Hi all, a few weeks ago my idle got weird like I was going to stall out and it eventually started to overheat. It ended up being a loose fan cable connector as nothing else was found. Since then I changed the oil about a week ago. I noticed lately that when I come to a stop it gets shaky and rpm rises up a bit (back and forth). A very small variation but not like it usually operates. I get the impression it is somehow linked to my previous issue but cant prove it, as my car does not overheat now. I cleaned the throttle body and maf sensor in november so I dont think its that. No engine codes, no other issues. Just curious what easy things I can check/replace first. Thanks in advance. I will probably clean the TB again as a first step but I doubt 3000km of driving would cause that issue. Could it be a coolant temp sensor? A fuse? I have no idea.
2007 Corolla low idle
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Does it happen to cycle? Like the idle RPM changes for a bit and then goes back to normal.
If so, it could be related to radiator fans kicking in. If for some reason both are kicking when idling, which should not happen at all during cold months, then it creates enough current draw that the idle has to be compensated, hence a bit of a shake and increase in RPM, sort of like AC compressor kicking in.
Are you in defrost mode by any chance? That would get the AC compressor to kick in as well.
If so, it could be related to radiator fans kicking in. If for some reason both are kicking when idling, which should not happen at all during cold months, then it creates enough current draw that the idle has to be compensated, hence a bit of a shake and increase in RPM, sort of like AC compressor kicking in.
Are you in defrost mode by any chance? That would get the AC compressor to kick in as well.
It can be that it needs to be reprogrammed to relearn its idling cycle.
How old are the spark plugs? Is the battery on the way out? I'd change out the air filter too.
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A bouncing idle is the TPS. Which is located inside the TB. If you plan to clean the TB, do it OFF the engine. Best way to get both sides. Don't worry about the calibration, its self learning. Disconnect the battery, remove TB. Clean reconnect. reconnect battery.
But there are other questions. Do you have a stock airbox?
You said the fan wire got disconnected somehow. Did you do work to the engine prior to this event?
But there are other questions. Do you have a stock airbox?
You said the fan wire got disconnected somehow. Did you do work to the engine prior to this event?
Originally Posted By: KrisZ
Does it happen to cycle? Like the idle RPM changes for a bit and then goes back to normal.
If so, it could be related to radiator fans kicking in. If for some reason both are kicking when idling, which should not happen at all during cold months, then it creates enough current draw that the idle has to be compensated, hence a bit of a shake and increase in RPM, sort of like AC compressor kicking in.
Are you in defrost mode by any chance? That would get the AC compressor to kick in as well.
No A/C in this car. No interior vent on or defrost. Yes it cycles every second or two.
Does it happen to cycle? Like the idle RPM changes for a bit and then goes back to normal.
If so, it could be related to radiator fans kicking in. If for some reason both are kicking when idling, which should not happen at all during cold months, then it creates enough current draw that the idle has to be compensated, hence a bit of a shake and increase in RPM, sort of like AC compressor kicking in.
Are you in defrost mode by any chance? That would get the AC compressor to kick in as well.
No A/C in this car. No interior vent on or defrost. Yes it cycles every second or two.
Originally Posted By: cjcride
How old are the spark plugs? Is the battery on the way out? I'd change out the air filter too.
Battery is 1 year old. Toyota OEM unit. Air filter is good, on for under a year/10k kms. I will maybe check the plugs. I had them replaced once so far with Iridiums. Im at 154,000 miles.
How old are the spark plugs? Is the battery on the way out? I'd change out the air filter too.
Battery is 1 year old. Toyota OEM unit. Air filter is good, on for under a year/10k kms. I will maybe check the plugs. I had them replaced once so far with Iridiums. Im at 154,000 miles.
Originally Posted By: LeakySeals
But there are other questions. Do you have a stock airbox?
You said the fan wire got disconnected somehow. Did you do work to the engine prior to this event?
Yes. Stock airbox and no other work done prior (since alternator swapped in december)
But there are other questions. Do you have a stock airbox?
You said the fan wire got disconnected somehow. Did you do work to the engine prior to this event?
Yes. Stock airbox and no other work done prior (since alternator swapped in december)
Watch your coolant tank
Check the IAC valve and fuel pressure regulator.
Disconnect the battery, touch the + and - leads together to reset the computer. Might run a little odd for a while but it might cure the problem.
IAC for sure
If it is drive by wire then you are correct but they list an IAC for 2003-2007 which means some models of the 07 model year probably still use a cable operated TB and late 07 DBW.
Its common to see things like this, some cars change after the month 05 production.
https://www.toyotapartsdeal.com/oem-toyota-corolla-idle-control-valve.html
Its common to see things like this, some cars change after the month 05 production.
https://www.toyotapartsdeal.com/oem-toyota-corolla-idle-control-valve.html
The 2003-2007 Corolla/Matrix xrs uses the 2zz-ge engine with throttle cable and IACV.
Other trims use the 1zz-fe engine with DBW and no IACV.
Other trims use the 1zz-fe engine with DBW and no IACV.
Have you had the intake manifold gasket replaced? It's a known problem on this gen of Corolla. It's just a matter of time before the gasket fails.
Eventually you will see a CEL but perhaps you are seeing early symptoms? Erratic idle is one of the symptoms.
Eventually you will see a CEL but perhaps you are seeing early symptoms? Erratic idle is one of the symptoms.
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