[Sanhino]

I've been trying to diagnose my compressor surge and sporadic BOV solenoid working for a few months now and am completely stumped. I have a thread on the non-turbo page since quite frankly I didn't even realize there was a turbo specific page.. if you want to see me slowly pulling my hair out and spending unnecessary money trying to diagnose it see below.

P2261 and HKS SSQV Flutter

I'm legitimately pissed - this one is doing the same thing and I'm back to the code so I either have the worst luck or it's something I'm doing wrong. Do you need to put any sort of lubricant into it or maybe because I have it laid horizontally? I am all out of ideas at this point other than...

www.veloster.org

Long story short I have an authentic HKS SSQV BOV (only a month or two old), correctly installed, and am on my second MAC BOV solenoid, with new vacuum lines and the lines are new, not cracked, and are correctly run.

The latest and greatest is it sometimes actuates and sometimes doesn't. For example on my drive home from work today it was working normally (love the PSSSSSSH sound) when I first started driving, then seemingly randomly decided to not work and it's clearly compressor surge, and then about a mile or two it started working again. I absolutely have no clue at this point what the issue is. I'm thinking it may be something electrical in the harness since it is able to work again but I have no clue since it's a new solenoid with a new connection. I'm just at a loss as to what it can be.

 

[DedMemBRaiNE]

My first thought is that there are a lot of fakes out there and even though some of the vendors claim to sell a real product, if it’s not on the HKS website as being an authorized distributor I personally don’t trust it... For example, I bought a fake one from Turbosocks back when I actually wasted money with vendors, it was fake and gave me surge. I sold it and bought one from an authorized company on their site and I’ve been good for years now...

 

[Sanhino]

So this one I have now was a replacement to one that was on the car when I bought about 2-3 years ago with no issues until the surge issue starting something like 4 months ago. It's definitely crustier but maybe it's worth it to swap back to the original and see but the new BOV worked fine for about 3 months running a SXTH Element solenoid and then it entirely stopped working for about a week until I spliced a new solenoid into the one from SXTH. It worked fine for 10-ish days and that's when it started acting sporadically.

 

[Sanhino]

There may be a development -I pulled off the replacement BOV and put back the original and was still getting compressor surge, so then with the car still running I popped the hood pulled the vacuum line off and swapped back to the replacement BOV. At this point my girlfriend came out and was asking what the issue was and I was explaining through it with her and while I was doing it I was plugging in and unplugging the connection to the solenoid (just because I like to have things to do with my hands when I'm explaining things).

Sensitive content, not recommended for those under 18 Show Content

With the solenoid unplugged there was vacuum coming from the line to the BOV and then when I plugged it in the vacuum from the BOV line stopped. This happened maybe 4 or 5 times and then all of a sudden when I was plugging it in and unplugging it was continually pulling a vacuum. Isn't it supposed to always pull a vacuum when the car is running? Also the metal clip that holds these two connections was just not on but I do have it (just wasn't on for the picture).

So then I put my intake back on and took it for a spin but I was still getting compressor surge, and pulled the BOV line back off and it was still pulling a vacuum.

 

[Sanhino]

I think over the weekend I'm going to try the swordfish P2261 fix where you install a vacuum reservoir but I'm not too hopeful. It looks like I can get one for <$20 at an auto parts store and just throw a tee onto the line.. worth a shot I guess

 

[trdtoy]

Issue in most cases is improper install and/or setup. Many say install is proper and truly do not know what that means.

So, show some detailed pics or video of the setup and we can go from there.

 

[Sanhino]

Here's the current setup (minus the air filter) realizing that things are temporary since I've been messing with it recently. From what I know the lines are routed correctly from the MAC BOV SXTH instructions. It's new 4mm vacuum hoses that are tight on all the fittings. This is the setup that works sporadically without any apparent changes in between it working and not.

 

[Sanhino]

I ran out to AutoZone and got a Dorman vacuum canister Part #47076 and did the stingray p2261 fix. He did a great job drawing out the visual below.

P2261 Mechanical Fix (Vacuum Reservoir for Aftermarket BOV)

OK, so I'm not going to write up some long winded explanation as to what the p2261 CEL is, but lets just say that its caused by the failure of aftermarket BOVs not opening for the duration that our ECS want. I installed TurboSocks SSQV (style) BOV at the same time that installed my 845 FMIC...

www.velosterturbo.org

I took it around the block and it sounds normal but I'm slightly skeptical since it's been sometimes working and sometimes not but I'll keep updating. I need to make a mount for the canister and make things more permanent if this actually fixed it.

 

[trdtoy]

Routing is correct.

Issue could be the hose. The thin wall hose you're using may be collapsed some or kink under vacuum causing issues. Replace it regardless to better hose.

