Overheating after some unrelated(?!) repairs

Ok - I did 3 things yesterday:
Changed a very old oxygen sensor
Replaced the air filter
Re-mounted my starter. At some point someone installed the starter using one bolt that was 10mm too short and may have also stripped the crap out of the threads, which was ok until I started driving on bumpy gravel roads. The short bolt stripped the rest of the way out and the other bolt worked loose enough to make the shifter wobbly but not enough for the starter to actually drop. I found the problem and got the starter mounted I think properly, but a lot of dust did get in around the gear.

It started and ran great but 10 miles later I notice the temp needle going up while I was in traffic. Cranking up the heater brought the needle back to the center but not that much heat was actually coming out of the vent. The needle went back up after I turned the engine off which makes me think it was a circulation issue and that maybe the engine was actually running hotter than the gauge indicated. After it cooled down I was able to add a few ounces of coolant into the filler cap. The reserviour was at a normal level.

Before I start looking for clogs or bad water pumps is there any chance I caused this with my repairs? I can't think of a way but perhaps I'm missing something.

That you ended up adding coolant at the filler neck suggests a coolant leak, particularly those locations fairly high in the system.

Of course something happening just after something you did doesn't equal cause and effect, but ..

Because to the position of the starter, I'd check over the hoses and pipes leading to the rear heater ... just in case something got compromised. Can't hurt!

If no evidence of leaks there, start with the rad cap (I'd just replace it on principle) and the tube to the overflow tank, both common culprits in situations when nothing is used from the reservoir. However, even a pinhole in the hose from the filler neck to the heater tee OR in the upper rad hose can cause the same symptoms.

Good luck!

Gwen

I couldn't find any leaks so I took it into a shop with a pressure tester thing and he couldn't find any either. He did find that the fan clutch wasn't working, though. Then he gave his standard "labor is like $150 to change it out, I'm not sure how much money you want to spend on this thing.." line. I felt like he was telling me I should just kill a beloved family pet and get a new one cause it has a broken leg. He did do a good job when I took the van in to him a couple of years ago, though, so I'll let it go.

I ordered an OEM fan clutch and radiator cap and will decide if I want to change it myself when the part comes. The heater is working properly now and it seems to be staying under temp fine if I leave it on. Our current theory is that the cap let out some fluid when it overheated and the parts I ordered should bring it back to normal.

Thanks!

Oddly enough, I am in West Vegas right now... changed out my TPS in the REI parking lot this morning.

If the job is sizable and you want to look at the shop manual for the 89'... I've got mine. I'm planning to leave town tomorrow night or Saturday morning. I'll be busy (out of service) tomorrow at red rocks, but you could send me an email.

I would be happy to meet you at a photocopier somewhere if you think its a big job and the manual would help.

good luck
chris
chrismael@yahoo.com

Thanks for the offer! I think I'm good with the manuals I have. Feel free to PM me if you need anything while you're in town, though. I'm near the strip.

Changing the fan clutch turned out to be pretty easy once I removed the passenger seat and moved the engine panel out of the way. The only complication was that the old aftermarket one used 4 SAE bolts to hold the fan in place but the new OEM one had 6mm studs. I had to pick up some nuts at an auto parts store.

The Toyota one is significantly heavier, not sure if that's a good for MPG but my engine temp is now at around 11:00 on the gauge instead of 12:00 like it always had been before and no hint of overheating.

The radiator cap was thoroughly trashed and has been replaced, thanks for that suggestion Gwen.

Attachment 1523

Curious on how that Toyota fan clutch is working out, last summer my van was running hot enough to constantly have me checking the temp on the dash. I notice my van has an aftermarket fan clutch and was wanting to go OEM, you pleased with your purchase?

So far the OEM fan clutch is great. The gauge hasn't gone past the mid-point since I put it in, and I've definitely been putting it to the test.

The old clutch was the same for at least 2 years though - at some point it just stopped working properly. Tim put up some videos on how to test them - I'd recommend giving those a shot to see if that is in fact your problem before spending $100.

I got a new aftermarket clutch fan from Napa about 1 year/13k miles ago. It failed a couple weeks ago. During inspection I noticed the thermostat shaft on the front had massive side play and all the silicone goo had been slung out from around this shaft (so much for the Napa clutch). Over the past year I had purchased a couple other aftermarket ones from a www.rockato.com "closeout" sale, so I put one of those on. So far it's working good, but when I've used up these I plan on going back to Toyota. I'd rather pay $130 for one that lasts 25 years then to pay $50 for one that only lasts 1 year. Tim

PS: The Rockauto ones only set me back $20 each. Hopefully these will last.

I bought a couple tubes of silicone from Toyota for around 10$ a piece a while back and put it in my Toyota pickup fan clutch. I just filled it up-it was very easy. The "roar" was very strong on start-up and lasted probably longer than it should have-I think I over filled it but I won't next time. I found a good write-up about filling the fan clutch up here : http://neuralfibre.com/paul/4wd/tuni...ous-fan-clutch
I still have some leftover and another tube I'll use for my Van fan clutch when the need arises. This guy says that Toyota under fills the fan clutch. :thmbup: