Wastegate failure?
Wastegate failure? So I have an on3 wastgate (comes with the kit I think 44mm), and when the car was tuned, it ran off spring pressure and made 8-10 psi consistently, about 2 weeks later its now up to 15-20psi. What could cause it to be overboosting now when it was fine before? Im gonna take it apart I guess to inspect/clean it, are there any mods needed on that gate to work properly? Sometimes it does stay at 8-10, but most of the time its well over that now. Its getting vaccum from the intake itself, I dont understand why it could be inconsistent? Should I just get it warrantied or just buy something better? Seems pretty simple so a Chinese part would be okay there?
What would cause it to stick after it was fine? Some kind of machining trash in there or just wear? Im not rulin out gettig a quality piece just wondering why it used to work and doesnt now.
If i where you i would just take it off and look first.
Last edited by oscs; Jul 21, 2014 at 11:30 PM.
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Verdad Gallardo I took it apart yesterday, the diaphragm was fine, no debris in there that I could find. The stem had some greenish yellowish grease on it, removed all that, polished the valve stem and lightly sanded the guide. I could see some wear on the stem and it was somewhat gritty moving it in and out, after polishing its much smoother now. I reinstalled dry, I was worried that lube there would dry out and cause sticking again. If this doesnt fix it I'll just get a quality gate.
I took it apart yesterday, the diaphragm was fine, no debris in there that I could find. The stem had some greenish yellowish grease on it, removed all that, polished the valve stem and lightly sanded the guide. I could see some wear on the stem and it was somewhat gritty moving it in and out, after polishing its much smoother now. I reinstalled dry, I was worried that lube there would dry out and cause sticking again. If this doesnt fix it I'll just get a quality gate.
Well, in the trash goes the on3 gate! Still overboosts, and I'm not gonna pawn it off on someone else to blow a motor. Thankfully mine took it like a champ. So Tial, JGS, Turbomart, any other good ones?
On The Tree
Joined: Feb 2014
Posts: 102
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If you have a hole in your line between the waste gate and the intake it will cause that. Some boost controllers work by bleeding off air from that line to increase the boost pressure required to open the waste gate. I would verify that your line is in good condition and has no bad connections before getting a new waste gate.
I have a precision 46mm wastegate on my car and have no complaints. Comes with all sorts of springs, it's priced right, and comes from a well known company. The kit I bought had a flange for a 44mm tial on it and this 46mm gate went right in place without having to modify the pipes. Go on ebay and type in "Precision PW46".
Because there are just as many failures as there are success stories. Also when you have a wastegate sticking issue with no boost controller there is only so many things it can possibly be.
I bench test gates using regulated air or a mityvac style hand pump with a gauge in these cases. Simply pump slowly to the desired spring pressure and watch it open. Same thing for vac on a BOV. Just attach a short piece of vac line from pump to gate. Let me know if you need pics or anything.
As mentioned above I have had gates overboost when the reference line was compromised.
Is that line to the gate split between multiple sources? In my case it was going to a fuel reg and leaking at that connection. So the gates would see less pressure and overboost.
I forgot to mention if you dont wan to do it on the bench just pop off where it references and pressurize that to the desired spring pressure and take a look at the gate under the car. You might have to remove the dump tubes though.
LASTLY sorry for the long winded post but I typically use the tial MVR or MVS gates
As mentioned above I have had gates overboost when the reference line was compromised.
Is that line to the gate split between multiple sources? In my case it was going to a fuel reg and leaking at that connection. So the gates would see less pressure and overboost.
I forgot to mention if you dont wan to do it on the bench just pop off where it references and pressurize that to the desired spring pressure and take a look at the gate under the car. You might have to remove the dump tubes though.
LASTLY sorry for the long winded post but I typically use the tial MVR or MVS gates
