About 2 months ago, I bought a car off of a local craigslist ad. It was an 86 GT with a '96 3100 + 4spd auto swap but it had a bad head gasket. Coolant leaked out the side of the block. Paid $1000
I'm thinking easy fix but then mechanic says to do it right you have to replace the gasket on both heads and deck the heads since they are aluminum...so my initial thoughts on an $800 fix became a $1300 estimate. So I decided to buy a $500 1999 3400. Original motor swap estimate was $1000 so for the $500 cost of the engine, I figured just 3400 it. Well as it turns out, the EGR and temp sensor are different as are the bolt pattern on the intakes.
Mechanic is going to swap the 3100 intake onto the 3400 for simplicity's sake on the swap. Are there any other gotchas I need to worry about?
[This message has been edited by lou_dias (edited 08-25-2014).]
About 2 months ago, I bought a car off of a local craigslist ad. It was an 86 GT with a '96 3100 + 4spd auto swap but it had a bad head gasket. Coolant leaked out the side of the block.
I'm thinking easy fix but then mechanic says to do it right you have to replace the gasket on both heads and deck the heads since they are aluminum...so my initial thoughts on an $800 fix became a $1300 estimate. So I decided to buy a $500 1999 3400. Original motor swap estimate was $1000 so for the $500 cost of the engine, I figured just 3400 it. Well as it turns out, the EGR and temp sensor are different as are the bold pattern on the intakes.
Mechanic is going to swap the 3100 intake onto the 3400 for simplicity's sake on the swap. Are there any other gotchas I need to worry about?
You definitely need to go to the 60 degree V6 forum for this as you could actually be cutting performance as a result of the different port sizes that are available at some point during their production.
About 2 months ago, I bought a car off of a local craigslist ad. It was an 86 GT with a '96 3100 + 4spd auto swap but it had a bad head gasket. Coolant leaked out the side of the block.
I'm thinking easy fix but then mechanic says to do it right you have to replace the gasket on both heads and deck the heads since they are aluminum...so my initial thoughts on an $800 fix became a $1300 estimate. So I decided to buy a $500 1999 3400. Original motor swap estimate was $1000 so for the $500 cost of the engine, I figured just 3400 it. Well as it turns out, the EGR and temp sensor are different as are the bold pattern on the intakes.
Mechanic is going to swap the 3100 intake onto the 3400 for simplicity's sake on the swap. Are there any other gotchas I need to worry about?
temp sensor I believe you can just change over, or if not british car conversions sells a sensor for the small port size with the 3wires.
as for the egr, im guessing its the trangle mount on your old one and the long flat on the new one? I believe they use the same connector, just need to get one for the newer style intake. im not sure if going from 3100 to 3400 will need a new tune tho, check with ryan at gmtuners.com to make sure... or if you don't have smog, you can have him tune-out the egr all togather, and just blockoff the ports....
temp sensor I believe you can just change over, or if not british car conversions sells a sensor for the small port size with the 3wires.
as for the egr, im guessing its the trangle mount on your old one and the long flat on the new one? I believe they use the same connector, just need to get one for the newer style intake. im not sure if going from 3100 to 3400 will need a new tune tho, check with ryan at gmtuners.com to make sure... or if you don't have smog, you can have him tune-out the egr all togather, and just blockoff the ports....
I'm not even sure what ECM this setup is running. I paid cash and just had it towed to the mechanic. They told me about excessive frame rust where the cradle bolts up. :/
I'm not worried about [high] performance, just want a winter car so I can park my Formula since my 'race' car is beyond daily-driver material and it also going thru an engine rebuild.
Got a link for that sensor?
[This message has been edited by lou_dias (edited 08-25-2014).]
I'm not a fan of it myself. I think there's a kit out there that puts those lights into the factory buckets... Yes, they've been glassed over but nothing that can't be undone...though the wiring has been converted...
It interior was in pretty good shape and it's a swapped car with 4spd auto cheap so I couldn't pass it up. I'm hoping it is running OBD2 so I can study that.
[This message has been edited by lou_dias (edited 08-25-2014).]
can tell if its OBD by 1 or 2 by if its running 1 or 2 cranks sensors (one 7x wheel on the crank itself, sensor in the side of the block, and 1 24x sensor in the harmonic dampener, sensor sits behind the pully) 1 sensor is obd1, 2sensors is obd2 also dont think obd1 runs a cam sensor, could be wrong on that tho.
can tell if its OBD by 1 or 2 by if its running 1 or 2 cranks sensors (one 7x wheel on the crank itself, sensor in the side of the block, and 1 24x sensor in the harmonic dampener, sensor sits behind the pully) 1 sensor is obd1, 2sensors is obd2 also dont think obd1 runs a cam sensor, could be wrong on that tho.
Thanks for the links. From what the mechanic told me there is a 1-wire sensor on the head going to the temp gauge.
I should have took a few pics of the engine compartment... I'll probably get a chance to do that on Saturday. Turns out there's some major rust in the rear engine mount area that was covered up with sheet metal... That will hold this up another week or so...
