twistedsymphony

I've got an 89 4x4 pickup with a 22re from a 1990 that the previous owner installed.

I've been battling with coolant issues ever since I bought the thing and I'm at a loss for what do now...

When I first start it up it will idle at about 2500RPM, once the truck has warmed up it will surge at idle between 1000 and 1500 (sometimes between 1500 and 2000).

Through this whole time the heat blows cold.

After about 20 minutes to a half hour drive the idle will FINALLY start acting more normal, though it will sometimes idle at 750RPM, 1000RPM or 1500RPM.. it seems completely random whenever I let off the gas. Once the engine gets to this point (where it's been at operating temp for 10-15 minutes) I finally get some "warm" air out of the vents... about as warm as someone breathing on your hands.

Also I lose about a half gallon of coolant every 2 weeks... I'm pretty sure I'm losing it through the overflow tank as there are zero signs of any leaks and zero contamination in the coolant or oil. Whenever I top off the coolant within a day or two I'll find the driver's front wheel well soaked in coolant from where it all barfed out of the overflow tank.

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So far I have done the following:

• completely tested the heater core, and heater valve, water flows easily through it, no leaks and it holds pressure fine.
• tested the radiator for blockage (no blockage, the rad is less than 4 years old anyway)
• replaced my radiator cap
• replaced my thermostat
• replaced upper and lower radiator hoses
• gone through the TPS calibration procedure (it was already in spec)
• completely flushed, refilled and bleed the coolant more times than I care to remember.
• I've done a compression test (170 across all cylinders)
• I've done a combustion gas leak test, which it passed without even the slightest hint of a leak.
• I've torn apart the dash to make sure all the HVAC cables and ducts are setup and working correctly (they are)

One other thing I should note my ECM throws a CEL for the O2 sensor... I've replaced the sensor but it didn't fix the issue, I'm not sure if it's related.


Any help or ideas would be greatly appreciated, because it's friggin cold here in NH these days and idle issues aside, the lack of heat makes me want to drive my truck off a cliff.

93toyrunner2

Check the water pump and be sure it is pushing water through. Sounds like the radiator has blockage. I would suggest pulling the radiator and either replacing it or take it to a radiator shop to have it boiled and checked.

twistedsymphony

I neglected to mention it in the list above but I have tested the radiator for blockage too.

Both the radiator and pump were replaced by the previous owner with the engine (I even have the receipts) I would think if either of those weren't working I would be overheating.

regardless I'd rather not leave anything unchecked... how would I go about testing the pump?

mightymouse

iTrader: (6)

Most likely you have a blown head gasket between the combustion chamber and a coolant passage. Causing an air pocket to form. Pull your spark plugs and check them to see if one is "cleaner" than the others. You can also rent a pressure tester from a parts store and pressurize the coolant system to find where or why the coolant is blowing through the system. Try this to figure out what's going on and report back with some results. You might just have a bubble in your coolant and it needs to be worked out but i doubt it.

clevelandsmostwanted

water pump or try to disconnect hoses to heater core or just one hook up compressed air to it it will blow it out then see if you have heat,

twistedsymphony

I've done a combustion leak test, it's a device that hooks up in place of the radiator cap and tests for the presence of exhaust gas in the cooling system. Supposedly the test is sensitive enough that it can detect even the smallest of leaks in the head gasket...
http://www.youtube.com/watch?v=WG-gDkWswjQ
You can see in the video the exhaust gas changes the fluid from blue to yellow, the fluid is sensitive enough that you can breath on and the CO2 from your lungs causes it to change color (I even did this to check the fluid) I ran the test 4 times just to be sure and it showed no head gasket leak. fluid stayed solid blue the entire time.

I also changed the plugs and wires a few months ago, none of the plugs showed anything out of the ordinary... they all had the typical "used" look (matte greyish/tan burn), none of them exceptionally "clean" or even dirty.

The pressure test you mentioned is something I haven't tried... I'll have to see if Autozone rents a pressure tester and try that out some time this week.

That is essentially how I pressure tested the heater core... I disconnected the hoses from the engine and hooked it up to a garden hose. water flowed through without any hint of blockage, I was even able to close the heater valve and let it build pressure without any leaks.

