My Valve Measurements :
This document will serve as a guide (not a step by step manual) for the DIY-mechanic who wants to tackle this semi-difficult and labor intensive timing belt maintenance on SW20. I highly recommend purchasing the official Toyota service mechanic manuals and going through them step by step. Also included in this write up will be the intercooler removal, water pump, thermostat, AC belt, alternator belt, valve lash check, and adjustable cam sprocket install.
The difficulty of this task is not the timing belt itself, but all the steps required just to get to the timing belt. The installation of other parts and the chassis prohibit access to the 3S-GTE.
<SOAPBOX>
Folks on the the MR2 list gossip about methods of cheating the Toyota dealers by using a $199 timing belt service coupon. Anyone who chooses to do this has made a poor decision. Why, you ask?
Timing belt maintenance requires several important things : time, patience, a vast tool set, all the right parts, extremely neat organization and work attitude, and a backup car. I easily put 30-40 hours into this task. I do not recommend a mechanical novice to tackle such a feat. Please consider bringing the car in to a professional mechanic with these directions to aid the wrencher. To see how you stack up, check out my mini-bio. I performed this task without the help of another person. I could see this not being for the case for other people. So another good thing to have around is a another set of hands. The second person should be someone doesn't have to be mechanically inclined but should have a moderate amount of strength (i.e. people with meek SO's or better halves should rethink getting them to help) I didn't damage any nuts or bolts, except for one. Again your mileage may vary, so be careful when removing fasteners (some did show signs of slight corrosion) ABSOLUTELY NECESSARY : You must have good parts removal organization (bag and label everything) Remember, you will be also be reassembling at least 15 hours from when you begin. So your memory will be disconcerted. When I physically reached the timing belt removal stage, I had about 6 brown grocery bags full of parts. Be afraid! Please note that the BGB indicates to never rotate the crankshaft CCW! I can't imagine what possible damage could happen, but it's possible. Make sure you practice lining up TDC before disassembling the belt so you have a feel for what lining up @ TDC takes (very small torque inputs on the crank as you approach TDC). Disclaimer : Do not hold myself responsible for any damage you perform to your car. These directions in no way are the only or the best way to perform this work. I can only officially say that I intend to give DIY-ers some hints on gettin through the tough times for this task. Please note, that I don't mention specifically cleaning anything off. It's your call when or if you wish to clean various parts or areas of your car. Since timing belt maintenance entails so much, you could easily work a little bit more and perform the following misc. work :
Many tools are required for performing this task. While I could in theory list them all, it would be such a long list (and I'm not very inclined to). Here's a noteable list :
You must have as many wrenches as possible. It would be beneficial to have short ones, long ones, and offset head ones.
| Part Number | Description | Discount Price | Notes |
|---|---|---|---|
| 13568-79045 | Timing Belt | 24.31 | |
| 90916-02365-78 | AC Belt | 12.56 | |
| 90916-02341-83 | Alternator Belt | 7.90 | no PS |
| 13505-88383 | Idler Pulley No.1 | 50.34 | 9105-on |
| 13503-63011 | Idler Pulley No.2 | 29.89 | |
| 13540-88382 | Belt Tensioner | 24.69 | 9105-on |
| 90179-10016 | AC Idler Pulley Nut | 0.66 | common nut |
| 90105-14011 | Crankshaft Pulley Bolt | 6.xx | -9308, your option to replace |
| 90311-35022 | Camshaft Oil Seals (x2) | 2.78 | |
| 90311-42026 | Crankshaft Oil Seal | 3.64 | |
| 11213-88381 | Outer Valve Cover Gasket | 10.09 | |
| 11214-88381 | Inner Valve Cover Gasket | 3.65 | |
| 90916-03075 | Thermostat | 12.50 | Same as 5S-FE, includes gasket |
| 16100-79126 | Water Pump and Housing Kit | 63.12 | Includes all gaskets |
| 15785-35010 | Small Gasket in Oil Cooler | 0.56 | |
| 90301-52006 | Large Gasket in Oil Cooler | 2.10 | |
| 16258-88383 | Rectangle Gasket From Cooler To Base | 1.86 | |
| 96732-19010 | Dipstick O Ring | ? | |
