Okay so I drove around after MOT and after a little while I started hearing more and more of weird vibrating noise, not sure how to describe this, coming from the passenger side corner of the engine bay. It is in sync with engine rpm. Usually can be heard slightly at idle and gets louder and more obvious as rpm increases. Especially easy to hear when rpm goes over 2000 and gets very loud at 4000 rpm.

Here is a video, sound track: At 0:10 easy to hear the abnormal noise.

 

My immeditate idea was timing chain because it sounds little vibrating chain. I replaced cam gear, timing chain, timing tensioner timing chain guides and oil pump chain when I rebuilt the engine. I did use kit from ENGINETEAM, I think it's a rip off in terms of quality/price ratio. Original set would have been cheaper and visually higher quality.

On a weekend I am going to do proper diagnostics by removing accesory belt and see if maybe a pulley or AC pump ( AC system not working currently ) is culprit. Meanwhile perhaps someone has heard something like this and can give me some pointers.

Regards

After using stethoscope I have determined that the noise is coming from timing chain. specifically the crankshaft sprocket area. Crankshaft sprocket is the one piece I did not replace because it needs a special tool to remove and install a new one. At the time I could not find any without having to wait for weeks. Not to mention ones I found were pretty expensive, over 200€. 
Noise coming from the crankshaft procket area is very obvious metallic chatter. At no point it sounds like typical chain rattle. Camshaft sprocket area is very smooth and quiet. I also found out that Febi chain tensioner is very soft and spongy when submerged in oil but old tensioner becomes rock solid when I try to compress it inside oil.

Anyway it seems I might need to replace the whole timing set again. I'm not looking forward to doing this. And no way I am spending over 200€ on a tool I'll use once.

 

 

Oh and when driving around I noticed that when I pushed rpm over 4000 then noise stopped. And noise sometimes also stops when doing right hand turns. Odd.

Edited 18 July, 20241 yr by Koreenium

According to VCDS timing chain is off by -5.18 degrees. I am pretty sure that is too much because with my old chain was -2.56 degrees. And I used tools to set correct timing. Anyways something fishy is going on.

The difference is a factor of 2 (to the second decimal place). Either the vcds has got its binary sums wrong or you really have done something silly in setting it up. Probably doesn’t help much but it might.

Only thing I can think of doing wrong is when I tightened the camshaft sprocket. Which can cause the timing chain to be slightly off because timing sprockets are not keyed.

I made sure that new chain and other parts were identical to the old ones. And I don't think it matters which way I installed the timing chain, atleast I did not see any mentions in the manual or in the package that it came in.

Thinking about how turning right can cause the noise to go away. Makes me think if perhaps the camshaft sprocket and crankshaft sprocket are no longer perfectly aligned with each other and this is causing excessive wear on timing chain and sprockets? Or perhaps chain guides are pushing against the chain? I guess we'll find out once I have it apart. Not looking forwards to this.

47 minutes ago, Koreenium said:

Only thing I can think of doing wrong is when I tightened the camshaft sprocket. Which can cause the timing chain to be slightly off because timing sprockets are not keyed.

I made sure that new chain and other parts were identical to the old ones. And I don't think it matters which way I installed the timing chain, atleast I did not see any mentions in the manual or in the package that it came in.

Thinking about how turning right can cause the noise to go away. Makes me think if perhaps the camshaft sprocket and crankshaft sprocket are no longer perfectly aligned with each other and this is causing excessive wear on timing chain and sprockets? Or perhaps chain guides are pushing against the chain? I guess we'll find out once I have it apart. Not looking forwards to this.

I missed the bit about turning right. Have you got a loose engine mount or similar? I don’t see how that would affect the engine timing.

On 21/07/2024 at 19:18, John2022 said:

I missed the bit about turning right. Have you got a loose engine mount or similar? I don’t see how that would affect the engine timing.

Engine mount looks fine and is torqued down. Gearbox mount and dogbone mount is also fine. I essentially can't feel engine vibrations at all in the cabin. Which is unusual because before engine rebuild I felt low idle vibrations easily.

When turning right, whatever part of the timing system gets shifted ever so slightly to the left from the g-force which causes the noise to stop? Could be that timing chain and the sprockets are slightly binding because they are vertically misaligned ever so slightly? Because the camshaft sprocket is bigger, it doesn't get affected as much as the crankshafts much smaller sprocket and that's why this noise is coming from the crankshaft sprocket and not from the camshaft sprocket. I can think of two reasons why sprockets may not be aligning properly with one another is because new camshaft sprockets is ever so slightly sticking more or less out than the original one. Or because I swapped the left and right main thrust bearings which shifted crankshaft slightly? Or I am just overthinking.

I have also noticed that there is no noise in the evening when the car has been sitting in the warm weather for a whole day untill engine starts to warm up after 5-10 minutes of driving. After which it gradually appears and gets so noticeable in the end that you can hear it even while idling. Perhaps there is oiling problem? Anyway I have to take it apart and inspect it closer. I hope it's fine til the next weekend when I have time.

