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I just picked up a new to me 91 4runner. The person who sold it was a friend of the seller and there weren't any maintenance records so I was planning on checking the timing chain and if worn replacing that. What else do people generally recommend replacing when in there? Water pump? oil pump? Oil pump o-ring? Crank oil seal? it currently has 340k on it so really curious what has been done to it to keep it ticking this long.
Looks like theres also an oil leak somewhere as theres oil spray on the alternator, most of the pan and the lower center part of the engine so i'll have to clean it all up and see if i can pinpoint that.
Get it clean, get it dry then assess what might be leaking.
Anything you can leave OEM is way better than an aftermarket part, these are way over engineered from the factory. For example if you ask a machinist to set the OEM piston clearance they will laugh and tell you $2k..
Fluid on the alternator is probably power steering if your luck it's the return line which means at worst a new hose.
If it's actually oil on the alternator, you might take a look at the crankshaft where the main front seal, the one in the oil pump, rides. It has a known problem where the crankshaft develops a groove where the seal rides. This allows oil leakage, even with a brand new seal in.
There are modified seals out, however, that ride on the crank in a slightly different position, avoiding the groove, allowing a proper seal again. They're about the same price as OEM seals are, and press into the oil pump same as the original. Pretty easy to find online, too.
Of course, to check this requires you remove the harmonic balancer and pulley assembly. That means not only breaking the main bolt, that holds it on, loose, but, when you're all done, tightening it down again. THAT'S the hard part. How to hold the crankshaft from turning while applying a large amount of torque to the bolt. There are a couple of threads in the forum on how to make a SST that allows you to torque the bolt down properly.
Naturally, once the oil pump is off, you'll need to replace it's seal, as well as the front main seal, anyway. It does give you a chance to check the vanes and pressure relief valve in the oil pump, too.
It gives you a chance to ensure the harmonic balancer is still in good shape, as well. They have a habit of slipping around as they get older.
After all that fun, of course is all the usuals. Oil, and transmission, transfer case, differential fluids, all the drive shaft u joint lubrication Water and main water hoses (system flush?), of which there are 3. Distributor cap and rotor, spark plug wires, spark plugs. Valve lash, belts, you know, the usuals
Of course, it doesn't hurt to take a quick look at the CV joints to make sure the rubber boots that hold in the grease haven't cracked or broken. Oh, yeah, the brake shoes and pads, as well as the brake fluid, which may well need to be replaced. It absorbs water from the atmosphere over time. It should be totally replaced not more than about every 5 years. Easy to do. Bleed the system until you get fresh clean, fluid coming out of the bleed valve, on each brake. Don't forget the LPSV as well!
Power steering fluid, which is actually AT fluid. Not dirty, contaminated, etc. Seals on the pump, where the hoses attach, are still good, the return hose isn't leaking.
Ok, now my brain hurts. Too much thinking.
Have fun!
Pat☺
I pop opened the valve cover, adjusted the valves and checked out the timing chain. Not sure if the motor was rebuilt but it does look like someone changed out the timing chain as the guide is there.
Timing chain guide passenger
I'm hoping that it looks good to you guys as it's my first time looking at one of these. The engine still has that clacky valve noise even after a valve adjustment so i'm assuming that's the way it is.
Spark plugs
The spark plugs were a bit white and ashy which according to the internet means timing is to advance or the plugs are too hot or it's lean. I'm going to look at timing since this is one of the NKG models listed as compatible. If not timing, should i be cleaning some sensor? or checking someting else? It does take a few cranks for the engine to start.
Underside
I forgot to get a shot of the engine from the front underside but it really looks like a hose or something catastrophic failed and sprayed oil or fluid everywhere. I cleaned some of it but it'll be hard to tell if anythings does leak and if so, where.
Moneyshot
Shot of the girl on the lift. No name yet. Not a fan of the rims.
Things to check out still
CV joint - The boot was torn but judging by the fluid color when i replaced the brake and clutch fluid, they might need a replacing. Any way to check? Throttle it like a motorcycle throttle? Also when i suddenly accelerate or take my foot off the accelerator theres this momentary driveline slack, sort of like when a motorcycle chain is too loose. I haven't checked if it happens in 4hi but i'm guessing it maybe the driveshaft.
