1991 V6 3.0 3VZ-E Overheating Please Help!

[sherrie]

I came across this radiator, thinking of buying it.

http://www.shepherdautoparts.com/all_aluminum_radiator/toyota/4runner/1989/3.0l_v6_182.html

I will consider the 3 row if the water pump does not fix!

[jjrbus]

If the water pump is not the issue I would be looking for a qualified mechanic that knows how to diagnose cooling problems. There are a million V6 Toyotas out there with old beat up, corroded, half plugged radiators that are not having the issues you are having.

Only my opinion and worth what you are paying for it.

Jim

[Derek up North]

Also, don't lose sight of the fact that most (yours included until recently) worked fine with standard Toyota components. Before you feel the need for a 4-row, aluminum racing radiator.

[Totem]

After further research with some engineers in the shop, I was advised if there are ways to lower amp draw to compensate for what the electric fan uses then the fan could yield 1.3 MPG as well as 2-3% power increase if properly installed.

So... LED marker lights, run on propane fridge or no fridge/no inverter etc; this might actually be a pretty good mod.

http://smile.amazon....ailpage_o00_s00

Only weaknesses verified purchasers noted were issues with the controller/thermo and water. maybe some extra caulking or epoxy on the controller could battle harden it to be more torrential rain proof... I want one of these I think.

[WME]

20 amps is almost 2hp
The Toyota setup with the clutch fan is very efficient.

[zero]

After further research with some engineers in the shop, I was advised if there are ways to lower amp draw to compensate for what the electric fan uses then the fan could yield 1.3 MPG as well as 2-3% power increase if properly installed.

Sounds like nonsense to me. No fan, regardless if electric, or belt-driven should be doing much of anything in most highway driving conditions. If not using horsepower when cruising at highway speed - how is an over 1 MPG gain going to be achieved with any sort of "new" fan setup?

[sherrie]

After further research with some engineers in the shop, I was advised if there are ways to lower amp draw to compensate for what the electric fan uses then the fan could yield 1.3 MPG as well as 2-3% power increase if properly installed.

So... LED marker lights, run on propane fridge or no fridge/no inverter etc; this might actually be a pretty good mod.

http://smile.amazon....ailpage_o00_s00

Only weaknesses verified purchasers noted were issues with the controller/thermo and water. maybe some extra caulking or epoxy on the controller could battle harden it to be more torrential rain proof... I want one of these I think.

Just a little note here. We definitely increased our gas millage from our first trip with the Fan Clutch and the Second Trip with the electric Fan. We went back to the same area so the driving was the same, still had the overheat problem both times, but we went from 10 MPG to over 13 MPG. Not saying all was due to the fan, but just thought I would throw it out there. We switched all the tail lights to LED and have had no battery problems. We run the refer on propane. But will watch for a electrical drain.

[Totem]

Sherrie, you don't need to defend what you saw. I work for a company that makes fan clutches. JDE the simple fact is that the Toyotas underpowered 4 cylinder motor is having to spin the clutch and all of its inertial mass and airflow resistance; this robs HP from turning the drivetrain etc as opposed to not having to spin it. Where it gets even more interesting is when your consider that many of the aisin clutches we have may not be functionally sound now; the fluid reservoir may be stuck "on" always spinning. even if not stuck on, they have ATF like fluid that is well past the number of years it was designed to be chemically stable and thus its viscosity is not optimal. WME is correct, a new or in "spec" fan drive will perform very well, but in a 1985 motorhome you may want to think about replacing the drive or trying this mod.

I believe Sherrie 100%

[jjrbus]

What is an ATF like fluid? Jim

[Totem]

Its similar to automatic transmission fluid, but proprietary.

The bimetallic viscous fan clutch we have on our toys is simple; heat makes the coil thermostat on the drive change shape opening a reservoir that releases fluid into the drive clutch that catches the fingers of the ribbed plates as they spin taking the fan along for the ride. the clutch, which was designed and tested for the pickup truck as an application project was intended for just that; the pickup truck; not excessive upperbound heat like what most of us have going on under the hood while at highway speeds, uphills, into the wind etc.

To WMEs point though, NOTHING with generate airflow like the HP of the motor and to get within the realms of it on electric takes buku juice. that juice comes from the alternator which is also spun by the motor.

The improvement is in the electronics of the electrics fan control unit. it can basically shut itself off completely if not needed, bring cool down to the motor even when the motor is shut off, etc etc. it will yield fuel economy as opposed to a bi metal that is always on when the motor is running to some extant and always robbing hp.

