AC/Heater question - Toyota Nation Forum : Toyota Car and Truck Forums

Troyfrezze · 03-01-2006, 05:34 PM

So I came here today to ask one question, and it ended up being two. I've been searching around the site trying to pull up what information i can before I had to post in hopes that I might find my answers, but so far i'm not sure I'm finding it. So here is the deal:
Gave my wife the 93 4cyl when I picked up the 95 1MZ last August. Right before I had the coolant recharged, R12, as it was still hot here in Texas and the car wasn't blowing much cool air anymore. Afterwards it blew some nice cold air again. Well, we finally got some cold air here over the last few weeks and I had to drive the 93 again to work while I replaced the valve cover gaskets on the 95. I couldn't help but notice the heat never got hot till I was almost on base, a 20 min drive away. I started trying to pay attention to the guages and noises I heard, and never heard any noises, but did notice the engine temp seemed to take forever to get warm. So based on this, and what I just read I'm going to assume it's the Thermostat stuck? Well, today my wife swung by my office while I was outside with the guys and I got to talking to her when I noticed that the AC wasn't putting out much cool air. It was blowing cool, but not very cold at all really. I had her pop the hood and I looked at the glass to make sure there were no bubbles and it was quite clear, maybe a small white bubble here or there...but not like before when it was low. I also checked the compressor to make sure the clutch had engaged and was spinning. I found on here that some people seem to think this could be a problem either with the condensor, possibly the compressor, or even with the lines running to the firewall. I have yet to go back out and check it since getting home a short while ago but I figured I'd ask anyways to see if anyone thinks the items could be linked. Should I just go let the car run at idle for a little bit then check the pipes to see if they are hot/cold? Thermostat I know will be easy to replace, but i'm not sure if this could be the problem. Figured i'd ask around first before I go through all the trouble only to find it's just something simple. So if you have any advice or tips from your own experience please let me know. Thanks!

Alan

Ferrat · 03-01-2006, 06:12 PM

Personally i replaced my themostat on my 88 and 89 camry. Its cheap so you might as well give it a go. It can't hurt.

Troyfrezze · 03-01-2006, 06:39 PM

Well I just got back in from looking at the system. I turned it on and put it on AC. As soon as I cranked it I went and felt the lower hose to the thermostat. I could feel the fluid pulsing through. After a few minutes I felt the two lines. The low did feel cool to the touch, and the high felt warm, expecially the one running from the compressor up to the radiator area. I took another look at the window and this time I can see it's not clear. It's got the rushing white foam through it again, so I take it i'm low again on freon. Possibly a leak somewhere i'm going to assume. After about 15 min of just sitting there the engine temp was about a quarter of the way up so I flipped it over to heat. Started blowing luke warm air, and finally got a bit warmer after about 4 more minutes. I looked at the valve at the firewall for the heater control and saw that when the cold air was selected it was pushed all the way back to where it made contact with the stoping point. When moved to Heat it left about a half inch or more of the line exposed from the sleeve to the round eye. Possibly it needs to be reclamped, maybe over stretched? This is what I go so far. I figure I'll go ahead and replace the thermostat...it's 6 to 10 bucks at Advanced so I'll do that this weekend. If anyone still has some advice for me here I'm still open. Thanks anyways...

Mike Gerber · 03-02-2006, 05:50 PM

It does sound like your thermostat is stuck in the open position. I would replace it, but I would get one from the dealer. That may run you a bit more money but I believe the OEM thermostats are better. Also, dont forget to pick up a new rubber gasket too. It actually goes around the edges of the thermostat. You'll see what I mean when you see the thermostat and it's rubber gasket.

Your second problem does sound like you have a freon leak and are loosing R12. You might consider having the leak repaired and then switching the system to R134. The system won't be quite as cool as using R12; some say they can't tell the difference and others say they can. The cost of R12 is just getting out of site.

Mike

Hajoca · 03-02-2006, 08:31 PM

Stick to the OEM thermostat. It fits with no problem and is straight forward. Only pick aftermarket if you are 1. Truly cheap, or 2. want that extra 2% fuel efficency.

I used an aftermarket on my I4 that was set to open at a higher temp in order to get the cylinders warmer (more efficiency) but then I noticed that I did not have an oil cooler and that would be a contributer to sludging due to the fact that my gen4 5SFE and 1MZFE (v6) does not have the water to oil cooler anymore, along with narrower coolant passages.

I do use my car on the highway and synthetic oil, so I am monitoring this closely.