I finally got around to fixing my insanely loud whistling today. The plenum gaskets were moved/bent up a bit during installation by the previous owner causing a very tiny vacuum leak(it's not hard to disturbo the gaskets considering you have to jockey the intake around, guide the pcv hose through the lower intake gap, move lines out of the way, etc. all while setting the plenum atop the lower intake. I have it down to a science these days as I've removed about 20 3.1 plenums at various times.)That tiny vacuum leak whistled so loud it would make your ears ring if you were within a few feet of the engine. You could hear the car whistling from a few blocks away with the hood up. :laugh:  I also picked up some stainless M8-1.25x25 bolts to reseal the turbo to downpipe connection with. There were only 2 or 3 bolts in the housing there so it has a pretty good exhaust leak there. I'm going to throw those bolts in tomorrow and then drive the car again. The car runs great driving normal, but is a bit on the slow side. I need to check over everything on it and see if I can fix that. ;) I'll likely update this with a few pictures tomorrow. The car is dirty and covered with pollen, so I'll probably just snap some better interior pictures and an underhood shot to add to my "before" pictures.  I'll post some more when I get more done to the car...

Awesome, I love these threads  :laugh: hopefully you get it back together and everything works right. I have to put my engine back in this weekend...

I tried resealing the turbine housing to downpipe connection by simply throwing new bolts in the places where they were previously missing = no dice. It's not leaking nearly as bad as it was, but it is still puffing out exhaust on one side. There's also one bolt in there that's crossthreaded like hell thanks to whoever worked on the car before I had it. :icon_frown: I attempted to pull it up tightly but there are still 2-3 threads exposed and that's as far as it would go, I tried to back it out with the 1/4'' drive ratchet I was using at the time and it felt like I was going to strip my ratchet out. :laugh: That bolt is on the opposite side of the leak by the way. I guess I'll take the turbo completely off and remove that bolt...I'm pretty sure it's going to snap off in the turbine housing before I can completely remove it anyways. I plan on drilling and retapping it for a slightly larger size. After that, I might try throwing the turbo back on as-is and see if it will seal. If it doesn't, I guess I'll have to get the surface milled flat again and/or try one of those gaskets that they make for these connections.

Besides that, the engine seems to have a small skip/misfire to it at idle. I'm going to check the plugs & wires tomorrow, I hear what sounds like a spark arcing on the front bank of wires. Also, the fuel pump is pretty damn loud on this car. I guess I'll throw my fuel pressure gauge on it tomorrow. It starts, runs, & drives fine, but it is significantly slower than it should be.

While I'm posting, here are two underhood shots. The car is missing the battery cover and passenger side beauty cover. I have the cross-directional brace sitting on my dresser along with the accessory belt guard. I'll probably grab a 91+ style coolant overflow bottle to install over there to make things look better and to free up more room so I can run a custom intake in the space the original coolant overflow currently resides in. I went over the black around the letters on the plenum with a flat black paint marker and then painted the letters "glossy red" with another paint marker.



W/ flash to show how truely dirty it is. It's not awful by any means. A bit of cleaning and a little paint work will have it looking good again.


I need to do some degreasing and swap out the valve cover gaskets. I'm holding off on that until I make a junkyard trip for some more 1.6 ratio rockers. I figure I might as well upgrade while I have the valve covers off...

Put some axle grease between the downpipe/turbine housing... first time you start it up that shit will melt like wax and seal it good. My friend suggested this to me, and surprisingly it worked great, considering I'm missing two bolts (ripped the helicoil out of one and snapped another, again :icon_rolleyes:)

Quote from: GutlessSupreme on April 06, 2008, 08:07:21 PM
Put some axle grease between the downpipe/turbine housing... first time you start it up that shit will melt like wax and seal it good. My friend suggested this to me, and surprisingly it worked great, considering I'm missing two bolts (ripped the helicoil out of one and snapped another, again :icon_rolleyes:)

hmmm, wish I would have seen this about 5 hours earlier! :lol: I have all 5 bolts though, so I think I'm alright

Looks pretty decent.  I have a question on those 1.6 rockers.  Are those bolt on and go?  Or do you have to set valve lashing?  Also, what engine do you find those in (I know 3x00, but what year/make/model) ?  Do you have to swap the rocker stud also?  Can you reuse your old rocker nut & rocker ball?

Thanks for the axle grease tip Tony, I might have to try that out if I can't get it to seal any other way.

Quote from: TGed on April 06, 2008, 09:35:40 PM
Looks pretty decent.  I have a question on those 1.6 rockers.  Are those bolt on and go?  Or do you have to set valve lashing?  Also, what engine do you find those in (I know 3x00, but what year/make/model) ?  Do you have to swap the rocker stud also?  Can you reuse your old rocker nut & rocker ball?

They're a bolt-on item. 1994-1995 cars that came with 3100 SFI engines have them. There's a pretty large list of cars with the 3100 for those years(among them Grand Prix's, Grand Am's, Corsicas, Regals, Cutlass', Luminas, Buick Skylark's, Olds Achievas, etc.!) . Our cars have a net lash setup, so there is no real "adjustment." Just put the rockers on and torque the nuts down to spec. You can reuse the stock studs, nuts, and balls. See my stickied post in the performance section for more information.

Cool, I'll have to get some for the whip then.  I have a set of comp cams (I think it's them) 1.6 and setting valve lash is not something I like doing in these engine bays.

Side question.  Can improper valve lash cause no vacuum while idling?

Quote from: TGed on April 07, 2008, 07:29:22 AM
Side question.  Can improper valve lash cause no vacuum while idling?

I sent you a PM to keep this thread on topic.


Well, it turns out that two of those plugs up front were loose because the threads are a bit messed up in the head. The plugs appear to have only been threaded about halfway to 3/4 of the way into the head and they've been like that for a while. The last few threads on those two plugs are rusty since they were not threaded into the head. I tried putting new plugs in today and they would not thread in fully as the threads are a very lightly messed up about 3/4 of the way into the head. I have a "back tap"(internal spark plug thread tap) on order that should be able to take care of this problem without me having to remove the heads. If by some odd chance that it doesn't work, it's not a huge deal for me to have to remove the heads. If they do have to come off, I will consider swapping to a 3X00 top end. ;)  This car is giving me plenty of little problems to solve. I guess I'm paying my dues for owning another TGP that I've had to put basically no work into. :icon_razz:

I'm crossing my fingers and hoping the threads on the rear head are still fine, I haven't looked at or removed those plugs yet. :laugh: If I get a chance tomorrow, I'm going to take the turbo off and extract the bolt I broke off in the turbine housing + drill/tap it to the next size up.

Here's a link to one of those internal taps for those of you that aren't familiar with them. ;)
http://www.back-tap.com/

^I purchased a different brand for about half the price by the way...

The back tap worked perfectly. My spark plugs are now threaded all the way in on the front bank. :icon_razz: I checked the fuel pressure on the car and I had 45 psi key/on engine off and about 38-39psi with it idling. Fuel pressure holds fine so it has no leaks...yay! I'm going to pick up a fuel filter tomorrow and swap it out because I don't know how old the one on there is. Other than that, I still need to extract the bolt on the turbine housing.