RX-7 Rebuild Notes
Start Date: March 2, 2003
Estimated Finish Date: March 23,
2003
Real Finish Date: April 4, 2003
After 75,000 miles my motor has finally given up and is having intermittent overheating problems. Apparently the water seals had started to detoriate and now there are hydrocarbons in the coolant and slight signs of coolant on my spark plug tips. These are sure signs of bad water seals. I am guessing that my problems started when my radiator burst about a year and a half ago in Sacramento. The engine was probably weakened a great deal in that mess but was still going ok. I think as time went on I had more and more cold startup white smoke from the coolant in my engine too.
After doing a few months of research of what to do I have decided to attempt to replace my old engine (and original) with a new Mazda Remanufactured engine from Malloy Mazda. Although I have heard mixed reviews on these engines (of course you should take everything you hear with a grain of salt on the internet...especially message boards) I do believe they offer the best bang for the buck out of all options out there.
The entire engine removal and installation will be taking place in my single car garage here in San Francisco. This is a huge project for me since I'm just a shadetree mechanic and don't have access to any airtools and have never even dropped my tranny before. I hope for the project to be completed in about 3 weeks if everything goes smoothly. With my track record of breaking little parts etc. though it will probably take twice as long. Let's get started.
| New Stock Parts | New Aftermarket Parts |
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Sunday March 2nd, 2003
After taking out my water pump months ago to make sure it was not the culprit of my overheating problems I needed to put everything back together in order to drive my car out and turn it around. Otherwise, I wouldn't be able to get the engine hoist or new engine into the single car garage. I couldn't just push the car out of garage and turn it around because there is quite steep slope leading up into the garage and fire hydrant close enough to the door to discourage me from taking that route. So basically the first day I spent and hour or two putting everything together again to turn the car around. These are all the steps I took in the actual engine removal.
- Disconnect negative battery terminal
- Jack up the car
- Remove the wheels
- Drain the oil
Thursday March 6th, 2003
I spent about an hour tonight taking out some easy stuff. These items don't really require anymore detail in their removal procedure.
- Plastic underbelly pan
- Drain coolant from block and radiator
- Remove intercooler and piping
- Remove intake, BOV, and all intake piping and hoses
- Throttle Cable
- Bracket between upper intake manifold and throttle body
- Bracket held by upper intake manifold nut near firewall
- Two bolts in from of UIM
- End of cable from throttle body
Friday March 7th, 2003
The first real working day allowed me to finally get some real work done. The goal was to get the car almost up to the point of pulling out the the engine and tranny as a whole unit. There are only a few thing left to be completed in order to pull the engine and tranny out. Something weird to not...my clutch release cylinder had the lower bolt sticking out about 1/2 inch. This is kind of freaky because my friend Reza said the same thing happened to his except for both bolts were loose. Something to look out for in the future.
- Greddy EGT Sensor
- Downpipe
- MAP sensor
- Radiator Hoses
- Thermostat housing coolant hoses
- going to overflow
- going to radiator
- Radiator - removing this is not required but will make installing my 2nd oil cooler and associated lines a little easier
- Brake booster vaccum line - this is on the passenger side of the UIM
- Engine Grounds - this is the one going from the UIM to the firewall and the one coming from the main engine wiring harness
- CRV and hoses
- Disconnect Greddy water and oil temperature sensors
- Disconnect 3 fuel lines near near oil filter - one of these was a major PIA to take off...you just have to be patient with your pulling and twisting. strong hands help too.
- Loosen and remove belt for PS and A/C
- Disconnect Heater Hose Line - this is the one on the passenger side that connects to a point close to the upper radiator hose. mine had a red dot on the hose.
- Power Steering Lines - i didn't have any air tools to take of the PS nut and pulley so I just removed the two power steering lines and drained the fluid out. i thought this would be much easier than fighting with the nut. if i air tools i would have done differently.
- Remove A/C Compressor - there are four bolts holding this thing in. it stays in the car during the engine removal process. i had to remove part of my alarm system to get to these back 2 bolts. the bolts might be hard to see if it's dirty or dark down there.
