General STS thread

[kevm14]

UPDATE: It is now two days since I tightened up the intake bolts and now my car runs as smooth as silk. Before you were able to tell it was running but now you can't even tell it's running it's so smooth. It hasn't idled so smooth since I purchased it 4 years ago. Wow what a difference.

Another update.

I re-checked mine yesterday, after finally getting a 1/4" drive U-joint, and they were all tight. Granted, I'd tightened them just a week ago, but still.

Let me caution everyone, there is one on the driver's side, middle of the engine front-to-back, under a part of the fuel rail which prevents using a socket on it. I had a crow-foot wrench, but was still damned unpleasant. Take your time on it is all I can say.

Probably should've tried a box-end wrench, but the crow-foot was doing something. Not much, but a little.

Oh, and I'm pretty certain my MPG is up about 1 MPG. This car gets driven the exact same way, every day, and I'm in the low-22's on the VIC (vehicle information center). Idle is definitely smoother.

It is kind of embarassing that it's been over 2 years with the SRX and I haven't checked this. Unless they fixed this for the 08s. Definitely not for the 05s...

[kevm14]

Sigh.

I checked mine yesterday. Two were loose again. Only 3,000 miles. Seems to be a continuing issue.

Definitely needs a thread locking compound.

[kevm14]

I tightened them. All were loose. Most I could actually rock a little bit with my fingers. None were about to fall out or required several turns to tighten. 89 in-lb correlates to "pretty tight" on a 1/4" ratchet.
10 total bolts, 5 per side. The one in the center on the driver's side required my ratcheting box wrench (again). The rest were doable with just a 1/4" U-joint, extension and 10mm socket.

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Results: A little better cold start, better off the line throttle response (it actually helped with that dead spot at light tip in), better general drivability and smoother operation. I would not say it was a huge difference but I noticed.

At next oil change, I'll check them again and consider doing Loctite blue.

I will check the SRX next.

[kevm14]

I may have just fixed a sunroof rattle. I'll know next time I drive it.

Here is the adjustment procedure, which I also performed.

[kevm14]

Results: A little better cold start, better off the line throttle response (it actually helped with that dead spot at light tip in), better general drivability and smoother operation. I would not say it was a huge difference but I noticed.

Confirmed: Cold start extended cranking is fixed. I got a tip to check the PCV system and brake booster vacuum line and I will do that.

[kevm14]

I wonder if my switch to GC 0W-30 has caused some excessive oil consumption. It was down 3/4 quart in only 861 miles which works out to 1,150 miles/qt. Which is about as bad as my Caprice. Unlike the Caprice, it is not leaving puddles everywhere. I suppose if it continues I could experiment switching back to M1 5W-30 and see what happens. When I bought the car it had like 15% oil life left and the oil was at the top. He claims he didn't need to add. So either that was a lie (possible) or the GC 0W-30 is causing sudden oil consumption (also possible).

Interestingly the SRX seems to have picked up its oil consumption at the end of the oil change interval (10,000 mile mark). However, the STS is at the beginning of its OCI. I will do some research but I wonder if I need to do some PCV maintenance on both cars.

[kevm14]

Northstar final redesign article.

http://www.autospeed.com/cms/article.ht ... -V8&A=1569

[kevm14]

A lot of my research suggested the Italian tune up. Specifically, wind out a gear (like 2nd) and let off holding that gear to decelerate and make a high vacuum in the cylinder. Do this a few times. Well, don't mind if I do.

[kevm14]

A lot of my research suggested the Italian tune up. Specifically, wind out a gear (like 2nd) and let off holding that gear to decelerate and make a high vacuum in the cylinder. Do this a few times. Well, don't mind if I do.

I did a couple runs of this on my commute. Wound out 2nd, holding 2nd, and coasted from redline. Did that a few times. Tried it in 3rd as well. I didn't notice any exchaust emissions but it'll be interesting if this changes anything.

[kevm14]

Northstar final redesign article.

http://www.autospeed.com/cms/article.ht ... -V8&A=1569

I'm sure everyone jumped right in here and read the entire thing.

Fun fact: this car uses factory wideband O2 sensors pre-cat. I wonder if that means closed loop fuel control even at WOT. I also know this car is capable of both individual cylinder knock retard as well as air/fuel ratio control. Which is fairly fancy.