The first order of business is to loosen the crank pulley bolt. If you can't get it loose, there's really no point in continuing. Remember don't remove it, just loosen it. Loosen the lugnuts, and then jack up the car on the USA rear passenger side frame rail. Remove the wheel to access the engine crankshaft area. I employed Marc Summers' method of using the starter motor to break the crank bolt loose, EXCEPT I put my breaker bar w/ 19mm socket on and then lowered the jack to wedge the ratchet onto the ground/concrete. Previous attempts to have a strong person hold it were unsuccessful. The starter motor has an intense peak torque output. Remember the engine rotates clockwise, so the ratchet should be set to loosen (counterclockwise). This is important because if you set it the wrong way and blip the starter, I don't know what will happen (you may need a new crankshaft) The starter overrunning gear (clutch mechanism) may engage sensing the high resistance but you never know! If this method scares you, I recommend finding an impact wrench. Remember : if you use this method, disconnect either the coil wire or the coil harness in order to prevent the engine from running. You may even want to disconnect the EFI fuse since the EFI will inject gas into the engine. Get the car up on stands. The higher it is, the more room you have below. You don't need a lot, but it sure beats banging your head on the under chassis/suspension/etc. and wiggling in and out from underneath. Keep in mind, you will also need a step ladder to peer in from top the higher it is. People with a lift need not listen to me here. Remember you will be doing a full coolant flush here, so make sure the car is on level ground too. Make sure the car is orientated in a way to facilitate ease of wrenching on the timing belt side of the car too. Remove the 3 plastic shields underneath the engine area. This should expose the coolant lines for the flushing as well. Also remove the one plastic shield underneath the radiator in order to drain it. Also, remove the USA passenger side engine lid panel (not necessary right away, but just a good thing to do early on). Finally, I would recommend disconnecting the battery cable sometime. If you intend to put this project aside for a week, you don't want the battery to die.
I wanted to measure my valve clearances, so you must get to the valve cover. This isn't as trivial as it would seem for a 4 cylinder engine. Remove the rear cross brace. Remove all intake piping from turbo to throttle body. Remove spark plug wires and plugs. Toyota routed two hoses above the EGR. I would recommend disconnecting them and putting them aside. This eases EGR removal. Now remove the EGR (I removed it as the whole unit). Remove the throttle body. I didn't have to remove the BOV from the intake piping. You will have to disconnect the water lines to the throttle body, so some will spill out. Be prepared. This may also be a good time to do the throttle body bypass. I removed both rubber hoses, used another short hose to loop the exposed water lines' nipples unto themselves. Also, disconnect the PCV rubber hose (from valve cover to turbo inlet hose). The valve cover itself is held on by screws (the longer ones go in the middle of the cover naturally) At this point, it's possible to measure your valve clearances. Ideally you should adjust your valve clearance after you reinstall the timing belt (since your cam timing may be slightly different than the previous installation) I wasn't feeling particularly anal about that, so I measured them @ this point (since I verified the cam timing was dead on, and I intended to reinstall the belt dead on as well) The 3S-GTE has two TDC camshaft profile positions. So if you find that the appropriate valves to check aren't lined up correctly, rotate the crank one more revolution. The cam lobes should be horizontal for the valve clearance you're checking.
My Valve Measurements :
Seems like a simple task right? Not at all! Why? The intercooler. Sounds painful already doesn't it? :) You can thank Toyota shoehorning for this engineering fit! Gonna break this up into subcategories now. I don't think it's necessary to remove the intercooler in order to get to the motor mount IF you have a Greddy intercooler.
Also, Dave Aucott reports on his 1993 SW20 -- the motor mount can be removed without removing the intercooler first. Try it out.
There are two pulley systems mounted above the motor mount. Both have plastic covers attached with screws. The one behind the strut pillar removes with a moderate amount of work (check the amount of harnesses you need to disconnect it may be 2-4 heat shrinked with it). The pulley directly above the motor mount deserves special coverage since it's mildly irritating to remove, but a pain in the ass to reinstall. On all of the cable linkage, I didn't have to loosen the nuts adjusting cable tension except for the linkage on this one. It's probably a good idea to mark the double nuts so you know where to tighten down during reinstall. 3 bolts hold this thing on. The hardest bolt is actually underneath the system attached to the fender area. You'll have to reach down and use a small 1/4" ratchet w/ an extension to remove this bolt. Just imagine reinstalling it now! You might need someone with smaller hands if you're big armed. While you're in the area, remove the brake booster vacuum hose (goes from the intake manifold to a hardline on the strut tower).
