Can a blocked oil pickup cause chain rattle?

Car is a MK6 GTI 2010 Totally Stock

So I had posted previously regarding some chain noise around 2.5k rpm and off throttle when the car has warmed up. I had taken it to a couple of garages and they suspected either the Timing Chain or Intake Camshaft VVT.

So I decided to do it all myself and I'm looking for more options as the noise is still present after

I have changed

Intake Camshaft
Timing Chain
Tensioner
Cam Bridge
Cam Sensor
Cam Adjustment Actuator
Cam Adjustment Valve

Car runs perfect until its warm and the VVT coming into play. I have had it on a scanner and it seems the VVT can't change properly to advance/retard the timing.

As the VVT is all controlled by oil pressure, the only think I can think of is if the oil pickup is blocked and the oil gets warm its struggling to pickup enough to pressurise the VVT.

Does this sound plausible?

Other than that any other ideas?

I'll see if I can post some video of the noise.

*edit just saw you replaced the cam bridge as well

There's a small screen on a check valve in the cam bridge bracket that goes to the vvt solenoid oil passage. Common for the screen to get gunked up, come apart and send bits of metal screen into oil passage. This can cause all sorts of issues including damage to the VVT solenoid, bearing surfaces and catastrophic engine damage. Might be a good place to check.

Also pulling the pan off and visually inspecting the oil pickup couldnt hurt either, it's not hard, just a bit time consuming because of all the little bolts and having to redo the gasket

After replacing my timing system I had weird issues with cam timing/misfires where the car would idle fine for a bit but as soon as you gave it any power the idle would be awful and the car would die. I chased my tail for awhile with a few ideas but what ended up solving the issue was taking apart the cam bridge and n205 valve and giving them a good clean. I didn't see anything wrong with the valve but I think I may have had a little piece of debris in there that caused the valve to stick. For reference, here's a link to a thread I started that documents this issue and the codes I was throwing.

You should log block 091 (intake cam timing) with VCDS/Cobb AP/OBD11/whatever else the kids are using nowadays and check if your intake cam timing differs from what the ECU requests.

As BudgetPhoenix pointed out, the cam bridge screen can cause issues if debris from it breaking apart gets stuck in the VVT oil passage ways. Did your old cam bridge have a blown out screen? For reference this is the screen we're talking about, on the back of the cam bridge:

I have a V-6 Camry that had a similar issue. Fix was the same as Tony identified, find the clogged screen in an oil passage. At least with the Camry it was super easy to get to.

I have replaced the cam bridge, the old one did have a damage mesh screen which I am thinking is stuck in one of the oil passages. If that has happened I really have no choice but to fine another engine.

I will drop the oil pan at the weekend.

Cheers for replies so far, if anyone has as other ideas to try let me know.

There has to be an easier way to deal with it than a new engine. Is it possible to push a borescope through these oil passages to see if that screen is stuck somewhere odd?

Its crazy that you pretty much replaced everything related to the VVT. I was gonna say maybe even possibly something related to the actual intake cam VVT assembly but you replace the entire intake cam as well. Which code is it btw?

Beavis, did you ever resolve this issue? I have an A4 with the same engine as you and the same problem. I've also replaced all of the same parts you did in this post along with also replacing the oil pickup tube in the pan but nothing has fixed it so far.

I did fix the issue finally.

I'll write a post about it soon.

So I went through everything to try and fix my car without taking the head off.

Tensioner
Cam Bridge (had missing mesh and though that was it but it wasn’t)
Spool Valve
Timing Chain
Cam sensor

Basically I changed everything I could think of and everything that a few of the specialist garages suggested I change.

I initially ran some super heavy oil to try and clear a blockage but that didn’t work.

The check valve is pressed into the cylinder head and is in the top left of the picture. Its just held in by an o-ring.



If you look closely at the valve the pin is offset and it cannot open, The design is a spring, ball bearing and a pin. It seems spring book and the pin dropped too low and thus wouldn’t open enough to let the oil into the variable timing camshaft.



So if you are not getting oil to the variable valve timing camshaft it will make a the rattle sound and won’t rev over 4krpm and EPC light will come on. Even if the valve is not completely blocked like mine is you can still get some similar issues.

Some notes….. Don’t use heavy oil to increase pressure to clear blockages, I did this and blew out my Rear Main Seal and ruined the PCV and that meant another 2 days off the road taking the gearbox off changing Rear main and another chunk of money for a PCV.

Finally able to drive the car!!!

Holy shit good job man been having this rattle issue for months even after changing the timing chain and tensioner. What would it cost to get this done?:thumbup:

Thank you for your post Beavis, I was battling this issue and nearly spent $1400AUD in a new intake cam. You really helped me out alot.

My symptoms were the car rattled between 1500rpm to 3000rpm. Sound was coming from the intake camshaft. Logged channel 91 in VCDS and my intake cam indeed was not changing positions.