Oil filter for tightness - Who thought it was a good idea to put the oil filter behind a wheel well at an angle. It felt tight but i saw some oil drips when i left the garage. Maybe drips from my install but nice to double check.
Tailgate window metal bracket - I popped the back cover off and the metal bracket that attaches to the window is incredibly rusted. Wild guess there's no easy replacement. Also the button to lower the tailgate up front isn't working, the key at the door does though. Another thing to look at.
Ball joints - I was reading how you check them is try wobbling the wheel vertically and horizontally. I did and didn't get any play so i'm assuming they are ok.
Noise relay for headlights - I keep forgetting to turn off the headlights when i leave. It will end badly. I'll have to find a way to have a sound play if the headlights are on and the key is out of the ignition.
Rear wiper- there was none when i got this bad boy. Anyone know the size of it and how the 2 screw to j hook conversion works on our 2nd gen's or just pony up for a OEM and replace the blade when needed
Sunroof - A previous owner basically tar'ed over the perimeter of the sunroof. I guess it stoped the leak but that's a ghetto repair and i want to use the sunroof. The interior upholstery is drooping anyway so i'm going to remove that, then the headliner and clear out the hoses. Then maybe take it to a window place? They should have the materials to seal this up right?
LED interior lights
Radio - poor signal, plus antenna is drooping to the back.
Wheel bearings - Are there any?
engine mounts - i noticed a lot of vibrations when the engine is idling. both inside and looking at it with the hood open. Maybe related to timing or maybe mounts?
Anything else I should be looking at to make this offroad reliable? Shocks are original so i'm guessing they'll need to be replaced, Bilstein's seam to be recommended on the internet.
Last edited by thomas.tc.young; 01-02-2021 at 08:48 PM.
CV joint - The boot was torn but judging by the fluid color when i replaced the brake and clutch fluid, they might need a replacing. Any way to check? Throttle it like a motorcycle throttle? Also when i suddenly accelerate or take my foot off the accelerator theres this momentary driveline slack, sort of like when a motorcycle chain is too loose. I haven't checked if it happens in 4hi but i'm guessing it maybe the driveshaft.
If the boot on the CV joint is torn, it allows the grease to spray out from the joint, and once it's dry, the joint wears very rapidly. Best to replace the rubber boot, at the very least, packing the grease in it when you do. Many just go ahead and replace the entire half-shaft, so there's a entirely new CV joint in it when the boot tears. They wear fast without the grease.
If the brake/clutch fluids are dark, they're at least dirty, and for sure have absorbed moisture from the atmosphere. Replace them.
Maybe the U joints are worn if they weren't greased often enough. Heck, I still have the factory ones on mine, and they're nice-n-tight. I lube them several times a year, though. If they are loose, replace them. Usually the last one on the line, that is attached directly between the drive shaft and the rear differential is the one that fails first.
Tailgate window metal bracket - I popped the back cover off and the metal bracket that attaches to the window is incredibly rusted. Wild guess there's no easy replacement. Also the button to lower the tailgate up front isn't working, the key at the door does though. Another thing to look at.
Did you try resetting the rear window circuit breaker in the left side kick panel? It's what feeds the switch in the cab. Easy to reset. Just need to stick a small phillips screwdriver, or similar, in the hole on top of the can, until it clicks. Worth a try, annyway.
Wheel bearings - Are there any?
Both front and rear, yes there are. Get an FSM, even a PDF version. It will explain replacement, pre-loading the front, and so on.
Anything else I should be looking at to make this offroad reliable? Shocks are original so i'm guessing they'll need to be replaced, Bilstein's seam to be recommended on the internet.
Don't forget the the steering stabilizer, as well!
As to the oil filter: Did you remove the small access panel in the wheel well? Opens things up for access the oil filter and so on, including the starter and it's solenoid.
As to where all the oil underneath came from: It's been my experience that if/when the oil pump seal, not the front main seal, but the seal for the pump it's self, fails, and it will, it does the oil everywhere thing. If you're moving at any speed, it pretty well washes the underside back to the transfer case, at least, with oil. It drains all the oil from the engine, almost as fast as the drain plug does. Speaking of which: Is the drain plug good-n-snug, and not leaking? It does have a crush washer on it...
