Engine Nocking / poping Noise

[Shafi]

Hi Guys,

Yesterday I started hearing a knocking / popping / like “water dripping” noise from the engine!
It comes mostly from the head around the oil filling cap.
Here’s a recording:

You can hear it at the beggining, then less as I moved the phone towards the back, and then again when I move it forward towards the oil filling cap.

The car drives fine and does not overheat or anything. Head gasket was done recently, new spark plugs.
Any ideas?

Thanks

Attachments:

• 106GTInoise.zip

Topic

[Kevin Criswell]

What kind of car is it?

[Shafi]

It’s 1997 Peugeot 106 S16 (GTI) 1.6L 16v

[Kevin Criswell]

[quote=”WRC-RUSH” post=75549]It’s 1997 Peugeot 106 S16 (GTI) 1.6L 16v[/quote]

Oh, Well I apologize, I won’t be off much help on that make and model.

If I had to guess, my first instinct is to think of a VVT system acting up. But I am not sure if that car has any kind of variable valve timing.

[Shafi]

It doesn’t have variable valve timing. It’s a TU5J4 NFX engine.

[Matt Brandsema]

Definitely sounds like a knocking. I don’t get the impression that the sound is coming from deep within the engine, so the first thing I would do is remove the valve cover and get a good look around. If you don’t see anything, run the engine with the valve cover removed to see what is going on. (They sell special plug things to put over the rocker arms so you don’t get a huge mess. You can also use a paper clip, in fact I think Eric does this in one of his videos.)

[Gumpy Guss]

Sounds like one of the cam followers has worked its way loose.

[Bill]

I would remove the valve cover and make sure everything is tight. Maybe an oil deflector from the valve cover has come loose and is rattling around in there.

[Shafi]

Hi guys,

So I removed the cam covers as advised, checked all the bolts including head bolts and all seemed to be tight :unsure:
I looked inside as much as possible for dirt or anything unusual but nothing.
I ran the engine with the covers off but the knocking / popping noise went away! instead I heard some oil bubbling noise which my mechanic friend says it’s normal.
Put the covers back on and the noise went away!!!
The next day the noise is back and stronger than the beginning! :angry:
This is how it sounds today:

My friend thinks it’s a hydraulic lifter (valve piston) starved of oil as a result of some dirt getting inside the lifter’s oil channel.

Here are some pics and details:

Attachments:

• Noise2.zip

[college man]

The engine internals look clean as a whistle.
Do you have oil pressure? sounds like valve
lash is loose/sloppy.

[Shafi]

I don’t have oil pressure gague only oil temp and water temp so I can’t tell for sure.
No warning lights on though. How can I check if have good oil pressure?
Oil level is right.
What do you mean by valve lash? Valve piston or half cone?
I tried pushing down on the valves pistons under the cams with something and they were tight/pushed back up.
How can I tell which is loose if any?

Here’s a video of it:

[video]http://youtu.be/68URV_xa4X8[/video]

Thanks for your help 🙂

[Shafi]

By the way, some ppl suggested engine flush! Now I’ve read the posts regarding this, and I know the engine head is clean, and the carter/sump too cause I’ve taken it out, but I don’t know what the situation inside the block passages.
Should I do a flush before changing the oil this time if I’m going to take the sump out and clean the oil pump components as well?
What should I use for flush if yes? some suggested Kerosene, is that a good idea?

Thanks

[Gumpy Guss]

I’ve never seen anything quite like this, it looks like you might have hydraulic lifters on top of the valves? I say this because I don’t see any valve adjustments or shims. So maybe one of those pistons under the cams is stuck. The usual symptom is that some of the time, when you start it up, there will be that tick tocking noise, and then it goes away, usually suddenly, in a few minutes. You see if the engine stops with the peak of the cam pressing down on the lifter, the lifter will drain down while the engine is stopped, then it’s supposed to fill up with oil in the first few revolutions on the next startup, but sometimes the internal piston gets stuck down for a while and then suddenly frees up. If the engine stops NOT at the cam peak, the piston won’t be pushed down and the engine will run fine at next startup. So it seems like you have these exact symptoms. The cure is to use a screwdriver or stethoscope to pinpoint which lifter or lifters is the noisiest, carefully remove the camshafts, carefully inspect and clean the lifters, inside and out, especially the most suspect ones.

[Bill]

It has to be something in the valve train as from listening the noise frequency is half of the crankshaft speed. Better have another look inside. There has to be something messed up in there.

[college man]

[quote=”WRC-RUSH” post=76204]I don’t have oil pressure gague only oil temp and water temp so I can’t tell for sure.
No warning lights on though. How can I check if have good oil pressure?
Oil level is right.
What do you mean by valve lash? Valve piston or half cone?
I tried pushing down on the valves pistons under the cams with something and they were tight/pushed back up.
How can I tell which is loose if any?

Here’s a video of it:

[video]http://youtu.be/68URV_xa4X8[/video]

Thanks for your help :)[/quote]

valve lash adjustment. something wrong with posting 🙁

[Gumpy Guss]

When the engine is knocking, shut it off and check the gap between the low part of each cam and the cam follower or piston. It should be very small, like close to zero. Each piston has a little Spring which should reduce the gap to Zero . You will have to crank the engine a few times to get all the cams off their high points. You will probably find one or two with a gap.

[Author]

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