93toyrunner2

Did you use an OEM thermostat or one from auto parts?

twistedsymphony

OEM thermostat... OEM radiator cap too.

to be perfectly honest I felt like the issue got a little worse after I replaced the thermostat

though it could also just be because it's been a lot colder lately.

mightymouse

iTrader: (6)

Good on you for looking into it. I had a similar problem as to the one you're dealing with. I couldn't get the coolant to push into the reservoir unless the truck was under load while driving. No matter what i did while in the drive way the coolant would stay inside the block and radiator. After some time the head gasket leak got worse and the signs became more prominent. Eventually i did get the wet plugs, sweet smell, bad running only getting worse. I added coolant and checked it before any trip no matter how short. I eventually replaced the head gasket with a quality set and called it good. That was the only fix had for my problem. Look at it this way you'r loosing coolant and it's not As far as i read leaving puddles right? it has to be going some where. You could very well be burning off the coolant while under load.

Obviously this is advice and not set in stone but given your situation here's what i would do. Bleed/burp the coolant system. make damn sure there isn't any air in there. Here's how i do it you might do it differently but this has yet to fail me.

Place the front end of your truck in an elevated position. Jack stands, ramps, what ever get the radiator up above the motor. Fill the radiator while squeezing hoses and checking to get as much air out as possible. Use a funnel that fits snugly into the fill hole on the top of the radiator. Snugly enough that you could potentially wrap a small towel around it's base and while the engine is running and your hand is off of it it will stay there. Set a jug of pre mix 50/50 antifreeze next to you at the ready to fill as needed. Use a helper or yourself start the vehicle while the funnel is in place. Keep it there and make sure there isn't any fluid leaking out. As the truck warms up it will gain pressure and the coolant will begin to overflow into the funnel but not on your floor. I like to squeeze the hoses and work out the bubbles as the truck warms up. When the truck warms up enough the thermostat will open and the coolant will run back into the engine and the funnel will empty quickly. While the truck is still running top off the coolant and put the radiator cap back on. Congrats you just bled/burped the coolant system and there shouldn't be any air for you to second guess you diagnoses. On a side note this would be a good time to check or replace the radiator cap if you have yet to do so.

So you just eliminated one part of the puzzle. Check your fluid levels and note where the reservoir coolant level is. Drive the truck with the heat off for a few miles and see if you can replicate your problem. By heat off i mean turn the blower off and make sure the valve is off as well. Meaning the temp setting is on the cold side(yes if you didn't know this shuts off the coolant flow to the heater core). let the truck reach operating temp as well and try to drive up some hills making the engine work a little. Drive it hard and put it through your normal paces. Come back to the house/shop and let the truck cool down. check your reservoir and look to see if any coolant has excessively flowed in meaning make sure there isn't too much. [I]If a lot of coolant has flowed into the reservoir and none is leaking out any where else then you might be looking at exhaust gasses pushing coolant out while the engine is under load or something as simple as a radiator cap. This is all to check the regular cooling system and eliminate any other problems by shutting off the heater valve and narrowing down the problem. If the radiator cap doesn't fix it then i'm afraid it could be the head just a funky type of issue that only rears it's ugly head while driving.

If the symptoms do not come back then go ahead and open the valve by setting the heater's temp on hot and let coolant flow in. If the symptoms occur after opening the heater core then congrats you just might have narrowed down your problem to the heater core. If this occurs then you can try and flush the core but to be honest that might work but i'd just replace it.

Try these two tests and get back to me with what you find. If you want to test the cooling system for leaks the pressure tester is great but at thins point it's not needed as there are only so many places the 22re can leak coolant. If you do get a tester don't pressurize it too much i believe only 15-18lbs of pressure is recommended.

mightymouse

iTrader: (6)

After checking your build thread check and set your timing to factory spec.
"Rear O2 Sensor question So the O2 sensor code is ambiguous but it's possible that it's a code for the REAR sensor, which my truck doesn't have. The truck was originally a California vehicle (which had an O2 sensor) but the motor is from a non-cali vehicle and the harness is missing the O2 connector. Anyone know how to tell if my ECU is for a federal or cali vehicle? I'm thinking if I've still got a cali ECU that could be why I'm getting that code."
this also worries me but should be a separate issue.

You seem to know what you're doing i'm surprised this has stumped you for so long. You definately covered all the bases i did before i did the head gasket when i had a similar problem. I think the only other thing i tried before digging in was the fan clutch. But it was too little too late. I finally threw in the towel after replacing and checking the cooling system on my old truck over and over again. Good luck.

WHAHAHAJR

What about the hose behind the alternator? Hows the shroud and fan clutch?

Gonzo4Runner

These two issues might be unrelated. Based on what you did not mention you checked, the following may lead to resolutions.

On the idle issue, check the coolant temperature sensor. It is fairly easy to test using an ohm meter or a multi meter. It is used by the ECU to adjust mixture, spark advance, and a few other things. It is also used by the ECU to put the system into closed loop (IIRC). The ECU is sensing an incorrect mix via the O2 sensor and is trying to adjust the mix, but cannot, since the ECU might be getting conflicting signals. The factory manual has some good details on this.

