Timing belt procedure I can't find really any information on the 660cc 4A30 motor in regards to timing belt procedure so here we go. Most people who are diving in this deep probably already know what they're doing but this will help the first timer. This will just also act as my note pad to remember what the I did so I can put everything back together again Vehicle Info 1995 Mitsubishi Bravo w/ aero roof Model Code - U44V Engine - 4A30, non-turbo, fuel injected Spec - Inline 4 cylinder engine with a single overhead cam (SOHC) w/ AC and Power Steering Resources The 4A30 Bravo / Pajero manual in English is useless. It's pretty much just a parts diagram blow out but I do have one if anyone needs info https://partsouq.com/ is my go-to for parts diagrams and ordering https://www.amayama.com/en has been a solid parts vendor for all things Partsouq doesn't have I found the videos below and everything seems to be the same in regards to timing belt but the description claims 1100 cc. I think that's what the Pajero has. This YouTube video shows timing marks. He shows the engine placard which says 4a30 but says it's 1100 cc. Another solid video claiming a 1100cc but seemingly the same setup for timing belt. It shows the timing marks very clearly but super quickly so pause video. This video is awesome for showing the procedure once you're in. Parts to order - Don't rely on these part numbers. Enter your VIN and verify before ordering *** If you have time to spare, wait until everything is taken apart and make a list of what needs to be ordered. I made the mistake of not ordering everything I needed and did 3-4 parts ordered. Shipping gets expensive**** At a minimum you'll need: Timing belt - Aftermarket is fine, made in Japan - A356YU22MM TB tensioner - Aftermarket is fine, made in Japan - GT90320 Spring for TB tensioner - OEM - MD309804 Washer for TB tensioner bolt - OEM - Fuso MF450154 >> May not be needed but might as well order it. Mine had a large gouge in it. Skip further down in this thread to see more " while you're in there " parts to consider Thermostat Kit w/ gasket - OEM - 1305A025 Radiator hoses. Top is easy to get at, bottom is hard. PS Belt Tensioner - Need OEM. The KOYO alternative on Amayama is TOO WIDE and will contact the timing cover >>MD307734 Oil dipstick O-ring since it's cheap Timing belt covers because they come with new seals and you may find yourself breaking the lower cover to remove the harmonic balancer Crank and Cam seals if you're brave. I ordered them and then decided not to replace. Tags to help google to find this thread: 4A30 timing belt, 4A30 harmonic balancer, 4A30 crank pulley, 4A30 tensioner pulley, 4A30 accessory belt, 4A30 how to repair, Mitsubishi bravo, How to with Mitsubishi bravo with 4A30, How to 4A30 engine, Bravo engine, Bravo timing belt, Mitsubishi bravo timing belt replacement.
Prep to get to timing belt cover If you are going on 80,000km /20+ years you should definitely open up and check out your timing belt. This part of the procedure isn't too hard to do with some basic tools If you plan to go deeper anyway, just remove the fan and center console first to get more room to work If you are just inspecting Remove PS and Alternator belt The alternator belt is the easier of the two The PS belt is a bit more of a pain to loosen the tensioner and get it out from around the fan. I removed the entire PS belt tensioner bracket as well. There are two bolts down below and one up top. Just get it out of the way if you plan to go deeper. I removed the power steering soft lines at the reservoir to get better access to everything >> This isn't necessary for checking the belt but if you plan to go deeper, might as well remove it now. Plug the hose lines to keep debris out once disconnected Remove all of the bolts from the top plastic timing belt cover At this point you can remove the top half of the timing cover by sliding it up **** The PS tensioner bracket may need to be removed to fully remove the cover but I'm not totally sure since mine was removed anyway. Inspect the belt Inspecting the timing belt With everything out of the way you can now take a look inside You can put your socket on to the crank and turn the engine over if you want to rotate it around to inspect. Remove spark plugs to make that easier. I got excited when I saw my timing belt looked to be in good shape I then got very sad when I saw my tensioner must be rusted up and the belt was very very loose. I've seen a few other forums where this seems to be a issue for the older 4A30 motors. I suspect this would have slipped soon and done some damage. Either defective from age OR previous repair that didn't install it properly. I'd say at this point for most folks, if your belt looks OK, you don't have any noises / squealing with engine running, and you don't see any oil buildup or debris in there, just turn back now and move on lol I mean really if you don't want to deal with what's to come on this thread it's probably just not worth it. Especially if you only drive your rig now and then for short distances it will take a long time to add up to any significant miles. Possible alternatives, I see some 4A30 motors overseas for sale for <$750 but logistics and probably the same maintenance will be needed . Plus, pulling and swapping this motor looks like misery especially if you're a driveway mechanic like myself. If you have a shop to work in and more tools it's probably best to just pull the motor Relevant photos below Alternator belt removed. No room at all to work in there prepare to bust some knuckles Parking cables. The one on the left clips onto the pawl with the cotter pin in place First sighting of the timing belt w/ cover off
