1991 V6 3.0 3VZ-E Overheating Please Help!

[sherrie]

Hi I just purchased a 1991 Toyota Winnebago Warrior with 50K miles. Had it inspected and mechanic said all was good. Took it on my first camp trip and it overheated? This is what I have done so far and it is still overheating. Radiator Caps twice, New Radiator, Expert Vacuum out the coolant and refill under pressure to remove air bubbles. Three Thermostats ( finally boil tested at last change and they were all good). I have a 180% thermostat installed. Installed electric Radiator Fan, 3000 RPM works great. Combustible gas tested the coolant- Passed no gas. Compression tested cylinders, 170 on 5, 150 on one. Leak down test at 100 PSI and no leaks. Weighed at end of trip and it weighed 6,640 Gross Weight . 640 over. It overheats worse going up hill, but will overheat all the time. Not the gauge because it is boiling hot. Not blocked because the guy who changed the radiator said that putting the coolant in under pressure would have reviled a blockage. He checked all the "new" hoses and said they were good. Not collapsing. We are looking at installing a new water pump and timing belt, even though the water pump is not leaking and appears to move the coolant. Any suggestions or help would be greatly appreciated.

[Pete1122]

Have you checked your timing?

[jjrbus]

http://toyotamotorhome.org/forums/index.php?showtopic=4890

The verdict is in: the spark plugs made the difference and man, what a difference. It feels like I've got two more cylinders under the hood now and on a nice, muggy hot day in central Florida, high speed travel on the interstate saw the temperature gauge hang out smack dab in the middle and stay there. Most excellent!

[sherrie]

I have new spark plugs already, bummer that would have been an easy fix I have not had the timing checked, I will do this A.S.A.P, thanks

[shibs]

how was the old radiator? scaled up? rust?

just cuz vehicle has 50k miles does not mean it was not neglected.

[shibs]

before you do anything take a sample of your coolant have it analyzed, I think it will cost $20, call around farm places like Cat dealership, Deere etc.There are online places like blackstone does it too but bit more expensive

[zero]

http://toyotamotorhome.org/forums/index.php?showtopic=4890

The verdict is in: the spark plugs made the difference and man, what a difference. It feels like I've got two more cylinders under the hood now and on a nice, muggy hot day in central Florida, high speed travel on the interstate saw the temperature gauge hang out smack dab in the middle and stay there. Most excellent!

How the heck does that work??? Spark plugs aren't going to make a difference unless the engine is skipping, not hitting on all cylinders, and lugging something awful. Seems that would be easily noticeable.

[jjrbus]

How the heck does that work??? Spark plugs aren't going to make a difference unless the engine is skipping, not hitting on all cylinders, and lugging something awful. Seems that would be easily noticeable.

Sgt Schultz and I we know nothing, I just copy and paste and provide the link! jim

[zero]

Yeah, I'm not blaming you. Still don't get it though. Maybe if it was a V-16 engine and just one cylinder was misfiring. But an under-powered Toyota RV? One cylinder misfiring makes a world of difference.

[sherrie]

So I called my Mechanic to schedule a new water pump and new timing belt and to check the ignition timing. He said he want to re-do the leak down test, I said why? He said he still thinks it is a blown head gasket! ? ? ? I said why - since the coolant - combustible liquid test was good, since the compression test was good, and since the first leak down test was good - why does he think it is the HEAD GASKET? He said that he did get 2 bubbles in the 4th cylinder when he first did the leak test, but he could not replicate these bubbles to me when I was there. ( I was there after 1.5 hours) He thinks maybe the head gasket only leaks when the engine is hot, so he wants to check it again when it is hot. I will let you know.

before you do anything take a sample of your coolant have it analyzed, I think it will cost $20, call around farm places like Cat dealership, Deere etc.There are online places like blackstone does it too but bit more expensive

What kind of test on the coolant? If it is the combustible gas test for a blown head gasket we did that and it passed - no combustible gas from a leaking head gasket. warped or cracked head in the coolant. Is there another test I should do on the coolant?

[sherrie]

how was the old radiator? scaled up? rust?

just cuz vehicle has 50k miles does not mean it was not neglected.

The Radiator that was in the Truck, we were told was new by the previous owner. It looked new and when we removed it it was clean. We replaced it with a larger Radiator. The Radiator guy said that it was the best and largest stock Radiator available for the truck. ( he is a Toyota 4x4 enthusiast) He said if we want a bigger radiator he would have to custom make it. I left him with the old radiator - In case I decide to have a custom Radiator made. His off the cuff estimate to make a custom radiator was around $600.00. Since it would have to be brass and copper as he does not weld aluminum.