Disconnect the O2 sensor harness, the fan harness, and the AC harness. Loosen the 3 bolts holding the fan on. Remove the bolts, and then the fan.
You will need to remove the engine hook mount first, to remove the AC idler pulley. 4 bolts hold this hook on. Now you have access to removing the pulley. You can either loosen the tension adjusting bolt and the pulley nut or cut the AC belt. I cut the belt since I was replacing it with a new one (the pulley nut strips easy and is hard to access) Two of three mounting bolts for the pulley are removed easily. The third one is a major pain in the butt. I loosened this one from beneath the car, and you're going to have to find a good ratchet/socket combination in order to get it. It is even tougher to reinstall. Here's a hint on the pulley nut : use an offset box wrench on it from down below.
Before you can remove the heavy compressor, you need to clear enough room for it to swing off the engine block as well as allowing it's lines to have enough room to flex/bend. I totally removed the 2 mounting brackets for the parking brake line. Disconnecting the parking brake line from the caliper is straightforward. Be careful not to damage the cotter pin, or else you'll have to get a new one. Next remove the two bolts holding the lower chassis brace on. Then I disconnected two brackets holding the AC lines to the chassis underbody. The BGB indicated only one bracket to remove. I did another one just in case. So now you can remove the two bolts holding the AC compressor to the block. One of them is a pain to remove/reinstall since one of the lines is sorta in the way. Be careful when removal/reinstall of these bolts -- if they don't thread smoothly adjust the compressor's position til it does. It may take a bit of fidgeting -- yes the compressor is heavy! Okay now you can swing the AC compressor down. I tilted the pulley downwards, and the pulled it toward me. It's a tight fit out of there, but you can do it! You will need strong arms here! Be careful as to not bend/kink the AC lines and be careful with manuvering it around the water hose. It's up to you when you want to drain the coolant. If you do it early on, then you can disconnect the large coolant hose and it will be out of the way of the compressor and the intercooler for removal. I don't like the idea of having the coolant passages staying wide open exposed to air for a long time (rust). Don't forget to find a way to suspend the compressor, do not let it hang by it's lines!
2 bolts hold the bottom of the intercooler to the chassis. And 2 bolts mount it
to a bracket at the top of it. 1 bolt holds the bracket to the chassis. Remove
everything. Now you can remove the intercooler. My advice is to swing it by the
thermostat area, and back it towards the firewall. Get it around the coolant
hose (very important) You should be able to pull it out now. Be very careful!!
If you bend any of the fins, you will be spending time unbending them w/
a pick! It may be possible to remove the intercooler w/o removing the AC
compressor but it would involve damaging it to some degree. Try it at your own
risk!
Remove the weight off the motor mount by jacking up the engine on the oil pan. Be sure to place a peice of wood or similar object to avoid denting the oil pan with the jack. Remove the engine mounting stay (top plate) by the two bolts and nut. Now you remove the two nuts and long through bolt holding the motor mount to the chassis. The reason the intercooler needs to be removed first, is you cannot remove the long through bolt of the motor mount w/ the intercooler in the way. Thank Toyota again here. Now remove the motor mount. Patience : the motor mount bracket was extremely annoying to reinstall. No motor how I positioned the motor, I just could not get it back into position. Remember how you slipped it out, for this may benefit you later during reinstall. Scratching up the chassis will happen a lot here. Also, if all else fails keep the No.2 timing belt cover off, then mount the bracket. Then put the cover on. I managed to get the bracket off by putting the cover on afterwards instead of before.
So now you can remove the 3 bolts holding the cast iron heavy and strangely shaped motor mount mounting bracket. The bracket is very close to the chassis so it's hard to get it out. You should either jacking the engine up higher or lowering it in order to get enough room to remove the bracket. In my case, I jacked the motor up higher.
Remove the no. 2 timing belt cover by removing the 5 bolts. Set the crankshaft at TDC for No.1 cylinder while also lining up the camshafts. The cams have TDC markings on the No. 3 timing belt cover (hard to see, use a mirror) and on the camshafts themselves. The latter method is what I used (you need to line up the marks on the camshafts w/ that of the No.1 camshaft bearing cap).
