92 Seville 4.9 - interesting mods in progress

[Luke]

This is my 92 Seville. Yes, it is a Seville and not an STS. I bought all STS body panels and bumpers from a salvage, painted them, and installed. It has been my daily driver for about a year and a half. I recently changed jobs and needed to drive 35 miles each way for 3 months of training.  I was getting about 17 mpg so, I bought a 2017 Jaguar XF 20d. 42 mpg. BUT, that doesn’t mean I am getting rid of my Cadillacs. I have 5. The Seville has been very slowly losing coolant for a year or more. I’ve tested for head gasket leaks several times and nothing. Time for intake gaskets. 
 

Anyone who has been around long enough to remember “the guru”, may remember talk about some factory test cars with the 4.9 that had some interesting modifications. There were quite a few back then who wanted to try this but to my knowledge, it was never done. Photo of the project in comments. 

[Luke]

Anyone recognize what this is?

[Logan]

Intake manifold......odd but your picture seems to show the Allante version intake. My '93 4.9L Seville did not have that style intake.  

[Luke]

You got it. I’m putting the entire Allante intake manifold on my 92 Seville. Here is a before photo. 

Edited May 13, 2020 by Luke

[Bruce Nunnally]

This should be interesting.  I agree it is the book answer on what to do to for airflow for around 20 hp

[rockfangd]

I am enjoying this. Don't see many Sevilles. 

[Luke]

I’ll keep posting updates.

Bruce, back in the day with your 92 STS, you got some pretty good gains with the chip, didn’t you?  I’ll likely get a chip for it once this is done. 

I’m not sure at the moment exactly how I am going to deal with the fuel rail. The Allante one has different hookups for the metal fuel lines. But with the Seville one, The fuel pressure regulator is in the way of the upper intake manifold. May have to figure out a way to bend it a bit without breaking it. 

I have to extend the wiring for the MAP sensor, ISC motor, maybe the IAT sensor but other than that, the wiring should pretty much reach. I have to put an Allante 124 amp early DS-144 alternator on. The Seville 140 amp DS-144 is too big for the space. I’m also not sure if I am going to keep the throttle body spacer that has coolant running through or not. But then again, if it helps the MPG  I mean, I have the 09 STS-V for when I wanna get into trouble. LOL 

This won’t be a long extended project. I’d like to have it done in a week or two. The pushrods tend to rust in the icky sticky Dallas air if out of the engine too long. Plus, when I bought this car, I got the leaky Freon hose repaired and kept it with R-12. Don’t want to let it sit too long and dry the refrigerant seals out. 

Today, I torqued the intake manifold bolts to factory spec. 8 lb/ft then 12 lb/ft. Then I reinstalled the distributor. Took photos so I knew exactly what position to put it in. 

[Luke]

7 hours ago, Logan said:

Intake manifold......odd but your picture seems to show the Allante version intake. My '93 4.9L Seville did not have that style intake.  

 

Hey Logan, wasn’t your 93 Seville the one you painted the steering column for a steering wheel update? I’ve updated my steering wheel. Luckily, no paint was required. 

[Bruce Nunnally]

Here was the mod page for my 1992 STS: http://www.caddyinfo.com/92sts.htm

Quote

PCM (Computer) - I installed a FastChip. Fastchip claims an increase at the flywheel to 220 HP, 310 ft-lbs of torque.  Easy to install - took 20 minutes. Ed Wright is easy to deal with

The Fastchip webpage is still there; possible they still have them. 

[Luke]

19 hours ago, Bruce Nunnally said:

Here was the mod page for my 1992 STS: http://www.caddyinfo.com/92sts.htm

Definitely takes me back looking at that page. I was on here even back in the netgetgoing days. If I recall, my 1984 DeVille limo and 93 STS were on your people’s cars page. I think I’ve owned something like 16 Cadillacs since the.  Currently have the 92 Seville, 92 Allante, 08 DTS, 09 STS-V, and 1980 Seville limo. 

[Bruce Nunnally]

3 hours ago, Luke said:

Definitely takes me back looking at that page. I was on here even back in the netgetgoing days. If I recall, my 1984 DeVille limo and 93 STS were on your people’s cars page. I think I’ve owned something like 16 Cadillacs since the.  Currently have the 92 Seville, 92 Allante, 08 DTS, 09 STS-V, and 1980 Seville limo. 

Certainly a nice set of Cadillacs.   Yes, I got the same nostalgic feel from that page.

[Luke]

Making some progress! I put new spark plugs in and managed to destroy two of the spark plug wires in the process. Had to order new wires. Interestingly enough, the 4.9 uses the exact same plug wires as a Bentley Turbo R! Next step is to do some careful bending on the fuel rail so it can clear the upper manifold. After that, it’ll be time to route the vacuum lines and do the wiring. Some of the harnesses will have to be extended to allow for the new sensor locations. 

[rockfangd]

Very nice. Show some pics of the car. 

[barczy01]

Allante intake manifold. The 4.5 and 4.9 are great motors . But, the inlet and outlet water pipes rust out that run underneath the engine and are no longer available.. It's a shame someone doesn't make those aftermarket! 

[Luke]

On 5/17/2020 at 7:28 PM, rockfangd said:

Very nice. Show some pics of the car. 

 

[rockfangd]

Beautiful. Surely a one of a kind body style. Thank you for sharing. I kind of like yours better than mine. It has less clutter on the body. Mine has black and chrome trims

[Luke]

6 hours ago, rockfangd said:

Beautiful. Surely a one of a kind body style. Thank you for sharing. I kind of like yours better than mine. It has less clutter on the body. Mine has black and chrome trims

Here is a before photo of mine. It looked very similar to yours before I got all the STS body panels and front and rear bumper covers and grill and fog lights and put them on mine. I even painted them all myself to match the car. Had to come up with all the little out of production clips to attach them all. Mine is a base Seville. Still has digital cluster and column shifter but STS body. Oh, and yes, the bright red is the factory original paint. Rare 92-93 only color. And for some reason, all 92 Sevilles had black rear view mirrors  I painted them body color when I painted the panels and bumpers.

Edited May 23, 2020 by Luke

[rockfangd]

I knew those had to be STS parts. . Looks incredible.

I thought about making those changes to mine but it would cost more than I would want to spend to modify it. 

Mine is a tri coat, is yours? I realize we have 2 different Reds. 

Black mirrors... Thats strange.

It sucks I have a set of foglamps and switch for my Seville but it will not work because the Foglamp option was only on the STS. There is no place in the bumper for them. 

I did add them in my Deville and it was not a fun job. I stress these were not prewired at all for the option. I had to run all of the wires. They are completely factory and add a nice touch. The wiring goes from the headlight switch all the way to the trunk, from the trunk back to the headlight switch(for the ON indicator), then under the hood to the relay. Fuse and relay are also not prewired. I had to do that as well.

If you don't mind me asking what was involved with changing the cladding on the doors? 

[BodybyFisher]

Very cool Luke, I'm enjoying watching this

[dbc2065]

Had a 92 Eldorado with 4.9 was a great running car. Now I have a 92 Sedan Deville with 4.9 113,000 miles on the clock also have 97 STS   seeking parts for very hard to find Dark tan or gold I'm not sure what Cadillac color drivers lock bezel  doing work on it  no start condition with B0533 hard code doesn't clear.Haven't been on forms in a while after reading about CCC dude in Texas

Edited October 31, 2020 by dbc2065