2012 Ford 3.5L Turbo with Odd Noise on Deceleration — *SOLVED
Hey DN members,
We've got this vehicle and I'd like to see if anyone has some insight they might be able to share. This vehicle was at another repair shop recently and had the passenger side exhaust manifold resealed to solve an exhaust leak. Since that repair was done, the customer states that there's a strange honking noise whenever they lift on the throttle. We've isolated the sound to the right side and from what we can see, there is a reversal of airflow in the turbo inlet pipe when this noise occurs. We performed a non-scientific paper test to illustrate this airflow reversal and would like some input on where we might look next.
From what we can see, everything appears to be connected properly. Any suggestions are appreciated.
EDIT — 3/15/19 - Problem solved, see the resolution report below.
Scott have you verified that the rod on the turbo will move? it may be stuck in place not allowing he wastegate to open?
Hi Matt, the waste gate is in the closed position and begins to move at approximately 5 psi and is fully open at 10 PSI. Thanks for the input!
OK we have seen several of these seize up and cause all sorts of issues. Just wanted to verify that it infact does move. Did you verify that the rod is actually attached? After that is all verified I'd look for a back pressure issue.
Yes, it's attached to the arm. Will keep you posted. Thanks!
Hi Matt, The back pressure test was negative. No excessive pressure observed. Have you run into this complaint before? Thanks!
You may have already performed this test in order to obtain the pressure reading you shared above, but there is a TSB I remember that states to use a coolant pressure tester to check the wastegate operation. Sounds like the wastegate is operating properly, but is it also holding pressure?
Thanks Ben, Yes we have the bulletin and have run through all the issues. Yes the wastegate holds pressure. Thanks for the input.
The turbocharger bypass valve is used to create a path from the high pressure compressor outlet to the low pressure compressor inlet. This path recirculates airflow to reduce turbocharger lag and prevent unwanted air rush noise from the turbocharger on heavy throttle releases. With this in mind compare operation of both turbo bypass valves. I would suspect the side making the noise is non
Following along with what Chris and Matt have said, this can definitely occur due to waste-gate failing to open. Turbocharger surging is a result of inconsistent or pulsing airflow to the compressor side of the turbo, think misfire or under-contributing cylinder, as well as not having proper waste-gate operation. This causes the air mass with the compressor wheel to become a large oscillating
Chris, We started looking at this last evening before we closed. When I arrived this AM I visited with the tech and mentioned that we might have a restriction on the right bank. I wanted to see if we had any FT data logs to compare one back over the other and we do not (yet). We're about to perform a back pressure check to see where that lands us and I'll keep you posted. Thanks for the
I'll be keeping an eye out for what you find once you drop the collector. The noise is definitely compressor surge and not waste-gate flutter; surge can only be caused by a combination of low air flow and high pressure. I find it strange that it occured after repairing an exhaust leak on the opposite bank, though perhaps the leak was masking the surge. Good luck and enjoy it; the strange ones
We dropped it and it didn't make a difference. Once it warmed up with a little penetrating oil around the O2 sensor it came out. We performed a back pressure test and it was negative. The exhaust leak repair was on the same side that is making noise. Sorry if I crossed that up.
You were spot on, I crossed up my reading. I'll have to do a little bit of reading on this one and see if I come up with anything useful. I've got a vague idea, just cant quite formulate it into a solid one yet.
Thanks Chris, We've removed the bypass hose from the inlet hose and the noise still occurs. I pulled the bypass hose off of the turbo and watched the valve operation and it appears to be functioning as designed. We're about to perform a back pressure test on that side to see what we have and will keep you posted. Thanks for the info.
if the turbo is held from startup (keep it from spinning maybe a pick in the compressor wheel?) does the noise still occur?
We took a shot at holding it and the first attempt failed and we decided to skip that step. The o2 sensor won't come out either so we're about to back off the collector pipe and retest. I'll keep you posted. Thanks!
The wave forms are from a 2012 F-150 3.5 Turbos, WPS500 in cylinder 1 and the WPS500 in bank 2 in cylinder 4 WOT snaps and the cats are not plugged. Ray
These wave forms are the GIFs from the PSD files The first one is CH A COP 1, CH B WPS500 in cyl 1 WOT snaps The second is CH A COP 4, bank 2, CH B WPS500 in cyl 4 WOT snaps Ray
Thanks Ray, Totally forgot we could have performed a back pressure test this way. Since we haven't tested the left side we may just perform this exercise to validate. Thanks for sharing those, I really appreciate it.
If you remove the oil filler cap does it still make the noise?
Hi Nick, we just tested that with no change. Thanks for the input.
It seems like after taking a gulp of air and the throttle closing the air is squeezing out somewhere. I wonder if a smoke test would show anything, You may have to adjust to a higher pressure for a turbo (if your smoke machine has that feature). This may allow you to reproduce the noise continuously, making it easier to find where it is coming from.
Thanks Nicholas, After looking deeper at the intercooler and hearing a few theories, there may be a pressure differential at the intercooler. We'll take a deeper dive tomorrow and keep everyone in the loop.
