Hello I've been having problems with my intrepid as of late and wanted to know could it be because I left the auto rx fluid in my transmission for too long? My idle drops to around 600 and below when coming to a stop at traffic and the transmission seems to shift a bit rough when I do so. I know the recommendation was for 1000 miles then change the tranny fluid but I have gone past that. Maybe 4000 or more miles. Any replies would be appreciated.
you have two problems and it does not sound liker either is due to autorx.
One is the transmission shifting, and I would check your transmission fluid level (when hot, and idling in park) and make sure it is exactly full. I had two intrepid transmissions die on me due to low fluid levels caused by slow leaks.
The other problem is your idle, which could be due to a bad pcv valve, bad idle air control valve, dirty throttle body, bad plugs or other causes. That's if the problem happens when the engine is warm. If it only happens with a cold engine, it may be your engine coolant temp sensor. If your check engine light is on go to a car store like autozone and have them pull your check engine codes (its free) then post the codes here.
Another thing to check is your MAF sensor. IF your engine has one (vs a MAP sensor), these can get dirty and give faulty signal to engine ecu, causing lean fuel mixtures at all times. Many times, it will not throw a code, since it is adjusting for less air volume such as higher altitude condition, and it is still within programmed parameters.
The other suspect device would be your idle air control valve. If it is not working properly, it can cause low idle. It is the device the engine ecu uses to raise or lower idle speed based on varying loads such as ac compressor, pwr steering pump, etc. If it gets dirty with carbon or dirt, then it can get stuck at times, causing low or high idle speeds.
I accidently left Auto-Rx in an automatic trans for 10k miles and had nothing but good results. I usually only run it no more than 3000 miles.
-- Edited by bmwtechguy on Saturday 5th of June 2010 08:34:13 AM
The problem with the idle is constant hot or cold. Before it use to idle less rough once warmed up but that doesnt seem to be the case now. When I first start it up it idles around 800 rpms which is good and then slowly starts droping. Before it use to stay at around 800 rpms even when in drive and slowing down. I notice the idle bounces up and down at time between 500 and 600 and it very frustrating. I've spend a bit of money trying to get this addresssed with no luck. I was thinking of trading it in for a 300M special with 71,000 on it.
You could be right about the MAF Sensor, I notice the air intake is sucking alot of air as I can hear it from inside my car. And when the idle does shoot up you can really hear the noise from inside the car. I was thinking it was a vacum leak but my mechanic said they dont think it is.
-- Edited by leeangelo on Saturday 5th of June 2010 07:20:40 PM
You should not be able to hear intake air noise from inside a normal, unmodified vehicle. If the intake tract has an air leak where intake air is bypassing the MAF sensor, then that will most surely cause running problems stemming from a lean fuel mixture. The MAF sensor is supposed to account for all air flow into the intake of the engine. It will send a faulty (voltage) signal if it is dirty or if some air is bypassing the MAF, usually through a cracked intake pipe or hose between the intake manifold/throttle valve and the MAF. If you are hearing the engine sucking air, my guess is that you are hearing an air leak that is allowing air to bypass the MAF, which cannot measure or account for any other source of intake air that is getting sucked into the engine.
-- Edited by bmwtechguy on Saturday 5th of June 2010 08:55:54 PM
That sounds right but my mechanic insists I do not have a vacum leak or such, all I know is I spend $365.00 for them to change the CrankShaft Sensor and it did not fix the issue with the car having a hard time starting after letting it sit after driving. Example: I first start up the car in the morining and it fires right up, but after I drive it and park it and try and start it up again 20 or more minutes later it will have a hard time starting. Today I had that issue and when it did start it was so weak. The idle was around 300 or 200 rpms and the engine was shaking until I gased it and then it went higher like around 600 or 500 rpms, which is still not normal? Could this have anything to do with the fuel injectors. One of my co-workers is insisting that that is the cause (he had a dodge ram which had similar symptoms and it was the fuel injectors going bad). I also noticed while the idle was super low (200-300 rpms) I could smell gas big time. It was only until I gased it that it stopped doing this.
-- Edited by leeangelo on Sunday 6th of June 2010 04:21:46 AM
Unfortunately, it sounds like your mechanic may have just "thrown a part" at your engine and you had to pay for his best guess at what the problem might be. The likelihood of having one bad injector or all bad injectors is very slim. If the injector is bad, then it should not get better just because you pushed the gas pedal really hard a time or two.
Start at the basics: Check battery connections and body/engine grounds for good connections. Check battery voltage at rest. Battery should be at about 12.6 volts with no load and having sat for a while after being run. (Interior lights and the underhood light are loads.) Then check voltage again after engine is started. It should come up to 13.5 volts or more very quickly and stay there, even if electrical load is turned on like ac fan on high. Basically, your battery voltage should never drop below 13 volts while the engine is running. If your voltage is too low (10 volts or lower), then engine will begin to run poorly due to low ignition coil voltage, in turn causing weak spark and incomplete combustion (gas smell?). Low engine rpm at idle just makes the problem worse as the alternator cannot keep the battery voltage up because it is spinning too slowly to make any real current.
