FAQ: Boost Bypass Valve/Boost Control Solenoid Questions (No Boost)

ClubGP wrote:

quote:

ORIGINAL: seen97
So, if you think you can always watch for KR, I guess you be ok, since THAT is the primary use of the solenoid, it forces the BBV open when KR is present. Well, its not my engine.


Actually, it doesn't...

It will open the bypass for traction control, or if the PCM goes into abuse mode (calculated torque exceeds programmed limits) It will also force the bypass open in reverse... But it doesn't open the bypass just because of detected knock.

PRJ .

I just removed my solenoid and from what Paul said, it's not terribly important anyway. My tune pretty much negates half it's function and I don't ever hammer it in reverse. Screw the bugger - at least for now

Cody,

Most of the time the actuator holds the bypass valve open by throttle-body vacuum, what we used to call manifold vacuum: low load, high vacuum. As you apply more throttle, the vacuum drops and the actuator allows the bypass valve to close, giving you boost.

NOW - The other port is not for vacuum! It is for blower-pressure bled out of the manifold by the Boost Control Solenoid, which pushes the diaphragm back in the same direction that the inlet-vacuum was originally pulling it, thus increasing the bypass and lowering boost pressure...

What is the name of this part? It's located above the thermostat housing and is it supposed to be leaking any air? I have it circled in the picture.


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That is the BBV or Boost Bypass Valve and no it should not be leaking vacuum continuously.
If it is indeed leaking or hissing, check all the vacuum connections and make sure none of the hoses aren't leaking before replacing the valve.

Alright, thanks. Gonna go through vacuum hoses tonight. Already had to change one dry rotted one last night.

It's a good idea to replace ALL the vacuum hoses and start with new ones. Sometimes they will look OK but if you look real close you'll see the ends cracked slightly where they attach to any nipple.
I just drove my car to the auto parts store and had the guy come out and look at the hoses to be able to give me a certain amount of each size hose and I replaced them right there. Cost me less than $10.00 IIRC.
Sometimes it's hard to identify the diameter of the hoses if you don't work around the engines everyday.
I was lucky and I got a knowledgeable guy to set me up with what I needed.
All I brought with me was a sharp razor knife to cut the old ones off if they were stuck on the fittings and a pair of good wire cutters to cut the new hose to size.
It really doesn't take much hose to replace the ones you can get at.
Some of them end into factory reducers and if you have a leak or see a crack on one of them be careful with them and try and find the necessary fittings at the parts store so that you can somewhat duplicate the reducers and get a good tight fit.

The hoses are next, but the boost bypass is leaking air off to.

If you do find that you need a new BBV do a search on this site. There was some issue about finding new replacements, but I can't remember what it was exactly. It may have just been a cost issue, but then again my memory fails me at the moment.

I've been looking online, but haven't found one.

Did you search this site for some additional info.

There may be another name it is found under from GM or other vendors. As I mentioned, I remember the topic coming up a while back but don't remember the outcome.

It's in this database somewhere.

GM P/N is 89018120. Monsterparts has no listing. I found this though, has no pic, but the pricing is the same as what GM shows under the P/N.
http://www.gmpartsgiant.com/parts/gm-actuator-kit-89018120.html

Is that seriously an M112 Blower on that thing?!!!

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/what-is-the-part-number-of-the-bypass-valve-actuator-t5880.htm?highlight=boost+bypass+valve


Take a look at the LINK above for the BBV P/N and it can be had from www.monsterpartsonline.com for cheap. If you can afford to wait for it, otherwise order from your local dealer.

EDIT: Based on Abaddon's post, maybe it is no longer available from Monster. Sorry if I confused the matter. And I think the part identified in the link above is the electrical actuator or solenoid. That is the least expensive part which is attached to the same bracket as the BBV. This is why I couldn't remember clearly from before as it was a bit confusing as to what GM Parts actually calls it compared to what the FSM calls it.

Ok, thanks again.

Be careful, there are different P/N's for different year cars.
I would verify the part number by going to my local dealers parts dept and ask them to look up the number for me.
The local dealer in my neighborhood is good like that and I ask for a printout with the picture of the part and part number, then I can go on-line and try to find what I need.

I located a used one for about $30.00 a year or 2 ago when I needed one but there isn't a P/N on it.

EDIT: If you should find and confirm the correct P/N for the BBV will you post it for reference and addition to the P/N List.
Thanks,
Rick

I'd sure like to find a good one for my '96.
Without paying attention, I braced against it with my Right hand as I leaned into the engine compartment and broke it off it's base.
Then later I found the top came off it. Thank goodness the vacuum hoses held it in place so it wasn't lost.
In both cases I used JB Weld to put it back together.
It works, but looks like hell.
Hard to believe it's a difficult part to find, and costs that much new.

