Rough idle=Bent Valves (in my case)
#1
Suzuka Master
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Rough idle=Bent Valves (in my case)
Yesterday, after an uneventful commute from Miami Lakes to Sunrise Blvd via I-75 and subsequently pulling up to a stop at the first eastbound intersection, I noticed that the engine idle on my CLS-6 seemed rough. I looked down and noticed that the 'Check Engine' light was on with the idle hovering around 500 rpm, feeling like it wanted to stall. Normally, for my car the idle defaults to around 750 to 1,000 rpm when sitting in South Florida traffic with the AC on. However, this time something felt weird. First, I turned the AC off, to lessen that load, but it did not help. Secondly, I then tapped the accelerator, while waiting in traffic, to minimally rev the engine to see if that would bring it (the idle) back within normal limits. The idle remained rough around 500 rpm.
In Short, I called the Dealer for an appointment to have this all checked out. At the same time I requested that they run my VIN to check if it qualified for any prior/current TSB bulletins for the model.
Today, When I visited the dealer the service writer informed me that I needed the Timing belt and tensioner replaced per the current bulletin that has been talked about recently here on ACL.Com. They checked the water pump, which was fine, and replaced the Timing related parts as mandated; however, he said that that did not cure the rough idle aspect of the problem. He called me at home an hour later and stated that the mechanic, working to resolve the rough idle, found that this was being cause by a few bent valves.
Lucky for me I only have 22,500 miles on the car and the upper tear down of the engine will be covered by the warranty.
I'm still trying to figure out what I did, if anything, to cause this? The car's been properly maintained and has performed flawlessly up to this point. What do you guys think?? Very strange indeed!
Thanks in advance for any input.
In Short, I called the Dealer for an appointment to have this all checked out. At the same time I requested that they run my VIN to check if it qualified for any prior/current TSB bulletins for the model.
Today, When I visited the dealer the service writer informed me that I needed the Timing belt and tensioner replaced per the current bulletin that has been talked about recently here on ACL.Com. They checked the water pump, which was fine, and replaced the Timing related parts as mandated; however, he said that that did not cure the rough idle aspect of the problem. He called me at home an hour later and stated that the mechanic, working to resolve the rough idle, found that this was being cause by a few bent valves.
Lucky for me I only have 22,500 miles on the car and the upper tear down of the engine will be covered by the warranty.
I'm still trying to figure out what I did, if anything, to cause this? The car's been properly maintained and has performed flawlessly up to this point. What do you guys think?? Very strange indeed!
Thanks in advance for any input.
#3
Suzuka Master
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no over-rev or missed shifts?
What is the highest you ever taken your tach?
It is your first post and you seem like a level headed guy, so I would not suspect that you beat the car..
There is another member on this board that has a rough idle, I will mention this to him...
What is the highest you ever taken your tach?
It is your first post and you seem like a level headed guy, so I would not suspect that you beat the car..
There is another member on this board that has a rough idle, I will mention this to him...
#4
Suzuka Master
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No over-revs or missed shifts at all.
I frequent V-Tech every blue moon or so. Nothing over 5,000 rpm. Just when I need to get out in front of some dump truck flying down the interstate. Don't really abuse the car at all. That's why I'm perplexed at the occurance. I guess it was just my time to contribute in regards to a bizarre event.
I frequent V-Tech every blue moon or so. Nothing over 5,000 rpm. Just when I need to get out in front of some dump truck flying down the interstate. Don't really abuse the car at all. That's why I'm perplexed at the occurance. I guess it was just my time to contribute in regards to a bizarre event.
#6
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Wow! Very strange to have a problem like that with no abuse of the engine. Thanks for sharing that info with us! If I ever have a rough idle I'll have the tech check valves too.
#7
GEEZER
I drive the PISS outta mine...not 1 problem except the Trans at 22k.
Sorry about your misfortune.
Sorry about your misfortune.
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#8
No great mystery here really .The tensioner failed allowing the cam gears to shift position .Once that happens and if they shift enough it is possible that even under relatively mild use the engine may bend valves as the valves are now opening at the wrong time and hitting the pistons .
Jens
Jens
#9
Suzuka Master
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I am the only driver.
The service writer asked me about over-revs and the like when he initially informed me about the damage.
He then suggested that perhaps, at sometime during the drive, the tensioner somehow loosened just enough to skip a tooth in regards to the timing. As a result, the car sustained minimal damage to the valves, which inturn, allowed the car to continue to run reasonably until I was able to park it at home.
This would validate the TSB currently out regarding the Timing belt and tensioner replacement.
He stated, had there been a major skip (two or more teeth) in the timing aspect of the whole thing, the engine would have really melted down and it would have caused some major damage to the valves and pistons in question. He also remarked that a valve(s) could have 'Floated' at sometime which would have allowed the pistons to come into contact with said valves, thus bending them.