[zero]

The Radiator that was in the Truck, we were told was new by the previous owner. It looked new and when we removed it it was clean. We replaced it with a larger Radiator. The Radiator guy said that it was the best and largest stock Radiator available for the truck. ( he is a Toyota 4x4 enthusiast) He said if we want a bigger radiator he would have to custom make it. I left him with the old radiator - In case I decide to have a custom Radiator made. His off the cuff estimate to make a custom radiator was around $600.00. Since it would have to be brass and copper as he does not weld aluminum.

With the kind of symptoms you describe - size is not going to be the issue. It's going to be a problem of coolant flow, air flow, or combustion gasses from a leaking head gasket. THAT assuming the RV is running well, has normal power, rolls fine (nothing dragging e.g. stuck brakes or burnt up wheel bearings). When radiators get "bad" and cause overheating - it's often from "solder bloom." This only happens with the older copper/brass core radiators. They get corroded internally and impede coolant flow. No real fix other then replacement. 30 years ago a good shop would remove the tanks and rod the core out and then solder back together. No very common anymore.

Poor coolant flow results in a rig that runs OK on the flats when air temps are 75 outside or less. Climb a hill and temp shoots way up. Or even on a flat road when air temps are 90 F and you try to do 60-65 MPH and the temp shoots up.

If it was mine - I'd check the water pump first. Doubtful it's the problem but still ought to rule it out. Slight chance the impeller could be eaten up from high acids in the coolant.

In ref. to having your coolant checked? There IS nothing to check except for hydrocarbons in the coolant and that test is only around 50% accurate. Yes, truck and diesel shops sell all sorts of coolant test strips to check for acid, sulfides, etc. but that is about engine longevity and cavitation - NOT overheating.

And timing? If your timing was so advanced you were overheating - the engine would be pinging something awful and likely burning up the pistons - even with high test. And if it was too retarded - it might run slightly warm and the gas pedal would not be as responsive as it should. I doubt timing is your problem.

[sherrie]

With the kind of symptoms you describe - size is not going to be the issue. It's going to be a problem of coolant flow, air flow, or combustion gasses from a leaking head gasket. THAT assuming the RV is running well, has normal power, rolls fine (nothing dragging e.g. stuck brakes or burnt up wheel bearings). When radiators get "bad" and cause overheating - it's often from "solder bloom." This only happens with the older copper/brass core radiators. They get corroded internally and impede coolant flow. No real fix other then replacement. 30 years ago a good shop would remove the tanks and rod the core out and then solder back together. No very common anymore.

Poor coolant flow results in a rig that runs OK on the flats when air temps are 75 outside or less. Climb as hill and temp shoots way up. Of even on a flat road when air temps are 90 F and you try to do 60-65 MPH and the temp shoots up.

If it was mine - I'd check the water pump first. Doubtful it's the problem but still ought to rule it out. Slight chance the impeller could be eaten up from high acids in the coolant.

In ref. to having your coolant checked? There IS nothing to check except for hydrocarbons in the coolant and that test is only around 50% accurate. Yes, truck and diesel shops sell all sorts of coolant test strips to check for acid, sulfides, etc. but that is about engine longevity and cavitation - NOT overheating.

And timing? If your timing was so advanced you were overheating - the engine would be pinging something awful and likely burning up the pistons - even with high test. And if it was too retarded - it might run slightly warm and the gas pedal would not be as responsive as it should. I doubt timing is your problem.

Hi, Thanks for responding. I do believe it is the water pump also. Heading to the mechanic I will keep all posted.

[Vanman]

" Installed electric Radiator Fan, 3000 RPM works great. "

I would like to do this with mine, which fan did you use, did you re-do the fan shroud, and what triggers the fan on/off???

TIA JC

[sherrie]

" Installed electric Radiator Fan, 3000 RPM works great. "

I would like to do this with mine, which fan did you use, did you re-do the fan shroud, and what triggers the fan on/off???

TIA JC

I bought this one from Amazon http://smile.amazon.com/gp/product/B004GWJE7S?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Flex-a-lite 674 S-blade Engine Cooling Fan with Controls. It comes with a shroud that fits the radiator and works great. It was very easy to install and had very good installation instructions. I hooked mine into the Air conditioning wires (on with AC) as instructed and to the starter coil, so I can run it if the key is on Aux, but it turns off if the key is off.There is also an adjustment knob on the side so you can adjust the unit to come on at various temperatures. There is a temperature probe that you push through the Radiator. It was expensive but given Las Vegas Temperature and the overheating problem I was willing to try it. PS I also increased my gas millage after removing the fan clutch, so I think that may not have been working properly.

[sherrie]

UPDATE! Took the Truck back to the mechanic and he did another leak down test when the truck was hot. NO Leaks! It has to be the water pump. ( I think it may now be leaking ) Any way I purchased a water pump and timing belt kit from Nappa auto parts. He will install on Friday this week. Timing was fine.

