whoa--van got really warm when idling....

[JFratzke]

Driving around town yesterday in my LE, I noticed some strange activity on the temp gauge. So it was hot yesterday, about 101, and I blasted the A/C full blast front and rear all day. As long as I was moving around and driving, the van temp ran just above half, just a little hotter than where it has been running. However, anytime I stopped anywhere and left the van idling (in order to keep the A/C on to keep the inside cool) the temp would spike all the way to the high end of the normal range. It never got into the red but it sat right there, pegged at the top of the normal zone. I was temped to shut it off and let it cool down but by driving it, the temp would go back down to acceptable ranges. I talked with my shop manager and he said possibly the fan clutch was going bad. I'd like to take it out of town this weekend but am starting to reconsider. It's been running cool at about the half way mark so I haven't worried about cooling at all yet until yesterday. The radiator was flushed when I first got it about a month ago and we put in a toyota themostat. Anyone have something similar happen?

thanks,

Justin

[JFratzke]

just read this thread which seems to confirm my shop's suspicion.

http://www.toyotavantech.com/forum/s...rom-Vancouver- (http://www.toyotavantech.com/forum/showthread.php?374-Hello-from-Vancouver-)!

How big of a job is the fan clutch?

[JFratzke]

So I take it nobody likes to talk about overheating anymore? :LOL2:

Obviously there are so many threads on here addressing it that it has been covered through and through. I just took the Falcon on a 300 mile road trip with no problems. 2 BIG grades to go up to in 95+ temps. I just shut off the AC for the uphills and I was fine--the temp gauge barely crossed halfway. I am thinking my overheating last week was either a loose belt or the fluid coupling assembly (fan clutch). I am going to order the fluid coupling assembly and all three belts and do the repair in my driveway. It looks easy enough and it would probably be good for me to know how to change the belts out.

Other than that, nothing new to report on the overheating front.

[timsrv]

Mine will overheat too if I leave it idling on a hot day with the AC on. I could be wrong but for a Toyota van I think this is normal. I make it a point to turn off the AC if it's going to idle for more than a few minutes at a time. Typically sitting at a stop light is okay but sitting still (like in a parking lot) for longer periods isn't a good idea. Here's a post from another thread on this subject:


Yes, this sounds good. Up to 210 is fine for short periods in extreme conditions.....like sitting at an idle on a hot day with the AC on or after coming to a stop immediately following freeway driving, pulling a heavy load, or driving up a steep hill. But in normal conditions while cruising it should be stable at around 195-205 (on hot days you will normally see it closer to 205). 210 is actually okay for extended periods, but if it gets this hot for long periods of normal driving it's an indication something is wrong. As mentioned earlier even up to 220 for SHORT periods isn't going to hurt anything but in normal conditions you should never see it that high. There can be exceptions though. You should not run the AC for long periods while at an idle. On a hot day while idling the fan clutch doesn't move enough air to keep up with both the engine & the AC. If you find yourself doing that a lot, you might want to adjust your AC amplifier to kill the compressor at low RPMs. This will prevent the AC from blowing cold while at an idle but it will return to normal as soon as you start cruising again (this can potentially save your van from overheating). If you're behind the wheel and you want the AC to run, you always have the option of putting in park, then increasing RPMs with the gas pedal. This will allow the compressor to run AND the fan clutch to move enough air (depending on where you set the amplifier). If you're stopped at a light don't increase the RPMs while in gear as this will create excess heat in your automatic transmission.

It's normal to see spikes in temp after shut-down. This doesn't hurt anything as the moving parts of your engine are at rest. When you start back up the temp will quickly drop as the air and coolant circulation begin again. Tim

[JFratzke]

Good info to know--I hadn't seen that particular thread yet. On that day I was trying to max my AC because I had my kids with me. We were running errands in town and it was HOT out. 101+, which is as hot as it can get here. It was the first time I had ran both front and back A/Cs at the same time. It would only spike when idling or at long stops and it never got into the red but it still freaked me out. I am still going to do the fluid coupling assembly because the fan does not 'roar' upon startup like my other van does. I also think I should change out those belts just because it sat so long. It just isn't as urgent now with that road trip behind me.

