bent valve
03-12-2008, 01:13 PM
#1
bent valve Anybody describe what a bent valve might "sound" like.
I have had what I thought was a small exhaust leak for awhile. Seems to be getting slightly louder but its not loud by any means. I went looking for the leak and couldn't narrow it down at all. Sounds like its coming form the top of the motor right in the freaking middle. Tap tap tap. louder when you give it throttle. Now I was thinking Lifter.
Guy who I know used to have a 9 sec car and was into cars big time, swears its a bent valve.
Anyone think so? I know if its a lifter or a valve I have to pull the heads regardless, and I have some 2000 heads to replace my 918's anyway.
Car runs fine, doesn't feel like its lost any power, although I don't beat on it much anyway.
I have had what I thought was a small exhaust leak for awhile. Seems to be getting slightly louder but its not loud by any means. I went looking for the leak and couldn't narrow it down at all. Sounds like its coming form the top of the motor right in the freaking middle. Tap tap tap. louder when you give it throttle. Now I was thinking Lifter.
Guy who I know used to have a 9 sec car and was into cars big time, swears its a bent valve.
Anyone think so? I know if its a lifter or a valve I have to pull the heads regardless, and I have some 2000 heads to replace my 918's anyway.
Car runs fine, doesn't feel like its lost any power, although I don't beat on it much anyway.
03-12-2008, 01:15 PM
#2
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It would be a little noisy but the most likely way to find out if its bent is to do a compression or leak down check on all the cylinders. If you have a low reading cylinder that cylinders valve may be bent causing compression loss from the valve not being able to fully seat.
Sounds to me like a rocker arm is losing the needle bearings or a bad lifter.
Sounds to me like a rocker arm is losing the needle bearings or a bad lifter.
03-12-2008, 01:16 PM
#3
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^ Beat me to it. This is the best way to check the overall health on your motor. It will give you piece of mind or point at what may be causing the noise/loss in compression. Slightly bent pushrods or rockers on their way out can also make similar ticks...
03-12-2008, 01:26 PM
#4
It would be a little noisy but the most likely way to find out if its bent is to do a compression or leak down check on all the cylinders. If you have a low reading cylinder that cylinders valve may be bent causing compression loss from the valve not being able to fully seat.
Sounds to me like a rocker arm is losing the needle bearings or a bad lifter.
Sounds to me like a rocker arm is losing the needle bearings or a bad lifter.
I am at 146,000 miles and its still all stock..
03-12-2008, 01:39 PM
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Anybody describe what a bent valve might "sound" like.
I have had what I thought was a small exhaust leak for awhile. Seems to be getting slightly louder but its not loud by any means. I went looking for the leak and couldn't narrow it down at all. Sounds like its coming form the top of the motor right in the freaking middle. Tap tap tap. louder when you give it throttle. Now I was thinking Lifter.
Guy who I know used to have a 9 sec car and was into cars big time, swears its a bent valve.
Anyone think so? I know if its a lifter or a valve I have to pull the heads regardless, and I have some 2000 heads to replace my 918's anyway.
Car runs fine, doesn't feel like its lost any power, although I don't beat on it much anyway.
I have had what I thought was a small exhaust leak for awhile. Seems to be getting slightly louder but its not loud by any means. I went looking for the leak and couldn't narrow it down at all. Sounds like its coming form the top of the motor right in the freaking middle. Tap tap tap. louder when you give it throttle. Now I was thinking Lifter.
Guy who I know used to have a 9 sec car and was into cars big time, swears its a bent valve.
Anyone think so? I know if its a lifter or a valve I have to pull the heads regardless, and I have some 2000 heads to replace my 918's anyway.
Car runs fine, doesn't feel like its lost any power, although I don't beat on it much anyway.
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03-12-2008, 02:11 PM
#8
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Well I never had the sewing machine noise or the knocking noise before I replaced the valve springs. When 2 of them snapped, I drove it for about 8 miles before I pulled over due to the "machine gun" sound getting louder and louder. The inner springs held up but the outer springs are the ones that snapped. I replaced the whole set with Patriots and now I have the hollow knocking sound.
03-12-2008, 02:51 PM
#9
I had a bent valve in my 98 TA and did not know what it was untill i tore the heads off, but they were brand new manely valves and the problems i was having was getting the car started. i tore the motor down and rebuilt it and didnt replace the heads but installed new valves and springs and about after a few days of driving with it after it was tuned the car shook like hell and would not start. when i pulled the heads off the valve was so bent that it was stuck inside the head, so i just broke down and order some stage II's