[zero]

Sherrie, you don't need to defend what you saw. I work for a company that makes fan clutches. JDE the simple fact is that the Toyotas underpowered 4 cylinder motor is having to spin the clutch and all of its inertial mass and airflow resistance; this robs HP f

I'm well aware of how thermostatic fans work - electric or mechanical. My point was and still is -the fan, during normal highway driving conditions - should not be doing hardly anything. Fans are used mostly for low speed travel or when you are stopped at a red light. If under hood temps are SO hot that the fan is engaged all the time - there is a problem.

[Totem]

I'm well aware of how thermostatic fans work - electric or mechanical. My point was and still is -the fan, during normal highway driving conditions - should not be doing hardly anything. Fans are used mostly for low speed travel or when you are stopped at a red light. If under hood temps are SO hot that the fan is engaged all the time - there is a problem.

"should" being the key word in your sentence above. unfortunately "normal driving conditions" per the spec Toyota required of Aisin do not include continuously carrying 4000 lbs of camper bolted to the bed of the truck and trying to maintain 65 mph. The fan drives application engineering process was never designed to support that much heat; maybe for short term intervals but not ALWAYS. what happens to fluids when they cook all the time? is the viscosity effected? does the drive continue to function at spec after years of abuse and age in a kiln like the toy engine bay? the problem is age + torture all the time + plus every bit of robbed power is really needed for drivetrain. so while your point is the fan should not be hardly doing anything, you are ignoring the temperature under the hood; the 3rd dimension of the environment if you will. "normal driving conditions" in context would mean just the truck.

[zero]

Just a little note here. We definitely increased our gas millage from our first trip with the Fan Clutch and the Second Trip with the electric Fan. We went back to the same area so the driving was the same, still had the overheat problem both times, but we went from 10 MPG to over 13 MPG. Not saying all was due to the fan, but just thought I would throw it out there. We switched all the tail lights to LED and have had no battery problems. We run the refer on propane. But will watch for a electrical drain.

I don't doubt what you are saying. I'm just making the point that with a properly running RV and thermostatic fan - you would not see an MPG gain like that. Fan should be doing near nothing at highway speeds with normal under-the-hood temperatures. But since your's was running hot - the fan was engaged all the time.

[Vanman]

Maybe I'm missing something but all the cars and trucks I have seen newer than 2008 have dual electric fans. Aside from the Toyota and the Aerostar everything seems to be electric. With the search for gas mileage if the belt driven fan was better why're they not around much anymore ????

[zero]

Maybe I'm missing something but all the cars and trucks I have seen newer than 2008 have dual electric fans. Aside from the Toyota and the Aerostar everything seems to be electric. With the search for gas mileage if the belt driven fan was better why're they not around much anymore ????

Who claimed the belt driven fan was better (or worse)?? I must of missed that comment. New cars and truck makers are doing anything to gain even fractional amounts of fuel mileage gains. Thus the reason for lower viscosity motor oils. Also electric power steering. Also electric fans. Also "low drag" aluminum brake master cylinders. None of these things make any remarkable gains in fuel mileage - but put together . they add up.

[5Toyota]

I have had on other Toyotas the belt driven fan clutch to freze lock up was ingaged full time . in winter would not warm up . they can also fail and cause overheating by slipping all the time.

[jjrbus]

Maybe I'm missing something but all the cars and trucks I have seen newer than 2008 have dual electric fans. Aside from the Toyota and the Aerostar everything seems to be electric. With the search for gas mileage if the belt driven fan was better why're they not around much anymore ????

An electric fan is far more efficient at cooling when stopped or at low speeds. A belt driven fan is limited to engine RPM's , the computer will be able to tell the electric fan to run at full speed. This also allows smaller cooling systems and related parts equaling lower weight, less cost, better fuel mileage.

Is the electric fan better? If you are manufacturing replacement parts or run a service dept everything is going to be more expensive with a higher markup. Also the the average person will no longer to be able to diagnose and fix the system, so depends on how you look at it.

