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Diesel Engines A forum dedicated to diesel engines fitted to Volvo cars. See the first post in this forum for a list of the diesel engines. |
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Engine KnockViews : 1700 Replies : 16Users Viewing This Thread : |
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Jun 13th, 2023, 22:44 | #1 |
New Member
Last Online: Apr 19th, 2024 21:34
Join Date: Jan 2023
Location: Kutina
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Engine Knock
Hi,
I am trying to figure out what is causing my xc70 d5 (D5244T20) to knock. The knocking / ticking is coming from the upper left side of the engine (cylinder 1) as shown in the video1 and video2, and it is more present when the engine is warm. Sometimes, when it is cold outside, the ticking can be barely noticeable. I have visited four repair shops. All agreed that the noise is present, but no one could say for sure what was wrong with the engine. At the Volvo shop (last visit), I was told that the engine should be removed for a detailed inspection. So far, the following has been replaced/performed. - Hydraulic tappets - Injector 1 and 3 ( refurbished by Bosch). - All belts, tensioners and pulleys, water pump - Engine compression test (warm): Cyl. 1: 25.5 bar Cyl. 2: 25 bar Cyl. 3: 25 bar Cyl. 4: 26 bar Cyl. 5: 25,5 bar According to VIDA, the injectors are within specifications. Leak off test is also within specs. The engine pulls well, maybe a little sluggish at low rpm. I also noticed the following: If accelerate while driving and suddenly lower the RPM and then slightly press the accelerator pedal, the knocking may also disappear. Any ideas? |
Jun 14th, 2023, 20:12 | #2 |
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Last Online: Apr 24th, 2024 20:45
Join Date: Jun 2017
Location: Chesterfield
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Hello
It is difficult to identify from the videos. My untrained ears can hear what I believe to be a noisy injector or tappet or pcv which is being amplified via other engine components. Have either you or any of the garage techs utilised a mechanics stethoscope? It's my go to piece of equipment for tracing noises. |
Jun 15th, 2023, 21:17 | #3 |
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Last Online: Apr 19th, 2024 21:34
Join Date: Jan 2023
Location: Kutina
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Hi Ruby,
I would exclude hydraulic lifters as I have replaced them. I think I've played with the stethoscope for several hours now and I'm 99% sure the knocking is coming from injector 1 or cylinder 1. Listening without a stethoscope, I would say the knocking is coming somewhere behind the camshaft pulley.:/ Today I went to another garage and they think it might be a combustion related problem rather than mechanical (maybe the injector). I have already spent 500 eur on remanufactured injectors with no succes. I noticed oil leaking (not much) from the turbo. Could a defective turbo cause such problems? The turbo itself does not make any strange noises. |
Jun 15th, 2023, 23:40 | #4 |
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Last Online: Yesterday 01:20
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Location: Groningen
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I find it hard to hear the knock, but if its there it is caused by the mismatch in flow by the refurbishing and the coded flow in the ecu.
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Jun 16th, 2023, 18:58 | #5 |
New Member
Last Online: Apr 19th, 2024 21:34
Join Date: Jan 2023
Location: Kutina
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The videos are not top quality, but please try to watch them on your phone. I am sure you will hear it clearly.
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Jun 16th, 2023, 20:33 | #6 |
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Last Online: Yesterday 01:20
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Location: Groningen
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Well if there is knock its caused by the mismatch in flow by the refurbishing and the coded flow in the ecu, concerning injector 3 you were probably lucky.
Many people have problems with the refurbished injectors because of the expected flow by the ecu code. |
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