Is this normal 22R Temperature Range? (1 Viewer)

[saywhat]

Hi All,

I have a 1987 Pickup 4x4 with a 22R (California Emissions). Recently replaced the thermostat (non dual stage), all coolant hoses, radiator + cap, temp sender and water pump. Noticed that the temperature will spike a touch higher than the middle of the gauge ("highest") for a minute or two, then go back to the middle. Sometimes, it'll go down even further a little higher than 1/4, "lowest". But it never has gone past the highest point, yet at least... . Before all the parts were replaced, the temp gauge always sat at the lowest mark IIRC after warming up.

It occurs most when driving on the freeway here in San Diego. Ambient temperature has been around 70 degrees +/-. This morning, it went to the highest point while in a drive-thru but dipped back down to middle, then to the lowest reading. Short drives around town, the gauge will be at or between the lowest point and mid point. I did "burp" the cooling system after replacing all the parts previously listed by parking the truck on a hill and running it with the cap off for a good amount of time. I'm inclined to burp it again but with the cap on and a hose as shown here



The temp readings are the same whether or not the heater control valve is set to cold or hot, which leads me to believe a dual stage thermostat will not fix this.

Also, I only get nice hot air when the RPMs are high. At idle, the heat air is luke warm at best. Which then leads me to believe I need to do more burping. Any ideas/suggestions? Dual stage stat? External temp gauge? Thanks for reading!

Highest Reading

Middle Reading

Lowest Reading

Pic of truck for posterity

 

[liveoak]

Nice truck!, did you replace all of the cooling parts because of an issue? When I replace coolant, it usually takes a few warm ups and cool downs to get the air out. Usually I just pull the cap when it cools down, top it off and top off the overflow(to full mark) and drive it some more with the heater on for part of it. Do that a few times and It's usually good.
Could you have put the thermostat in backwards?
Did you use any factory parts?
What is the temp of the new thermostat compared to the old one?

 

[pappy]

I agree with liveoak on getting the air out. Every time I've started with a new radiator, new engine, anything that causes me to drain everything, I have to top if off cold several times. It's always got air.

As far as the gauge, that looks normal to me. If it hits the red line I would be concerned. Keep in mind that the thermostat does not maintain a constant temperature. It fluctuates about 10-15°. Digging deep into memory cells ... my thermostat closes at 180°, but opens at 195°. So, when I turn on the truck on a cold morning, my thermostat stays closed until the engine warms. My Autometer gauge will climb to around 195°, then all of a sudden "pop" down to ~180° where is stays. On warm days it stays at ~180°. On stupid cold, intermountain west days, it will bounce between 180-195° because the thermostat is forced to close to keep the engine warm. I only run OEM/AISIN thermostats.

 

[saywhat]

Nice truck!, did you replace all of the cooling parts because of an issue? When I replace coolant, it usually takes a few warm ups and cool downs to get the air out. Usually I just pull the cap when it cools down, top it off and top off the overflow(to full mark) and drive it some more with the heater on for part of it. Do that a few times and It's usually good.
Could you have put the thermostat in backwards?
Did you use any factory parts?
What is the temp of the new thermostat compared to the old one?

Thanks! I replaced all the cooling parts as part of my baselining. I bought it with 250K miles on the clock and unknown service history.

Definitely not in backwards, but I should double check. The new radiator is a 2 row CSF, cap from Toyota. Waterpump from Aisin. Hoses a combination of Toyota + Napa. Thermostat and temp sender are Toyota.

The PN used for the thermostat is 9091603078 90916-03078 Genuine Toyota Thermostat - https://www.toyotapartsdeal.com/oem/toyota~thermostat~90916-03078.html . From the description, it's a 88C tstat. Unfortunately I don't recall the temp of the old tstat.

I agree with liveoak on getting the air out. Every time I've started with a new radiator, new engine, anything that causes me to drain everything, I have to top if off cold several times. It's always got air.

As far as the gauge, that looks normal to me. If it hits the red line I would be concerned. Keep in mind that the thermostat does not maintain a constant temperature. It fluctuates about 10-15°. Digging deep into memory cells ... my thermostat closes at 180°, but opens at 195°. So, when I turn on the truck on a cold morning, my thermostat stays closed until the engine warms. My Autometer gauge will climb to around 195°, then all of a sudden "pop" down to ~180° where is stays. On warm days it stays at ~180°. On stupid cold, intermountain west days, it will bounce between 180-195° because the thermostat is forced to close to keep the engine warm. I only run OEM/AISIN thermostats.

