Strange vibration noise

[Fogazi]

Hello, new to the forum. Loads of great advice here so thanks in advance.

I have a 2013 D40 ST 2013 Spanish built Navara.

I have this strange noise that I have recently noticed that I am sure is coming from the engine bay. It is a hard noise to describe but sort of a hum/vibrationy noise. It sounds like it is coming from the engine bay on the left hand side.

The noise only occurs when the car is at normal temps and I can pretty much replicate it when accelerating through 1900-2000 revs. Not at any other times. It is even more noticeable/louder when going up hill, so under more load and at extremes I can start to feel it vibrating. But only when accelerating through 1900-2000 rpm.

It is also a little smokey on take off and under load but not sure if that is related?

I have checked the engine bay over and cannot find anything out of the ordinary. At first I thought it may have been the air intake hose as the car was recently serviced and thought maybe they cracked/split the hose. There is a tiny mark/scratch but looks to only be the outer layer of the hose.

1 thing I did notice was that the inter-cooler hot side pipe that has those stupid clips(juniper clips I think someone called them) that are far inferior to a hose clamp IMO, the hose was sort of loose and has a lot of play in the connections. I pulled this hose off and notice that the turbo side o-ring had perished and fell out. I thought I had solved it!
This o-ring was impossible to source so I more or less welded the pipe back on with some high temp liquid gasket and let it cure for a day. Then took it for a test run and still had the same noise. I checked my repair and it was still firm and definitely not leaking air from there. I could observe the pipe ballooning as I revved the engine. The inter-cooler side of the hose is still wobbly but the o-ring is in tact and I'm thinking this is not the problem. About to bite the bullet and upgrade this regardless to an ally pipe and bugger off the stupid clips

I have also bought an EGR blanking plate and will fit that as soon as it arrives.

FYI my car has the newer YD25 boost/vacuum controller etc. Not the older style that I see many photos of in these forums. My boost actuator is horizontal, not vertical. I did try to observe the actuator moving at idle and didn't notice it moving, took of the vacuum line and sucked on it and it moved no worries.

One more thing is at idle, boost is at -0.4 or there about, gets up to 18 psi under throttle. I did read somewhere that maybe it shouldn't be at vacuum at idle?

Hopefully someone has some ideas... As I am almost stumped!

Again, thanks in advance.

 

[Fogazi]

I did just go and have a 2nd look at the boost controller.

It definitely isn't moving but I did notice when I start the engine, it sucks fully in. And when I unplug the controller, it releases fully and then goes all the way back in when I re-plug it in. Same happens when I take the vacuum line off and on. Is this normal?

Also there doesn't appear to be any exhaust or EGR leaks anywhere.

 

[KevinE]

I don't want to over simplify it, as it could be a lot more complicated, but.....

I had a similar issue in my D22 YD25 earlier this year & I thought I had a turbo issue, because that's what it sounded like. Long story short, there was a missing bolt in the cowling above the intercooler, allowing the metal surface of the cowling to vibrate against the metal surface of the intercooler. It only happened in the rev range you mention, unless I upped the revs while driving & then it would happen again.

I don't believe that your intercooler is the same as mine? but I'd start looking for a missing bolt somewhere that's allowing 2 metal surfaces to vibrate together & keep your fingers crossed that is what it is.

The noise sounded very concerning until I found the problem.

 

[Old.Tony]

It's also possibly a gasket in the turbo->exhaust manifold joint. Mine started to deteriorate and when the right pressure built up, it sounded like a reed instrument being played (very badly, I might add).

If your actuator is sucking in fully and staying there, it's holding the vanes open all the time. This would imply that the BCS is faulty and has failed in the "open" position.

Test the theory: connect the vac hose that comes across the top of the motor directly to the actuator and see what it does. If its behaviour is identical, your BCS is stuck open. Replacing it (either with another BCS or with a Tilix or Dawes valve) are the fixes.

 

[KevinE]

Take two (I managed to delete my 1st go at replying lol)

Ironically it happened again after I posted yesterday! Same noise in the same rev range.

The bolts in the intercooler cowling are all present this time.

Just washed the car & discovered that the top mount on the passenger side of the front bumper had come very slightly adrift (it wobbled as I washed it)

No metal surfaces involved this time, only plastic & it made the same noise!

Popped it back in & all fixed!

 

[Fogazi]

Here are some photos of my engine bay with cowling removed, just so you know our layouts are slightly different:


https://imgur.com/gallery/vL5BdtK



I have searched high and low for anything loose or missing to no avail.

I did your actuator test Tony and it did the same, sucked straight in when I swapped the lines. I then returned it to normal and got the wife to rev the engine a bit whilst I observed the actuator. At about 1500rpm the actuator went full out, then obviously back in when she let her foot off.

I am certain that it doesn't move at all when idling.

I also took it for a short drive with the vacuum line disconnected from the actuator and the sound/vibration was still present.


I also did just take a squizz at the dipstick and seems over full, granted the engine is hot at the moment but could that in anyway be causing something? I'm going to confirm level again when cold and drain/change if necessary. Noting this just came out of a service where they changed the oil....

 

[Fogazi]

It wasn't the oil. It certainly was over full though.

 

[Fogazi]

Well, I finally figured it out. Due to covid19 I kinda had to deal with it for a while for reasons.

Anyway, it was the coolant lines that run to the heater matrix behind the passenger dash. The matrix and lines had a bit of play in them and seemingly once hot enough it began to vibrate/resonate at the 1500-2000 RPM range.
There is a little cover over the connections that has 3 screws holding it on, I took this off and added a bit of high density foam to the foam already there to try and add a bit of compression to the matrix/coolant lines connection. Hopefully that foam can withstand the temps.

So far so good and I am back to vibration free driving, now just to re-assemble the dash!

At lease now I know how to completely disassemble the dash for any future wiring requirements etc!

Cheer

 

[Sotiris85]

Well, I finally figured it out. Due to covid19 I kinda had to deal with it for a while for reasons.

Anyway, it was the coolant lines that run to the heater matrix behind the passenger dash. The matrix and lines had a bit of play in them and seemingly once hot enough it began to vibrate/resonate at the 1500-2000 RPM range.
There is a little cover over the connections that has 3 screws holding it on, I took this off and added a bit of high density foam to the foam already there to try and add a bit of compression to the matrix/coolant lines connection. Hopefully that foam can withstand the temps.

So far so good and I am back to vibration free driving, now just to re-assemble the dash!

At lease now I know how to completely disassemble the dash for any future wiring requirements etc!

Cheer

Can u get me a pic how it looks. Seem to have the same problem

 

[Hazlow]

Also interested in a pic if possible! think mines the same

 

[Tms40]

Did you have to take whole dash out to locate them or was that done trying to find the problem. Could you access it by removing glove box like replacing cabin filters? Mine seems to have developed a similar noise but only after my mechanic replaced cabin filters