Sweepspear wrote:

I'd sure like to find a good one for my '96.
Without paying attention, I braced against it with my Right hand as I leaned into the engine compartment and broke it off it's base.
Then later I found the top came off it. Thank goodness the vacuum hoses held it in place so it wasn't lost.
In both cases I used JB Weld to put it back together.
It works, but looks like hell.
Hard to believe it's a difficult part to find, and costs that much new.

It must be that the part is unique to the Riv or maybe very few models, which we know drives up the price and makes used hard to find.
I don't know if the P/N is Riv only, as I'm still confused as to what the correct P/N's are for each year Riv.
I wish one of us worked at a GM dealership and could do the research for the P/N's for all years and we could then post it in the P/N List that is on here.
Currently that list shows the Actuator which I believe is the electric solenoid part, yet it confuses things by also calling it the boost bypass valve. But after looking up that P/N on Monster Parts it shows a cost of less than $30.00 and we know the vacuum canister BBV is much more than that.
I would like to solve this one once and for all.
Next time I have to go to the Dealer for a part I'll try and remember to ask the counter guy to look up all years for me and get correct GM P/N's and current cost and availability.
But maybe someone else has that capability also.

I found used, removed from a 1998 Riv, about 2 years ago on Ebay IIRC for $30.00 shipped. Saved the Paypal receipt but there is no P/N visible on the unit itself.

ZZP has one but don't know if it's proper for our cars. What's a good test to see if this is actually bad?

J. Chris Davis wrote:

ZZP has one but don't know if it's proper for our cars. What's a good test to see if this is actually bad?

The unit has a vacuum controlled bladder in the middle of it. If you suck from the top port you should be able to pull the linkage arm up and hold it there.
It can be done by mouth or with a vacuum pump. If you do it by mouth, just hold your tongue over the upper port once you have pulled it in all the way and it should stay there.

If you can't pull it in due to a leak it is obviously bad or if it doesn't hold itself up after blocking the port then it is bad.

You can try this with the valve still attached to the SC and use a longer length of new vacuum tubing and draw the air by mouth. (If you don't have a vacuum pump)

I doubt very much that the one ZZP has is the correct one for the RIV. The vacuum ports may be orientated the wrong way and the mounting bracket could be wrong. That is why I believe the particular one that is on the Riv, fit's the Riv and not any other models or a minimum of other vehicles. The vacuum canister may be the same and do the same thing but the vacuum port orientation and the way the bracket is made may be unique to the Riv.

Ok, thanks. I'm gonna try that test when I get home tonight.

Sweepspear wrote:

I'd sure like to find a good one for my '96.
Without paying attention, I braced against it with my Right hand as I leaned into the engine compartment and broke it off it's base.
Then later I found the top came off it. Thank goodness the vacuum hoses held it in place so it wasn't lost.
In both cases I used JB Weld to put it back together.
It works, but looks like hell.
Hard to believe it's a difficult part to find, and costs that much new.

The P/N 89018120 that I listed is the same for '96-'99.
P/N 12480246 is for '95.

Thankfully I don't have a '95, cause that part (from GM) lists for $440.56, but available from MonsterParts for $289

I hope mine isnt bad, but I'll find that out tonight. Didn't expect this small part to be so much money.

Abaddon wrote:

GM P/N is 89018120. Monsterparts has no listing. I found this though, has no pic, but the pricing is the same as what GM shows under the P/N.
http://www.gmpartsgiant.com/parts/gm-actuator-kit-89018120.html

Is that seriously an M112 Blower on that thing?!!!

Monster Parts has that part number listed for $157.84
Need to enter P/N only and Buick to get the listing without a pic.

That explains it. Thanks Rick.

At those prices, I would see if I could find used at Morads or Ebay or any local junkyard.

As I said, I replaced mine almost 2 years ago with good used for about $30.00. Maybe I just got lucky, IDK.

The Link I put up on the previous page was when Nate needed one back in July of last year. He found one at Morads but I'm not sure if he went with used or new. But he posted the correct P/N for the BBV when we were posting the P/N for the switch or solenoid or whatever it's called. The electrical part of the unit.
The used one I got had both electrical and vacuum part still attached to the OEM bracket.

Abaddon wrote:

Is that seriously an M112 Blower on that thing?!!!

No, he posted a non-Riv photo... (Bad boy! )

Notice the 'wrong' parts mounted to the passenger-side strut-tower?