Also possible is the BOV being bad, fake, or simply poorly or not maintained.

BOV flange can also be an issue.

Check for leaks in the system boost and vacuum to be 100%

The MAC valves and vacuum tanks are a bandaid fix due to something not functioning properly that's setup wrong to start or malfunctioning. They just allow for larger margin of error. The solenoid does have some true benefits on some cars but for the avg owner modding the car they're a waste of $.

 

[Sanhino]

It's been a few days and no significant change in the system either way. I also got 6mm hose and replaced the 4mm I was using and used hose clamps on all connections. Just this afternoon I put it in but didn't connect in the vacuum canister to see if it would work without it and it did for a few pulls but then went back to not working. All connections from what I can tell are tight with no leaks so I'm still just as baffled as before.

 

[trdtoy]

Both sizes are too big and probably not proper hose either. And who know what the other issues may be. You really need to vacuum and pressure check things to see what's going on, check solenoid operation, and be sure the BOV is well maintained and works properly.

 

[Sanhino]

If I remember correctly when the BOV came in the installation paperwork said specifically to use either 4mm or 6mm tubing which is why I specifically used those sizes, and when I removed the tubing when I got home before putting in the 6mm hoses there was still vacuum in the system from the canister so I know at least the previous 4mm tubing held vacuum and it still didn't operate correctly. Do you know if when you shut down the vehicle if there should be residual vacuum if there's a canister attached? If not then maybe I can trace it back to whatever is stopping it from releasing when the car's off or something.

 

[trdtoy]

Issue is bov barb and solenoid barb can be different sizes. This is a no no. Then you have most hose used will kink or collapse or blow out larger under heavy vacuum or boost. This has to be tested.

Solenoid has to be tested for leaks and function.

BOV has to be tested for leaks and function as well.

Then everything has to be installed correctly and be in spec to components operating in the system.

Just holding vacuum in general means 0
BOV working occasionally means 0
Hose size in general from directions means 0

These are universal BOV that have general directions and setup. Cars tbat operate electronically operate under specific parameters unlike older cars when these universal type valve came out. So it requires the installer knowing more about how everything operates for things to work as intended. So what we have is avg Joe knows 0 buys valve because it sounds cool and install by general directions and has issues. Throws $ at various hoses, solenoids, configurations, etc. And here we are. Happens too often.

 

[MrNicG]

Turbo surge isn’t necessarily caused by any one thing. Your solenoid could be working just fine. It could be that you are just genuinely moving more air than your engine can flow. Read more about turbo surging in general and look for other causes if you are confident the solenoid is connected properly.

 

[MrNicG]

What PSI, RPM, gear, etc is it at when it is surging? Unless you are getting surging in the stock boost range then I would suspect something other than the solenoid being erratic.

 

[Sanhino]

What PSI, RPM, gear, etc is it at when it is surging? Unless you are getting surging in the stock boost range then I would suspect something other than the solenoid being erratic.

When I get what I imagine is compressor surge it's after letting off throttle after accelerating to really any RPM in 2nd-6th gear under any load so 2K rpm or higher. Sometimes it happens in first when the RPM is higher but before I would rarely have the BOV release in 1st unless I was punching it.

As an update to the working / not working it had been working for a few days until it cut out on my way home from work.

When I parked I kept the car running and I listened for any vacuum leaks without touching or removing anything. I heard the slightest hiss from the solenoid side of the line which connects to the BOV, and that was the only potential leak I heard. I removed the line from the BOV side (air was still pulling through the line) to put my finger over the end to see if the sound would get louder to which it did slightly. I unplugged and lifted the solenoid to check to see if the barb had backed out a bit and that was still tight. I tightened the hose clamp and put my finger over the end where it would plug into the BOV (air was still pulling into the line) and I didn't hear a leak - so tightening the hose clamp solved that.

Then I plugged the solenoid back in (with the line to the BOV still removed from the BOV end) and immediately the air pulling from this line connecting the BOV to the solenoid immediately cut out. I unplugged the line and air started pulling back in, and rinse and repeat. I plugged and unplugged say 10 or 15 times and still the same - when it's got plugged in there's no air flowing from the solenoid to BOV, and when it's unplugged there's air flowing.

Thinking back to earlier when I was getting compressor surge - when I parked and undid the hose clamp from the BOV there was air flowing through it (with the solenoid still plugged in). So now I'm thinking there may be some shmoo inside the solenoid preventing it from closing fully - or there's not enough (or any) lubricant on the pin that slides to allow air to flow through - or seal it etc. I removed the front barb (connecting the solenoid to the manifold) and sprayed just a dab of WD40 inside to see if that would do anything - reassembled and checked to see if there was air pulling through the line connecting the BOV to the solenoid and there was no air flowing through with the solenoid plugged in, but again there was when it was unplugged. Again all of this was while the car was running.