QUESTION? Should I go buy Toyota water pump and timing belt kit? The water pump has a metal propeller and the mechanic said the timing belt kit was fine. I just don't want any problems as the labor for this is more than the parts.

[Pete1122]

Can you post details on the radiator you installed? I need to pick up a new one.

[zero]

Should I go buy Toyota water pump and timing belt kit? The water pump has a metal propeller and the mechanic said the timing belt kit was fine. I just don't want any problems as the labor for this is more than the parts.

I have never experienced an issues with aftermarket waterpumps versus OEM as of yet. With some timing belts - yes. With all the work involved - if it was mine I'd buy the complete pump, belt and component kit from Aisin. That is who supplies most of this stuff OEM to Toyota. Amazon has the complete Aisin kit for $187.79, kit # TKT-016. Some on Ebay too for $148. Aisin makes the water pumps, idlers and tensioner, and as recall, Mitsubishi makes the belt for Toyota. Get the Aisin kit and you likely to get OEM components with Japanse bearings instead of Chinese bearings.

http://www.amazon.com/Aisin-TKT-016-Engine-Timing-Water/dp/compatibility-chart/B00HFKEPH2

[Vanman]

JD , Would you get the one with the oil cooler or without. I don't think mine has that oil cooler now. All the 1991's show the cooler.

JC

[Vanman]

"I bought this one from Amazon http://smile.amazon....ailpage_o00_s00 "

looks great, thanks. I'm gonna call them monday and see if that can come with the advanced controller kit, doesn't seem to show that on the Flex-a-lite web page. Also that's the excuse to get a higher output alternator, 19.5 Amps draw.

[sherrie]

Can you post details on the radiator you installed? I need to pick up a new one.

Sorry I don't really have the details. Eric Armstrong from Armstrong Radiator 435 674-7767 might have more information. All he said was that it was the best stock radiator he could get to fit the 91 Toyota V6 3.0. All it says on the receipt is #1190.

[sherrie]

JD , Would you get the one with the oil cooler or without. I don't think mine has that oil cooler now. All the 1991's show the cooler.

JC

Same goes for me regarding the oil cooler. Question: With or With-out/

[Derek up North]

Sorry I don't really have the details. Eric Armstrong from Armstrong Radiator 435 674-7767 might have more information. All he said was that it was the best stock radiator he could get to fit the 91 Toyota V6 3.0. All it says on the receipt is #1190.

Probably this:-

http://www.amazon.com/Spectra-Premium-CU1190-Complete-Radiator/dp/B000C7TTS0/ref=sr_1_1?s=automotive&ie=UTF8&qid=1442112458&sr=1-1&keywords=cu1190

[linda s]

That seems to be a 1 row radiator. There are 2 and 3 row radiators available and I think the cab and chassis came stock with at least a 2 row. Weird that he told you a better radiator would have to be custom made. Not true. This is a very well made all metal 3 row radiator

http://www.ebay.com/itm/CSF-89-95-Toyota-4Runner-88-95-Toyota-Pickup-Radiator-3-ROW-AMR-2056-/262025371893?fits=Year%3A1992%7CMake%3AToyota%7CModel%3APickup%7CSubmodel%3ABase%7CEngine+-+Liter_Display%3A3.0L&hash=item3d01ede0f5&vxp=mtr

Linda S

[jjrbus]

I ordered a new radiator for my Toy and was shocked when I looked and it was only a one row radiator. My first though was I have been shafted on the internet again!

But doing a bit of checking, may even be a thread here on the forum? The new aluminum radiators with one row are more efficient than the old 2 or 3 or 5 row copper and brass units. The theory is there is up to 20% more cooling area exposed to air flow than a multi tube radiator. Color me surprised.

A disclaimer here, I am not a mechanic or heat transfer engineer, I am only parroting the info I found on the internet. Speaking of not being a mechanic, I have to question a mechanic replacing a brand new radiator? I do not know all the details, but it is unlikely I would not have let him do it! Jim SW FL

[DanAatTheCape]

if you keep throwing parts at it you will eventually fix it. A good mechanic makes an accurate diagnosis first.

Here is what I know:

1) the V6 cooling system can trap air - and you will overheat until it works it way out.

2) the stock thermostat has a jiggle valve which helps release air but that (releasing air by jiggle) is not fool proof by any means.

3) I would take out the thermostat for diagnosis purposes. After that when the engine is running (without the radiator cap installed) - you can see the coolant moving inside the radiator. It should rise from the hose on the passenger side and if the system is full you can see it moving from the passenger side to the drivers side. (time to remove thermostat - about 15 minutes)

4) yes spark plugs can affect how hot the engine runs - I use the ones that were put in by the factory, not substitutes. (NGK BKR5EYA). Doubt this is your problem but a "hotter" plug can have an affect.

5) Timing can affect how hot the engine runs too. Easy to check. Put the jumper on the correct pins in little box and use a timing light. Should take a KNOWLEDGEABLE mechanic 5 minutes.