For the plugs: Did you try replacing the O2 sensor? Easy, and quick to replace. Sticks up out of the exhaust pipe, just downstream of where they all go down into one. Two bolts on the bracket that seals it up, which the new one comes with. Pop them out, very easy to reach with an extension or two on your ratchet driver, it pulls out, put the new one in and connect the wire, done. I think it took me a total of a half hour, and that was making sure I was doing it right, dropping one of the bolts and retrieving it off the skid plate, etc. I did use the antistick thread lube, high temp, on them. Make sure to use the OEM brand, NOT a Bosch, or anything like that. Denso is best choice, I believe NTK is the second choice. Rock Auto carries them.
The rattling, even after adjusting the valve lash, is perfectly normal, not a factor. BTW: did you adjust them hot, and in the correct order? It matters. Again, it's all in the FSM.
If the boot on the CV joint is torn, it allows the grease to spray out from the joint, and once it's dry, the joint wears very rapidly. Best to replace the rubber boot, at the very least, packing the grease in it when you do. Many just go ahead and replace the entire half-shaft, so there's a entirely new CV joint in it when the boot tears. They wear fast without the grease.
If the brake/clutch fluids are dark, they're at least dirty, and for sure have absorbed moisture from the atmosphere. Replace them.
Maybe the U joints are worn if they weren't greased often enough. Heck, I still have the factory ones on mine, and they're nice-n-tight. I lube them several times a year, though. If they are loose, replace them. Usually the last one on the line, that is attached directly between the drive shaft and the rear differential is the one that fails first.
So today I went back and inspected the propshaft. The joints actually feel tight at least when i manipulated them. Where there is slop is the transfer case and differential. I can rotate the shaft maybe 1/2". I couldn't get the front prop shaft to do the same though 4wd wasn't engaged so maybe that's the difference.
Originally Posted by 2ToyGuy
Did you try resetting the rear window circuit breaker in the left side kick panel? It's what feeds the switch in the cab. Easy to reset. Just need to stick a small phillips screwdriver, or similar, in the hole on top of the can, until it clicks. Worth a try, annyway.
I'll try that now
Originally Posted by 2ToyGuy
As to the oil filter: Did you remove the small access panel in the wheel well? Opens things up for access the oil filter and so on, including the starter and it's solenoid.
Yes I saw the oil filter through the wheel well. I also found out the fuel filter is there as well... What silly placement.
Originally Posted by 2ToyGuy
As to where all the oil underneath came from: It's been my experience that if/when the oil pump seal, not the front main seal, but the seal for the pump it's self, fails, and it will, it does the oil everywhere thing. If you're moving at any speed, it pretty well washes the underside back to the transfer case, at least, with oil. It drains all the oil from the engine, almost as fast as the drain plug does. Speaking of which: Is the drain plug good-n-snug, and not leaking? It does have a crush washer on it...
Yup, hopefully it was that as the PO said something in the engine was replaced after it lost a whole lot of fluid on the highway.
Originally Posted by 2ToyGuy
For the plugs: Did you try replacing the O2 sensor? Easy, and quick to replace. Sticks up out of the exhaust pipe, just downstream of where they all go down into one. Two bolts on the bracket that seals it up, which the new one comes with. Pop them out, very easy to reach with an extension or two on your ratchet driver, it pulls out, put the new one in and connect the wire, done. I think it took me a total of a half hour, and that was making sure I was doing it right, dropping one of the bolts and retrieving it off the skid plate, etc. I did use the antistick thread lube, high temp, on them. Make sure to use the OEM brand, NOT a Bosch, or anything like that. Denso is best choice, I believe NTK is the second choice. Rock Auto carries them.
Originally Posted by swampedout
You got a long list but its good to be thorough.
id be most concerned abt the lean condition.
Whats your idle speed?
Haven't tried the o2 yet. I was tracking down the lean issue today. I got 4 new plugs but i was noticing there was a lot of misfiring/stumbling going on as well. I figured starting at plugs would be easy enough. Well I thought let me check timing first just for kicks. Timing was advance probably 30 degrees. Well that would explain the lean condition. I try to jump the e1 and tc1 wire but idle doesn't drop. Whatever, i set it to 5 along the timing marker. Start it up and now idle is low, 500 but no misfire/stumbling. Going around the block, it was like the engine had no power in the low range like it had 2 cylinders lopped off. I take it back and a little search fu reveals it maybe the TPS. I go to check resistances and closed and open are ok but between aren't. Not being able to get this to idle properly now is probably connected with the TPS as well. I advanced it back so i could make it home.