[zero]

A belt driven fan with a thermostatic-controlled viscous drive is variable speed. It can and will run slower then the engine when needed, and often - not run at all. What it cannot do is run faster then the engine. An OEM fan on a Toyota 22RE can move around 1000 CFM of air with the engine at idle speed (like when stopped at a long red light and it's really needed). A good electric fan can move 2000 CFM regardless of engine speed but I question how much of that air-flow gets wasted since it is not direct-coupled to the radiator with a perfectly fitting shroud. Also - and there can be a special high speed, or just an extra fan to kick on if the AC pump is going. I don't see any huge advantages either way. In most driving conditions - unless all you do is stop-and-go city driving - the fan does very little. Lots of air flow through the radiator when cruising down the highway - even with no fan. Another factor with newer vehicles is engine efficiency. No huge gains but the more efficient an engine is - the less waste heat it makes and the less cooling it needs. That's why the radiators in direct-injection diesels are smaller then the radiators with indirect-injected diesels. I assume newer higher tech engines also have less heat loss and can get by with less cooling needs. Heat in the coolant or out the tailpipe is just wasted gas or diesel fuel.

[shibs]

Sherrie

Great u did the coolant analysis, I am guessing it passed and it did not show any combustible gases i.e. head gasket issues?

Pls tell us again the symptoms of the over heating

1. Does it overheat while you a moving at high speed?

2. Does it overheat after you slow down or come to a stop?

Injecting coolant under pressure: how they can say that air will NOT be introduced is questionable.

I had a 90 v6 camry, it had a radiator leak around the neck, it had sludge in the engine, the radiator was half empty, I drove it from Kansas city to Michigan and added water to overflow tank when I did not get heat on I-80, the air temp was 73 F when I started and was low 50s when I go to MI.

can you pls post a pic of your overflow tank (inside)

[Totem]

I'm assuming thermostat in the engine was replaced, engine cooling track flushed, and all the bases were covered.

as far as electric fans, many peoples assumptions in here are missing the real reason they are used; cost. they are FAR cheaper in OEM than the viscous clutch drives. Stock alternator in a toy is probably near output of 39 amps give or take, at idle; leaving only 20 amps left for the entire vehicle... (if using the fan.) High output alternators only get rated outputs at higher RPM.

So what happens if the engine bay is VERY hot at speed, fan is at full power and you come to a stop such as a traffic jam or light etc? My guess there is a deficit in the available amp output of the alternator. The engine will still initially be VERY hot and still need the full 19 amps to run the fan at full. theres also the fact that newer vehicles operate on a lower idling RPM than older vehicles like the toy. So in essence, is the vicsous better for the toy? possibly, possibly not; its does seem to be more in spec with allowing the cooling while running but none at all when off and very unintelligent cooling at that; but reliable. Electronic cooling on the other hand may have the ability to see AMP output available from the system, I am just not sure. In my mind and in theory the fan Sherrie used was in fact designed for this application, has custom shroud that does mate up to the radiator. I for one would like to try it.

[zero]

It takes 15 amps to run an electric fan to push the same air as a mechanical fan. The bigger electric fans that flow 2000 cfm draw 30 amps. A stock alternator on a Toyota rv can only make 30 amps at idle speed. This is why newer vehicles have big alternators. A 120 amp alternator can make 50 amps at idle

[sherrie]

Sherrie

Great u did the coolant analysis, I am guessing it passed and it did not show any combustible gases i.e. head gasket issues?

Pls tell us again the symptoms of the over heating

1. Does it overheat while you a moving at high speed?

2. Does it overheat after you slow down or come to a stop?

Injecting coolant under pressure: how they can say that air will NOT be introduced is questionable.

I had a 90 v6 camry, it had a radiator leak around the neck, it had sludge in the engine, the radiator was half empty, I drove it from Kansas city to Michigan and added water to overflow tank when I did not get heat on I-80, the air temp was 73 F when I started and was low 50s when I go to MI.

can you pls post a pic of your overflow tank (inside)

Hi, Thank you for taking time to review my overheating issue. I did test for head gasket leaks in 3 ways. (1) Combustible Gas in Radiator. No dye color change, no indication of Head Gasket Leak. (2) Compression Test- 170 PSI on 5 cylinders, 155 on one cylinder. (3) Leak Down Test (twice) - No detectable problems. I do not believe it is the Head Gasket. Basically the truck overheats when it is being driven. Does not overheat when not moving. I had it sit in the driveway for an hour and it did not overheat. That does not mean it might not overheat the next time. As you drive the temperature increases. Takes around 15 minutes to get hot! If you go up hill it overheats faster. Once it has gotten hot it will get hot again even faster. IE You drive on the Flat Highway for 15 minutes and it gets hot. You pull over - pour water on the Radiator - cool things down - wait 30 minutes until the gauge is less then 1/2 and then take off again and it will overheat in 10 minutes. etc. It overheats at 60 MPH and at 15 MPH and once it starts it continues until you turn the engine off. So if it is overheating and you stop at a light it continues to keep rising in temp. I will take a pick of the overflow tank tomorrow when I take it to the mechanics. Thanks Again

[jjrbus]

Good luck at the mechanic, may your drive home be uphill at 60MPH with the radiator icing up! Jim

[shibs]

Sherrie,

1. Fan issues will not cause overheating at hwy speeds, there is enough movement of air to keep it cool

2. Your cooling system either has a restriction or is getting air or your water pump is not working correctly.

3. Pls take a peek at the overflow tank and post a pic of it if possible, kinda gives Hx of the gunk that was in the system.