Oh and the timing chain stretch or whatever it's called in VCDS, does not change when driving. It always stays at -5.18 degrees. I even reset the value but after starting the engine it goes back to -5.18.

Edited 22 July, 20241 yr by Koreenium

It’s a difficult thing to suggest what to do next. The change of noise with engine temperature does suggest the chain/ tensioner shifting somehow or maybe the oil level is wrong or the oil flow is blocked. But  that is unlikely to be affected by the direction the car is moving in. The turning right thing does suggest suspension/ drive train/ mounts/ wheel bearings etc. 

I’m afraid I can’t help any further but it will be interesting to know what the problem is.

John

Hello, just one theory but could you please check the fuel lines that go under the car? It’s on the right side and according to some other posts i read, this can be a common problem on TSI cars. I got a friend with the same exact engine and the sound is similar, took it to a mechanic and from what he said, the fuel filter was vibrating pretty rough, changed the fuel filter but without success, so the vibration could come from the front of the car. If you get the chance and do a video about it as well, it would be great. PS, you need to remove the plastic cover from the side of the car to really see the fuel lines, some people fixed the issue by zip-ties and some sponge to dampen the vibration from what i heard. 

I have been driving around and trying to do diagnostics.

I have used stethoscope to try and point where the noise is coming from. It's not coming from fuel lines while idling, Don't know if it makes noise while driving.

While idling I can absolutely hear metallic clatter coming from crankshaft timing chain sprocket area. I had the top timing cover off and did my best to inspect everything visible from there but I could not see anything out of place. I retimed the engine and did an oil change ( I had changed oil already several times before ) and for the next 30km noise stopped completely but then came back.

 

 

Another area that seems to be noisier than before is the camshaft area. It seems to make louder noise than before engine rebuild. Could perhaps indicate lower oil pressure on the top end? Camshaft sprocket makes almost no noise.

 

Any idea if there is a way to install oil pressure gauge to 1.2 CBZA? I have not seen low oil pressure warning since very first start after rebuild.

 

 

Using VCDS I recorded all types of different readings while driving to work and back for few weeks. Things I noticed that some times you can feel how the engine jerks just as if it misfired but VCDS did not record any misfires. 1 misfire in last 1300km.

Real interesting thing I found was that knock sensor reading for cylinder nr. 2 was constantly higher than other three cylinders. So I though it would make sense because high pressure fuel pump is mounted on top of cylinder 2. But then I noticed that fuel injector time pulse was also constantly 10-20% longer than on other three cylinders. Other cylinders were very much even. Can't remember what the actual readings were but something in milliseconds. Believe me or not but my dog ate my laptops charger and battery is empty so I can't check the readings.

I removed the high pressure fuel pump to see if maybe it's leaking fuel into the engine. Years ago my original pump failed by flooding the engine with fuel. I did not see anything wrong but I swear I could smell little bit of gasoline on the plunger spring part but I'm not sure. When I did last oil change then oil was hazy looking but that could be because I just rebuilt engine and cylinders are still breaking in. I have only driven around 2500km so far.

I have all new injectors. Original ones were not good even after cleaning them. Probably good idea to do compression test to make sure all cylinders are good.

Not sure what else to do other than keep on driving and see how far I get before it gives up.

I am still baffled. But now I have even more problems but still no check engine light.

I now have rough idle. Before even with this noise engine ran smooth but now I can feel how the whole car vibrates while idling. And just few days ago rpm started to fluctuate more than normal. Before issues idle was 650rpm +/- 10 and fuel rail pressure 4480 kPa +/- 30. But now I get 650rpm +/- 50 and fuel rail pressure is +/- 150. Ofcourse HPFP is mechanical so engine rpm directly affects the fuel rail pressure.

After cold start if I start driving immediately I can feel how engine loses little bit of power for a second then drives normal and then loses slight amount of power again and then feels fine again. It feels little bit like when clutch slips but instead of rpm going up, it drops slightly. Otherwise seems to make power just fine but I can tell that engine does run just bit rough. 
Also on cold start engine starts bit sluggish and hesitates/stumbles some times but not always.

I checked compression and all 4 cylinders had 140psi which is on the low side but considered I did cylinder honing myself and this engine uses moly piston rings it's not really surprising. All 4 cylinders and spark plugs look alike. Cylinders have maybe little bit wetness and typical carbon build up. I have been doing oil changes pretty often so I can't tell if it consumes oil but atleast I can't see smoke or smell anything odd from exhaust. Spark plugs look perfect and gaps are same on all of them. 0.8mm ( Bosch plugs ).

 

Oh and before fuel lines were not causing problems then now because of how much engine vibrates, fuel lines have started to rub paint off on some spots.


Great fun.

I believe customers are becoming to gullible to car manufacturers 

 

maybe its time car manufacturing took a secondary role in this process we call humanity 

 

 

 

 

Well, my engine is officially toast. One of the cams has gone bad. And just to add insult to injury, auxiliary water pump seized and caused engine to overheat.

Atleast that's over and I have learned a lesson. I'm buying an engine from a junkyard.

Edited 21 January, 20251 yr by Koreenium