3pointslow

I am brand new to this site, found it in a google search. My experience with working on vehicles is some what limited.

I have a 94 4runner 3.0 auto 4x4. I bought it in January of this year, the guy told me it had overheated a couple times and he replaced the waterpump. He told me his wife was driving it for awhile and one day it overheated again and they parked it. I got it dirt cheap ($600) with almost no rust, everything else worked, and I needed a 4x4 at the time (lots of snow)

I got my $600 worth of use out of it and I drove it for about a month and a half with no problems (other than it being a 3.slow) Than one day I got about 3 blocks and the temp gauge went almost instantly in the red. I had to drive it about half a block to get to a safe enough spot to park it, but it was too late. Blew the head gasket.

I had to waite until a few days ago to fix it due to lack of funds. Last night I got a couple guys (licensed mechanics) to rebuild the top end. Everything looked good as far as the block/heads being straight and no cracks. I bought a gasket/seal kit as well as new water pump, thermostat, plugs, wires, cap, rotor, timing belt, filters, and fluids.

I had to get these guys to do the repairs because I am not experienced enough to tackle something that big yet, and watching them work I was glad I hadn't tried it.

They worked very fast and thorough and spent a lot of time cleaning, checking, and cleaning everything again before puting everything back together with the new parts.

When everything was done they started it up and it ran beautiful. They left and I let it go through a couple of heat cycles like they recomended without driving it yet. Than today I went to go drive it and noticed the idle was very rough. At almost the same time the temp gauge started to rise very fast, I was about 3 blocks from the house and pulled over to let it cool down.

After letting it cool I started it up and started feathering the throttle a little and noticed it was still idling rough (around 400-600rpm and surging) and the temp gauge was rising. But if I held it at around 3k rpm it would run very smooth and the temp gauge would drop very fast and be just under half way (just under what I would think is N.O.T.) I drove it back to the house paying very close attention to the gauge. If I let it drop to idle at the stop light it would overheat and idle very rough and die. However if I put it in nuetral and rev it to around 3k RPM it would cool down and run like normal.

I have looked through the posts on here and noticed several people having similar problems and all the suggestions but these people don't seem to post the results after fixing the issue (If they ever fixed it, or gave up)

I checked the radiator and water runs smooth through it. I'm waiting for it to cool down right now so I can try running it without the thermostat as suggested by others on this site.

I am wondering if I'm chasing 2 different ghosts or if the rough idle and overheating are somehow related.

I "burped" the coolent system like suggested on here, and all the fluids are full.

Before the head gasket blew I had no problem with the idle and it wasn't overheating (except for that one time when the gaskets went)

I was standing there with the guys working on the gaskets when they put the head gaskets on and said something about how I had heard about the gaskets being put in backwards. All three of us looked at them and douple/tripple checked they were in right before puting the heads back on.

Everything went together like a tight fitting glove (I was "helping" them, handing them tools, getting in the way, trying to learn what I could, etc)

I would like it if I could get some replies from people that have had similar experiences and what the end result was, as well as suggestions, ANYTHING will help.

I was also thinking about checking the TPS and MAFM, but again I have to waite for it to cool before removing either, I burnt my hand pretty good on the intake manifold trying to unplug the TPS while it was running.

Thanks
andrew

wd21_sr5

You have the heads plained when they were off or just "looked at" proper removal and torque sequence/specs when putting the heads back on? All vaccuum lines on correctly and in good shape? Intake and plentum gaskets new and didn't get harmed when installing?


off the top of my head...

3pointslow

We didn't have the heads plained, they recomended getting them checked by a shop but I did an old trick my grandfather taught me (dunno how well it actually works) I took a piece of 1/4" glass, put a thin layer of oil on the heads and block, then laid the piece of glass on it. My grandfather told me if the oil touches the glass on the entire surface, than the heads are "true".

Like I said, I don't know if that is a correct way of doing it, we always did that when working on vehicles when I was growing up.

Everything was to specs torqueing down all the bolts, I can't remember exactly but I think the headbolts were something like 38lbs then turn 45 degrees, or something like that. Whatever the Haynes manual said.

All gaskets and seals were replaced with new ones (from the head gaskets up) and they took special care not to bend/crack/scrape and of them when installing them.

I believe all the vaccuum lines are on and correct, I took pictures before they tore down the top end and more while they were working on it of the lines and hoses as a refference just incase they got stuck puting it back together.

A vaccuum leak was one of my first thoughts about it idling rough, so I took another page out of my grandfather's book and did another trick (again, I don't know if this is the correct way to do things, just how I was taught) I took some starting fluid and while the engine was running, sprayed it all over every vaccuum line and around the intake listening to the engine to see if it changed speed or sound at all. And there was no change.

I don't know a whole lot about working on engines, other than the backyard-mechanics I was taught growing up. I hope there's not too many people cringing at my inexperience or the "tricks" I'm doing... lol

Thank you for replying and any help is good help. It makes me feel good that I'm at least checking the right things.