Gaining access to the timing belt Looking around it seems like the old saying comes in to play " the longest and hardest way is the quickest and easiest" In other words, take the time to remove all of this shit out of the way to make your life easier Tip the seats back and remove the seat belts Remove the center console. This is kind of a pain in the ass but just pay attention , mark the cables, take pics along the way. The center console will stay semi-connected, I just propped it up with a piece of wood and didn't want to further disconnect lines Once all of this is out of the way I decided to drain and pull the radiator....Is it necessary? IDK ....probably This is a very tight space to work. I don't think it'd be possible without removing the radiator. The drain is down below on the driver side Two bolts with rubber bushings and metal sleeves within on each side of the radiator I had to remove the stupid plastic shroud and it was tough to get all the bolts. I broke some pieces and glues back together, whoops You may be able to get the hoses off and luck out but I think the shroud needs to come apart to get better access to the hose clamps Disconnect coolant and transmission lines. Be gentle, your radiator may be fragile at the connections and they could break. Mine were very yellow Once it's out, remove the fan. Be careful as it may be cracking All of the radiator foam fell apart and I can't find a good replacement My radiator looks a bit banged up. OEM is expensive at $550 plus so I will just clean and re-install What to inspect at this point Upper timing cover - There is a seal around the edge. Mine is dry rotted and cracked. I ordered an entirely new cover and it comes with a seal Lower timing cover - Still partially hidden by the harmonic balancer but I can see the seal is cracked. Order a new cover , it comes w/ seal Camseal - Mine is leaking. No way I am going to try and remove and replace. I will dose this engine with some ATP205.....maybe ....maybe not idk Crankseal - Can't really see it yet, pulley will need to be removed Tensioner, washer, and spring - My tensioner seems frozen and isn't applying any force to the belt. The spring looks rusty and the washer is chewed up Water pump - I lucked out and the previous owner replaced the WP after it was leaking pretty bad. For some reason he didn't do the timing belt Oil dipstick o-ring. Cheap and might as well Relevant photos below What you're working with once the radiator is removed and center console is out of the way Photo of lines still attached to radiator. Keep track of where the transmission cooling lines go. Longer one on PS side goes to the top. Take that fan off, it's easy enough . I think you may need to remove the oil dipstick as well
Harmonic Balancer / Crank Pulley Bolt Removal Bolt head size - 17mm ** There is also a washer on the bolt that may get stuck behind, don't forget it. Here is where it gets interesting and you'll be happy the radiator is out of the way Soak the bolt in PB blaster and let it sit for a day or so I doubt you can fit any air tools down there and I don't own air tools anyway so hmm I wrapped a belt around the pulley and tried to hold it tight, that was comical and didn't work at all I don't suggest the rope trick you may read about on google, works well on single cylinder small engines, not this motor. The 4A30 engine rotates clockwise *** Be very careful doing this trick it can go bad quickly Remove spark plug coils on all plugs so engine can't start Use a 17mm 1/2" deep impact socket At first I tried to just hold the breaker bar and bump the key. Maybe if you have another set of hands this would work but it ripped aggressively out of my hand so I don't advise it Get your socket on the bolt and I just used a regular 1/2" wrench( not a breaker bar, it was too big ) Make sure it's sitting flush on the crank bolt Wedge it against the top side frame rail on the passenger side ( or whatever that solid piece of metal is ****Watch out for the brake line running below the rail**** Very carefully turn the key for a second and let go, just enough to turn the engine over. First time, fail Second time, fail About to give up and on the third time , BOOM bolt came loose and I was able to take it out by hand