ddc_5114

1992 4runner 3.0 4x4.


Recently purchased and noticed that on a cold day the engine was not getting hot. Replaced the thermostat only to find that the one that was in the vehicle had been gutted. Since then it over heats. Ive burped the system, replaced the thermostat for the second time, replaced the fan clutch, and radiator, and hoses. Ive pulled the waterpump and it seems to be fine. It hasnt really pegged out the guage but it gets really close to red. Ive held a high idle and got the temp to drop under half way. It even would hold that temp at a normal idle for 20 min after. But after getting about 1 mile from the house the temps starts to rise. No mixing of water and oil, no steam from the tail pipe, not loosing any water, and seems to run just fine. Any Ideas???

bigarms23

are the heater hoses new or you have a defective radiater

ddc_5114

I replaced the radiator hoses and the hose from the oil cooler. The heater hoses look new and seem ok. I just installed the radiator 2day but I guess it could be faulty. Can a radiator be tested for anything other than leaks?

ddc_5114

Oh, Forgot To Mention, The Fan Shroud Is Missing. Could This Be Causing My Problem?

ORTIZ303

I'm Having The Same Problem Somebody Help! I Replaced Everything On My 4runner And It Keeps Doing It Pos!

DCYota

Man, lots of overheating going on lately. The fan shroud should be there, but I don't think that's the only cause for your problem. It may contribute to it, but not that much. If it's running fine, how about your coolant temp sensor and sender? Have you replaced those? Particularly the sender...your gauge could be faulty because of a bad sender. Also, even if you don't have a CEL coming on, have you checked for codes anyways? That will give you more info if it's the temp sensor as that will store a code once it realizes a fault even once...but won't always trigger a constant check engine light. Timing set correctly per the FSM/factory spec?

ddc_5114

I'm not exactly sure what the sender is. I assume that the sensor is the located at the back of the intake. Where is the sender? The check engine light hasn't come on at all. Do you think this could still be my problem? .....
I read about someone having similar problems and it turned out that the head gaskets were installed on the opposite heads.....Is this a common mistake? If this had occured would it make sense that it wasn't overheating when the thermostat was not installed? I appreciate all of y'alls participation...Thanks !!!

DCYota

Was the head gasket replaced by the previous owner. If so, then it's possible it was put on backwards. It's happened to people before. That blocks the passages and will cause an overheat. The only solution obviously is to do another HG job and put it on right. If you run your hand across the back of the block and feel a gasket sticking out, then it was put on backwards. That's one easy way to tell on that one.

As for the sender on the 3.0...I'm not sure where yours is. I think, IIRC, it's in the same row on the back of the engine as your temp sensor..but you'll have to verify that by checking out the online FSM (stickied at the top of this forum), or with another 3.0 owner. I have a 22RE, so I'm not much help on the location of yours.

I've had to replace both the sender and sensor on mine. Mine was throwing a sensor code, now that's taken care of, but I'm still having temp issues. So I may be tearing into my old girl to do a head gasket myself, or at least a water pump if it ends up being the culprit on my end.

But, just because the check engine light hasn't come on, or isn't always on, doesn't mean a code wasn't logged in the ECU. You have to do the diagnostic box jumper method to pull out any codes from the ECU. 4Crawler's site has that on it if you want to check that out. It's simple though...in your small diagnostic box in the engine bay, take a paper clip and jump terminals TE1 and E1 together, and your engine light will flash a number of times...count those flashes and you'll have whatever codes are stored. You can cross reference those with the FSM as well to find out what they mean if you have any.

If it's not overheating without the t-stat installed, you could just have a bad t-stat. Sometimes new, out of the box t-stats are bad from the start. Test it on the stove in a pot of water with a thermometer to verify it's opening at the proper temp...then you can rule that out.

ddc_5114

Awesome, that is very helpful info...I'll try that. I appreciate it.

ddc_5114

OK, I checked the codes and it gives me a fourteen I think.....which is an ignition coil or something....dont think it would be related to my problem....I get a 1, then a 4 about 2 sec. after the one....so i assume its 14... if it was a 1 and a 4, then the 4 would indicate a temp sensor....how exactly do i test the ohms on the sensor?(i have a meter)

INFINITY

temp sensors are cheap. also rad cap? have you tried no thermostat? if you have the time i would say pull the thermostat and see if it makes a difference, because if there is no themo and the temp says it is high and your water pump is working then for sure it is the sensor(s).
also search this site for a while and see if you can find anything:
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

ddc_5114

That was my original problem. When I bought the truck it wouldnt get warm enough to blow hot air. I replaced the t-stat only to find out that the t-stat that was in it had been gutted. Since then it overheats. Ive tried 3 new thermostats just in case the new ones were faulty and the problem is still there. I have also replaced the radiator cap but even when it runs hot it does not build enough pressure to spew water in the overflow.

loacyota

That fan shroud def needs to be on. It is what forces the air through the radiator. When its not there then the air doesnt get pushed forward. Thats why when you bring it at a high idle it cools off, the fan is spinning faster and it pushes more air. put the shroud on and then run it

ddc_5114

for grins i took the thermo out today and the guage never read higher than about 2/5ths of the guage.....with the rad cap off the waterflow was quite fast as compared to barely moving w/ the thermo in and open...could there be a possibility that 3 new thrmostats were bad..or is this an indication of some other flow problem? Maybe I'm not burping it completely.....Is the 3.0 more prone to trap air in the cooling system than other engines?? In any event, im ready to give up and leave the thermo out....It justbothers me that ive thrown $800 bucks at this problem and im back to square one...

williemon

I was a victim of a botched HG install. The guys that did the work did not realize it at the time. I had the same issues as you do, but it was hot weather too. They took it to another shop nearby their shop that supposedly knew how to "burp" the engines. After that shop was done, the truck ran well for 4 months untill the weather got colder. Then it would not get up to proper temp. I decided the t-stat must be stuck open. I went to change it and found the gutted t-stat.

I called the shop that did the work and told them what I found. They were stand up about it. They had not known the other shop had gutted it. They took the runner back in, put a new t-stat in and then we found it started to overheat again. They said to leave it with them, then called and said that they would most likely need to redo the HG. They feared that one was on backwards. Once they pulled the heads they saw it. They were straight up about it and apoligized. they redid it all no charge to me. Even used new HG, head bolts and a lot of other stuff. Even the Toyota dealership admitted that they have done that as well.

Id look into a backwards HG. Have to wonder why the shroud is gone. Have you tried to detect the gasket at the back of the head by reaching back there like DCYota said?

williemon

Forgot to mention, a backwards HG blocks a water passage between the block and head. This may make the head run hotter all the time while the rest of the engine does not.

ddc_5114

I tried to feel for the gasket at the back but as you know its not the most accessable place. I did not feel the gasket. But Im not sure of anything.