Hey guys. I am a proud owner of a 98 Golf MK3 Variant. I've had the car a little over a year and it's been a blast. It started off a very very basic 1.4 liter CL model which has undergone a "GTI" conversion on the outside and inside along with an engine swap. I got a hold of another variant that was rotted to pieces but had a very solid 1.8 liter AAM engine, 8v with 75BHP!!!!! Since then, the car has been driven every weekend and I am slowly working through all the things it needs. Now onto why I am here! Last week, I got a 2.0 8v AWG engine from a fellow MK3 owner out of a 2001 convertible. I got the engine, 2 transmissions, ecu and the wiring loom. I initially planned on doing a swap like I previously did from the 1.4 however I realized I am missing a few bits like the MAF, Fuel pump, Lambda sensors etc. The looms for the headlights is also different as that particular car had the MK4 front end and a few connectors have been snipped off.. Soooooo, I am planning to strip the engine down, take the 2.0 block and mate it to my 1.8 Bosh Mono Motronic head so that I can keep my original loom, exhaust etc. So, a couple of question: 1.) As far as I am aware, I use a headgasket made for the 2.0 block correct? 2.) I also use a timing belt for the 2.0 engine? The block is obviously taller. 3.) Am I ok to use the 2.0 distributor? It has same coil, same wires and same harness connector. 4.) Can I still use my 1.8 transmission/clutch/flywheel? 5.) The 2.0 has a crank sensor, I assume I just leave that unplugged? That is all I can think of right now, thanks for any replies.
short answer: 1) yes 2) yes 3) no, you'll need a 2E code one to match your injection system, or use adaptor ring so 1.8 distributor will fit with 2.0 gear swapped over 4) yes 5) yes, its not required with 1, you may need the earlier type 2E/AGG/ADY gasket to suit the 1.8 head. Looking at the 2 part numbers there are a few blanked off holes in the AWG gasket which are open on the earlier 2.0 gasket. The overall shape looks the same so the head looks liek it should fit otherwise, head bolts all the same for the 1.8 and 2.0 cross and counterflow cabrio heads. long answer, I would consider trying to run the engine complete. you would need to strip both looms down to remove the ecu wiring from the 1.8 harness and strip the lighting wires from the 2.0 harness then combine them. You could source a spare post-96 mk3 loom to work on, that way the car can still be driven main fuel pump any mk3 gti, 16v or vr6 will do so no problem there, just need to attach it to your level sender assembly. MAF+airbox probably wont be hard to get either. exhaust wise if the 1.8 has the 4-2-1 system with 6 stud flange between manifold and downpipe you could keep it (even if not, it will still fit the head, just the toilet bowl style downpipe doesn't flow quite as nice) otherwise use a 2.0 8v manifold & downpipe, might need the 2.0 cat or the 1.8 one might fit. the 1.8 exhaust diameter is probably 2", if so its the same as the 2.0 8v one was originally so no problem there. the 1.8 lambda probe will probably work too, just you wont have a post-cat lambda or fitting unless you get the AWG parts. Only thing I'm not sure of is if you can delete all the SAI system and post cat lambda without issue, I believe the engine will still run fine with fault codes logged for this system? If not you can probably get it all coded out same as you can with MK4 20v ECU. Though on the flip side, for the same effort you could fit an abf or vr6 engine, or with a little more effort you could do a mk4 20v swap even. so it can still make sense to chuck in the 2.0 8v bottom end in with old head for a quick and easy boost in torque. save the big effort for something else down the line...