the rest of the way. >> The key is making sure it's sitting square on the bolt, second set of hands would help here. Harmonic Balancer / Pulley Removal OK you go the bolt out, nice work. Now take that good feeling and stuff it in a sack The pulley doesn't have any threaded holes or slots to pull it off. To make maters worse it's right against the timing cover so a three jaw puller won't work How the heck do you remove this thing? Hmm well I bought another timing cover anyway so fuck this original one, I broke it into pieces and removed it . Why did I do that? IDK I'm and idiot but now I have space behind the pulley and I can spray some PB in there A local mechanic was nice enough to tell me to just whack it with a dead blow hammer. I got a 2x4 against the pulley and bashed it a few times , rotated, bashed again. After a few whacks I could see it broke loose but not good enough I used a pry bar from the passenger side and sort of used the tensioner pulley as a fulcrum which seemed to work to break it loose. ( This is sort of risky, just don't put too much force on that tensioner and break something) Then I spun it a bit, did it again and again then I saw it broke free. I was able to remove it the rest of the way by hand Relevant photos below The starter bump trick for breaking the crank bolt free No space at all for a three jaw puller with timing cover there Lower timing cover broken off . First view at tensioner spring and lower belt Harmonic balancer / crank pulley inside with no bolt or any option to pull and remove
Harmonic Balancer Removed - Inspect Timing Belt and Surrounding Components With the pulley removed take some time to look around and inspect everything and figure out what you'll replace Covered in oil Screenshot from that youtube video showing spring orientation, camshaft upper timing marks and crankshaft lower timing marks. Tag: Mitsubishi 4A30 Timing Marks Crank shaft sprocket lower timing mark Mitsubishi bravo 4a30 engine
While you're in there repairs to consider Seals Crank and Cam seals - I decided not to swap these out and may regret it but I really didn't want to remove pulleys and start pulling / replacing seals. Oil pump drive/driven gears + seal - To go this deep would require splitting the oil pan and would be really hard with the engine in vehicle. If you pull the engine you can consider replacing these parts Oil dipstick o-ring. One 12mm bolt up top holds the dipstick tube in place. Remove it and pull the dipstick tube out. The o-ring on mine was dry and cracked. Remove and replace Hoses Top radiator hose - Easy to change and might as well get a replacement if you're ordering parts. Bottom radiator hose - Looks like a bitch to get at from above. Maybe if you're on a lift or can pull the tire off. I'm not touching it. These hose clamps are also a pain in the ass to deal with. Other coolant lines - I see some other lines floating around but if they aren't leaking I'm not touching them Vacuum lines - The fuel injected version of these motors doesn't have too many lines. Whatever I could get my hands on, I removed, cut back an inch or so, and reconnected (if they were cracking ) Radiator and related parts Fan - My fan blade has several pretty decent cracks around the blade. I use JB weld plastic epoxy and it's worked well in the past so it should help reinforce this blade Radiator - The radiator plastic is showing it's age and the fins are a little banged up, probably from previous repairs .OEM is $550+ so sticking with this one for now.. Clean up the fins, straighten as many as possible, and flush with water Radiator shroud - cracked in a few places. JB weld and duct tape for the win Transmission cooling lines - Mine are weeping from the bottom. Local auto parts store for line and new clamps, 20 bucks later and you're good to go. Be gentle when pulling off the lines, the connections could be brittle >> Re-installing the clamps on these was a bitch. I realized you can sneak in from the front side, remove that metal plate thing for a better view. I used a small socket with long extension to tighten the clamps. A second set of hands from above would make it easier Thermostat - I swapped mine while I was in there. Easy to do with the center console out of the way. My gasket was rock hard and broke upon removing. Clean and replace it all ** The jiggle valve was oriented towards the front of the vehicle. Usually you put this at the highest point but this thermostat lays flat so I'll just replace it as I found it Fan clutch - Should probably be replaced but at $200 for OEM it ain't worth it unless it's overheating Engine parts PS Tensioner Pulley - You need OEM. Koyo aftermarket is too wide Might as well replace your accessory belts sine they are removed anyway Ignition coils - Tough call, it's running fine but they are old. Should replace if it's in the budget but easy to do once everything is back together Relevant photos below: Valve pointing to the front of engine, lined up with bolt hole Timing belt tensioner spring has longer prong on the outside / contacting the tensioner bracket. Shorter side on engine block
