A4 2.8l Timing belt loose. Bad tensioner?

[Phishnvdub]

I have about 1700 miles on a new timing belt and the parts that go along with the service. Ordered the gates blue belt kit from ECS tuning. I have been noticing a rattling kind of sound once engine is warmed up.

Couple days ago I pulled the covers and saw the belt was moving a little side to side on the water pump pulley, in sync with the noise. The belt between the cams where it goes around the WP pulley is loose enough that I can get my hand in there and manually turn the pump. That has got to be too loose. Also looks like the backside of the belt, the blue is wearing a little down from slipping. Car runs fine and is not over heating at all. The belt opposite side of cams seems tight.

Could this be caused by maybe not properly pre tensioning the belt or is the new tensioner maybe shot? Even if pre tension was not done correctly, wouldn't the tensioner take care of that? I did everything to spec from the blau parts and happy wrenching DIYs. Only thing I could see messing up was the previous tension. I had got to the part where I was putting fan clutch back on and realized I had forgotten to put the metal plates back on the end of the heads...Duh. It was about 11PM and tired. I ripped every thing back down and reassembled up to the fan clutch before going back to bed. The pre tensioning is all I can think I may have messed up being so tired. Not even sure I did mess that up. Hence the question about the tensioner taking care of that.

Dreading it, but if I get some time today I am go to start digging into this. Would really like some thought or opinions on what to look for when doing this. Is it a case of locking cams and crankshaft at TDC and redoing pre tension, or will I be able to tell if tensioner is bad? Would hate to retension everything and find out is a bad tensioner and rip apart again. Really appreciate any input. Thanks guys.

[Phishnvdub]

Just realized this may have been better in the engine tech thread. Sorry for posting here if not the place.

[Phishnvdub]

Went out to start disassembling the front end and checked belt and it's tight. Explains why I hear noise when warmed up. Would a tensioner fail in a way that once warm it starts to loosen up?

[Quattro420]

I had the same issue with my brothers 2.8l did the tb all the goodies 1000km it made a slapping noise, belt was loose tore it apart took the tensioner off looked at it didn't see anything (brand new tensioner) re tensions belt and it did it again went loose I had my buddy do it and it went loose on him to we ordered a Vw/Audi tensioner installed it and it never went lose again

[Phishnvdub]

Thanks Quattro420. I ordered the kit from ECS Tuning. Will get a hold of them about this tensioner and start sourcing an OEM one. It's an NTN tensioner in car now which I thought was the OEM supplier. Man I hope I can get front end out enough without having to drain the cooling system to do this haha.

[a4kamila6]

With the aftermarket timing components its really hit or miss. Sometimes you are lucky, other times catastrophe

[Nollywood]

When it comes to a critical set of components, which are also labour intensive, I go with OEM every time, no if's or but's.

[Phishnvdub]

Good points. I wIll see about sourcing an OEM tensioner if that turns out to be the problem. About 100% now that it is. Emailed ECS about it also. Will see what they say. Sitting here looking at the A4 trying to get the ambition to do this again. Guess shouldn't be that bad if I can get to everything just pulling carrier out and not having to swing it out of the way. No water pump or T stat this time either.

[Phishnvdub]

Figured out the pics thing. Got most tore down. Tomorrow night I will put at TDC and lock cams and crankshaft down and continue. I found a red powder on the tensioner roller by the washer. Of course I already put my finger thru it wiping some away. There was some on back side of cover right where it sits over that roller. Anyone have any clue as to what that could be?

[Phishnvdub]

Edit. Got some links to work next post.

[Phishnvdub]

https://www.instagram.com/p/BFu0lyugrAr/

[Phishnvdub]

https://www.instagram.com/p/BFu0n0QArAx/https://www.instagram.com/p/BFu0WpsArP_/

[Phishnvdub]

Everything is apart. About to take tensioner out. While spinning motor to get TDC I noticed the belt would be tight, spin a little it would be loose, spin a little more tight again. Looking at tensioner it doesn't appear to be leaking. How would you tell of it is bad?

[Phishnvdub]

Replaced tensioner with another NTN brand. Pre tensioned properly before tightening cams back up. Belt had the same tension all the way around, even after rotating engine two full revolutions by hand. F'n noise still there. Yesterday got home from just driving only a 5 mile round trip to the store and piped the left timing cover and the belt was snug. Two hours later after dinner I went out and the belt was very loose. Atleast 3/4 an inch up or down. Basically you could jiggle the belt.

Here is a video I made last night of the belt moving around on that cam and water pump pulley. The noise is in sync with belt sliding on the WP pulley. It's the quieter of the noises. The whine in video is either alternator bearing or PS. Haven't got into that yet. https://youtu.be/IZXH3snb0uw

[audinutt]

get a new waterpump and rollers is what I would do.... might as well do it all and be done.

I would get a waterpump from the dealership.

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[Phishnvdub]

Water pump and all rollers are new when I did the timing belt 3 months ago. Pump spins freely with no play or noise in bearing when I had belt off last time 2 weeks ago. Have car in service mode with coolant system still hooked up. All auxiliary belt stuff is off. If safe I may try to start it and see if still making noise. I noticed the power steering pump if I move the pulley mount back and forth it's pretty noisy inside.