- Remove Tranny Underbelly Tray - this is the metal tray protecting the transmission. it is held in by 4 bolts. this thing was caked in old dirt and oil.
- Remove Starter - this is held by two 14mm bolts. the upper bolt/nut also holds one of the brackets for the driver side ignition harness. so basically pull the long bolt out and let the bracket loose because you would have to disconnect it later anyways when undoing all those ignition harness connections. the starter also has a connector and a power line for it coming from the ignition harness. this power line is held on by a nut. these are easy to do.
- Remove Clutch Release Cylinder - this is just held in by two 12mm bolts. you also need to remove the bracket holding the line higher up. this bracket is held to the tranny by two 10mm bolts. of course when i looked at mine one bolt was missing!
- Disconnect Heater Hose Line - this one is on the driver side. i disconnected it at the block from underneath the car. this was close to the big coolant plug in the block i think.
- Disconnect small air pipe to main cat - this is held in by two nuts between the cat and block. it is hard to get leverage on it wbecause it is rather flexible. some liquid wrench helps here as does cleaning off the nuts.
- Disconnected ECU harness from ECU - there are four yellow harnesses and one blue one. there were a couple other little connectors that needed to be taken out too.
Saturday March 8th, 2003
Success! The engine is out of the car and sitting on an old motorcycle tire in the garage. With the help of Reza and Calvin (also true RX-7 fanatics) we got the engine and tranny out by 8pm. I worked on the engine by myself for about 2 hours this morning retapping one of the upper intake manifold bolt holes that holds the engine hook. I spent a whole bunch of time fighting with the nuts between the main catalytic converter and catback too. Those suckers were on there tight and rusted but a couple quenches of liquid wrench, some tapping, some swearing, and a 3 foot breaker bar it came off. Of course I had to put my downpipe back on to give myself more torque on the nuts which I should have just done in the first place! Reminder to self: Loosen those nuts before removing downpipe next time to avoid wasting hours....
Hoisting out the engine was actually the most fun and quickest part of the whole process. Pulling the ECU harness through the firewall was a trip too. We had to loosen the wiper arm motor to get better access to the harness and big grommet that holds it in the firewall. Tracking all the places the driver's side ignition harness connects to was fun as well. Everything is detailed down below.
- Remove support bracket under transmission - 4 bolts
- Remove main catalytic converter
- Remove driveshaft cover
- Remove support bracket under tranny
- Remove the shifter from the interior of the car
- Drain tranny fluid
- Pull ECU harness through firewall - i first taped all the harnesses together so nothing would get caught going through the firewall hole. it also helps to have one person pushing on the rubber grommet inside of the car while someone else pulls from the engine bay. this also requires removing the bracket holding the harness to the firewall and the bracket holding it to the block where the small air pipe connects to the block (see item # 20 from yesterday). we also removed all the bolts holding in the wiper motor to get better access to the harness. there were 4 bolts to remove this. it took a good bit of tuggin and pushing but it came out without a problem. be careful of the abs lines in the way.
- We then removed the black crossmember bar that the IC sits on. This allows us to bend the AC lines back a bit as we hoist out the engine.
- Driver Side Iginition Harness - this harness is
hooked up to multiple places. you will need to look at the harness
from both below and above the car to remove all points of attachment.
i also needed to remove the UIM to undo the 3 ignition harnesses and
single GND (sub-items 8 & 9 below).
- alternator connections - one terminal held on by a bolt and one connector
- two tabs - one on the top and one on the bottom holding the harness to brackets connected to the block. just use a pair of pliers to squeeze these tabs and pull the harness away
- black connector - not sure where this goes to since there's no more description in my nots (bad notes!)
- small black connector - goes to the oil pressure sensore
- white connector - goes to the oil pan for the "low oil" warning
- small ground terminal - this connects to the engine block with a 10mm bolt
- harness bracket - this is held on by the top starter bolt as mentioned before in the starter section (item # 17 from yesterday)
- 3 ignition harnesses - these connect to the coils underneath the UIM. from left to right they are white/black/blue
- GND terminal - one 8mm nut holds this ground to the coils. remember to put the nut back to not lose it.