Final steps - Installing timing belt and tensioner Install the tensioner pulley and pull it back towards the water pump. Snug up the bolts so it holds with spring tension I'm not really one for toque specs, IDK just put your wrench on it, get it wrist tight, and then snug it down with a little more leverage Install the spring. Hook the short side first and then the long side. It can be done by hand but If you're having trouble here wrap it with a skinny rope to pull the spring. Once it's hooked, pull the rope out ** Remember the longer part of the spring is to the outside of the motor and contacts the tensioner bracket. Shorter side to the motor Getting the belt on was sort of tough with only one set of hands. It worked best when you start with the crank pulley, keep it tight and then wrap around the oil pump. Walk it up to the cam but if you pull to hard you're going to spin the crank out of time Last step is to get it around the the tensioner. The crank kept turning on me so make sure you double check timing and spin the engine a few full rotations to verify. This is done by grabbing the bolt on the oil pump and rotating clockwise. A bright flashlight, phone camera on wide, and break your back to get a good view of the bottom mark. Line up the camera nice and square to verify timing marks are lined up right Top mark is much easier to see
Engine Timing Marks on 4A30 660cc SOHC Lower mark is on the inside between the crank and oil pulley. The engine block has a dot and the pulley has a half moon notch. It's kind of hard to see, from the passenger side is the best angle. If you're not looking square at it, it may not be as lined up as you think Top mark is easy to spot above the cam. It's a little notch and the cam has an arrow
Replace timing covers Bottom first then top sort of slides in / overlaps the bottom I think there was one longer bolt in the mix here. I used it on the top part of the cover that overlapped with the bottom cover Install Harmonic Balancer Remove flywheel inspection cover (?) Located under driver side between engine and transmission. 4, 10mm bolts hold it in place I expected to see a toothed flywheel but instead was met with some plate. This would be a lot easier if not on a gravel driveway with no assistance I used a narrow 18" bar with a hook at the end ( harbor freight pry bar set ) Get one of the holes in the plate to line up at 9 o'clock Use the hook side of prybar and place it in the hole Wedge the other side into the frame. This held strong enough to allow me to use a break bar and tighten down the crank bolt Do this once and do it right. After test driving for a few weeks I can't help but be slightly paranoid about this bolt loosening up but it's too tight to get down in there and check once it's all back together. Maybe, from down below but too much snow to check for now. Relevant Photos: Upper Timing Cover Pry bar technique to hold engine for tightening crank bolt Lower timing cover w/ pulley installed
Re-install everything I tried to test run the engine but transmission fluid was weeping out of the hoses with the radiator disconnected Assuming you are confident in your timing belt install, it's time to just put it all back together and hope it works Install the cooling fan first. I forgot to do this and had to pull the radiator after fully installing everything Then install your PS belt first , alternator belt second Then you can drop the radiator in. Lay it on it's side, shroud side down. Slowly get it lined up and then roll the bottom side in to place around the fan Before mounting it, get that bottom radiator hose on Then, line up the radiator and maybe peg one bolt in place to keep it steady Work your way up to the lower transmission line to the radiator >> The lower line is the shorter hose connected to the outer fitting Connect the upper transmission line to the radiator >>The upper line is the longer hose connected to the inner fitting. See parts diagram if in doubt Pop the longer line into the bracket on fan shroud Ziptie hoses gently together near belt so they don't rub belt Secure the radiator with the four bolts Install top radiator hose PB blaster and crack weep hole in thermostat housing Fill radiator with Green / Asian coolant Install power steering res and top off fluid You can either test run now or button up the center console