3pointslow

Also, as far as removing the thermostat to see if thats the issue, I have to waite till tomorrow because it started storming outside and I don't have a garage... Kinda sucks because I was wanting to go fishing tonight and I was wanting to use the 4runner to pull the boat...

Oh well, getting to the bottom of this is more important than sitting in a boat all night not catching fish... lol

TNRabbit

If any stop leak was ever run thru it, your radiator is stopped up inside & needs replacement. Ask me how I know....

3pointslow

Ya it had some stop leak in it from the previous owner... we cleaned it all out, radiator is all clear, I checked that by flushing it backwards without the hoses connected to the block...

Update, I removed the T-stat and that solved the overheating problem. So I think I might try that trick of drilling a couple holes in a new one and puting it in.

It idles really really rough still, I was checking the fluids and found that the guys that rebuilt the top end put too much oil in the engine... I drained a bunch out (till it was at the right level) and I think the problem with the idle is either the TPS or carbon build up.

Obviously I'm hoping its just carbon build up, and thats what I'm going to try and fix first. I'm gonna sea-foam the engine and see how that works out.

The truck seems to run ok on the road, its just that idle thats buggin me. It will sit right at 500rpm and jump back and forth to 7-800rpm about every half second. It won't die though, just sits there, the sound reminds me of a built up monster truck running alchohol.

It lives up to its nickname though "3.slow" guttless as can be... it takes me forever to get up to 45, maybe 3/4 mile. And going up any big hill I have to put the peddle to the floor and it drops 2 gears and hits 6krpm but doesn't get any faster, if anything it slows down.

TNRabbit

I know you say you've flushed the radiator, but that stuff WILL NOT come out! I'd better a dollar to a donut that's your problem.

If you're getting a loping idle, trying disconnecting THIS & see if it clears up:

http://s251.photobucket.com/albums/g...t=MOV01806.flv

3pointslow

HEY THANKS TNRABBIT!!! That video was very very very helpful. I disconnected the hose and just like in the video it idled perfect. I plugged the vaccuum line with a screw for the time being.

I've been keeping an eye on the coolant, it seems to be pretty clear, so I don't think theres any of that stop leak floating around anymore after the recent top end rebuild. I'm gonna run it for awhile without the t-stat to make sure it flushes what it can out of the radiator, then try a new t-stat, this time I'm gonna drill the 2 holes like I seen someone suggest on here. (One at 12 and one at 6 o-clock, 1/8")

Back to the EGR valve, is there any reason I would need to get a new EGR valve? (other than emissions, and they don't test them here) I don't want to do any more harm to this tired 3.slow

thank you again for your help

TNRabbit

FYI: the stop leak attaches itself to the interior radiator holes. You can still get flow thru but it's not flowing thru the cooling fins sufficiently. I know of what I speak~

3pointslow

ok, is that something I can take to a shop and have them clean out? or do I need to just get a new one?

3pointslow

Ok, so it's been awhile since posting last, almost a month... Here's all the updates:

The truck has been running good (well as good as a 3vze paired up with an aod tranny can be I guess...)

I took the T-stat out of it to see how it performed, and honestly, the headache of taking it out made me wonder if I really even needed to put another back in? It takes a little longer to get up to normal temp, but I'm ok with that. It seems to run a little on the cool side, but thats better than the alternative right? Any opinions are welcome, am I just being a cheap dumba## for not buying a new T-stat? or are my worries of having another HG problem enough of a concern to just keep driving a "cold" engine?

The Idle problem was fixed thanks to TNRabbit's post about the EGR valve. I've noticed it tends to idle high now though, around 1200rpm. Noticed a difference in power as well, not much, but enough to notice.

I did however notice a new problem, I think it's totally unrelated to the above issues. The overdrive doesn't seem to want to kick in sometimes and other times I can't get it to shift down. I checked the cables and linkage from the throttlebody to the tranny, and even adjusted either direction. Seems to do it more when I first start out, once it gets down the road about 5 miles it tends to clear up.

I have a 1992 4runner with the same engine paired up with a 5spd, the 92 is in great shape. (the guy I got it from had junked the title to use it as a "parts" vehicle, theres nothing wrong with it though, now i'm having a hard time selling it because it doesn't have a title) So I'm thinking of doing a 5spd swap with the 94, any advice? I've looked through some of the threads on auto/5spd swaps, but noone really posts the performance/economy difference afterwards... just wondering if its worth it.

Also, if I were to do a auto/5spd swap in this situation as long as nothing is broken or too worn, should I need to buy anything? other than the fluids, I would also buy a new clutch kit. Just wanting to know what I'm getting into... again, any advice is welcome...

on a side note if anyone is wanting a 92 4runner for an offroad or parts vehicle lemme know, I live in the louisville kentucky area