rb20 Boost Problem

[govtworkhorse]

So I have a problem with my engine and I am confused as to what it could be. Not long ago I was out driving and everything was going well, car was running perfect and I was happy. But then I hit a pile of snow that was frozen and I bent a tie rod. I drove the car up the road and put it in the garage and left it for a few days. I went out to start the car and it started acting funny. I let it warm up and I noticed the boost gauge was reading funny. And if I revved the car past 5k when it came back to idle it would bog down and die. Now here is a video that shows the boost gauge acting odd. Normally it reads 12lbs vac and when I get on it, 12lbs of boost. Nothing out of the ordinary. But after I hit the snow, It reads 16-18 vac and when I lightly press the gas it goes to 12lbs vac and then bogs to 18-20 lbs vac. for a second until I press the gas pedal a little more. And when I rev it up, and let off, it reads as much as 22lbs vac. Does anyone have any idea how simply hitting pile of snow would mess up engine stuff? and what is wrong?

Here is the video of the car idling and then lightly pressing gas. You can see how it bogs out for a second.


Modified by govtworkhorse at 10:58 PM 4/9/2007

[govtworkhorse]

bump

[Carl H]

sounds like a boost leak, check all couplers even the intercooler as i could have a crack or some kind of leak in it.

[Bwana]

sounds like a boost leak, check all couplers even the intercooler as i could have a crack or some kind of leak in it.

[govtworkhorse]

Well I do have the side mount still and my tire rubs on it a little durning sharp curves. I though that might have been it but I took two pieces of short hose and hooked them to an intercooler I know is good and still had problems. Maybe I will check the bolts on manifold and turbo. Any other suggestions?

[govtworkhorse]

bump for more great ideas...

[Carl H]

have you pressure tested the system, most of the time you cant find boost leaks without doing that.the fact the motor pulls more vac is an indicator that there is a leak somewhere.

[govtworkhorse]

I will try that DIY pressure test this weekend and let you guys know what happens. Thanks again

[Sil240]

How to you pressure test the system???

I've never done it or seen it done before??

I would guess get two silicone caps poke holes in each and attach them to each end (pipe near the T-body and compressor outlet)Use a compressor on one end and pressure gauge on the other.

[mello88]

You don't really need to seal off the end by the TB, if you want to test the entire system for leaks. If you wanted to test a specific component you could do like you say and put a cap on the "other end" of the cold pipe. All you really need is a pressure test adapter, either build your own or buy one:











Then clamp it to the MAF or compressor inlet or hotpipe inlet with a silicone coupler. Set your tank (or inline) regulator to your test pressure (5-20psi) and pressurize the system. You can listen for leaks and/or spray suspected leaks with soapy water.