New to forum... a few '91 4Runner problems. Please help?

[Redfox]

Hi guys,

I just got a cheap second hand 2nd gen '91 4runner SR5 Limited and it's got a few probs that I would like to fix up or diagnose. If you have experience with this model and could help me, i'd much appreciate it.

GEARBOX:
Firstly I have some pretty noisy gearbox whine. When I'm idling it has a small whine when clutch is engaged. If I clutch in, it disappears. That leads me to believe it is probably the thrust bearing. When I take off in first, it's noisy, all the way through to 4th gear where is it quiet and doesn't whine at all. Then in 5th the whine is back but not as bad. The whine is also only present when the accelerator is on and transferring power into the box. I thought that since it's quiet in 4th, it may not be the thrust bearing. Could it be an input shaft bearing? Either way, I'm going to change the gearbox oil and put some of that PTFE additive in it. So can anyone pinpoint a possible problem area with these symptoms? I'm not that well versed in this type of transmission and even reading the service repair manuals don't help much.

ENGINE:
It's seeping some oil from the sump gasket and also somewhere higher up on the back. Not sure if it's the rear main seal or the valve cover gaskets. I put some stop leak in there and hopefully within a couple of hundred km's, it stops leaking. Also the lifters are a bit noisy all the time, especially on start up. Am i right in saying these are hydraulic lifters? Would you recommend a thicker oil? Maybe they are a bit gummed up. There is some gunky residue built up inside the oil cap, so maybe the engine needs an oil flush additive and then oil change?

WIPERS:
The wipers were working fine in the rain a few days ago, then suddenly one day the fuse blew and they stopped mid screen. I pulled into a servo and replaced the fuse. It started again but was going very slowly and wouldn't change between speeds or intermittent. Also, the rear wiper wouldn't work. Then the fuse blew again. Now I just have to replace the fuse and it will blow without me even touching the wiper stalk. So I'm thinking it's the combination switch, as the power for the wipers goes directly through this, and it's the common link between the front and rear wipers, right? These models don't have a body control module do they? I don't think it's the motor, because it did seem to go, just not change speed. So I might try changing the combination switch, but if anyone has any other suggestions, let me know.

PASSENGER ELECTRIC WINDOW:
When I first got the car, the front passenger window wouldn't go down with the switch on the passenger door. Only would go down on the switch of the drivers door. Now it doesn't go down at all. For a while, if you flicked the passenger and drivers door switches at the same time, you could coax it down. I'm convinced it's not the regulator because when it moved, it moved fine. I'm guessing it's the drivers door switch panel? Also, the power mirrors don't move. I got one to move briefly, but I think that switch is also gone. Does anyone have any other ideas?

Any help would be much appreciated! Thanks a lot

 

[JoeHill]

Hey.
I am alos new to this forum as I just picked up a 1990 4runner. I am also having trouble with an oil leak. I have also noticed that when I park on an incline I cant start it up. its as if the starter was totaly dead. my theory is that when its on an incline the oil begins to drip into the starter and thus hampering some connection to get it to started.
I also have the same problem with the passanger window. it will only go uo and down using the driverside controls.
J

 

[Alex 400]

Yeah my 94 has a problem with oil seeping from the walve cover gaskets, but it looks like its coming from the sump too, but its not.
In reguards to the sludge, the 3.0L V-6 had the dendency to sudlge up in the cylinder heads and caused oil comsumption issues, so you would want to have it flush or pull the valve cover off on the easy side, (no intake plenum) and check to see how bad it is.

My tranny whines more than other manuals that i have heard but its not that bad. Try changing the fluid or at least checking it.

Good luck. Once you get it going it is a great rig.

 

[Redfox]

Hey guys,

Thanks for your replies!

In regards to the oil leak, I'm pretty sure it's coming from the back of the valve covers. I put in some stop leak stuff (not the oil thickener, but the one that rejuvenates seals). It seems to have stopped the leaking... well that was until I put some lifter free in there (which is basically a milder form of engine flush) and it's started leaking a bit again. As you have said alex, it looks like it's also coming from the sump gasket, but that might just be run off from up top.

