mysterious rough idle???

[phatboyslim12]

first this thread really began within another thread and its time to create its own.

also thanks a bunch to bsydes and all others who have continued to help through this process in a/c compressor issues?!!!

so i will start from the begining.

i began the other thread because the car would run rough when the a/c is on, only after about 5 minutes of running fine, but i believe the current issue is NOT related.

the rough idle began as an intermittent problem which wasnt bad at all, it would run rough for only a second or two then run fine again.
the day before it began to run rough basically all the time, i took it out at work, went 2 blocks and on the way back it started idling bad, i parked it and let it idle after 20-25 seconds it cleared up, the odo revved up to 2k rpm then went down to normal idle and it was fine.

basically since then its run pretty bad, but it drives fine and idles pretty bad also its only stalled once on its own.

heres what has been suggested and replaced.
1st was the cleaning of the iac, which now i have seen can be bad for it.

then i ordered the new iac, installed it and had no change

sent it in to shop 1 and they didnt notice it at first due to a high idle of the iac, then smoked the vacuum lines and found a leak said it was fixed. it was not fixed.

sent it to shop 2 same day of picking it up from shop 1, and after 4 days i got a call saying the idle was too high and they lowered it, and it needs an egr valve, got it replaced and did not fix.

today i went and got an maf sensor and that also did not help.

so things i did notice last night and today after getting it back from the shop, is when the car is running i hear the new iac clicking and there is a noticeable idle change with each click, but this happens whether its rough or not, also i noticed coolant on the ground under the backup res tank the ground was wet from rain but could tell where it was coming from and the res was almost on the empty mark but the overflow was bone dry rad was full, and i noticed the fans come on earlier than i feel they should have.

some other possibly helpfull info.

has new timing belt and waterpump
new cap and rotor, had issues starting after battery pull start and stall after reset, no longer has this issue???
egr vacuum solenoid
if theres anything else ill add it.

anyway any help would be great

[phatboyslim12]

nobody wants to help???

anyway im going out to do more diagnosis today i need possibilities here im on empty with ideas...

ok so i saw a bunch of threads that say mounts, i can hear the rough bogging through the exhaust pipe so its def not the mounts, and i can say that i come to a stop, then hit the gas like normal it hesitates a little then goes

also i plan on cleaning the throttlebody again, as shop 2 cleaned it and now it looks like dried dirty coffee all over the inside of the tb. it was new looking before then. i can use the carb cleaner on it right??

the shop said they had a high idle issue after they put the new egr in, i dunno if that is related but ill add it.

[E_Emerson88]

did you or the shops check for spark or if fuel is being delivered? check connections. maybe there is a loose connection, melted/chewed up wires. do you have any codes?

[NCamiolo]

I have no idea myself, but I noticed a very audible clicking from the same area you do after I changed my EGR solenoid. Although mine through a code when it went...

[tamim13]

also i plan on cleaning the throttlebody again, as shop 2 cleaned it and now it looks like dried dirty coffee all over the inside of the tb. it was new looking before then. i can use the carb cleaner on it right??



Yes Carb cleaner is what you need.

[GTZ413]

I feel as though mine is starting to do what yours is doing. I cleaned out my Thottle body and it will go away for a few. Next morning it will come back. It seems to hesitate on stops also.

[gallant]

Mine is starting to do what yours is doing. Started yesterday after i made a few changes

Before changing the serpentine belt.
Front drive side headlight keeps going off after ether turning up the radio or hitting a bump.

During the change
Changed the belt and was put in the same way, cleaned the battery post

After
Normal in park, car revs up from 500 rpms to 800. Feels like it’s going to stall out and lights dim down. What did I go wrong when I changed the belt?

Going to get new ballast for my hid headlights and have my battery tested at AutoZone. Hope it’s not an alternator problem

[phatboyslim12]

Hey galant, if u pulled the battery when you cleaned the posts then your car is in learning mode.
drive it around for like 10 mins.

Gtz, at first my car was barely noticeable and gradually got worse, and yes mine hesitates From stop but only when it's running bad, the car also sounds bad through the tail pipe and sometimes s.ells funny too

[gallant]

your right phat boy... i was coming back to mention it was fixed

[GTZ413]

Replacing my stock air filter with a short ram. well let you guys know if that does anything maybe it could be the throttle body needs to be replaced idk.

[Bobby~d]

Try changing your fuel filter.


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Dw@r!k@

[GTZ413]

Looks like replacing the air filter with a short ram did the trick doesn't seem to be doing it anymore. knock on wood. Doing a tune up hopefully this week and replacing everything from spark plugs, wires and gaskets along with an oil/filter change should help also. Gotta prepare for winter ughh.

[Galanttuner10]

question is are there any codes? if the IAC goes out or the EGR does you get coeds, if you have a miss and its not throwing a code its either not bad enough to throw a code but it seems like its bad to it may be mechanical. i would do a leak down test or have a shop do it as you need to be on power stroke and the leakdown will tell you if you are mechanically sound as it can tell you if the head gasket is bad, if the rings are bad or if you have a burned valve anywhere.