Great info, thanks @pappy What temp tstat are those numbers from? You mention here correct 22re thermostat temp? - https://forum.ih8mud.com/threads/correct-22re-thermostat-temp.320588/ that for the 22R, the tstat should be a 82C? Wishful thinking, but perhaps my old one was also a 82C?

Getting an external temp gauge is on my list. I might just be OCD about where the temp needle sits. I'd be lying if I said I don't constantly stare at the gauge while driving. I'll give bleeding another shot.

 

[welder7018]

I really recommend a default open thermostat for all Toyotas, they have saved a lot of blown head gaskets

 

[saywhat]

So I'm still fighting this. There is a nice hill nearby where I can reproduce the problem. I took it to a local shop, they drove it up the hill three times, and said the needle never moved past the middle mark. They did a block test, and that came back just fine. The tech there felt confident that it was conclusive enough not to do a leak down test, etc. Had them to a coolant flush and I took the truck back.

I found this thread on yotatech Overheating 22R-E, Possible Bad Head Gasket? - YotaTech Forums - https://www.yotatech.com/forums/f116/overheating-22r-e-possible-bad-head-gasket-309962/index4.html which was promising, but really I'll take any ideas at this point. I pulled my temperature sender and tested resistance against the FSM. It didn't match factory spec 100% but reasonably close, I replaced it anyways with another OEM sender. Then, I checked timing, slightly retarded by about 1 degree @ 950RPM vacuum advance lines plugged. Nothing out of the ordinary there.

Next day (been unseasonably warm for SD), I drove it up the hill and the temperature shot up like before. When the needle was near the top white mark, I measured roughly 220F at the thermostat housing with an infrared temperature gun. The bottom radiator hose was approx 210F. So it's not the temperature sender.

What I've replaced so far from a cooling system perspective:

OEM Thermostat (first time)
OEM Dual Stage Thermostat (second time)
Aisin Fan Clutch
Aisin Water Pump
3 x Heater Core Hoses (non-oem)
Top/Bottom/Chain Side Radiator Hoses (non-oem)
2 Row CSF Radiator
OEM Radiator Cap (first time)
CSF Radiator Cap (second time)

After replacing so much, I'm running out of options. Some paths I think I can take?

• Running lean
  • Will set the throttle and fuel mixture to factory baseline and see where that goes. Not sure how to really dial in the fuel mixture besides by "feel"?
• Bad radiator
  • Hard to believe but maybe? My power steering pump started leaking onto my alternator and now I'm getting a Charge+Brake light on high load. I'm thinking about just replacing the CSF radiator with a new Toyota OEM radiator when I swap out the alternator since the bottom radiator hose needs to be removed anyways.
• Head Gasket
  • Maybe the block test isn't definitive?
• Clogged catalytic converter
  • Had some issues last year getting the truck to pass smog but the shop was able to get it to pass by adjusting the timing. No notes on what the timing was before and after though.

Any other thoughts or suggestions would be greatly appreciated!

 

[aztoyman]

When you say this all started AFTER the parts changing, I have to wonder if you had a T-stat with a lower temp spec. You covered all the other bases.

One other thing that you might check is the wire or connector at or near the sender. Sometimes these old wires/connectors are ok until disturbed.

 

[saywhat]

When you say this all started AFTER the parts changing, I have to wonder if you had a T-stat with a lower temp spec. You covered all the other bases.

One other thing that you might check is the wire or connector at or near the sender. Sometimes these old wires/connectors are ok until disturbed.

I'm thinking the same about the lower temp tstat. If that was the case, then I'm inclined to believe that was just masking another issue.

I tested the sender wire this morning at the connector. FSM states 4.5V but I was getting around 7.5-8V with a digital multimeter. And it wasn't constant which is interesting. Adding this to my long list of things to spend time digging into.

Whether or not the gauge is reading accurately is one thing, but measuring 220F at the thermostat using the infrared reader is too hot in my opinion.

 

[ntsqd]

What is a "CSF" radiator? If aluminum I have strong bias against adding those to vehicles not originally equipped that way. Do you still have the original copper/brass radiator? Would be worth having it cleaned and possibly re-cored.

Looks like you have a new cap, but my experience has been that when I first see a 22R running warm to replace the cap. I had that cycle happen 3 or 4 times in the ~20 years that I owned Patch. It would start running a little warmer than usual, I'd replace the cap and it would go back to running at the normal temp.

When cold in particular do you hear a gurgling noise coming out the the front-center of the dash while driving? If you do, you still have air in the system.

 

[saywhat]

What is a "CSF" radiator? If aluminum I have strong bias against adding those to vehicles not originally equipped that way. Do you still have the original copper/brass radiator? Would be worth having it cleaned and possibly re-cored.

