Topic: Why does my 22RE run hot???

[Addicted Offroad]

First of all, I have changed everything with the exception of one thing.

Anyway, I bought this 88' 4runner with a bad headgasket a couple weeks ago. Changed it out with a new Toyota one, a new timing chain kit, new water pump,  all new hoses and lines. Since then I have put about 700mi on it. Timing is normal and is set at 5*. The headgasket is good. I see no oil in the coolant or vice versa. I am confident that its NOT the headgasket. So, I swapped out the thermostat from a 180 to a 195 tonight in hopes it would cool the coolant in the radiator more before allowing it into the engine. That didn't work. At idle after a hard run it starts to warm up. It doesn't overheat, but its not running at a normal temp either. I swapped what I thought was a bad fan clutch a couple days ago too. No help.

I also had an exhaust leak at the collector weld. It was cracked about 3/4 of the way around. I welded it up on Saturday. Before then it never ran warm on the freeway. Not at all. But, today it was around 84 degrees. I drove it into the airport to pick up my wife and it ran warm the entire time. Like between halfway and the upper white line. I kept it cooler by turning up the heater, but it still wasn't at normal temp. However, when just cruising at 45mph or so it will cool down to normal temps. I am thinking it may be a clogged cat, but wouldn't a clogged cat make it run warm all the time?

I am waiting for a new Thorley header to arrive from Summit tomorrow. I also already have a new highflow Magnaflow cat and muffler to go in with it.

However, if this doesn't fix it I don't know what else to do. Anyone have an ideas or can think of anything else it may be?

The motor runs sweet, just too warm for my liking with summer on the way and wheeling season here.

[79coyotefrg]

get the cat changed out  and let us know,   since it started heating up  after  you welded up the exhaust leak  im sure its  a plugged up cat

[Addicted Offroad [OP]]

get the cat changed out  and let us know,   since it started heating up  after  you welded up the exhaust leak  im sure its  a plugged up cat

That is what I was thinking. Besides the 2.25" exhaust and header should really wake it up anyway.

[myyota]

You might also change the temp gauge sending unit, mine went bad and would always read cold or just a hair above cold on the temp gauge even though the engine was at normal operating temp. so im sure they can go bad and read to hot as well.

[jimbo74]

so are you sure that the engine is actually running hot? or does the gauge just say its hot?


Some 1984 pickup trucks and 1983-1984 Celica models, equipped with 22R-E engines, may experience a condition called "temperature gauge overshoot". After starting a cold engine the temperature gauge will indicate a higher than normal engine temperature for a short time just prior to the thermostat opening. After the thermostat opens, the temperature gauge will return to the normal range. A new double valve thermostat has been made available to reduce temperature gauge overshoot.
And calls for part number 90916-03070 which according to the TSB replaces 90916-03055.

it says RE but i had this same issue with my 22R, and it also said certain years but I know people with different years withthe same issue... and the RE wasn't offered in the 84 trucks, I have seen them in 84 and earleir but they weren't officially avaialble at that time.

[*ROKTOY*]

Put the 180 thermo back in too, its not going to run cooler with a 195 in it.

[fatt_matt]

Put the 180 thermo back in too, its not going to run cooler with a 195 in it.

x2..  why would putting a hotter thermostat cool the engine???

just curious?

[Addicted Offroad [OP]]

x2..  why would putting a hotter thermostat cool the engine???

just curious?

Because it allows the coolant in the radiator to cool longer. That is why a 160 degree thermostat won't make your engine run cooler. Factory spec is 195 anyway.

And, this was doing the same thing before the 195 was put in.  Regardless of what thermostat is in it, its not the problem.

[*ROKTOY*]

Because it allows the coolant in the radiator to cool longer. That is why a 160 degree thermostat won't make your engine run cooler. Factory spec is 195 anyway.

And, this was doing the same thing before the 195 was put in.  Regardless of what thermostat is in it, its not the problem.

WRONG!   Once the thermo opens it mixes with the hot coolant in the engine to maintain the temperature. A 160 thermo will maintain 160 in the winter ambient air temps are to hot in the summer to maintain 160.

[Addicted Offroad [OP]]

I took the 4runner into my shop today to do some exhaust work. I pulled the cat out and welded in a 2" piece of tubing in its place. Again, not the issue. Still runs warm at idle.

I am beginning to think that the radiator may not have been as new as the PO told me it was. So, will a 3.0 radiator work in its place??? Meaning will it bolt in, or do I need to fab some brackets for it?

Also, this is NOT the dual thermostat issue. I am well aware of the fact that the temp will go up high when cold. Its because the heater core throws out on the thermostat, so until it gets to operating temp the thermostat won't open. This is a constant issue. Not just at start up.

[Addicted Offroad [OP]]

WRONG!

What is wrong? The 195 being factory spec? Actually its a 190, but still.

