Mgrene Posted September 21, 2020 Share Posted September 21, 2020 Good day Forum. I hope you can help me identify the root cause of this rattling (in lack of a better word) noise. Or at least help me to rule out what it cannot be. Here is what I know: When the car is stone cold the noise is not there. After approx. 1 minute the noise starts to appear. The noise is only present at idle and disappears ones I rev the engine. I find it quite difficult to locate if the sound is coming from top or bottom. But I'm 80% sure it is coming from the bottom end. The video I have attached is filmed from the bottom end of the car and the car has passed the 1 minute cold start. You will notice in the video that when I rev the engine, the sound disappears. Don't pay attention to the angle of the camera. Just focus on the sound :-) I did a compression test not long ago and compression looks good on all cylinders. Hope to receive some guidance on how to narrow down to the problem (if there is a problem). [video=youtube;rnpY--BD6MU] Quote Link to comment Share on other sites More sharing options...
Ric Posted September 21, 2020 Share Posted September 21, 2020 Could it be a rattly bearing? you can take off the AUX belt and run the car for a few minutes to see if its anything related to that. If it goes away it could be waterpump, aux tensioner, AC pump etc. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted September 21, 2020 Author Share Posted September 21, 2020 Could it be a rattly bearing? you can take off the AUX belt and run the car for a few minutes to see if its anything related to that. If it goes away it could be waterpump, aux tensioner, AC pump etc. Just tried with the aux belt off and the rattle sound is still there. I also did a more thorough listening and the sound is definitely (I think) coming from the front of the engine, around the cambelt tensioner pulley/mid engine. The tensioner pulley is almost brand new so it would surprise me if that is the root cause, but guess I should remove the cambelt cover and have a closer look. Freakin' pain as it would require I have to remove the crank pulley. Quote Link to comment Share on other sites More sharing options...
evinX Posted September 21, 2020 Share Posted September 21, 2020 Sounds like a bearing to me Quote Link to comment Share on other sites More sharing options...
Mgrene Posted September 21, 2020 Author Share Posted September 21, 2020 Sounds like a bearing to me If it is a bearing, wouldn't the rattling continue to be there when also revving the engine? I'm no mechanic so just asking :-) Quote Link to comment Share on other sites More sharing options...
tayr Posted September 21, 2020 Share Posted September 21, 2020 My thought would be after the cold start sequence and the revs drop, maybe it's idling so low as to make something start to rattle that is loose somewhere? Then as revs increase the car gets out of that "jolty rough idle" stage? Quote Link to comment Share on other sites More sharing options...
rider Posted September 21, 2020 Share Posted September 21, 2020 Fuel injector solenoid. If you run a stethoscope along the manifold you may be able to pinpoint if that is the problem with one of your injectors. You should be able to pinpoint to whether the noise is originating from the front, rear or side of the engine - thats impossible to discern from the video and not detailed in your OP. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted September 21, 2020 Author Share Posted September 21, 2020 Fuel injector solenoid. If you run a stethoscope along the manifold you may be able to pinpoint if that is the problem with one of your injectors. You should be able to pinpoint to whether the noise is originating from the front, rear or side of the engine - thats impossible to discern from the video and not detailed in your OP. I can try and unplug the injectors one at a time and see if it helps? Quote Link to comment Share on other sites More sharing options...
mellonman Posted September 21, 2020 Share Posted September 21, 2020 Loose crank pulley . Check the bolt is tight . With it making that noise you should get a half turn on it with out the locking tool Quote Link to comment Share on other sites More sharing options...
Supra-love Posted September 21, 2020 Share Posted September 21, 2020 Mine was similar to this noise and it was the tensioner pulley! Quote Link to comment Share on other sites More sharing options...
Konrad Posted September 21, 2020 Share Posted September 21, 2020 Sounds like tensioner pully to me Quote Link to comment Share on other sites More sharing options...
Mgrene Posted September 22, 2020 Author Share Posted September 22, 2020 My thought would be after the cold start sequence and the revs drop, maybe it's idling so low as to make something start to rattle that is loose somewhere? Then as revs increase the car gets out of that "jolty rough idle" stage? That sounds like a reasonable theory. As other mention, it could be the cambelt tensioner pulley. That will be the next thing I'll check. Will keep you all posted of my finding. Cheers. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted September 22, 2020 Author Share Posted September 22, 2020 Loose crank pulley . Check the bolt is tight . With it making that noise you should get a half turn on it with out the locking tool Thanks for the suggestion. Since I'm going to check the cambelt tensioner, I will automatically also check the crank pulley. Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted September 23, 2020 Share Posted September 23, 2020 When mine did a similar noise, the hydraulic tensioner seized up and cracked the bracket on the pulley. Don't rev or drive it until you checked as my timing belt jumped a few teeth. Quote Link to comment Share on other sites More sharing options...
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