or will look into doing it myself after I go in for the inspection.

Thanks again!
 
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