b6 1.8tmQ knocking-like sound when accelerating

[kolan67]

Hey guys,

It's been a real real long time coming. Well anyway, I have 123k on the clock now and recently did a turbo and clutch replacement (8-10k ago).

APR1+, TT225s

Within the last 4-5 months I've been noticing my car making a knocking sound from somewhere around the engine bay when I press the gas. If I stay under 10 PSI, I'm golden. But if I push my car then I hear a knocking sound like once every 2-3 seconds but seemingly random.

My mechanic said it might have been my spark plugs so he changed em. For like 2-3 days my car ran great, no knocking, then it came back. Don't know what to make of it, and any help would be appreciated.

Thanks.

Ignore my SIG sell stuff it's been a real long time.

[MikeWire]

Knocking like a misfire? Are you running a FMIC or the stock cooler? What other mods?

It could possibly your DV, but I would think only an aftermarket with a piston could make a knocking noise.

[SleeperAvant]

OP, where are you located? How hot is it where you are, what fuel are you using? Are you still running on the stock SMIC?

[kolan67]

Thanks for the reply guys.

I never had this problem before so I don't know what a misfire would be. Stock Intercooler is what I'm running. Other mods aren't really relevent I dont think but I have an AWE boost gauge, oettinger coilovers, and thats about it.

I'm located in the Bay area, it's like 70-80 degrees. I'm on 91 oct.

Still happening right now when I press on the gas, it's really annoying. But thanks for your help!

[AudiA4Turbo22]

check your oil level

[kolan67]

Will do, and I'll get back to you thanks!

[kolan67]

Hello everyone!

Thanks for the replies again. I apologize for the late response but it took me a while to figure this one out, I wasn't really sure for a long time. AudiA4Turbo, you're correct about the oil problem! It isn't a problem of oil "level" perse, as I will tell you soon.

After checking your message, I checked my oil level a week later. I saw that the oil level was completely full, but still having the knocking problem whenever I accelerate hard I decided to add a tiny bit of oil. Wala, the knocking almost completely disappeared. A week later, the knocking came back. I added a little bit a oil again, knocking almost disappeared again completely (what I mean by almost is that it was knock once to three times total on a hard acceleration from gears 1-3/4; as opposed to like 1/sec or 2/sec knocking in each gear).

So thanks to you, I now know it's an oil related problem and not a turbo problem. I'm thinking I may have sludge or maybe something is inhibiting my oil pressure. I've done some research and I have read that it may be something called the "oil pump strainer" that is clogged. My VW mechanic puts regular oil filters, but i doubt that is an issue with the knocking but i'm going to make the switch back to large oil filters.

Would you guys suggest a seafoam? I think the oil pump strainer is really hard to get to, but would it be worth it (and a correct thing to do)?

Thanks again, I will definitely post the solution to audizine to add to the database of solutions on this great forum community.

[walky_talky20]

I would suggest that you get the oil pressure checked. As you said, it is a lot of work to get to the strainer (usually called the oil pickup screen or tube), so you want to be sure you have pinpointed the problem correctly. The oil pressure should go up as you rev the engine higher. If it is going down when you rev it, or the pressure is below spec, a clogged pickup screen is very likely.

If it is clogged enough to affect oil pressure, I don't think any product like seafoam will help quickly enough to make a difference. I like Auto-RX as a maintenance defense against the problem. But if you know the screen to be clogged, the correct fix is to immediately drop the pan and replace or clean out the pickup tube.

[kolan67]

Thanks for the reply walky. Put my car in the shop today and explained what you think may be happening. Don't know if they bought it or not, but I should get a call shortly and I'll keep this thread updated. I think you may be right.