- Power Plant Frame Nuts - 4 nuts connecting the PPF to the transmission. you might need a breaker bar for these and the ppf will probably start to sag a little bit after these are out.
- Motor Mount Nuts - 2 nuts that disconnect the motor mounts from the subframe. at this point the engine and tranny will be free and loose from the rest of the car.
- Remove engine from car w/ engine hoist and load leveler - the load leveler is a must when taking the tranny and engine out in one piece. hoist the engine out nice and slow and use the load leveler to tilt or level the transmission so it clears the tranny tunnel and bumper. it definitely helps to have more than one person doing this job. after the tranny is pulled forward about 6 inches the driveshafter will slip out and transmission fluid will start to leak out. have a drain pan ready. we also had to loosen the bracket holding the passenger side heater hose to get the engine free. ymmv. make sure the ac compressor gets out of the way ok too.
Monday March 10th, 2003
I took off the turbos and exhaust manifold on this day for inspection. There is huge crack in between the primary turbo exhaust port and the secondary pre-spool but the turbos still boost fine. I think I will use them till they die completely.
Friday March 14th, 2003
The engine arrived today from Malloy after being shipped all the way from Virginia over the course of 4 days. I highly recommend ordering an engine from them. It is easy and they have great service.
I also installed a 2nd oil cooler on the passenger side. This was a broken oil cooler off a 2000 RZ clip but I had it fixed and it'll work great now...
Saturday March 15th, 2003
I started swapping some little parts and disassembling the old motor today taking off the accessories. I also took the time to tap the new thermostat housing to fit the stock water temperature sensor. I have my Greddy sensor mounted in the stock location while the stock on resides in the thermostat housing. The tap required to do this is a M10 1.00 pitch. That is a very very fine pitch for a hole that big and is a rather obscure size. The drill size required it a 24/64" or 9.1mm which was also hard to find so I just used a 11/32" which was 1/64" off but worked well.
Monday March 17th, 2003
Wow this project really is taking a lot out of me. I just finally completed stripping the old block of just about everything and started swapping the old stuff to the new block. The significant things I completed today was switching out the weak solenoid rack bolts with new grade 5 hex bolts of the same length. The old ones come off with a phillips head screwdriver and are easy to strip. This is probably obvious to anybody who has done the vaccuum hose job. Replacing the 11 bolts with the new M5 0.8 pitch (standard pitch) will make taking them off with a hex a breeze. The 3 bolts near the firewall are almost impossible to remove normally.
I also picked up a used Jspec downpipe from my friend Calvin. It is just like a US downpipe except there is no catalytic converter so it is just a straight pipe. It will definitely fit better than my messed up M2 downpipe. I'll be getting rid of my EGT sensor in the process and replacing it with a new Greddy Oil Pressure sensor that I received from rx7.com today.
Saturday March 22nd, 2003
Today the new Racing Beat Flywheel went on. I weighed both the stock one and the Racing Beat Flywheel/Counterweight to get a better idea of what the weight savings would be. I weighed the components on my Tanita digital scale that has resolution down to 0.2 lbs. The weights turned out to be the following:
Stock: 20.4 lbs.
Racing Beat: 8.0 lbs. + 4.0 counterweight = 12.0 lbs.
The weight lost with the lightweight flywheel turns out to be 8.4 lbs. or 41.4%. However, looking at the picture you can also tell that much of the stock flywheel's weight is on the outside of the wheel versus the Racing Beat which has basically an even spread of mass over its radius. This mass on the stock wheel means that the rotational inertia loss is probably greater than 50%. Most likely is it around 60%-65% less. This is just by me eying the wheel and guesstimating though. I didn't do any math other than what is above.
Anytime you put on a tranny you should have the clutch alignment tool. Well that's at least my take on it since it only costs a couple bucks. It probably would have saved us about an hour versus trying to figure out whether we were going to align it by eye or tighten the pressure plate after the tranny was one. It finally went on though.
I think that is all we did this day. I'm trying to remember this from about 2 weeks ago as I write this.