Test Run It took 6-8 turns of the key to get it to rumble to life, which isn't too out of the ordinary for this engine A few squeals for the first minute or so which sucked but I'm assuming it's due to greasy / some fluid on belt OR I may have tightened the PS belt too much. The noise went away after a while and I stopped worrying about it. Test run went well, no issues to note Run engine / drive full heat cycle, turn temperature control to full hot and turn on rear heat as well ( I think it's coolant powered and not electric , haven't looked to close ) Let cool overnight, check coolant levels again. I topped off two more times but it seems to bleed the air pretty easily as I didn't have any issues. The radiator was fully empty and the lines drained as well. It took barley half gallon to fill up I noticed my coolant gauge stays a lot more steady at just below half way but then again it's cold outside. The true cooling test will be next summer Conclusion on Timing Belt Replacement What a back breaking and knuckle busting engine to work on. Being bent over the "hood" for a prolonged time sucks A lift or garage would make this repair a lot easier. Along with a second set of hands for some of the tasks It took me 3-4 weeks to get it done while waiting on parts and doing a few tasks at a time I'd guess I probably spent 12 hours in there. 4 of those hours were just staring at things , re-doing what I just did, fixing screw ups, etc. Now that I know what I am up against, I suspect I could get in to the timing belt and back out again in 4-6 hours It's not a terribly confusing job, it's just tight spaces with a lot of crap in the way. Access from down below would make a lot of this easier. Did it single handed in a gravel driveway with flashlights. I can just barley squeeze my head and arms in from the side and up front to get to the lower bits I needed to Glad it's done, hope I don't have to get back in there anytime soon. All buttoned up, coolant topped off and ready to rally Always easy to diagnose engine noises when driving
The roo' has been doing good after a dozen or so longer test runs but the belt squeal is annoying me. Luckily I found out it's not timing belt related so that was a huge relief. Belt squeal The power steering belt tension was the culprit of my belt squeal At first it would squeal at start and go away so I just ignored it. Then it hung around for longer I sprayed a bit of water on the belt when it was squealing and luckily the noise instantly went away. This usually relates to belt tension. You can tension the belt with everything together although it's a knuckle buster. When the belt was squealing I was able to roll the belt over more than half way, almost a full rotation, too loose. Adjusting power steering belt tension 14mm socket on a 3/8 ratchet can wiggle it's way on to the locking nut 12mm socket with long extension on 1/4" ratchet can get on to the adjustment nut Use low torque here, choke up on the wrench and you'll start to feel it getting harder to turn when the belt is snugging up. Test belt as you tighten. Don't forget to re-secure the lock nut when done. Currently I can turn the belt over slightly less that half way and the squeal went away. Fast forward after a 20-30 minute test drive and first I could smell belt rubber burn then I honed in on sort of a rotational groaning noise. So I think I tightened the belt too much I backed it off a little bit and will test again soon . I can now turn the belt over about 180 degrees , a little less
The squeal is back on cold starts, maybe even louder now, what the heck. If I pour water on the PS belt, it goes away temporarily then starts back up. Upon closer inspection it kind of looks like my idler pulley is a few degrees out of line with the other pulleys , sort of tilted, or I'm just nuts. So I loosened everything up , pulled the belt , busted a few knuckles , and made damn sure the idler was seated in the adjustment groove properly. It seems like it's in there but it also seems tilted a little bit. I should probably remove the bracket and inspect closer but ughhhhhhh I don't want to. When I reinstalled and adjusted the tension again, a bit looser this time , the squeal is gone. So maybe this is a belt tension issue and the alignment issue is in my head . Will see if the squeal is back on the next cold start ***** Calling any 4A30 engine owner , can someone out there open the passenger seat up and take a look down into the belt area. Does it all seem in line ? Does your idler look sort of tilted ? How tight is your belt ? Can you snap a pic nice and square with the belt looking down into the abyss
The belt squeal is driving me crazy. I'm positive it's the PS / WP belt but I don't know if it's an alignment or tension thing. The belt doesn't look glazed over and seems to be in good condition still. I was convinced maybe the belt was too tight, so I backed it off a bit more than I would usually do, and the noise went away. Fast forward til this morning, and it's back but quieter and doesn't stick around for as long. It could still be a matter of trying to get the tension right. On the other hand the idler looks mis-aligned as well but I can't see how that's possible and it may just be a weird angle that I am looking from. I also think maybe oil from the VCG is dripping down there and that could be another cause. Oh well, for now there isn't much I can do but monitor it. When I open it back up to do the VCG I will hopefully solve this problem too.
