Blow off problem? SR20DET

[Big_Daddy_Johnsen]

Ok, here's the deal. I have a 93 Vert with the SR20 swap with the five speed. Running a pretty tame but still fun 8# boost. After a long drive (220 Miles) averaging 75 MPH I noticed that the Turbo wasn't boosting anymore, talk about your gutless wonder now it lost about 50% of its horsepower. It sounds to me like the blow off valve is stuck open.

Has anyone had this happen to them? Am I on the right track? I'm going to be pulling the BOV this afternoon to have a look at it.

HELP!

[Big_Daddy_Johnsen]

Ok, well I took a look at what I thought would be the blow off valve and I found a blackstone intercooler there (had to pull out the wheel wells to see it)

Do these have blow off valves on them? Does anyone know what company manufactures them? Web site? Anything?

[Big_Daddy_Johnsen]

Ok, so I found the blow off valve, I was looking for one of those ricey crome ones but I have a bosch recirculating blow off valves. I took it out and it wasn't stuck open as I'd imagine it would be. I'm not sure my turbo is enguaging at all. I checked the whole system for leaks.

Anyone?

[Eikon]

hey Big Daddy...

There are a lot of possibilities. The first and foremost is that your turbo could be blown. You might have blown the impellor wheel or something like that. You might need to take it off the car and check it out by hand.

if you think the turbo is OK you might have problem with your wastegate instead of your blow-off valve. You wastegate might be stuck open?

A very strong possibility is that you have a vaccuum leak. Is your intercooler in good condition? Have you checked all the fittings in your pipes to and from the turbo and to the IC and then to the engine?

You could have a large exhaust manifold leak?

Just some ideas... hope they help..

But for the best advice... Post your problems in the SR forum. zeroforum?id=138They really know there stuff and will be able to help you much more than most in the 'vert forum.

Unless Tenkawa Akito checks in... He also has an SR

[Big_Daddy_Johnsen]

I pulled the blow off valve out, it wasn't stuck open. There was however continuous vacuum to the unit (which would hold it open.) Had the wife rev the motor up and kept my eye on the actuator, it never moved. I checked the vacuum lines to the actuator and they seem fine. It looks (and sounds) like the turbo is not spinning up.

[Hijacker]

best thing to do is to pull the intake pipe going to the compressor housing and check to see if there is any shaft play on the turbo.

[Big_Daddy_Johnsen]

Hey Bart!Wouldn't you think that the wastegate would open at higher RPM? It's not moving at all. The car only has 2k miles on it since you last saw it. I wouldn't think the turbo would digest itself that soon. On the long drive it was fine, it was the next day that it never boosted.

[Big_Daddy_Johnsen]

Verdict is in, I smoked my turbo. Didn't let it cool down like a dumba$$ and it's seized up. Any suggestions for a replacement? It's a T25 right Bart? Should I replace it with a T25 or something beefier?

[Big_Daddy_Johnsen]

Apparently I didn't smoke my turbo, took the intake off and checked the propeller and it's fine, started the car and watched it and it spun. Checked out the actuator and it was a pain to move, worked it a few times and it seemed ok. Put it all back together and it does the same thing. It seems like it's blowing out of the BOV and never building pressure.

Help?

[Big_Daddy_Johnsen]

Ok, I hooked the cold pipe into my compresser and pumped some air into the system. It never pressurized and the air comes right out of the air filter. What does that mean?

[Eikon]

Sounds like it's time for a new BOV.

[Big_Daddy_Johnsen]

Ok, I pulled my head out of my arse and I plugged the air breather with some plastic and tried it again. I have a hole in the intercooler (blackstone model) that it looks like there used to be a bolt in. Which now there isn't, so therefore it leaks pressure like a mother.

[Big_Daddy_Johnsen]

Tah-Dah. I put a bolt in the hole (sorta) and took it out for a run, still leaking pressure but it is actually working, turbo spools up, blow off valve blows off. Now to find the right sized bolt, anyone parting out a Saab?

[Eikon]

LOL... glad you finally got it figured out. Bet you learned a lot about a turbo air system in the process.

I don't know what a Blackstone intercooler is like you are calling it, but I will have a sidemount IC from my RB20 available this weekend. I am getting my frontmount mounted and piped. So if you need a new IC you could have mine pretty cheap.

Where in Wisconsin are you? All of WI is BFE... but what part. I will have my car in Oshkosh this weekend and you could pick up the IC if you want...

edit... i figured out what a blackstone IC is... it's the 10 row variety used in some saabs. http://cgi.ebay.com/ebaymotors...=WDVWheres a link to a current ebay auction for one.

[Big_Daddy_Johnsen]

Actually the intercooler I have is exactly like this one http://cgi.ebay.com/ebaymotors...wItem

I live in the township of Frankfort, about 30 miles west of Wausau. You're right I learned a crap load about the turbo system. Is there any way to get your hands on a factory service manual for the SR20DET motor? I have the one for the S13 and the Convertible but I'd like to know a little more about this motor. I found one on the internet a few years back but I lost the link.

[Hijacker]

Ok, I pulled my head out of my arse and I plugged the air breather with some plastic and tried it again. I have a hole in the intercooler (blackstone model) that it looks like there used to be a bolt in. Which now there isn't, so therefore it leaks pressure like a mother.

That's odd. When we put that intercooler in, I don't remember anything like that, and it was boosting just fine. I do remember, however, that we had never used that style of intercooler before.