4. Are you losing coolant? white smoke in tail pipe?

[sherrie]

Sherrie,

1. Fan issues will not cause overheating at hwy speeds, there is enough movement of air to keep it cool

2. Your cooling system either has a restriction or is getting air or your water pump is not working correctly.

3. Pls take a peek at the overflow tank and post a pic of it if possible, kinda gives Hx of the gunk that was in the system.

4. Are you losing coolant? white smoke in tail pipe?

Hi . FYI - no Gunk in the overflow, I will picture it tomorrow. Not loosing coolant, no leaks. No white smoke. Installing new water pump tomorrow - so excited hope its the end of my over heating problems.

[zero]

Hi . FYI - no Gunk in the overflow, I will picture it tomorrow. Not loosing coolant, no leaks. No white smoke. Installing new water pump tomorrow - so excited hope its the end of my over heating problems.

I hope it works out. I had a 1986 Chevy diesel Blazer that ran hot for 10 years. I could find nothing wrong with it and in frustration - just started replacing parts. New head gaskets, both sides. New radiator, water-pump. New free-flowing exhaust system. Updated thermostat and housing. Ran the total advanced timing at many different settings. Turned down the fuel delivery. It ran great those 10 years but never got any better as far as running too hot. I had another diesel Blazer set up exactly the same way and it ran cool all the time. One mystery I never really solved. If this had been a customer's vehicle coming to my shop to get fixed - it would of been kind of embarrassing. I will note that in this case for the GM 6.2 diesel - GM had many issues with them running too hot and redesigned the cooling system around 1990. But why did my run Blazer run cool and the other hot and both were the same vintage? Guess I'll never know. Hope you do not have the same experience. I suspect some RVs built on to the backs of Toyota trucks can have some strange air-flow problems that the bare trucks will not have.

[kgibson4]

Any chance that the transmission is causing this? Do you have a transmission temp gauge? Have you checked the trans fluid level? If the fluid smells burnt It might be overheating.

[WME]

Here's Bozo Good cool running engine.....bad sensor or temp gauge

[sherrie]

Any chance that the transmission is causing this? Do you have a transmission temp gauge? Have you checked the trans fluid level? If the fluid smells burnt It might be overheating.

Maybe the transmission, I do not have a temp gauge on the Transmission. Fluid is fine and smell not burnt,

[sherrie]

Here's Bozo Good cool running engine.....bad sensor or temp gauge

Not the temp gauge I don't think, as when gauge says cool, Radiator seems cool. When gauge says HOT the Radiator is boiling hot!

[WME]

Harbor Freight has a IR gun cheap, you can get the engine hot then check the top tank.

http://www.harborfreight.com/catalogsearch/result?q=ir+reader

[jjrbus]

My IR gun bit the bullet so was looking for a new one, found Northern tool has an IR gun on sale for $25.

http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&N=0&Ntt=infrared%20temperature%20gun

[zero]

Infrared heat sensors are fun but seem to be very inaccurate when checking for hot spots on an engine. I have three of them all give some pretty wild readings. Two are cheap and one is on a high-end digital multimeter. Different colors or types of reflective surfaces seem to corrupt the readings.

[linda s]

I don't know about reading engine temps but they rock when it comes to radiators. My radiator seemed to flow great and I had flushed it several times but I was still overheating. IR gun found a big dead zone in the middle and I knew I had to replace it. No problems since

Linda S

[jjrbus]

My Temp guns have always been the cheapest I can find, I rarely spend big $$$ on pro quality for something that gets only occasional use.

The IR guns like most modern things have some quirks. They don't like shiny things, so a bit of flat black paint and good to go. Read about one recently I have to try. A temp gun should tell when and if a thermostat is opening and at what temp. Be interesting to see if that works?

I check my tires and bearings at every stop, a low tire will be warmer. A bit of a learning curve there. Tires on the sunny side will be warmer than the shaded side.

Jim SW FL