Another AC/Overheating question

[mooker82]

Ive found lots of good info on here about this issue but I need some opinions. My 97 has 120xxx miles and while driving today with the AC on in 95+ degree heat the AC would kick out during hill climbs. The fan still blew but the AC was not cold. A minute after the climb the AC would kick back on. The temp gauge would move from 1 needle below middle to middle( I know the gauge sucks from past posts). With the AC off the temp was normal no matter how hard I pushed the engine. At idle the temp gauge was normal as well even in heavy traffic. I did the radiator bubble test and did not see anything. The coolant was changed last year (September) and the dealership flushed the system but put in Green stuff. I do not have any leaks that I am aware of (I park on grass so its hard to tell). Hoses all look good even the PHH. Radiator looks good and clean. I am not how old the radiator cap is. I think from my reading that I have it narrowed down to either the temp sensor or the fan clutch. Does this sound reasonable? Any other suggestions? Does this sound correct.
thanks in advance
Steven

 

[cruiserdan]

The engine is reaching 226 degrees F and the compressor is being cut out. You have a cooling system issue. Possible problem areas include: Fan clutch, radiator, blocked air intake (radiator fins full of debris), head gasket.

Since you do not see bubbles my money is on the fan clutch and radiator. I would start with the clutch and be prepared to replace the radiator (Been there and done that on both).

D-

 

[mooker82]

I just did the bubble test again and got up to about 3500 rpms and saw some tiny bubbles. Not the dime sized bubbles every few seconds that I think indicate a HG but tiny pinsized bubbles in clusters. I think these may be from moving around the hose in the overflow tank as I could get the same bubbles with the engine off by moving the hose around. Held at 3500 rpms for over 3 minutes and the AC still cooled and the temp gauge did not move. When the original problem occured it was only at about 2000- 2200 RPMs for less than 1 min.

 

[Lars]

Cdan or anyone---

Where is the location of this 'fan cutoff' sensor that measures engine temp?

 

[cruiserdan]

In the head, LH side, aft of the distributor about 10 inches or so.

 

[mooker82]

Just read a post about the fan fuse in the underhood fuse box. Checked mine and there is no fuse in the slot that reads CDS fan. Could this be part of the problem.

 

[MLX450]

I did the fan cut off test and pulled the sensor and the AC did not cut off. Well first of all i need an FSM from C-Dan (will contact you soon) and and ac gauge to diagnose the problem, but i think i know whats cutting it out. Its the dual pressure switch near the window sight glass. I jumpered it for a few seconds and the compressor kicked in. (warning don't do this to long) I figure out the switch is ok. Theres something wrong with the pressure and the safety switch is keeping the signal open.

 

[cruiserdan]

Just read a post about the fan fuse in the underhood fuse box. Checked mine and there is no fuse in the slot that reads CDS fan. Could this be part of the problem.

Nope, sorry. Not a North American application item.

 

[mooker82]

Thanks for the quick response. I guess I will try Robbies fan test tommorow when it is light out and I have not had a few beers. The method does not seem like something I want to try at this very moment. If it turns out to be bad I guess I will order up a new one. I wish the dealer was open tommorow so that I could atleast get a gasket, thermostat, and radiator cap so that I could flush the radiator on my day off. Then kind of go from there. From my reading I guess it is pretty agreed upon to stick with OEM parts for these applications. After more reading I can hear the fan at start up but it is not as loud as I remember it being when I first got the truck.

 

[mooker82]

Also will changing my tranny fluid help? I read that this can potentially help as well because of the tranny cooler. Mine looks OK but not fantastic.

 

[cruiserdan]

That is a waste of time.

 

[mooker82]

I love this site. Its 1:15 AM by my time and Im getting live help. Thanks once again CDAN. I will most likely be placing some sort of order on Monday. Will a new radiator cap, thermostat, Gasket, and fan clutch be under $150 or somewhere thereabouts. If not I might try and hit up the old parental units for some $$$. Can you ship toyota red coolant? or should I stick with green since its already there? Anything else recomended?

 

[CJF]

I wish the dealer was open tommorow so that I could atleast get a gasket, thermostat, and radiator cap so that I could flush the radiator on my day off.

If you have the time to do it tomorrow (today, now), then go for it. It's easy to drain a little coolant into a clean container, change out things like the thermostat, and then dump the coolant back in. As for your red green (I love that show!) question, that issue will never be resolved. Use either and don't neglect it; change every year, or evey two at most.

Curtis

 

[IdahoDoug]

Dan has told me in the past (twice - I'm not too smart) that he can't ship coolant due to EPA regs. I'd source it locally after doing a quality flush and back flush with water. Also, do the Simple Green trick I have outlined to clean your condensor and radiator fins for a significant improvement in itself.

DougM

 

[mooker82]

Thanks Doug I will source the coolant locally and also try the simple green trick.