Joe, it's very possible that the oil leak is the problem. Is there a way you can deflect the oil from reaching the starter motor? Then you can test whether this is the cause.

With the passenger window, I discovered that if i flicked the passenger switch a bit whilst using the drivers one, it works intermittently. You know how the switches interfere with each other, and when u press down on the driver's side, and then touch the passenger switch, the window stops? Well that's what happened to mine. I discovered that the problem was the passenger switch, and replaced it and everything works now.

I also fixed the wiper somehow. It seems that the terminals on the connector to the wiper motor were a bit dodgy and had somehow shorted. Dont ask me how... but after a bit of a spray with some electrical circuit board cleaner, it started working again and didn't blow fuses.

I also changed the gearbox oil and that didn't fix the noise, so I put in some PTFE additive (bad for internals apparently, but should shut it up)... and that didn't work. So I'm sure my gearbox is on it's way out. The question now is when rather than if. Oh and it's definitely not thrust bearing. Apparently 4th gear is straight through on these boxes... so since it whines in every other gear, it means it's actually in the box. Probably one or more of the roller bearings.

I'm starting to regret putting in the engine flush. If anything, I can hear the lifter noise a bit more now. I think I'll change the oil soon and put in some heavier stuff. Maybe 10W60 if I can find some. I am also suffering from slightly low oil pressure, so the thicker oil should be good. I also think it's best to leave the sludge in there. As long as I do regular oil changes, and the sludge doesn't come off and clog up the oil galleries, it should be fine.

I got the car for cheap, so I really can't complain. I guess the saying "you get what you pay for" holds! I would love to do an engine conversion on it, because the 3VZE is really quite gutless. I would like a GM 3.8L V6. Apparently they are really quite easy to bolt right in with adaptor kits. I just dunno if it's worth the money and effort. Even getting a new and in good condition 4runner (when I have the money) will still leave me with a really weak engine.

I am yet to take it offroad, and I wonder how well it will perform. I'm scared that since it has not much power down low, I might be burning a bit of clutch trying to do anything. Have any of you guys had experiences offroad with your 4runners?

 

[Alex 400]

I'm starting to regret putting in the engine flush. If anything, I can hear the lifter noise a bit more now. I think I'll change the oil soon and put in some heavier stuff. Maybe 10W60 if I can find some. I am also suffering from slightly low oil pressure, so the thicker oil should be good.

I ran into this "low oil pressure" and was questioning it until i read the manual. If you are at idle it can be anywhere from the bottom to the middle of the gauge (depending on how hot it is) And regular oil pressure while running is from the first line up. I run delo 400 15w-40 in mine and it works quite well. Its the closest thing to synthetic without being synthetic.

 

[montana_cowgirl]

i know a few folks who have built theirs to be pretty much the equivalent of a jeep grandcherokee or cherokee ... if you're interested in seeing some of the 4runners being built up for offroading, timbercrawler.com is a great little place to poke around ... some of the folks there can be a bit "grr", if you know what i mean, but there's a few food topics on their 4runners with pics you might find interesting ... and most of them can be slightly willing to answer questions ... it all depends on their mood, but like i said there are some sweet rigs out there ...

 

[Redfox]

Great, i'll go and check it out! I am kinda undecided on what to do with my rig. I got it for cheap, but since it was an auto to manual conversion, I'm not sure I want to put money into something that could potentially have wiring issues. There are a whole lot of plugs that have been disconnected (esp underneath to the auto trans), and some of the wiring under the dash is a bit messy. I just worry that this may cause problems later on. I guess if I end up doing an engine conversion, this stuff shouldn't worry me too much.

I'll probably change the engine oil later today. I've never done a change on a 4runner before. The oil filter kinda looks hard to get to. Would I be correct in saying that you reach through the passenger side wheel arch? Or is it best to do from underneath? I'm going to put in some Valvoline 25W60. Should be thick enough i think.

Regarding the low oil pressure, my gauge is right in the middle when i start it up and start driving. However after a bit of driving, the oil pressure drops to just on the lower white line (within the acceptable range for high revs), and can sometimes drop a bit below. I will see if this oil change makes a diff.