Or, the fact that a 160 won't necessarily make your engine run at 160 degrees?

Prove it then.

[skid]

Because it allows the coolant in the radiator to cool longer. That is why a 160 degree thermostat won't make your engine run cooler. Factory spec is 195 anyway.

incorrect,  sounds like you're confused with flow.  Once hot, t-stat rating shouldn't matter.  If it's open it'll flow.   If using you heater helps, your radiator may not be up to the job.  Opening the heater valve increases the flow.   This is bypassing the t-stat.  
Might try flushing the radiator backwards, have it cleaned by a shop or replaced.

[Addicted Offroad [OP]]

WRONG!   Once the thermo opens it mixes with the hot coolant in the engine to maintain the temperature. A 160 thermo will maintain 160 in the winter ambient air temps are to hot in the summer to maintain 160.

That is more or less what I said. Fact of the matter is that when its 85+ degrees outside, and you are running a 160 degree thermostat, it doesn't necessarily mean that your motor is running at 160. Its likely running much warmer because the thermstat remains constantly open. Same thing as not running a thermostat at all. The coolant in the radiator never gets cool enough to keep the motor temps down because the thermostat is always open.

[skid]

normal opertation, the thermostat was design to stay open after reaching operating temp.   Meaning it doesn't need to close to keep the coolant in the radiator to lower the temp.  t-stats primary purpose is to decrease warm up time.

on another note, still have the fan shroud?

[Addicted Offroad [OP]]

normal opertation, the thermostat was design to stay open after reaching operating temp.   Meaning it doesn't need to close to keep the coolant in the radiator to lower the temp.  t-stats primary purpose is to decrease warm up time.

on another note, still have the fan shroud?

Yeah, shroud is there.

[*ROKTOY*]

That is more or less what I said. Fact of the matter is that when its 85+ degrees outside, and you are running a 160 degree thermostat, it doesn't necessarily mean that your motor is running at 160. Its likely running much warmer because the thermstat remains constantly open. Same thing as not running a thermostat at all. The coolant in the radiator never gets cool enough to keep the motor temps down because the thermostat is always open.

WRONG! The thermo's job is to maintain engine temperature and aid in warm up. It does this by controlling the amount of coolant passing through it, But once open it can only restrict so much,not running a thermo does not allow enough time for the coolant to pick up enough heat from the engine, as the cooant flow is too great. The gauge may read 180 or 190 but the engine is much hotter. A good way to blow a head gasket is to not run a thermo.

[skid]

WRONG! The thermo's job is to maintain engine temperature and aid in warm up. It does this by controlling the amount of coolant passing through it, But once open it can only restrict so much,not running a thermo does not allow enough time for the coolant to pick up enough heat from the engine, as the cooant flow is too great. The gauge may read 180 or 190 but the engine is much hotter. A good way to blow a head gasket is to not run a thermo.

getting close to mixing facts with rumors and opinions.

[*ROKTOY*]

Well you do what you want you will find out some day. There is no way putting in a 195 is going to make it run cooler than having a 180.

[brainlessfool]

Well you do what you want you will find out some day. There is no way putting in a 195 is going to make it run cooler than having a 180.

Well I can agee with that.

butt I think where he was going was having it open less time would give the water more time to soke in the rad.

butt a themo is not just a fully opened or closed thing all the time, it can just open a bit if need be. ie  a 195 thermo @ 193. it will be open some of the way butt maybe not all the way.

any way sounds like the rad is shot.

[twistedtoy92]

flush your system out, keep the 180 thermo, it IS COOLER THAN A DAMN 190!!! make sure you have a 50/50 mix of antinfreeze, oil level is good, and your air cleaner is CLEAN! then your truck should run good!! replace your cat as well, im up in WA and run NO cat!! 2 1/4 exhaust, pacesetter headers, and a 40 series flowmaster with a 180 thermo and a k&n filter........... COOOOOOOL RUNNNNNIN~ as long as it doesnt get above 210 you will be just fine!! if you are that worried, get a high flo water pump, a 4 core radiator from lcengineering and electric fans... no more worries!!

[Addicted Offroad [OP]]

butt I think where he was going was having it open less time would give the water more time to soke in the rad.

butt a themo is not just a fully opened or closed thing all the time, it can just open a bit if need be. ie  a 195 thermo @ 193. it will be open some of the way butt maybe not all the way.

any way sounds like the rad is shot.

Exactly. That is how a thermostat works.

Anyway, I ended up getting a 3 core from radiator.com delivered today and its running right at 195 where it should be. The new one is much thicker than the stock 2 core and it was only $124 delivered to my shop in less than three hours.

[YotaChris]

I put a 3.0 v6 radiator in my truck because I was having overheating problems and it worked perfect. It bolted right into place and the old shroud even bolted on.