Help! What did I do? Boost leak issue, or?.......

[todzilla]

I don't know what I did - but I'm scared!...well, a little freaked.

I was cruising along in the car ('86 951) and all was tickety-boo. Then, I turned up a rather large uphill and this kid in a new Focus ST decides he wants a little challenge. Ordinarily I'd let him fly past as I tend to not push my car and I'm not a the kind of guy to race on the streets...too old, and wise? =) But as it's a long, striaght uphill with a divider between both directions of traffic - and nobody around us, I figured I'd at least take her to third to see if old Betsy can play with the new kids. (more like a causeway/parkway....nothing but trees on both sides of the road, btw)

So I punched at in first and got full boost (2 bar...the car has an Autothority chip) Then I hit second and wound it out to near redline....at which point, when I lifted to shift, I heard what sounded like a blow-off valve...a rather pronounced 'whoosh'. You hear it on Subaru's and Eclipses, etc...when they add that blow-off valve (I think it is?) Anyways, my car has never made that sound so I was like, wtf?! I shut it down at the top of the hill (yes, he lost) - in 3rd gear.

Then as I had to stop at the first light about 4 blocks from that point and noticed that the idle was stumbling and it sounded like all of a sudden it was running on 3 cylinders...at idle. Almost wanted to die, but tried to smooth itself out. It was dipping to around 800-900 rpm. I was a little nervous at that point.

Then I started to move and noticed that once going, it got better UNTIL you gave it a little boost. As soon as you hit 1 bar, it would stumble, and when you shifted (at slight boost) - the 'whoosh/swish' sound was back!

I popped the hood and all looked ok - no hoses seemed dislodged or leaks or weird sounds, but definitely not running right. Like a boost/vacuum line had popped off or something? I know the plumbing on these is a nightmare, and trying to diagnose a boost issue can be mind-numbingly labor-intensive. I'm sure it's nothing catastrophic, as the car gave full 2 bar boost before and there were no other issues..but right now, she runs like a$$!

Anybody have any idea before I bring it in and get financially compromised??

Much thanx!

[kdjones2000]

Check your boost charge pipes, you blew one of them.

As usual, the defect is probably at the bottom of the hose, either a split or an end blew off the pipe where you can't see it.

Should be an easy, inexpensive fix...

[todzilla]

?? I've never even heard of those...and sadly, no shop manual. Are they 'up top' and easy-ish to access or do I need to tear into it to get to it...or rather, leave it to the pro's?

Much thanx for the advice!

[kdjones2000]

Look at those big pipes up near the front of the engine compartment, they are something like 1-1/2" in diameter, connecting to the turbo, going to/from the intercooler, and to your throttle body.

Pretty hard to miss them. Look at the rubber bits carefully: either one end has popped off the pipe (likely due to the oil residue normally inside), or one has split on you. A blade screw driver and some choice swear words are all it takes to take things apart and see what's up.

[todzilla]

OK thanx again brother! I'm no serious wrencher - minor tune-ups type stuff - but that at least sounds traceable? I had a bad experience with my first 951 years ago and the shop spent hundreds of dollars trying to diagnose a major bucking/boost issue until we realized it was ll in the ignition system. Plugs and wires solved it, but that was much $$$ later =( I'm hoping this is much easier to pinpoint....I really over-freak when these cars act up! haha

~T~

[TrailRider]

It really does just sound like a vacuum line came off some where. A vacuum leak would cause the car to idle rough and perhaps want to stall out. If that is it should be an easy fix! Granted, the vacuum lines are basically a spider web...

[GorillaFoot]

I'm with KD on this. Sounds like the rubber hoses connecting your intercooler pipes need to be tightened. I've had mine pop off on boost (that's your whoosh sound) then when I checked under the hood, everything looks fine, because they pop right back into place again. Get out the screw driver and tighten them all down, including the hoses going to the diverter valve. Let us know how it goes, after that.

[todzilla]

OK check this out - hope the pics help ($hitty camera phone!) The rubber coupling (?) underneath the large diameter plastic hose seems tucked under - like if you were to hold your upper lip to your nose!! It looked like it was torn/broken at first, but then I realized it somehow got sucked up and curled up underneath the plastic? I can hear a leak/hiss out of it so I know this is the cause..at least I hope? I'm going to remove the 2 (or possible all - 4?) clamps holding the drivers side pipe on and see if I can put the rubber back in its proper place.

Let me know if I'm not on the right track. And again, MUCH than guys and gals!!

[todzilla]

As I had no real template and made no mental note of how it looked previous to this ^^ - I didn't know what to really look for, as far as what looked out of place! But now that I see how obvious this rubber coupling's misplacement was, it makes so much sense as to why it ran like crap! Fixed - and boooost is back and stronger than ever! Musta been off for a while. The one real (uphill) push I gave her today finally made it very apparent how poorly seated it was!

Gotta love devoted sites and people like y'all! You likely saved me at least 30 minutes of shop time!

Cheers

[TrailRider]

That looks like the problem! Good find... and easy fix!

[GorillaFoot]

...And boom! There you go! It seems many problems with our cars end up being expensive, but this one is free! If you want to make sure this never happens again and make this free fix cost a few bucks, replace the clamps with t-bolt clamps. You can probably get them at your local boat supply shop.