unsettling engine knock

[boostboostboost]

What's up guys, I have an 06 gti with 86k, stock clutch and all, and in the recent weeks the car has aquired a weird noise that I've never heard in the ownership of the car.

Two actually, one is when I'm slowly letting off the clutch at about 40% release, there's a very small click, or "pop", no damage that I can tell its just a noise that irritates me. I do have a neuspeed intake, if that helps the diagnosis.

The other problem is a small knock when I come off the accelerator, very light but I I'm confused as to the origin of it because my mechanic didn't identify it.

Had a broken oil pan that I drove on for about 5 minutes before the oil pressure indicator came on and I shut off the car and had it towed. This is baffling me and any help would be greatly appreciated.

Thanks guys.

 

[nkresho]

I would do a compression test to make sure the low oil condition didn't hurt your rings/pistons/rods in any way. Should tell you if there's a major issue in there.

I cracked a rod on my turbo focus a number of years ago and I had a light rhythmic knock in the clutch pedal, that varied with rpms. Within 2 days, it let go and went through the block.

 

[boostboostboost]

How would i run this compression test?

 

[nkresho]

You might want to have shop do it. You need a pressure gauge with an adapter to screw the end of it down where the spark plugs goes. You crank the motor (with the injectors dissabled and the spark plugs all out) and see how high the pressure goes for each cylinder. I think they sell them at auto parts stores, but the adapters may not reach all the way into the head.

It measures the pressure retained by each set of piston rings. You, ideally, want all 4 cylinders to read approximately the same number. If one's off by a lot, you're not getting a good seal around the ringlands of the piston. It's a sign of shot rings or beat up pistons.

 

[boostboostboost]

Alright, your experiences are a bit different, my knock is just when i come off the accel.

theres a pop when i come off the clutch, same spot everytime, every gear.

Heard it could be the intake snagging the slave cylinder does that sound right?

Ill check up on the compression test ill ask my mechanic. thanks

 

[nkresho]

The intake hitting the reservior usually does it when hitting or letting off the throttle (thus torquing the engine on it's mounts). You can wriggle it around where the pipe meets the silicone for the turbo inlet to see. There's about an inch or two of play moving it at that point.

The other pop might be somewhere in the clutch pedal? Maybe the spring? There are a couple sensors in there too. Or does it sound like it's coming from outside the cabin?

 

[mrbikle]

axle or subframe clunk.

 

[The Fed]

Or a bent finger on the pressure plate. OP, do you beat on your clutch?

The knock could be a main bearing or rod bearing knock. How fast were you driving/revving when the oil light went on?

 

[Heffery117]

If you can't figure out your irritating noise then maybe you shouldn't own a gti. A small knock sound is not really something to be posting about. Come back when your clutch or tranny falls off. I bet you there's a little boy in Africa that would appreciate your car despite your measly irritating sounds....addle::attention_whore::thumbdown::fighting0030:

 

[boostboostboost]

The thing is that this small knock if its a bad cylinder or anything of more value would get worse, it needs attention and I rather keep my cars 100% integrity than be lazy and allow a noise to go on, its not a squeak or a rub its a knock.

Asked my mechanic about a compression test and he said sched. An appt so well see.



@Fed, I'm second owner and got it at 79k, all jersey highway miles but it was a young owner so yeah its possible. When the light came on I was in 4th cruising down a steeet low rpms not high enough to shift yet.

@Heffery, I feel bad for your gti if you don't even care enough to post a thread to get some info..
Getting shot down isn't near as bad as letting a problem get worse, and just like I read up before I post, there's tons of noises gti's on the forums make, just trying to identify.

@Bike, this isn't when moving or over bumps, strictly in and out of gear, still possible? Trying to narrow.

Thanks guys appreciate the feedback