Can a failing variocam make a noise - 986 Forum - The Community for Porsche Boxster & Cayman Owners

itsnotanova · 10-20-2016, 01:20 AM

I have a noise I'm trying to track down and haven't had any luck finding out what is causing it. It only happens at idle after the car has warmed up and goes away above 1000rpm. It goes away instantly if you hit the gas. Sometimes the noise comes back right away and sometimes the noise kind of creeps in after a few minutes. To me it sounds like a metallic scrapping noise. I pulled the pan and oil filter and there's no metal in the oil, but there was about 5-6 little green particles in the oil filter. That's a sign the vario cam unit is going out. I don't have a way to measure cam deviation but the green particles are a sure sign of a bad adjuster. I guess my question is has anyone with a bad variocam adjuster also had a noise go along with it? I'm wondering if I have one or two problems?

I'll post a video of my car running as soon as it gets done downloading.

particlewave · 10-20-2016, 01:30 AM

I can't help with the noise as I've never heard an engine with failing variocam, but if you need to borrow my Durametric to check deviations, etc., let me know.

You'll need a laptop and the latest software installed.

itsnotanova · 10-20-2016, 01:50 AM

Thanks but I'll be pulling the motor in the next day or two. I have a 3.2 going back in until I can get time and money to fix the 3.4. The engine runs great and if I were deaf I wouldn't know a thing was wrong

Smallblock454 · 10-20-2016, 03:50 AM

Hello Woody,

the variocam system kicks in at much higher rpms than 1.000. So i think the noise must have another cause.

At 1.000 rpm and below maybe it's a bad main chain tensioner. Means that the timing chains are too loose. That makes a metallic scrapping noise. There are 3 main chain tensioners. Sometimes one or more fail.

Could you describe the noise a bit more detailed. Or better provide us with a video and the sound?

Regards, Markus

itsnotanova · 10-20-2016, 05:51 AM

I can't get the video to download from my phone onto Youtube or Photobucket. I can get it to download on my business facebook page. https://www.facebook.com/Woodys-Parts-LLC-866155110110548/
The motor only has 40,000 miles. In the video it has more of a tapping noise than what you hear in person.

Smallblock454 · 10-20-2016, 06:29 AM

Hello Woody,

thanks for the video.

Noise seems to be louder on the right side of the car. I would say it comes from the valvetrain.

Sounds like this could be a hydraulic lifter problem. If it doesn't go away if the engine is warmed up and you've changed your engine oil lately you should go into that.

There are 2 ways an hydraulic lifter can fail. 1 it's worn mechanically. 2 it's oil lines are clogged. In second case you could try an engine flush. There are special products that clean the engine internally. You have to put them in the engine oil, let the engine idle for about 1 minute and than have to change the complete engine oil. Sometimes this helps to get hydraulic lifters back to work, but no guarantee. A proper repair would be to pull the engine and inspect the valve train and hydraulic lifters.

Hope that helps…

Regards, Markus

itsnotanova · 10-20-2016, 06:44 AM

Thanks Markus, The noise is louder on the back and top of the motor. Almost where the starter is. You can barely hear it from underneath. I'm shelving the motor until I can get a look at it internally.

Smallblock454 · 10-20-2016, 07:18 AM

Quote:

Originally Posted by itsnotanova

Thanks Markus, The noise is louder on the back and top of the motor. Almost where the starter is. You can barely hear it from underneath. I'm shelving the motor until I can get a look at it internally.

If the noise is louder on the top of the engine, than it might be an intake valve / intake hydraulic lifter, because they are on the upper side of the cylinder head.

You could use a long iron bar / screwdriver and try to locate the noise by pressing it on the cylinder head and your ear. Will be very difficult to reach the cylinder head from the top. But in general it's a good method to locate noises, because sometimes you have internal and external reflections.

Regards, Markus

Gelbster · 10-20-2016, 08:07 AM

Electronic Engine Ear to pinpoint the source of the noise would save much speculation. And perhaps save an R&R of the engine?
https://www.amazon.com/Steelman-65001-STEELMAN-EngineEAR-Stethoscope/dp/B00FAC38QG

first boxster · 10-20-2016, 08:20 PM

I have one of those units, and they work great.

Meir · 10-21-2016, 06:59 AM

much cheaper does the same job
Mechanic's Stethoscope

Gelbster · 10-21-2016, 07:22 AM

You could use a long screwdriver
This may change your mind ?
https://www.youtube.com/watch?v=rp9kS4wwviY

bwdz · 10-21-2016, 12:58 PM

If you can get near the problem with a stethoscope the next thing to do would be the cutout test. To see if it is rod or piston related you need to kill spark on that cylinder and see if it makes the noise go away. Getting kind of old school here but that is what we used to do, pull spark plug wires on individual cylinders while looking for a knock or tick. If the noise goes away you have a problem in the bottom end of the engine and should pull it out, if not I would pop the valve covers off and see what's going on.

itsnotanova · 10-21-2016, 01:13 PM

Thanks everyone for the suggestions. I've already pulled the motor and started switching everything from the 3.4 to the 3.2 that will temporarily replace it. I'm thinking Markus is right about it being a lifter though.

Smallblock454 · 10-21-2016, 02:13 PM

There is one more aspect i have forgotten to tell. Oil thinning. This can for example be caused by old not 100% working thermostates and short distance runs. If the engine didn't really get warmed up, because the thermostate doesn't work proper the ECU let the engine run too fat. That means the oil is thinned with fuel. And this sometimes can cause hydraulic lifters to become really loud, because the viscosity of the engine oil gets wrong.

But because Woody did mention he had changed the engine oil lately (pulled the oil filter and pan) i didn't mention that.

Regards, Markus