3100 intake swap

[3100 MPFI]

Just letting everyone know that I finished swapping the upper, and lower intake manifolds on the Grand Prix. The Grand Prix is a STOCK 1996 3100 SFI (Vin M). I put on the newer, intake manifolds (Vin J), and a 56mm Throttle body from a minivan (Thanks Larry).

Everything went right in without a single problem (other than I needed to get a new heater pipe that goes in behind the thermostat housing, and it took the dealer 3 days to get it). Now that everything is back together, the car seems to like it.

Low end power feels the same, but mid, and high are noticable improved. The car always felt quick, but it is even better now. I am one step closer to having the ultimate sleeper (ugh..... PINK)

Anyways. I know that some people were wondering about what doing the intake alone would do, and that is pretty much it. Nothing close to being track material, but it does have a better feel to it.

Here are some pics:

[Darkhorses]

What kind of van did the throttle body come off of? Anyone know if the throttle bodies are the same on the 3100 and the 3.1.

[blackbombshell95]

i'm doing the same thing as we speak. but i'm doing the heads and all is going to be P&P.

Looks Great. engine is really dirty. i'm sure it will look better if you clean it up.

i have a 95 grand prix 3100. what did you do for an egr? where does that heater hose go from the thermostat to? what is the part number? or when i call up parts what can i tell them?

[bszopi]

The 3.1L and 3100 TBs mount differently, so they aren't interchangable.

[3100 MPFI]

I think that all 3400 minivans got the 56mm TB. I did do a little cleaning to the engine. The front valve cover was BLACK when I took it off. After 30 minutes of cleaing, that is how it turned out. Next time I go to the car wash, I am going to clean the engine compartment. I am also going to try to get some pink engine paint, and give the engine an "make over" UGH.

For 1999, the Malibu got the newer 3100 (Vin J). The plunum for 1999 is the one that you see there. It has the larger intake ports, but it has the older EGR mounting area. 1996 3100 cars have a Linear EGR (one big round looking thing), and that is what was on the Grand Prix when I started. It bolted right up without any modifications. If you have the older digital EGR (the one with 3 small parts on one plate), you will need to get the newer 3100 plenum, and an adapter (which is what I had to do to the 3100 in my Cutlass Supreme so that I could use the digital EGR).

The pipe behind the thermostat is the one that goes to the heater core. 1993-1998 3100 cars have an adapter that is screwed in, and the pipe clips into it. 1999 and later cars do not have the screwed in part at all (the hole is not even threaded). It just has a pipe that is pressed right in with an o-ring, and held in place with the same stud that the other one is held in on. If you get the lower intake manifold from a 1996-1998 3400 minivan, then it should be the threaded one, and you can just use your stock pipe (thanks Brian for telling me that). I don't have the part number for the pressed in one. When I went in to the dealer, I told them it was for a 2000 Grand Prix 3100. It cost me $8.10 with tax. If you call the dealer, just tell them that it is not the thermostat housing itself.