Remember : before totally tearing the timing belt apart, memorize how the belt is routed underneath the timing covers. It may be intuitive for the seasoned mechanic, but novices may not see it as readily. Okay now remove the two mounting bolts and the belt tensioner. The belt should now have a lot of slack now. Now remove the crank pulley bolt and the pulley (you did loosen it already right?) This may be bothersome to loosen if you've spun the motor over too many times trying to line up TDC. Once loosened, a mild impact wrench should get it off quickly. The pulley itself will wiggle off. Take care not to damage the crankshaft. Okay now remove the 6 mounting bolts and timing belt cover no. 1. I believe some of the 6 mounting bolts may be different in length, so remember where they came from. Go ahead and rip the belt off the various pulleys at this point.
Idler Pulleys : Removing these two pulleys is very straightforward. I highly recommend removing them to judge the shape of the sealed bearings. I spun my original units, they spun w/ a lot of drag and noise. Probably better to buy new ones flat out. Crankshaft Oil Seal : you will need to remove the inner crank gear pulley. Just slide it off (be careful not to scratch the crankshaft, and watch how it slides off the keyways). The oil seal needs to be pried out. Be VERY careful. I highly recommend a prying tool that won't scratch metal (like a strong toothpick or plastic pick). Slide the pick between the crankshaft and seal and pull it out (will take some hand strength). Working around the oil seal in various spots helps. Destroying the old seal in the process is acceptable; just don't scratch anything!!! Apply a light grease to the inside edge of the oil seal (if it doesn't have it) You don't need the SST to drive it in, just find a decent size strong cup to tap in the seal w/ a light mallet. Cam Timing Gears and Camshaft Oil Seals : Remove the cam gears takes quite a good deal of strength. You will need a 24mm wrench to hold the cam still while you loosen the bolt. The intake cam gear bolt came off w/ medium amount of effort. The exhaust cam gear bolt would not budge. I wound up jacking up the motor to its highest position and squeezing in my $50 impact wrench in there. This loosened the offending bolt. Be careful not to strip it. Unbolt the bearing cap over the cam oil seals. Put a light grease on the inside of the new cam seals seat them on to the end of the camshaft. Reinstall the bearing cap. Try driving them in as far as possible. It's too tight of an area to use a mallet to drive in the seals like the BGB indicates. My cam seals were leaking slightly. Be careful not to lose the knock pins (woodruff keys) that align the cam gears!!I purchased an AEM adjustable cam gear. Installation was simple. Merely swapping the OEM unit for the AEM one. You should cut the No.2 (upper) timing belt cover so as to ease dyno tuning sessions. Make sure you perform the cut so as to expose all three adjuster bolts on the cam gear. I made my cut a wee bit on the high side so only 2 of 3 bolts are exposed. I have not tried dynoing the cam gear yet. Make sure you use loctite and the provided washers on the slider bolts.
Replacing the water pump is pretty darn easy compared to everything else at
this point. Thank goodness! It sure is nice to do something easy for a change.
Okay before you can physically remove the pump, you need to loosen the things
attached to it.
Note : if your MR2 doesn't have AC, it will use a different water pump
altogether. I am told it mounts w/ 4 bolts instead of 3. The 1991
BGB does not document this. The 1993 BGB does.
Remove the one bolt mounted the dipstick to the thermostat housing. The dipstick will be loose now and can simply be pulled up and out of the block/oil pan area. You should replace the gasket that seals it into the block. Also, before removal it may be wise to wipe/wash off the base of the dipstick mounting area (so that no crud falls into it during your removal of it) Remove the oil filter (I opted to drain the oil too and put some fresh oil in). Use a 30mm socket to remove the oil cooler bolt. Be very careful not to crossthread this during reinstall. It should thread smoothly, if it doesn't you may need to wiggle the oil cooler base a bit (the bolt mounts the oil coiler to the base, so if the holes aren't aligned correctly you will know) Next remove the two nuts and gasket on the flange area of the oil cooler. After this the oil cooler will flop around on the rubber hose connecting it to the water pump. Disconnect the hose on one end (I chose to remove the hose clamp on the water pump side) This may be troublesome to do. Now you can remove the oil cooler. Don't forget to put new gaskets on the underside of the oil cooler before reassembling. You will need a pick to remove them.
With the oil cooler out of the way, you can now remove the two nuts mounting the the water pump housing to the coolant hard pipes. Now you can remove the 3 bolts mounting the water pump to the block. The removal sequence is important. Make a note of it. You can tug the water pump assembly out now. Be sure to remove the o-ring and gasket from the water pipes.