Originally posted by hookdonspeed: can tell if its OBD by 1 or 2 by if its running 1 or 2 cranks sensors (one 7x wheel on the crank itself, sensor in the side of the block, and 1 24x sensor in the harmonic dampener, sensor sits behind the pully) 1 sensor is obd1, 2sensors is obd2 also dont think obd1 runs a cam sensor, could be wrong on that tho.
Or just look at the ALDL connector, and if it's the 16-pin trapezoidal connector, it's OBD-II. If it's rectangular 12-pin connector, then it's pre-OBD-II.
Or just look at the ALDL connector, and if it's the 16-pin trapezoidal connector, it's OBD-II. If it's rectangular 12-pin connector, then it's pre-OBD-II.
but thats `hidden` the sensors and all you can just glance at lol.
I also found out why they cut the dept of the trunk. They put the catalytic converter near the muffler...well I don't get emissions testing in RI and MA so that will have to be "fixed" at some point... Also, I got to look at the wiring harness going into the firewall and it looks strangely stock so right now I'm suspecting a '7730 conversion was done since it is running DIS...
[This message has been edited by lou_dias (edited 08-31-2014).]
The mechanic had transferred the timing cover and front engine mount over from the 3100. He told me he had to use lower 3400 intake gaskets to mate to the heads...while retaining the upper 3100 intake gaskets. I was able to see the different bolt patterns on the intake and the gaskets. He still didn't have the 3100 intake on but was getting close to putting that on. The mount repair was supposed to be finished Saturday.
All this extra labor will cost an arm and a leg. I am slightly disappointed that it doesn't look like an OBD2 install.
The mechanic had transferred the timing cover and front engine mount over from the 3100. He told me he had to use lower 3400 intake gaskets to mate to the heads...while retaining the upper 3100 intake gaskets. I was able to see the different bolt patterns on the intake and the gaskets. He still didn't have the 3100 intake on but was getting close to putting that on. The mount repair was supposed to be finished Saturday.
All this extra labor will cost an arm and a leg. I am slightly disappointed that it doesn't look like an OBD2 install.
toobad you wasn't closer... 3100 to 3400 swap is cake (IMO). and wouldn't have been too bad to go snag a harness from local yard and make you an OBD2 swap.
Originally posted by hookdonspeed: toobad you wasn't closer... 3100 to 3400 swap is cake (IMO). and wouldn't have been too bad to go snag a harness from local yard and make you an OBD2 swap.
I'm surprised they even agreed to do the work... Keep in mind they didn't want to mess with the harness and that's why they are swapping intakes. The 3400 I bought came with the engine harness.
I'll be able to take the oil pump drive gear off the old 3100 and put that on my 3400 hybrid motor finally. I may rebuild the 3100 block and put that in my 93k Formula if/when that 2.8 fails. Would prefer to keep that one looking stock. I've got a DAWG-modded intake I can throw on that car...(screw the EGR).
I don't understand why this swap is so involved. This is a small port 3100? Why can't you just move the sensors over to the 3400 that are needed to keep running OBD1? Aren't most of the sensors the same but the OBD2 has more of them?
I don't understand why this swap is so involved. This is a small port 3100? Why can't you just move the sensors over to the 3400 that are needed to keep running OBD1? Aren't most of the sensors the same but the OBD2 has more of them?
kinda what im wondering too, all the ports should be the same and same threads, cept the CTS they did change, but that's an easy fix.. shop doesn't sound like they are qualified to do this as they know nothing about the engines.
IDK. Bolt-patterns did change. Looking at the family tree, there were supposed to be no changes from '96 to '99 but apparently there were. The 3100 has a 6 bolt intake and the 3400 has an 8 bolt where the upper meets the lower. I'll convert the CTS to the 3-wire version later myself. The temp gauge is broken anyway currently. Rather than mess with a harness, they just swapped intakes, that's all I know. I'm going to have all the left-over parts from both motors so I'll look more indept when all is said and done. I just want a running car. I don't care about losing performance.
IDK. Bolt-patterns did change. Looking at the family tree, there were supposed to be no changes from '96 to '99 but apparently there were. The 3100 has a 6 bolt intake and the 3400 has an 8 bolt where the upper meets the lower. I'll convert the CTS to the 3-wire version later myself. The temp gauge is broken anyway currently. Rather than mess with a harness, they just swapped intakes, that's all I know. I'm going to have all the left-over parts from both motors so I'll look more indept when all is said and done. I just want a running car. I don't care about losing performance.
The 3100 was changed over to the same intakes/sensors and the same revised timing chain setup as the 3400 in 2000, there was no change in the 3100 mechanically from 94-99. The early 96-99 3400 came after the original 3100 and it got improved/different parts to start with. The only difference between the 2000+ 3100/3400 was the bore.
Edit: And the throttle body size.
The difference in 3100 performance by factory rating is 155-160HP for the small port vs. 170-175HP for the large port.
Edit again: Here is an excellent guide to the differences in the upper intake manifolds for the Gen III 60* V6 engines that has somehow been lost on WOT-TECH's site. 3100/3400 manifolds
[This message has been edited by carbon (edited 09-03-2014).]
the sensors and all you can just glance at lol.