[phatboyslim12]

hey galanttuner, so to answer your question, no codes came up at all during this rough idle. i was getting a p0430 "cat below efficiency" code but was told this was due to the egr after the fact. also the code stopped popping up after it got emissions done about 2 weeks ago. that was the only code i have been seeing since the car was timed, and it did stop coming up. i have a master mechanic friend who is good with mitsu's and says the symptoms i have a timing related, ive had a teeth grinding sound when i start the car for the first time each day, and the rough idle, which presented itself after a few weeks from getting the belt done, plus the car has been in the process of getting work done so id say the rough idle started and got worse after 100-200 miles after the timing was done...

plus ive only had the car for 2 months, and ran and drove great when i got it, had timing done a week after buying and its all down hill from there...

my friend is going to tear the engine down to check it out but i dunno when.

[Galanttuner10]

Don't just pull the motor apart without doing a leak down. You need to understand if it was timing related it would not have shown up a while after the timing job it would have been instantaneous. Out of time is out of time all the time. Check all the timing marks and do a leak down test and that will tell you everything you need to know about the motor without taking it apart and wasting money.

How about pulling the plugs and seeing if there is any issue there, coil could be going out, good enough to make spark but not strong enough etc.

it's hard to diagnose not seeing it but I am 100% against tearing down the motor until you are over 100% sure it's the problem.

[phatboyslim12]

yea thats what i thought, but he is insisting lol. how much is the leak down in aprox. price? also i have yet to check out the plugs but the old rotor was broken and missing a chunk when i replaced it so its possible the coil had some feedback for a while, ill post a pic of the rotor, its kinda unbelievable. and ill check the front plugs, i do not know the last time they were changed, i was planning on changing them when i do the valve cover gaskets, the rear one is getting pretty bad, anyway ima get ready and check plugs andpost back.

[Galanttuner10]

If the friend is insisting on taking out your motor and tearing it down he just wants your money. You have a V6 so to do the test you have to pull the intake manifold off then pull the plugs. Then you need to put the number 1 cylinder at TDC on power stroke as this is when both sets of valves are fully on their seat and you will get the right numbers, then you need to follow the firing order to check the others and rotate the crank 120 degrees so have the next piston at TDC. Talk to your friend about a leak down test, if he is a master tech he should know everything about this cuz what you do is you feed air into the cylinder and see how much pressure you lost and you can tell where the issue is coming from cuz you will hear it, if you hear it with the oil cap off its rings, you hear it coming out the intake then it's an intake valve bent or burnt, hear it out exhaust it's an exhaust valve, hear it out of the radiator it's a head gasket. Best test you can ever use. Now remember you are supposed to lose some pressure due to ring gap and the test should be done with the engine warm.

[Galanttuner10]

I also have to ask when you put in the new rotor did you set the timing to number 1 at TDC so as to make sure it was pointing at cylinder 1?

[phatboyslim12]

ok so this is possibly new... when i put the new rotor on, i put it in the exact position as the old damaged one was when i took it off. i did not know to set the timing to #1???

i also had issues with it starting right after the install, i believe you may have helped out with that.

it would start up as normal then die, i fixed it by giving a tiny bit of gas when rpm was dropping, then it settled and ran fine since. that happened after pulling the battery, i can say now that it does not have trouble starting after battery pull

also i installed the rotor and cap the day before it was timed.

hey, i thought you only had to tdc if you were replacing the distributor itself???

[Galanttuner10]

Wouldn't you want to make sure you are doing it correctly and everything is good? When I replaced my rotor I put it to TDC and made sure everything was good. Maybe it's me but I believe in doing it right the first time.

Just saw a post about a fuel filter which could be but I would check fuel pressure before I condemn it.

You have a master tech as a friend he should be able to help you run these tests or at least know where to go.

[phatboyslim12]

Hey galanttuner, my friend doesn't wanna pull the motor just pulling the mount etc to get to the timing area to do a good inspection of the timing lol

I also went by the manual posted on this site and only mensions tdc if replacing the distributor itself. Ill have the leak down done prior to him checking the timing...

Also I can run a pressure test as the filter is normal maintenance and the car seems to have no maintenance after 150k and its at 217k

[Galanttuner10]

Idc what the manual says lol I do it to know its right, and you check the timing before the leak down test or your numbers will be all wrong

[phatboyslim12]

I hear ya, I'm going to have a shop do the testing, so before I send it back in, should I reinstall the cap and rotor at tdc?

ok so here is what i think im going to do as of now, in this order...

fuel pressure test.
plugs, wires, and both valve cover gaskets, plug o-rings, and intake plenum
leakdown test

is there anything i am missing here, i dont know if the plugs and wires have been done but since its a bit tough for the average person on this car im guessing not, could the wires that run under the iac be causing issues with the iac, if there old enough?

[phatboyslim12]

the car has been in the shop for the last 24 hours and i just got a call saying its a egr vacuum control valve??? sound like it can be the issue?

ok so the problem still occurs according to the shop. they are saying they have some more to check out but they suspect an ecu issue

[phatboyslim12]

UPDATE::

so i got the results...

low compression in cyl. 2, likey valve hit...

not sure where to go from here, im trying to work with the shop that did the timing and i dont know if they will help.