3.4 DOHC Compatibility

[Jon89le]

My dad has a 3.4 in his '95Z34. If i were to get a motor from a 'yard, will any 3.4 work? I know in '96 certain things changed, but cant recall what exactly. Thanks a lot.

[fastbird232]

OBD issues.

[slick]

OBD issues.

 

Not really. Many obd 1 guys are running obd2 engines.

 

Anyways, there are a few issues you will have to deal with. Your dads 95 has a second cam sensor, and an oil level sensor in the oil pan. Those are the big two I can think of. The 96-97 has a different style intake and different vacuum lines and routing. The 91-93 doesn't have the second cam sensor or the oil level sensor in the oil pan.

 

IMO, for the least amount of work, look for a 94-95 engine.

[99RegalGS]

Yes, I would pick engines in this order (from easiest to hardest to swap in)

 

#1. 94-95

 

#2. 96-97

 

#3. 91-93

[patgizz]

94-97 no problem.

 

91-93 lacking the second 24x crank sensor and the cam position sensor.

[Psych0matt]

i have a 96 in mine. few sensors unused, I had to block off the AIR tubes, make my own egr tube (the ends are different from each other on both ends), and relocate my coils. i think thats about it

[JakeMetz63]

My 94 GTP has a 96/97 style engine in it. If you decide to get the 96 style, keep your 95 top end (manifolds up) and you need a "doughnut gasket" from napa to connect the manifolds. You will also need to weld the EGR in the manifolds but it is a very easy swap.

[CNBZ34]

My 92 Z34 has a 97 crate motor, just reused original lwr and upr intake and all accessories. Have unused sensors is about it. I do have an idling problem when cold about a minute or 2 after start up, a little low and uneven. Every once in a while will stall when stoping to change from drive to reverse to back into a parking space. Again these are intermittent, but still a PITA to me. Any suggestions from anyone?? Would like to have the chip burnt for it but told that car needs to be present for tuning.

[dohcfiend]

only "issues" i remember is the egr, redoing your heater hoses a little, lengthening your tps and iac wires 6 inches or more and relocating your coilpack wires(optional). pretty much all of it is gravy except for the egr.

[GrandAmSE]

Ok my cars a 92 but the motor has cam positioning sensors so what year engine do I have?

[patgizz]

91-93 have no cam position sensor(the one on top, where the front cam cover is notched to clear it).

[GrandAmSE]

So mines a 94-96?

[patgizz]

94-97. the heads are different and the 96-97 intakes have a separate throttle body, but thats not a good indicator as people swap intakes from the original when they do engine swaps.

 

 

[dohcfiend]

i agree. easiest way to tell are the exhaust manifolds between a 91-95 and a 96-97. if the exhaust ports/manifold shape looks like a square, it is a 91-95. if they look like rectangles, it is a 96-97. also another dead give-away is if the manifolds have evap ports in them(which signifies a 96-97). but so do 91-93 5spd lq1's. other than that, the egr ports are different also. the 91-95 have a oval flange with a retaining bolt and the 96-97 egr tube just screws in with no flange or retaining bolt.

[GrandAmSE]

Ok the engine/trans are both 94 but its running on a 92 computer. Should I put in a 94 computer?

[patgizz]

no