Really scary. Imagine, cruising down the interstate at 75 mph and having your engine suddenly sieze.
The service writer asked me about over-revs and the like when he initially informed me about the damage.
He then suggested that perhaps, at sometime during the drive, the tensioner somehow loosened just enough to skip a tooth in regards to the timing. As a result, the car sustained minimal damage to the valves, which inturn, allowed the car to continue to run reasonably until I was able to park it at home.
This would validate the TSB currently out regarding the Timing belt and tensioner replacement.
He stated, had there been a major skip (two or more teeth) in the timing aspect of the whole thing, the engine would have really melted down and it would have caused some major damage to the valves and pistons in question. He also remarked that a valve(s) could have 'Floated' at sometime which would have allowed the pistons to come into contact with said valves, thus bending them.
Really scary. Imagine, cruising down the interstate at 75 mph and having your engine suddenly sieze.
#10
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Originally posted by Jens H.
No great mystery here really .The tensioner failed allowing the cam gears to shift position .Once that happens and if they shift enough it is possible that even under relatively mild use the engine may bend valves as the valves are now opening at the wrong time and hitting the pistons .
Jens
No great mystery here really .The tensioner failed allowing the cam gears to shift position .Once that happens and if they shift enough it is possible that even under relatively mild use the engine may bend valves as the valves are now opening at the wrong time and hitting the pistons .
Jens
Thanks Jens..
P.S. Eric noticed/mentioned a rough idle to me today when I spoke with him so track him down and drag him in before he starts playing with his ESM or something dumb...
#11
Suzuka Master
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Thanks for all the responses and interactive questions.
I have browsed/searched this forum many times and have always found excellent information.
Cheers to: ACL.Com
I have browsed/searched this forum many times and have always found excellent information.
Cheers to: ACL.Com
#13
I'm glad I've got my appt for this Saturday (along with my free 15,000 mile maintenance) and hopefully TSX loaner (service advisor said he'll reserve it for me). I'll check out the new TL while I'm there too!
#17
Suzuka Master
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Fuzzy02CLS
I took it to Rick Case Acura.
This sounds very familiar to your experience. My car had 65 miles on it when I took delivery back in July02. God only knows how it was treated for those first 65 miles. I wanted the Red/Parchment color scheme, and that dealer was the only one in S. FL that had one at the time.
I'm thinking that if it was used as a demo strip racer on SR 441 during those first 65 miles, I would perhaps have had trouble earlier on instead of at the 22,500 mile mark.
Funny thing though, when the service writer informed me of the damage, he mentioned that there was no code present when they did the diagnostic function for the 'Check Engine' light. Even though it continued to idle rough.
I'm waiting for further details as to the extent of the current damage/time frame and will follow up here with the results.
I took it to Rick Case Acura.
This sounds very familiar to your experience. My car had 65 miles on it when I took delivery back in July02. God only knows how it was treated for those first 65 miles. I wanted the Red/Parchment color scheme, and that dealer was the only one in S. FL that had one at the time.
I'm thinking that if it was used as a demo strip racer on SR 441 during those first 65 miles, I would perhaps have had trouble earlier on instead of at the 22,500 mile mark.
Funny thing though, when the service writer informed me of the damage, he mentioned that there was no code present when they did the diagnostic function for the 'Check Engine' light. Even though it continued to idle rough.
I'm waiting for further details as to the extent of the current damage/time frame and will follow up here with the results.
#18
Way Fast Whitey
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My 6 speeder has a slight tapping in the top end at idle. It also squeaks at startup. At first I just thought it was a lose belt. I called my local acura dealer and he said to bring in the car immediately. I informed him of the tapping and he sounded like he expected it but was dissapointed all at the same time. I assume one thing has something to do with the other. TL premium loaner here I come. LOL
#19
registered pw
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now i don't have an idling prob when it is warm.
when i start my car in the morn it runs rough for about 30 seconds sitting, and then when i pull out it is rough for about 100 feet and then is ok. they have cleaned out the throttle body and cleaned out the usual carbonbuildup. but some times i wonder if it is something else.
my 01 maxima was always a little rough at startup and then smoothed out
when i start my car in the morn it runs rough for about 30 seconds sitting, and then when i pull out it is rough for about 100 feet and then is ok. they have cleaned out the throttle body and cleaned out the usual carbonbuildup. but some times i wonder if it is something else.
my 01 maxima was always a little rough at startup and then smoothed out
#21
I believe there were ~35 miles on my 2003 CL-S MT when I acquired it. The car has performed well - there is no 'check engine' light - but the idle is certainly rougher than that of the RSX-S I traded. It was difficult to determine whether the RSX engine was running or not - there is no doubt with the CL-S.
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