Sunday March 23rd, 2003
We finally dropped the engine/tranny back into the car today. Let me say this....dropping the engine in is way harder than taking it out. It took us about 5x longer.....we ran into a couple problems some people probably would not run into. First, the surface of my garage is not perfectly level. The whole thing is slightly on a downgrade with the garage door being the bottom. There is also a small drainage grill where the engine hoist needs to reside when putting the engine in the car. Second, the hoist we were using has an arm that is not quite long enough at the setting we were using it at (500 lbs). This meant the front of the hoist was hitting the bumper which was made worse by the incline of the garage! No damage though. By the time we had dropped the engine in we were dead tired because we also went to the SCCA autocross that morning. We basically were toast after that and just let the car rest for the remainder of the night too.
Just to add, we spent some time rerouting the engine wiring harness because not all the connectors were reaching their destinations on the UIM. What a nightmare!
Sunday March 30th, 2003
Well, I felt completely sick the past week while struggling to get the rest of the parts hooked up to the car. I seriously think I inhaled too many toxic chemicals. Reza came by today to help me get everything else hooked up and we started the car. It was nice to finally see where we were at. It started up on the first try but died immediately because there wasn't enough gas. Starting it the second time yielded a successfuly idle and every looked normal until....I noticed the low coolant buzzer going off and there as a small stream of coolant coming from the passenger side behind the wheel. So much for our midnight joyride! We jacked up the car and I figured out the coolant was leaking from the heater core copper pipe that I had...uhumm....bent out of shape when changing out the silicone heater hose.....my mistake. So, we gave up for the night and let the whole thing rest again.
Thursday April 3rd, 2003
So close yet so far away. After an entire month of working on the project I was very frustated at this point. I had fixed the coolant leak with a new clamp but now had a new mysterious problem that was holding me back. Oh yeah, I had installed the new oil pressure gauge and redid some wiring in the meantime. The problem was a loud, high-pitched, metal on metal fluttering sound when revving up the engine above 1800 rpm. The car drove great other than this sound. At first I thought it was the belts squeaking but adjusting them did nothing. I then replaced the airpump. Three times! All of these pumps still gave me the same sound. I finally localized the sound down to somewhere underneath the upper intake manifold. Any key symptom to the problem was that when the airpump connector was disconnected the sound went away. Therefore, the sound had to come from something to do with the secondary air injection system designed for emmisions. I was about to swap to a midpipe and ditch all thi stuff when I decided to take out the ACV and test it. What a PIA it is to remove all this junk just when you are about to seriously drive your car for the first time in 5 months! Well, I took out the ACV and had to wait until the next day to buy a vaccuum tester to test it....All this stuff had happened earlier in the week. Thursday I went down to Reza's to check out the ACV he had. We tested both of them and they both performed flawlessly. Wonderful, what could it be then? After dinner, Tapioca drinks, and almond cookies, we finally figured out it was the 1" round check valve that was making the noise. The tell-tale signs of this were an elliptical shaped smashed carbon on the back of the check valve. There was also a new black mark on the LIM from the check valve being squeezed by it and the acv in the incorrect position. Thanks to Will at C2 Automotive and Reza for helping me troubleshoot this one....reinstallation commenced the next morning...
Friday April 4th, 2003
Well, after reinstalling the acv,uim,ic, etc. i started up the car and to my surprise there was no more fluttering sound! Problem solved. Looked underneath the car and zero leaks! Hooray! I readjusted the idle and it was time for the test drive. I took it about 125 miles today. Most of the miles I did on PCH between SF and Santa Cruz. It was a great day out weather wise and was just enhanced by my excitement to finally drive my RX-7 today. What a day. I did not encounter any problems and everything was running smoothly.
Looking back I'm happy I took on this huge project. Not only did it save me a little bit of cash but it was a huge learning process from a technical RX-7 point of view and a project management experience. Thanks to Reza, Calvin, Adrian, and Will for all their help. One big huge thanks to my girlfriend, Anna, who was patient with me the whole month even though I spent most of it in the garage! Thank god it is done!!! I took a pic of a nice secluded beach to say farewell with. If you got this far reading I hoped you enjoyed my write up. E-mail me at alexwan@alexwan.com if you have any questions. Till next time................ ~Alex