Looking at rockauto right now, I see NTK makes TPS's and their a part of NGK spark plugs. Are they any good or should I just pony up for OEM
Last edited by thomas.tc.young; 01-03-2021 at 08:29 PM.
ALWAYS OEM if possible, especially electronics...
take the throttle body off to set the TPS and clean the TB as well.
Set your valves cold at 7 and 11
this is worth a look for anyone with a 22re
goggle:
22re performance value adjustment
Last edited by 87-4runner; 01-03-2021 at 08:53 PM.
Yes I saw the oil filter through the wheel well. I also found out the fuel filter is there as well... What silly placement.
But did you pull the access panel? It really makes getting to the oil filter etc much easier. And yes, stupid place for the fuel filter. It was like they got all done designing everything, and said "Oh heck! We forgot the fuel filter. We'll just stick it on where no one can notice..."
I was tracking down the lean issue today. I got 4 new plugs but i was noticing there was a lot of misfiring/stumbling going on as well. I figured starting at plugs would be easy enough. Well I thought let me check timing first just for kicks. Timing was advance probably 30 degrees. Well that would explain the lean condition. I try to jump the e1 and tc1 wire but idle doesn't drop. Whatever, i set it to 5 along the timing marker. Start it up and now idle is low, 500 but no misfire/stumbling. Going around the block, it was like the engine had no power in the low range like it had 2 cylinders lopped off. I take it back and a little search fu reveals it maybe the TPS. I go to check resistances and closed and open are ok but between aren't. Not being able to get this to idle properly now is probably connected with the TPS as well. I advanced it back so i could make it home.
You know there is a screw to adjust the idle speed, yes? Top of the TB, just to the left of the intake to the TB as you look at it from the front of the truck. There's a big, relatively, screw that covers it. Take that screw cover off, there's the idle speed adjuster inside. Did you try shorting the test connector, to set the timing, setting it to 5°, then adjusting the idle up to 800?
First though, definately, if the TPS doesn't ohm out right, it needs replacement. Rock Auto has a Beck/Arnley TPS for $55.79. Don't forget to adjust it according to the FSM once installed!
I believe that's the OEM unit. I may well be wrong, though.
Looking at rockauto right now, I see NTK makes TPS's and their a part of NGK spark plugs. Are they any good or should I just pony up for OEM
They have NGK 7734 spark plugs, which are factory installed plugs. Strongly recommend them. Did you check that they all have good spark? Like pull one out and touch metal on the head? Should see a nice strong spark when the engine is cranked. That checks everything, from the coil to ground. Coil, wire to distributor cap, distributor cap and rotor, plug wires. If the spark is weak, or missing, work your way back from the plug to the coil. Just find where the spark goes missing.
Speaking of which, is the ground from the head to the body in good shape? That's where the plugs get their ground. If that's not good, the spark will be weak, or even skip a rotation, now and then. It should be connected to the lifting hook on the back of the head, driver's side, then to the body right behind the engine. Right on the firewall.
Of course, the ground from the battery negative terminal to the body must be good too. Both of those matter greatly, and are frequently ignored during maintenance. Both ends of the wires must be clean, bare metal, both the wire, the ring terminals ON the wires, and the metal they're bolted to. Very important.
There are 4 main grounds in the engine compartment. The two I just described, the one from the battery to the engine block, usually bolted onto the AC compressor mounting bracket, and last but not least, the one from the alternator to the PS pump's mounting bracket. All 4 are very important to the proper engine function.
Another one to check is the one for the injectors. It's bolted on where the TB bolts to the intake manifold, about 1/2 way back, on one of the two bolts that holds the fuel rail on. Very easy to identify. 2 sets of 2 wires all going into one ring terminal. Looks unique.
There is also a ground point behind the driver's side kick panel. It's critical as well. One for the ECU behind the passenger's side kick panel, too.
All are important to the operation of the vehicle. The two I initially mentioned are the most for the problem you're describing, though.
All right, shutting up, now. Good luck to you!
Pat☺
12-31-2020, 07:41 PM