[JFratzke]

Had a strange overheating incident this morning and not really sure what to do. I was pulled in a drive through grabbing some breakfast when my temp needle started to spike. Went up almost into the red before I was able to pull it into the parking lot and shut it down. Then I raised the hood to let it air out. Wasn't sure what to do really. I did notice the overflow from the rad had puked out a little antifreeze but not much.

After sitting for ten minutes I started it up and it registered 3/4 hot and started to rise. I only had two blocks left to work so I wasn't really worried. As soon as I gunned it and got out into traffic, it immediately went down back to where it normally sits at about half way. Once I got to work, I sat at park and attempted to recreate the issue but it stayed right about half way.

Not sure what to think. It was similar to what happened to me last summer in this thread so I posted it here. But it was super hot out that day and today its really cool, like 38 degrees out.

Since last summer I have replaced the water pump and belts along with the pulley. Rad was flushed right when I got it and the thermostat was replace OEM. I notice I need a OEM cap and none of my rad hoses have been replaced yet.

Did I past a chunk of crap through my cooling system or is my head gasket giving me warning signs?

[timsrv]

That sounds suspiciously like a sticking thermostat. I know it's not that old, but sometimes they can stick. I've seen them stick closed before, but then open when gunning the engine. In my mind it's the most likely thing. It's also the cheapest and easiest thing to replace, so if it happened to me I'd probably replace again. I've seen this more on vehicles that had a "stop leak" type product run in them so make sure the coolant still looks nice & clean. I know you flushed it, but if the system was contaminated before the flushing, some of the contamination always remains.

I know this probably isn't the answer you wanted to hear, but it's all I got...........better than a head gasket anyhow. Speaking of which, that too is a possibility, but I wouldn't jump right into that............I'd replace the t-stat again and keep an eye on it. Head gasket failures are usually accompanied by an unexplained consumption of engine coolant. Other signs are more obvious like steam out of the exhaust, coolant mixed with engine oil, and/or oil in the cooling system. Have you seen any of that?

[JFratzke]

Haven't had any of the other head gasket symptons you mentioned. It does smoke white smoke for a bit when i first start but its not excessive and it burns off quickly. Considering how dirty this motor is internally, I'd say it is normal. No coolant in the oil and haven't had to add any coolant yet. Going to order a new thermostat and a cap, as well as the upper and lower hoses (haven't changed them yet). Maybe time to have the rad re-cored or at least professionally cleaned.

I haven't used any stop leak type products in the rad but who knows what the previous owner did.....

Thanks Tim!

[JFratzke]

Ordered all of the above mentioned items today OEM. I topped off the coolant (it took almost a quart) before I drove it home. I pushed it pretty hard on the way home and the needle stayed a little lower than where it usually sits just below the half mark. Also rechecked the oil for any water/coolant and found none visible. Add the remainder of the gallon of coolant to the collection of fluids that I am now carrying in the van.

You know what's strange? Just before this incident this morning I had a weird premonition that I needed to watch my gauges more closely because something might happen. I am dead serious I really did. Don't get me wrong, I usually keep an eye on the gauges anyway and am always watching out for the next "problem" but this was different. The van was driving beautifully too. I had just finished my commute at HWY speeds. Everything was fine when I got off at my exit but something told me I needed to be vigilant this morning. When the needle started to rise my first thought was "Look at that, you worried so much something did happen."

Not sure why, not sure how, but I felt that one coming. Hopefully she'll always give me that much notice before she decides to melt down....

[timsrv]

I put a 220 deg temp switch, a warning light, and a buzzer in mine. If the temp EVER hits 220 deg F the light and the buzzer will alert me. Tim