One more problem I ran into was a high idle the other day. It was sitting at around about 1500rpm when i stopped at the lights on numerous occasions. Sometimes i could get it back to normal (800rpm) by flicking the throttle pedal a few times. Other times i couldn't get it back to normal and was high idling anywhere between 1000 and 1500rpm. Now it seems to have gone back to normal, but i'm still not sure why it happened in the first place. I might have a look at the dashpot adjustment when I have time. What else can cause a high idle? There is an internal choke i presume? Can someone tell me how the ECU controls the engine revs (ie. when A/C is switched on). There is a module on the passenger side of my truck (it's aussie, so probably drivers side for you guys) and it's got a cable running to the top throttle arm. Is this cruise control or is this for the ECU to control revs? Or does the ECU control it on some internal valve or something?

 

[montana_cowgirl]

i'd be interested in knowing that myself ... i grew up with older trucks that require you to tap and sometimes thump the throttle to get it to idle in lower rpm's ... now that i think about it, i've had to do it a handful of times on my 4runner when i know full and well it's plenty warm enough that it's not idling high because it's still warming up ...

 

[Redfox]

Well I had a poke at the dashpot. It seems that the dashpot is not even functional. It doesn't even compress. Either way, I don't think it matters because the screw thread on the throttle lever seems to be adjusted so that it touches the dashpot when the throttle is at idle.

So I guess if anyone in here knows much about the 3VZE carby, let us know what could be causing this high idle! I haven't had it happen to me in the last couple of days, but i'm still interested to find out.

Another problem I found over the last few days is something in the front suspension. When I accelerate and then hit the brakes fairly solidly, there is a clunk in the front left suspension. Then if I accelerate fairly quickly, u can hear another clunk. However, if you brake hard and hear a clunk, then come off the brake, then hit it hard again, there is no second clunk. It's almost as if the suspension arm is sliding on it's pins back and forth. I was under there today whilst changing the oil, and I noticed that there is a bit of longitudinal clearance where the lower arms mount to the chassis. I think there's about a 2mm gap where maybe a bushing or rubber washer might be? Could this be the problem?

Btw montana_cowgirl, what kind of 4runner do you have? 2nd gen with V6?

 

[Alex 400]

25w-60 will send the oil pressure through the roof! If anything use 20w-50 thats as thick as i would go with an OHC.

 

[montana_cowgirl]

yeh, i've got the v6 ... a 1990 ...

 

[Redfox]

25w-60 will send the oil pressure through the roof! If anything use 20w-50 thats as thick as i would go with an OHC.

Hehe, yep you're spot on there mate... it's definitely pushed the oil pressure up. I don't think it's through the roof though. What are the disadvantages of too high oil pressure anyways? Will that possibly cause premature failure of the oil pump? Next change I do, i'll put in 20W50 and see how it goes...

 

[Alex 400]

Hehe, yep you're spot on there mate... it's definitely pushed the oil pressure up. I don't think it's through the roof though. What are the disadvantages of too high oil pressure anyways? Will that possibly cause premature failure of the oil pump? Next change I do, i'll put in 20W50 and see how it goes...

Its not that the oil is going to spraying out like it has alot of pressure, but when its that thick it makes it a little harder to push the oil through the oil passages. I run 15w-40 Delo 400 and my oil pressure is perfect. Right where it should be. 20w-50 would be fine too, in the spring summer months but in the cold you want 10w-40 or 5w-30

 

[Redfox]

Its not that the oil is going to spraying out like it has alot of pressure, but when its that thick it makes it a little harder to push the oil through the oil passages. I run 15w-40 Delo 400 and my oil pressure is perfect. Right where it should be. 20w-50 would be fine too, in the spring summer months but in the cold you want 10w-40 or 5w-30

Ok, thanks for the advice... I figured that even though it's a bit harder to pump up, it's thicker so it won't drain down so fast. Over here in australia it doesn't get that cold either, so I don't think I need to worry too much about that. I will keep monitoring my oil pressure, and if I think it's too high I'll change oil again. I intend on doing frequent changes to get all the crud out of the system anyways.