Engine knock? Maybe lifters? Could use some advice (includes video clip)

[AutoX-FIB 0]

Hi everyone,I'm idling really loud/knocking right now, and I'm getting worried about this. Probably taking it to a good VW mechanic ASAP but I just wanted to get some feedback here.

It's a 02 12v VR6 with 141,800 miles on it.

Recent or notable maintenance:

Timing chain and guides replacement - 94K

intake shifter rod replacement - THIS WEEK

Coolant temp sensor - 115K? 2 years ago

coil pack replacement at 115K with ford coilpack

plugs and wires - not done

It's loud at idle and startup, but I don't hear it at driving speed or on the highway. It doesn't sound like a "isht is gonna blow up" knock, but I'm worried about it. It sounds like I have a TDI instead of a VR6. Sometimes I don't hear it til it's warmed up, but it's not unusual to hear it on startup if I've already been out driving it before I stopped briefly someplace and resumed driving within a short time frame. For about 20 min. after a cold start up (like in the morning on my way to work) it sounds completely normal. After I run it for awhile, the noise returns. It sounds like it's coming from the top end, but I can't pin point it being localized to one cylinder. I have no CEL light, no burning or leaking oil, and I have not seen the oil pressure light come on.

I'm running Mobil One 5W30 Synthetic and I have about 4K on it since my last oil change. It probably has started getting louder since then, but I have a hard time believing that's it? I do not feel a power loss, and it doesn't seem to sputter or hesitate through the power band. The only time it feels like it's running rough is when I'm starting it up. I took it to a mechanic who replaced the WHOLE shifter rod :banghead: instead of just the bushings because he claimed that he could hear noise from that and felt vibration there, but that did nothing.

So any ideas?

I've read some past threads being about a rod bearing?

Some people had a bad oil pump?

Here's a video I took of it this evening so you can hear it.

http://youtu.be/Tun8RLevom8

AT the end I reved slowly from idle to 4,000 RPMs. North of 2,000 RPMs it seems to stop knocking, or at least at that point you hear the Magnaflow exhaust more then the motor.

[oldmandon 1]

One point, your oil is a bit thin, 10w40 would be better. Also you say that the knock started since you changed the oil. It's quite feasible that your oil is the cause of your knocking sound do to it being too thin so it's not offering the same amount of protection. It will still be lubing, but not sticking so to speak. It also may be that the thicker oil was masking the sound originally, and what you can hear now is maybe a bit of play in the main bearings, or more likely the hydraulic lifters in the head are slapping about as there is no oil in them as it's too thin to stay there.

I would suggest dropping the oil and putting in some 10w40 and see if that makes a difference. It's gotta be cheaper than a mechanic to start with. Hope this helps a little

I'm sure others will be along to come up with other ideas

[legvw 0]

Oil does seem a bit thin for a 12v, can't remember putting fully synthetic oil in my 12v.

[Lukey. 381]

That could tie in with the fact it doesn't do it when cold, as the thinner 5w30 would be at its thickest from a cold start. As it coincided with the oil change that would be the first thing I'd do, change to 10w40 semi

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Thanks for the responses guys. I'm going to change the oil and drop the pan tomorrow for piece of mind to see if there is any metal accumulated in it. It doesn't sound like it's ready to blow any time soon and I will really kick myself if all I needed was a different oil. It might be wishful thinking to think that this is the whole problem, but it's worth a shot. I will really kick myself if it is as simple as that though.

One quick question, do I really need to let the car sit overnight to let the oil pan sealant cure completely (I'm using the VW OEM stuff)? I

Is that just overkill or can I run it a couple hours later?

[oldmandon 1]

You don't need to let it cure. Take the pan off, make sure that BOTH faces are clean, put the sealant on the pan face, spread evenly, offer pan up to block. Tighten up all the bolts evenly. When all bolts are in and tightened to correct torque, put correct oil in to the correct level. When finished start car, and drive off to your fave Burger bar and have a snack.

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So the oil didn't do the trick. I changed the oil and put in Mobil 1 10w 40 high mileage full synthetic. I did at least get to see if there was any metal shavings in the pan at that point and I only had a couple of small "crumb sized" plastic pieces which I'm guessing are from the timing chain guides. I replaced them at 94,000 miles so I don't think that's the issue. This sounds nothing like the way the chains did on my MK3 VR6 either.

But anyway, it's sounding more like the lifters are the issue and I'm going to bring it into a VW mechanic this week. After doing the long screwdriver listening rod trick some more I'm starting to think that it could be the No. 4 cylinder lifter.

[spadam 7]

You dont want to use fully synthetic oil in the vr6. You need 10w 40 semi synthetic. Fully synthetic is to thin. As mentioned above.

[oldmandon 1]

You dont want to use fully synthetic oil in the vr6. You need 10w 40 semi synthetic. Fully synthetic is to thin. As mentioned above.

Poor Chap, Just spent best part of £50 maybe more on fully Synthetic oil to be told it's STILL too thin!!!!

[spadam 7]

Does so above in previous post that fully synthetic is to thin. Tgis may not be the cause though and could be other problems but this wont help matters.

[AutoX-FIB 0]

It's fixed! I brought it back to my mechanic this week to have him look at the lifters and he noticed that the Upper Timing Chain Tensioner was only about half extended and had a nasty bend in the shaft! Amazes me that it failed after only about 3 years since I had a BRAND NEW OEM one put it when the timing chains were replaced, but regardless the car is running fine now.

[oldmandon 1]

Good to hear that you have managed to sort it out