Hi Scott: I couldn't see the whole video due to some internet issues on my end. Your symptoms kind of remind me of the bad IACs from almost 20 years ago. Is there any chance that you have a weak PCV Valve spring? HTH, Guido
Hi Guido, Good thought, Nicholas above recommended removing the oil cap and retesting which we did and there was no change. We'll take a close look at that in the morning and see if there's any relationship. Just before everyone bailed out of here I was looking the system over and saw that the left bank feed the intercooler at the bottom and the right side is just up above that. The bottom
Hi Scott: Is the oil level high? If so, I believe there is a bulletin (I can't remember if it is a TSB or SSM.). Depending on the application, it will get new booster hoses, PCV Valve, etc. and a reflash. Edit: Also, since the spring is for backfire protection, pulling the oil cap won't necessarily prove it out. HTH, Guido
Oil level is right at the full mark. Also, saw your update about the oil cap, good thoughts and we'll revisit in the morning. Thanks!
Scott Not sure of flow schematic for boost air but is it possible after the short throttle increase with ensuing boost, that a restriction (possibly in intercooler) is allowing a pressure increase rather than flow through. Then when the throttle is lifted the restriction (pressure) back feeds and "squeezes" back (resulting in the noise). I don't have experience with this engine so I can't
Hi Mark, Great to hear from you. Excellent points, as I mentioned above, I noticed that the lower intercooler hose coming from the left bank has quite a bit of oil residue. Here's a crude drawing of the layout: I'm all for testing and validating, we'll take a look in the morning to see if there's a way to sample each side of the intercooler. Thanks for the input!
What were the results of inspecting/testing the R turbo by pass valve and associated control components
Hi Glenn, we pulled it out and inspected and compared it to a new unit. Everything looks good, We also removed the bypass hose at the turbo so we could observe operation and compared it to the drivers side and they both appear to behave the same. Thanks for the input, I really appreciate it.
This thing has 2 bypass valves. Id disable both and see what happens. (Sometimes the unexpected/unexplained is the problem,like a bad valve on the opposite bank.)
Good thoughts Rudy, however, are you proposing that we simply unplug the signal ports at both actuators? I'll see about performing this test and report back. Thanks for the input.
Hmmmm ,Id say pull the hoses off of them both first,if no change,Id probably still want to inspect the valve itself on the side where I think the noise is coming form.
Hi Scott, This may be completely different but these trucks like to warp the manifolds toward the back of the engine where the turbo mounts. If the previous repair did not include a new manifold or at least a resurface, it still may have an exhaust leak. I purchased some new manifolds for mine out of Canada. crpengineering.com/product/2011-2… The new design creates more airflow
Hi Mike, this isn't leaking exhaust anymore and a new manifold was installed. From what we can gather, the noise is coming from the reversal of airflow within the turbo inlet hose/pipe which results in this honking noise.
Is the noise heard from the fresh air intake side? I think that on a gas turbo engine there’s a momentary reverse flow when you close throttle. When I’ve chased whistles on diesel turbo systems, it’s usually a split hose on the CAC system.
Hi Rusty: Those (CAC) sound like a clogged exhaust if you're driving next to a Jersey barrier. Tis an unmistakable sound. Guido
Hi Rusty, Yes, if you watch the video you can see the back flow occurring on the right side. We've been all over this which I'll summarize in a response to my original post soon. Thanks for the input.
Update: We've performed numerous inspections on this system and have yet to find a solid solution. We examined this system top to bottom and then some! The Intercooler, piping, and connections were all disassembled and inspected. Nothing out of the ordinary was found. We also pulled the scope out to check the bypass valve solenoid operation and they both seem to be performing the same…
I would be inspecting all gaskets on removal first then if a new turbo is being installed what would it hurt to remove and inspect the bypass valve.
FIXED Hello everyone, I'm pleased to report that the vehicle anomaly has been solved. The problem: Waste Gate sealing. Looking at this image, you can see that the waste gate rod connections are adjusted to different positions. Thanks for all the help and I hope this adventure can help someone address a similar challenge in the future.
Congratulations on the find Scott, to you and your tech. That's awesome. Perseverance is one of the greatest tools. Thanks for keeping us updated, and the videos are an added bonus. That feeling of the find is why I got into repair and diagnostics.
Hi Scott: I'm glad that you got to the bottom of it. It was obvious once you touched the wastegate valve. I'm confused about the rod length comment though. Are you saying that someone changed the length of the rod on the original (for whatever reason)? Or are you saying that the replacement has a different length due to a change in design? Also, is the servo a different size between the
Hi Guido, We found that this vehicle returned to the shop that originally replaced the exhaust manifold more than once to address this noise complaint. We suspect that they may have adjusted the rod length. Both servos are the same. Those are not my knuckles, I just hold the camera, someone more skilled than I get's to do all the work!
Ford wants the turbo the oil supply filter replaced at the same time, see SSM 47662. I came up with part # BL3Z6L625F
Hi Glen: In …e someone wants to see it. static.nhtsa.gov/odi/tsbs/2018….pdf HTH, Guido
Thanks for the tip Glen, I’ll follow up with the guys on Monday to make sure that gets done.
Good stuff Scott. I'm glad to see I was in the right area with what I thought was a wastegate problem. I've seen several do similar issues with wastegate issues.
Thanks Matt, Yes, you asked early on if the wastegate actuator was working and not stuck closed Which we can see it was not. Have you run into the scenario we uncovered? I appreciate your feedback.
I have seen the 3 bolt gasket between the turbo and the manifold flipped and the bolts holes still lined up but it was blocking part of the hole between the turbo and manifold. I have also seen manifold bolts tightened but not to torque spec cause a weird sounding leak. They felt tight but just because of the oe stlye locknuts turning hard they weren’t tight enuff but the technician didn’t use a