Since I bought a new water pump assembly (including the housing), I didn't need to dismantle the original assembly. I simply replaced it outright. Don't forget to use the new gaskets included w/ the new assembly. I did swap over the thermostat housing and put in a new thermostat and gasket (the gasket should come w/ the thermostat) When installing the thermostat, you need to align the thermostat's jiggle valve w/ the cast housing protrusion. Accuracy isn't important here, as the manual indicates a +/- 5 degree position. During reinstall, you need to apply soapy water to the o-ring going to the water pipe. And the torque sequence of the water pump is the opposite of removal.
At this point, it's time to start putting the car back together. You should put on whatever is beneath the No.1 (lower) timing belt cover (oil pump, crank timing pulley, idler pulleys, install the timing belt on the lower area, crank pulley, the lower cover, etc etc). Ensure the cams and crank are both @ TDC. Now thread on the top portion of the timing belt.
I opted to buy a brand new belt tensioner. The new tensioner has the grenade pin set already; so you're already to go ahead and install it. However, if you need to reuse the old or one reset the grenade pin -- a good sized c-clamp can be used to do it (although it may take a few tries). You don't need a press, but take care not to damage the tensioner with the c-clamp.
Remember, you need to keep the cams and crank in sync while tensioning the timing belt! Be sure to pull up on the water pump side of the timing belt. This will ensure the belt has no slack. Now pull the belt up and over the cam gears. Make sure the camshafts don't walk under the valve tension! If necessary, hold the cam gears still with either the 24mm wrench or on the cam gear bolt. In my case, the exhaust cam had sufficient tension to hold the timing belt tight. This really helped me out a lot. I don't know if this would be the case for others. Loosely install the tensioner. Don't tighten all the way down, but snug. While you tighten, apply torque CCW on Idler Pulley No.1 as far as it will go.Okay now insert your 1.9mm/.075in feeler gauge between the tensioner and the No.1 Idler pulley. Apply 18Nm or 13ftlb of torque CCW on the No.1 Idler Pulley. At this point, alternately tighten down the belt tensioner fully w/ 21Nm/15ftlb.
Okay! Now your ready to let the tensioner keep the belt tight. Release the grenade pin. Afterwards, you should rotate the crank over a few times and make sure the cam timing is still correct. Be careful though! If the crank moves and the cams do not, your timing will be off. If you suspect this may happen, you can cheat and use your wrenches to walk the cams along as you rotate the crank. This may be necessary until the tensioner takes effect on the belt. You're all done! Hopefully you will do this all correct on the first try! Good luck!
Both the AC and the alternator will be covered with some oil depending upon who's been doing your past oil changes. It's your decision whether or not to clean them. Also, you will need some way to measure your belt tension otherwise you may need to re-tension them in the future. Overtightening them can cause premature belt failure as well as excessive wear on the accessories. When using new belts, it's probably wise to check & retension them after they break in (several hundred miles).
I opted to install the alternator belt before reassembling the motor mount
area. Of course you will need to put the crank pulley back on, so you can
install the belt. You need to loosen the alternator pivot point on bottom
(a bit hard to get at) Be careful with this -- don't round it! It may be hard
to loosen and you don't need to remove it completely. I used a ~2 foot pry bar
to force the alternator to move -- be careful to not to damage any metal
surfaces while doing so.
New : 120 +/- 20 lb Used : 104 +/- 20 lb
Before putting the AC, reinstall the intercooler (if stock), the idler pulley,
and various motor mounting components. Be careful not to bend the intercooler
fins during belt tensioning. If you're upgrading the intercooler fan, make
sure the fan doesn't hit the pulley. The AC belt tension procedure is
straightforward. Problem areas are 1) the cruise control must be out of the way
and 2) the idler pulley nut is hard to get at for locking down or loosening up
the belt tension.
New : 160 +/- 25 lb Used : 100 +/- 20 lb
The pulley nut locks the pulley into position. The long bolt that
passes through the pulley bracket adjusts the pulley height.
Turn this bolt to adjust tension, then tighten the pulley nut
when you're confident of belt tension.
Thanks go out to Jeff Barton @ Cabe Toyota in Long Beach, California for the great prices
on the parts, Ted Ng @ AEM for the tips on the cam sprocket, and of course my girlfriend
for loaning me her car to drive when RumpShaker was dismantled.