Looks like you have a new cap, but my experience has been that when I first see a 22R running warm to replace the cap. I had that cycle happen 3 or 4 times in the ~20 years that I owned Patch. It would start running a little warmer than usual, I'd replace the cap and it would go back to running at the normal temp.

When cold in particular do you hear a gurgling noise coming out the the front-center of the dash while driving? If you do, you still have air in the system.

CSF is the go to aftermarket brand that a lot of 22R/E folks seem to like for OEM equivalent. It is a copper/brass type like OEM. Csf MyCarParts - https://csf.autocaredata.com/items/895

I didn't know at the time, but OEM is still available PN 1640035350

Yeah I have a new cap, tried both OEM and the CSF branded one. No gurgling noises when its cold either. I'm starting to think it's a flow restriction problem and swapping the radiator out with an OEM could be my last hoorah for throwing money at this.

 

[aztoyman]

Weird how this is happening AFTER new parts. Sounds like it was ok prior. The only thing that you can't confirm is the temp of the original t-stat. It's a lot cheaper and easier to install a lower range t-stat just for some piece of mind. Everything else is new. I'd try it before buying another radiator or other expensive parts. Good luck with whatever you decide.

 

[saywhat]

Well, I bought a new OEM radiator and hoses since the alternator is going out. Decided to do a compression test beforehand. 1/3/4 look good but 2 not so much. Thinking I should do a leak down test. I don't have a compressor here so that might be a bit tough at the moment.

Edit: I went back and did a wet test for #2. Compression increased by 10 for a total of 140PSI. Is this a good indicator that it's just a worn piston ring?

Cylinder #	1	2	3	4
PSI	160	130	166	165

 

[saywhat]

The hard pipe that connects the lower hose to the water pump had some nasty gunk in there. Not enough to cause a flow restriction but I ordered a new one.

 

[aztoyman]

That #2 spark plug looks really clean compared to the others. Hopefully not because of coolant steam cleaning it. I know you had a block check for exhaust in the coolant but, it would get my attention.

Yes, generally a wet test would indicate rings. Kind of unusual to have just one cylinder with worn rings. Another clue to think about.

Have you ever checked valve adjustment? I've found tight adjustment on one or two cylinders before. No it doesn't explain the wet test but it might be good to do before you do a leak down test.

You're being very methodical so I'm sure you'll get it figured out. Good luck with your truck.

 

[saywhat]

That #2 spark plug looks really clean compared to the others. Hopefully not because of coolant steam cleaning it. I know you had a block check for exhaust in the coolant but, it would get my attention.

Yes, generally a wet test would indicate rings. Kind of unusual to have just one cylinder with worn rings. Another clue to think about.

Have you ever checked valve adjustment? I've found tight adjustment on one or two cylinders before. No it doesn't explain the wet test but it might be good to do before you do a leak down test.

You're being very methodical so I'm sure you'll get it figured out. Good luck with your truck.

Good call out on how clean #2 is. I've had a local indy Toyota shop do a valve adjustment in the last 5K miles. Probably wouldn't hurt to double check that as well if time permits.

Next steps are probably one or both: Get a small pancake compressor (30 gallon compressor is in a storage unit of course ugh) and do a leak down test. And/or rent a boroscope so I can take a closer look down #2. Cursory internet search seems like a blown HG would render it clean as a whistle.

 

[aztoyman]

I've seen people ignore the warning signs of a blown HG on these engines only to be stranded when they go from a just starting to fail HG to water and white smoke out the exhaust when it gets really bad.

If it fills a cylinder overnight you can get bend a rod when you try to start it. Coolant in your oil can damage your bearings. Coolant out the exhaust can damage the o2 sensor.

It's good that you're troubleshooting this.

 

[ntsqd]

Teslong $50 borescope

good grief it shouldn't be that hard to insert a link!!!

 

[gnob]

Note how clean #2 plug is.

 

[88repo]

So #2 has a plug that's far cleaner than the rest AND it's down on compression...hmmm.

Something you can also check without a bore scope is pull all your plugs, cycle each cylinder to TDC and peek thru the plug holes with a flashlight to see what the top of the pistons look like. If #2 is noticeably cleaner than the rest, well my bet's on a blown H/G.

G/L....sounds like you're almost there.

 

[saywhat]

Got my hands on a boroscope. I didn't cycle up to TDC for each but I got decent video of #2 and #3. Top of the pistons look pretty similar. #2 looks wet, but that might be from the oil I squirted in during the wet compression test. What do you guys think?