Starts with rough idle then revs up
04-10-2020, 10:25 AM
#1
Member
Thread Starter
Join Date: 03-11-2020
Location: Massachusetts
Posts: 82
Starts with rough idle then revs up
2010 2.4L HHR 2LT with 83 k miles.
Recently purchased to use as a towed vehicle behind my RV. I am the 3rd owner. Car was totaled by insurance company in 2011 with 6,700 miles. Was salvaged/rebuilt/sold to 2nd owner who put over 70k miles on it. Prior to me buying it the independent used car dealer had the VVT valves replaced, exhaust pipe section replaced and some brake and suspension work done. I have replaced the air filter, cleaned the MAF and throttle body and checked the charcoal canister purge valve (under the hood) for proper operation (I removed it from the engine. Could not blow air through it but when activated with 12 volts the valve opens and can blow air through it). Car passed its Massachusetts Emissions Test last week with no issues.
OK. Since right now is not the best time to go to Auto Zone I do not have any idea if there are any codes to help with the problem I am having. Am hoping to glean some knowledge and ideas here until I can get the scan for codes done.
Since purchasing the car a few weeks ago I notice that about once out of every three or four starts the engine will stumble and rough idle and even stall sometimes and after restarting or waiting a bit the engine will accelerate to 1500-2000 rpm and then settle down to normal idle. Sometimes I can keep the engine from stalling by applying the accelerator on and off until it seems to catch, run up to 1500-2000 rpm and settle down to idle.
Given what has already done as far as valves and cleaning etc listed above, What would be the next best thing to try or check or do I just need to wait until I can check for codes?
Appreciate any help. :)
Recently purchased to use as a towed vehicle behind my RV. I am the 3rd owner. Car was totaled by insurance company in 2011 with 6,700 miles. Was salvaged/rebuilt/sold to 2nd owner who put over 70k miles on it. Prior to me buying it the independent used car dealer had the VVT valves replaced, exhaust pipe section replaced and some brake and suspension work done. I have replaced the air filter, cleaned the MAF and throttle body and checked the charcoal canister purge valve (under the hood) for proper operation (I removed it from the engine. Could not blow air through it but when activated with 12 volts the valve opens and can blow air through it). Car passed its Massachusetts Emissions Test last week with no issues.
OK. Since right now is not the best time to go to Auto Zone I do not have any idea if there are any codes to help with the problem I am having. Am hoping to glean some knowledge and ideas here until I can get the scan for codes done.
Since purchasing the car a few weeks ago I notice that about once out of every three or four starts the engine will stumble and rough idle and even stall sometimes and after restarting or waiting a bit the engine will accelerate to 1500-2000 rpm and then settle down to normal idle. Sometimes I can keep the engine from stalling by applying the accelerator on and off until it seems to catch, run up to 1500-2000 rpm and settle down to idle.
Given what has already done as far as valves and cleaning etc listed above, What would be the next best thing to try or check or do I just need to wait until I can check for codes?
Appreciate any help. :)
04-10-2020, 11:21 AM
#3
Administrator
Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 37,609
Welcome to the site, check for Vacuum leak, damaged throttle body ( you didn’t move the throttle plate manually)
If the MIL or CEL is not lit try a battery lobotomy, simply disconnect the negative terminal cable at the battery for a full 30 minutes to reset the computers.
It’s free, no contact is required at parts palace and it might just fix the idle issue.
If the MIL or CEL is not lit try a battery lobotomy, simply disconnect the negative terminal cable at the battery for a full 30 minutes to reset the computers.
It’s free, no contact is required at parts palace and it might just fix the idle issue.
04-10-2020, 12:03 PM
#5
Member
Thread Starter
Join Date: 03-11-2020
Location: Massachusetts
Posts: 82
I can confirm I did not move the throttle manually. Had my better half open it via foot on the accelerator while i cleaned the plate. Will try the battery disconnect as advised. As you say..it's free and might actually solve the issue! :) Beyond that will look for vacuum leak if problem persists. Thanks!
04-10-2020, 12:13 PM
#7
Senior Member
Join Date: 08-03-2010
Location: Lake Ronkonkoma, N.Y.
Posts: 3,564
skysailor
How does the engine run when up to operating temp ?
If you did have a vacuum leak it would be there all the time. It's a physical mechanical problem.
MIL (Malfunction Indicator Light) and CEL (Check Engine Light) mean the same thing. Is it on ?
These cars are funny. Do you know how old the battery is ?
How does the engine run when up to operating temp ?
If you did have a vacuum leak it would be there all the time. It's a physical mechanical problem.
MIL (Malfunction Indicator Light) and CEL (Check Engine Light) mean the same thing. Is it on ?
These cars are funny. Do you know how old the battery is ?
04-10-2020, 12:18 PM
#8
Senior Member
Join Date: 04-06-2020
Location: Missouri
Posts: 911
Vacuum leaks on brake booster is a big leak, then various lines running to TB or PCV... I usually check connections and lines by CAREFULLY spraying brake cleaner on the lines and fittings. I use brake cleaner as it wont attack rubber and plastic parts like carb cleaner does. If the engine revs theres a leak !
04-10-2020, 12:36 PM
#10
Senior Member
Join Date: 08-03-2010
Location: Lake Ronkonkoma, N.Y.
Posts: 3,564