6) if no antifreeze was run in the system for a long period of times the vanes on the water pup can deteriorate. Never seen it first hand but if you google that you can see photos. Water transfers heat better than antifreeze so some people in areas that never freeze (southern California) have done this.

All in all, my first guess is air in the system.

[sherrie]

That seems to be a 1 row radiator. There are 2 and 3 row radiators available and I think the cab and chassis came stock with at least a 2 row. Weird that he told you a better radiator would have to be custom made. Not true. This is a very well made all metal 3 row radiator

http://www.ebay.com/itm/CSF-89-95-Toyota-4Runner-88-95-Toyota-Pickup-Radiator-3-ROW-AMR-2056-/262025371893?fits=Year%3A1992%7CMake%3AToyota%7CModel%3APickup%7CSubmodel%3ABase%7CEngine+-+Liter_Display%3A3.0L&hash=item3d01ede0f5&vxp=mtr

Linda S

Huh? Maybe he meant available that morning in Saint George UT. As we told him we needed to get back to Vegas ASAP.

[sherrie]

if you keep throwing parts at it you will eventually fix it. A good mechanic makes an accurate diagnosis first.

Here is what I know:

1) the V6 cooling system can trap air - and you will overheat until it works it way out.

2) the stock thermostat has a jiggle valve which helps release air but that (releasing air by jiggle) is not fool proof by any means.

3) I would take out the thermostat for diagnosis purposes. After that when the engine is running (without the radiator cap installed) - you can see the coolant moving inside the radiator. It should rise from the hose on the passenger side and if the system is full you can see it moving from the passenger side to the drivers side. (time to remove thermostat - about 15 minutes)

4) yes spark plugs can affect how hot the engine runs - I use the ones that were put in by the factory, not substitutes. (NGK BKR5EYA). Doubt this is your problem but a "hotter" plug can have an affect.

5) Timing can affect how hot the engine runs too. Easy to check. Put the jumper on the correct pins in little box and use a timing light. Should take a KNOWLEDGEABLE mechanic 5 minutes.

6) if no antifreeze was run in the system for a long period of times the vanes on the water pup can deteriorate. Never seen it first hand but if you google that you can see photos. Water transfers heat better than antifreeze so some people in areas that never freeze (southern California) have done this.

All in all, my first guess is air in the system.

Thanks for the reply,

(1) It can not be air in the system because of the vacuum and pressure pump system that the Radiator guy used to inject the coolant. Then he did a pressure test on the system as well as checked all the hoses for collapse.

(2)I have boil tested 3 thermostat's had have a 180% working thermostat installed.

(3) We have watched the coolant move in the Radiator, but is it working properly and all the time? I don't know.

(4) Replaced all the Plugs they are fine

(5) Timing was checked it is fine

(6)Water Pump is next replacement - Keeping my fingers crossed this fixes it!

Thank you again for taking the time to respond - all the info is greatly appreciated!

[Kane]

Can you post a pic-s of how your fan looks installed please

I like your idea a lot.

Mahalo

[Vanman]

I went out to measure my radiator and found 3, a small 8x4x1 at the top left, think it's the trans cooler?

Next inside is the rad for the cab air conditioner, it's huge all the way accross the width and almost as deep as the coolant one.

Next is the coolant rad measures 20" wide and is almost as deep. The amazon page says the Flex-a-Lite 674 is 16x18x41/2 which is much smaller than the shroud and rad stock set-up on mine. Yet many web pages say this is for the Toyota but do not seem to mention the engine size. Do the 4 banger Toys have the same rad as the V6's???

Also seems after this install you have a lot more room between the fan and front of the motor??

Second the request for pictures

edit: Aluminum is a better heat conductor then brass or copper so maybe this could be true.

[sherrie]

Can you post a pic-s of how your fan looks installed please

I like your idea a lot.

Mahalo

I had a video so I put it on Youtube

[jjrbus]

Thanks for taking the time to make and post the video. Looks like a nice clean motor. Jim SW FL

[Pete1122]

I came across this radiator, thinking of buying it.

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

[jjrbus]

This is what I ordered from EBay, not trying to hype it, just for comparison purposes. No issues with it. Jim

[Totem]

"I bought this one from Amazon http://smile.amazon....ailpage_o00_s00 "

looks great, thanks. I'm gonna call them monday and see if that can come with the advanced controller kit, doesn't seem to show that on the Flex-a-lite web page. Also that's the excuse to get a higher output alternator, 19.5 Amps draw.

I was intrigued at this product when I checked it out. unfortunately if you need to put a bigger alternator on, you are shifting the parasitic loss onto spinning the alternator; which in fact can only be done properly at speed.

I'd rethink using this electric technological terror unless you have a good solar generator on the roof and inline into your isolator traveling by day.