As for the "no heat", check the heater control valve. It is usually on the fire wall, and connects to the temperature setting slider on the dash through a cable. If the flapper valve inside has broken off, it would block coolant flow into the heater core.

Good luck.

twistedsymphony

hmm... I hadn't considered the timing, I'll definitely check that out.

I wouldn't be surprised if the O2 issue is aiding to the idle problem... though it still doesn't explain the lack of heat.

The test you recommended I've actually performed several times, I've got one of those radiator funnels that seals right on the cap, park my truck on the incline in my drive way and run it while squeezing tubes until it's been several minutes since the last time fluid burped out.

I am getting puddles, as I said I find the coolant coming out of the overflow tank and soaking the driver's front wheel well. I can even emulate this while parked, if I fill the system but leave the funnel attached and empty.... the level will eventually rise so much that it spills out the top. It goes in cycles and will go back down (I believe once the thermostat opens) without any bubbles.

hose behind the alternator was replaced (it was actually leaking a while back and killed the alt so that got replaced too.

there's no shroud on the truck but the fan clutch works... you'd swear there was a helicopter under the hood when it's running. I've actually been considering swapping to an e-fan I already bought a controller I just need to find a good fan.

I'll add the coolant temp sensor to my list of items to check, if it's cheap enough I might just replace it to rule it out.

as for the heater valve, as I mentioned above it's one of the first things I checked, it works perfectly.

robroy75

Hi, just a suggestion, there are a lot of egr lines on those manifolds that connect to a variety of sensors etc. I know it is a crap job, but you may need to trace these to make sure that the previous installer of the engine just didn't pick the closest line that would suit and connect them together. I think the workshop manual covers this. I will check in mine and if so post the pic.
I had a similar idle/running problem with my carb 22r, when the person helping me (my dad) connected a couple of hoses from the manifold incorrectly. Your eyesight does fail when you get old!

Hope that helps.
Thanks, Rob.

twistedsymphony

ugh... so yesterday on my 30 minute drive to work the temp gauge crept up to 3/4 (it probably would have kept going if I hadn't arrived at work).

I've been keeping coolant in the truck so at lunch I topped it off and it drank a half gallon... on the short drive to get some lunch (~3 miles) it started creeping up past the half way mark both on the way there and back.

Before I left work I topped it off again and it drank the other half of the gallon. Thankfully no overheating issues on the way home.

to be sure I topped it of AGAIN this morning before driving to work and it took about 1/4th gallon. again no overheating on the way to work.

I'm thinking this weekend I'm just going to bite the bullet and tear the head off to replace the headgasket and water pump, whether it needs it or not... really those are the only two major elements of the cooling system that haven't yet been replaced.

WHAHAHAJR

Good luck.

mightymouse

iTrader: (6)

obviously do the water pump first as it's the easiest part to check but yeah the head gasket is the most likely culprit. Sorry to hear nothing has worked. Like i posted before i went down almost the exact same road a couple years ago. Get a quality head gasket from toyota and have the head checked for cracks/straightness while it's off. I could barely tell that the head gasket was gone when i did mine but low and behold the problem never came back.

twistedsymphony

I had a complete FelPro gasket kit laying around because I had considered upgrading to a performance head a while back and fell into a deal on the kit...

I picked up a water pump and drove the truck to the shop owned by a few friends of mine (Fujii SPL in Concord, NH)

Spent all day Saturday tearing everything down, completely cleaned up the head and checked for flatness (it was good! which was a huge relief).

The head gasket didn't really show any major signs of blow through, though there was a little bit of deterioration in a few spots.

so far there are zero leaks and the coolant level has stayed solid, I also have heat! (though the heat still isn't as hot as I'd like it to be).

surging and the super high idle are also gone, though the idle isn't as consistent as I'd like it to be. it still idles somewhere between 750 and 1750 everytime I let off the gas, it's completely random, I think maybe my TPS either needs to be cleaned or replaced as we did the adjustment procedure again.

Thanks everyone for all the suggestions.

WestSideVB

You said the gasket looked pretty goodm how was the water pump?

Im in a very similar situation.

twistedsymphony

The water pump looked good too but I replaced that anyway... I did timing chain while I was in there too (If I'm going through the effort of tearing everything apart I'm going to damn well replace everything while I'm in there).

Truck hasn't got much use but since replacing the head gasket I haven't had any coolant consumption, surging, or lack of heat... it still has a high idle but I think that's due to the IACV.