I recently had my truck in the shop for no boost control. So they replace the turbo wastegate assembly. All new,,$$$$$ Still no boost control. what a waste of money. What is going on. If I kick down on the highway from OD. It buries the needle way past 20 lbs. If I do WOT from a role the boost keeps rising till I let off. I am studying my manual and refuse to give the truck back to them so they can tell me everything is fine. I dont have the tools yet but if anyone has advice please.
No boost control??
- Thread starter luthier_1
- Start date
I didnt do anything. The truck is always stock. The new wastegate parts are doing the same as the old. I hope the ecm isnt crap. everything is new. The acuator ,the solenoid and I even think the turbo is new. I am not complaining about having new parts but holy cow. What I thought was funny is I asked how often he repairs our trucks and he said all the time. I am the only one in a 50 mile radius. The warrantee paid so.
Syclone#1992
SyTy.net Moderator
IMO you should have went with an external wastegate and regulator or aftermarket set up instead of paying for the new stock stuff.
Syclone#1992
SyTy.net Moderator
Missed that part.
InvisiBill
Active member
bdubb said:
For once he's not being an ass, so listen...
If it has a modified exhaust, the turbo faces less backpressure, so the undersized wastegate becomes even less effective.
If you're reading the stock gauge, don't. Mine's pretty close overall, but just today it was maxed out when I was only at 10psi in reality.
When you unplug the wastegate solenoid's electical connector, it won't modify the boost signal at all. Like that it should get base boost, around 8-10psi.
Probably not an issue with new parts, but if the arm doesn't move... well... it's not going to work right.
If it's not adjusted properly, your boost will be wacky. I think this is even more of an issue if everything was just replaced. There are details around somewhere, but I can't find them. You want the arm to overlap by 1/2 to 7/8 though, by the service manual.
ghettosled
SYTY SUPERSTORE
check to make sure both vacuum lines are connected properly to the wg selenoid. If there are any tears, cracks, etc it could affect boost control.
I would try uplugging your selenoid if the lines look fine. Perhaps the rod is too tight, and not adjusted properly on the actuator?
Also is it possible your cat is gutted, and looks factory from the outside?
I would try uplugging your selenoid if the lines look fine. Perhaps the rod is too tight, and not adjusted properly on the actuator?
Also is it possible your cat is gutted, and looks factory from the outside?
hey bdubb
hey bdubb
Are you an idiot. This has been may daily driver forever,... Dont tell me to sell what gets me to work because you think it is some sort of dragster . Fucking moron. every part is new. I just hope it isnt the computer. But I have a life and wish GM dealers were competent enough to keep my truck working.. My only worry is when I want to pass someone on the highway.I dont leave a piston behind. At least I can say my truck is treated the way it was intended. Replacing the turbo and wastegate was a waste.
hey bdubb
Are you an idiot. This has been may daily driver forever,... Dont tell me to sell what gets me to work because you think it is some sort of dragster . Fucking moron. every part is new. I just hope it isnt the computer. But I have a life and wish GM dealers were competent enough to keep my truck working.. My only worry is when I want to pass someone on the highway.I dont leave a piston behind. At least I can say my truck is treated the way it was intended. Replacing the turbo and wastegate was a waste.
Wow! None of the 'turbo-brains' asked the basic question ... What part is telling you that you have an 'overboost' problem?
BTW, the stock gauge is an electronic unit that taps into the MAP sensor signal line. A problem with the MAP sensor or its wiring will give a 'false' high boost reading. (A wrong replacement MAP sensor calibrated for a non-turbo engine will also do this.)
Step 1: Ask the shop that replaced all the parts if they used a mechanical compound (vacuum/pressure) gauge to verify the problem.
If not, have this done or check it yourself. For this, you will need to pick up a compound gauge, vacuum tee, and extra vacuum line from your local auto parts store. Tee in at the manifold connection going to the MAP.
Post your results and if needed, I'll suggest step 2.
BTW, the stock gauge is an electronic unit that taps into the MAP sensor signal line. A problem with the MAP sensor or its wiring will give a 'false' high boost reading. (A wrong replacement MAP sensor calibrated for a non-turbo engine will also do this.)
Step 1: Ask the shop that replaced all the parts if they used a mechanical compound (vacuum/pressure) gauge to verify the problem.
If not, have this done or check it yourself. For this, you will need to pick up a compound gauge, vacuum tee, and extra vacuum line from your local auto parts store. Tee in at the manifold connection going to the MAP.
Post your results and if needed, I'll suggest step 2.
InvisiBill
Active member
BW asked what gauge he was looking at, which is about as close as you can get to asking that, without using those words.
Since you say the needle is buried past 20psi, I'm going to guess it's an aftermarket gauge, so the reading should be accurate.
If you answer the questions asked, it will be much easier to help you...
Since you say the needle is buried past 20psi, I'm going to guess it's an aftermarket gauge, so the reading should be accurate.
If you answer the questions asked, it will be much easier to help you...
sorry Bdubb
sorry Bdubb
bdubb Sorry about exploding. I didnt see my Ty for 3 months because of those Mechanics. I have an after market boost gauge . Right now thanks to them 1st to 2nd shift is nonexistent with any significant throttle,... The boost creeks all the time and with kickdown it pegs. I dont have the tools and time to do these things myself. I am aware of how things work but I cant fix it myself right now. Maybe I should sell it. I just wish they still made these trucks. I would trade it for a new one.
Thanks all. It works fine for normal driving. I just cant surprise ricers right now.
And thanks for the private message. I will keep that in mind.
sorry Bdubb
bdubb Sorry about exploding. I didnt see my Ty for 3 months because of those Mechanics. I have an after market boost gauge . Right now thanks to them 1st to 2nd shift is nonexistent with any significant throttle,... The boost creeks all the time and with kickdown it pegs. I dont have the tools and time to do these things myself. I am aware of how things work but I cant fix it myself right now. Maybe I should sell it. I just wish they still made these trucks. I would trade it for a new one.
Thanks all. It works fine for normal driving. I just cant surprise ricers right now.
And thanks for the private message. I will keep that in mind.
Wow! Three months is too much time to repair anything. I take it this is not a GMC dealer?
Step 2: As ghettosled suggested, unplug the connector from the solenoid that's located at the top front of the turbo (no tools and very little time needed).
Post your results. If that doesn't reduce the overboost, I'll post further instructions to help you disconnect the wastegate and tie it open. (Hopefully, also not requiring much for tools and time.)
The idea here, is to eliminate the overboost so you can still drive the truck without fear of blowing the engine. If any of the basic checks leads to a diagnosis, maybe you can fix it yourself (then tell the shop that worked on it 'where to go').
Step 2: As ghettosled suggested, unplug the connector from the solenoid that's located at the top front of the turbo (no tools and very little time needed).
Post your results. If that doesn't reduce the overboost, I'll post further instructions to help you disconnect the wastegate and tie it open. (Hopefully, also not requiring much for tools and time.)
The idea here, is to eliminate the overboost so you can still drive the truck without fear of blowing the engine. If any of the basic checks leads to a diagnosis, maybe you can fix it yourself (then tell the shop that worked on it 'where to go').
JSM
Active member
Do this.
You may also check for a sticky flapper. It will require you to pull a pin, do you have time for that?
If you don't have time to trouble shoot even the basic stuff on this truck, you will become very flusterated. Unless you find a mechanic who also owns a syty, you are screwed.
The list will help you, just don't jump off the handle and get angry at the suggestions.