What have you done to your Tacoma today? 1st Gen Edition

Sounds like the Tstat?

 

No chance the water froze? Not sure where you are but it's cold enough here to freeze.

Think the jiggle valve is better at the 12 o'clock position. This will allow air pockets to circulate.

 

Agreed that the symptoms sound like thermostat, but two malfunctioning thermostats, one brand new from the Toyota dealer and one working fine before we took it out, and both appearing to work find in boiling water on the stove... I think it has to be more than just bad thermostats.

We've been in a warm spell, I don't think anything could have frozen. Lows in the 30s but still pretty well above freezing. The problems started the same day we drained and stopped immediately when we put in the gutted thermostat with glycol. I don't think for freeze/thaw could have occured in between.

The jiggle valve is supposed to be at 6:00 in a 5VZ (12:00 is correct for a 3RZ though). Nobody seems to know why, but the FSM says 6 and folk online say the engine will run 10 degrees hotter with it at 12.

My best guess now is that the problem was the water boiling and turning to steam. We were working at close to 7000ft, so water has lower boiling point here: 92C/198F, vs 100C/212F at seat level. The thermostat is supposed to open at 82C/180F. Glycol will raise the boiling point of water by by several degrees C--not a ton (and I don't have exact numbers because they vary with different glycol mixes), but maybe enough to make a difference.

I'm thinking maybe the unpressurized system, with a lower boiling point, started forming steam bubbles before the thermostat opened?

I'm not super confident in that explanation but it's the most plausible I can come up with.

Thanks to everyone who's given this some thought.

 

Purposely taking your trans out of OD is a must when towing, when you use the OD off button it enables torque converter lockup in 3rd gear which with both together lessens load and heat generation

 

Stove test seems like check of tstat. Why was only water being run instead of coolant? It is working now with proper coolant mix?

 

Water was temporary. We were flushing the system and wanted to verify that the water had flowed through the entire system before putting coolant back in.

Things are sort-of working now. We put in a gutted thermostat (basically, always open) at the same time we put in the coolant, so those two variables are confounded. At that point it was late, we thought the problem was the water pump, and our main concern was getting the engine into a good enough state that it can sit through freezing temps for a few nights until we have time to look at it again.

 

Installed a LCE Stage 1 longblock with Haltech Elite 750 ECU. The stock motor was worn out at 240k/mi. Crack in head between valve seats, Chain tensioners/guides worn out and the harmonic balancer bolt broke off in the crank nose. I’m the original owner of this truck and put every mile on it and felt it deserved a solid freshen-up.

Also LCE heavy flywheel and clutch kit, LCE long tube header, rebuilt the factory alternator and starter, new NGK coil packs, Mishimoto radiator, Mishimoto PCV catchcan/filter, custom air intake and some custom wiring, plumbing, etc. Truck is amazing to drive! I live in Northern Arizona and it pulls steep interstate grades no problem. Hardly ever have to downshift. Yeah, I have about $13k in it, and that's with me doing all the labor, but you can’t find a new truck for that. Love it!

 

You should definitely be doing the flush heat cycle with the truck at an angle(front high, preferably quite steep to get the radiator fill port higher than the heat exchange valve) and with NO radiator cap on. Otherwise the air can't escape.

It'll be really helpful at this point to go to Napa or some auto parts store and buy the burp funnel. https://www.napaonline.com/en/p/SER24680 It's not that expensive and works great for this. And ensures you don't run low on coolant during the process. And no spills.

 

The truck was parked facing up an incline. Roughly equivalent to having the front end on ramps, maybe even a bit higher. The radiator cap was off except when we went to test drive it.

We didn't have the burp funnel but we did always have someone watching the radiator and overflow and topping them off regularly. Maybe the funnel would have helped but it should be possible to burp a 5VZ without one, right?

 

I don't own one of those funnels and never had an issue burping any of the stuff I work on.

 

Things are going back together on the timing belt/water pump. Used my tap/die set to clean the rust from the threads on the bolts, nuts, & mounting holes before reassembly as best I could. Hopefully it helps next time this job comes around. Or if I somehow screwed up something and need to redo.(Not too worried about the latter possibility.) Had an amusing realization looking at the old & new water pump side by side - I suspect they use the same casting & grind off the "Toyota" logo for the ones being sold as Aisin brand as opposed to Toyota pumps.

 

I just put nerf bars on, as well as a good tonneau cover.

 

Is that a hard cover or roll up? What brand?

 

Dash rattle persisted after my latest fix attempt. After driving and listening to where the sound was coming from I found the passenger side a pillar trim was rubbing against the side of the dash. I removed the trim and affixed a small strip of rubber where the contact occurred. the following pic shows where the contact was.
It’s the black smudge.

 

Most of the way through reassembly on the timing belt. Pretty much need to put the radiator back in, and once I bleed it I should just need to do final tension on the alternator and PS belts. After I take it for a couple drives, I'll take it in to get the R134 evacuated and start on the compressor at my leisure. (Sooner rather than later, it heats up fast here in the Carolinas). Might need to take the AC tensioner assembly off the truck & either replace or completely strip off the rust & repaint it, I tried to adjust the idler by way of experimentation and it is STUCK, even with several applications of penetrating oil + plenty of swearing. Also gonna need a new lock nut for the AC idler, the old one's threads are completely gone.

On a slightly more amusing note, the crank pulley bolt needs more torque than my 1/2 (F):3/8 (M) adapter could take. This was not on my list of things I was worried about breaking with muscle alone.

Oops.

 

Needs more booze

 

Just installed a backup camera and some sweet speakers and a sub

 

Dash rattles get annoying quick. I recently stuffed a black silicone vacuum line between the dash and windshield that goes all the way across and that made a serious improvement and it's hardly visible

 

That is a damn good idea! Do you remember what size you used?

 

I just installed it.
It is a RealTruck TruXedo Lo Pro Soft Roll Up. Around $500.

I tried an economy one, but it was $hit. This one says quality 100%. There are alot of youtubes on it. Lifetime warranty.