I reclamped the line to the BOV, stuck my ear around and didn't hear any leaks, and took it for a spin around the block and everything was working correctly - the normal sounding PSSSH from the BOV.

So I'm thinking there's my discrepancy - if the solenoid doesn't seal when it's plugged in (and at idle there is vacuum between the solenoid and BOV) I get compressor surge if I was to drive it, and if the solenoid seals when it's plugged in (and at idle there isn't vacuum between the solenoid and BOV) it works the way it's supposed to. Does that make sense or sound right to anyone else?

Can anyone confirm with a working set-up that you are not supposed to have vacuum between the BOV and solenoid when the car is running and idling?

 

[Sanhino]

This also makes me think about my earlier post:

There may be a development -I pulled off the replacement BOV and put back the original and was still getting compressor surge, so then with the car still running I popped the hood pulled the vacuum line off and swapped back to the replacement BOV. At this point my girlfriend came out and was asking what the issue was and I was explaining through it with her and while I was doing it I was plugging in and unplugging the connection to the solenoid (just because I like to have things to do with my hands when I'm explaining things).

With the solenoid unplugged there was vacuum coming from the line to the BOV and then when I plugged it in the vacuum from the BOV line stopped. This happened maybe 4 or 5 times and then all of a sudden when I was plugging it in and unplugging it was continually pulling a vacuum. Isn't it supposed to always pull a vacuum when the car is running? Also the metal clip that holds these two connections was just not on but I do have it (just wasn't on for the picture).

So then I put my intake back on and took it for a spin but I was still getting compressor surge, and pulled the BOV line back off and it was still pulling a vacuum.

Except it basically happened opposite what happened today - in the pose when I kept plugging and unplugging the solenoid something might've stopped it from sealing correctly (small piece of grit, smooze, or whatever) and me mistakenly thinking that it was supposed to always have air pulling I re-connected everything at idle and drove it - it still didn't work correctly. Then when I parked again and pulled the line from the BOV it was still pulling air at vacuum - which makes me think the solenoid wasn't sealing correctly.

Now I'm thinking I was incorrect in the earlier post and it's not supposed to have vacuum between the solenoid and BOV at idle since when it does I get compressor surge, and when it doesn't (at least in my experience today) it works correctly.

 

[Sanhino]

After delving further into trying to figure out what the deal is I've pulled out the multimeter to see if the wiring itself is the issue. Still it's been working on and off with no vacuum leaks that I can tell of, and when it's not working correctly at idle there is constant vacuum in the line from the solenoid to the BOV (indicating the solenoid isn't closing).

Unplugging the solenoid one of the wires has about 12-14V and the other reads at about 0.02 - 0.6V. I don't know how the system works but I'm imagining that when it's powered the solenoid is supposed to be closed and when it's not powered it's opened since when it is working correctly there isn't vacuum between the solenoid and BOV and when it's not working there is vacuum. Therefore I'm imagining one wire is constant power and the other wire is what is what tells the solenoid to blip off and back on to trigger the BOV release. Obviously if I'm wrong please someone correct me.

I stripped off a small portion of my splice to the solenoid to see if power was actually getting through the connection to rule out that the connection was loose or bad and long story short the wires past the connection are getting power. I zip tied which one was power just so I didn't have to check again later on and when it's not working correctly there's still 12.5V in the power wire and about 0.06V in the second wire.

So from what I can tell again there's no vacuum leaks in the connections themselves, and there seems to be power getting to the solenoid so I'm thinking still it's either a failure inside the solenoid or the connections inside the solenoid itself are loose or something. Any thoughts?

 

[RPW00Mirage]

what is the part number on the mac?

https://www.macvalves.com/product/35-series/

 

[MrNicG]

A couple of notes for your troubleshooting. The solenoid is PWM, which means that it is not just open or closed. It sounds like you are thinking of the function like a relay, which is not quite how they work.
You can also test to see if the solenoid is closing by removing it from the car and checking the airflow at the ports. One should be normally closed and two should be normally open.
Turbo surging can occur for several reasons, not just the BOV not opening. If your wastegate is not actuating as expected, you will overboost too, which results in surging. You can also end up with surging when all of your components are working properly if you are just simply producing more airflow than your engine can take in. I have a pretty modified car and I will occasionally get turbo surge if I back off the throttle some after suddenly getting on it hard. The inertia of the turbo just tries to keep going. This is something I have been messing with for a few weeks now by way of tinkering with my JB4 settings to have the max boost taper off sooner. I can go out to my car in a little bit and check some of the things that you want verified.