Cooling system- taking to long to reach operating temp?

[bcsbadboys]

'97 Camry with 4cyl, 5SFE engine

Noticed the temp gauge is very slow to reach operating temperature (10+ mins for the needle to even start moving) so I replaced the thermostat with a new one. Same problem! The needle will eventually reach the L mark on the dash (about 4pm on a clock) and hold steady regardless of idle or freeway driving. I remember the 4cyl warming up much, much faster in the past!

A few things I've done:

Burped the upper hose of air pockets. Tested the ECT sensor (resistance is good and matches those of the manual) Tested the Temp sender (when grounding the connector the gauge does not peg all the way to hot)

I've noticed:

Heat will come from the vents in the cabin after a few minutes even though temp gauge is cold. The reservoir stays level (not losing coolant) Upper radiator hose gets hot and pressurized at operating temp. The lower radiator hose is often cold and was warm once when I felt it but that's the only time I've noticed it. Haven't seen the radiator fans come on lately (it's 20 degrees in Minneapolis now)

Why is it taking so long for the temperature gauge to reach normal???

[fenixus]

2.2L 5s-fe engines are usually very fast to reach full operating temperature. even in Winter they can get fully warmed up in 5 minutes or after driving literally a quarter mile distance in around 30F ambient.

I'd say your thermostat is the problem. it might unable to fully close, or opening too fast. it's a $15 part (+ gasket) from dealer and do get the OEM one with OEM gasket. replacement requires coolant drain, at least enough to safely open thermostat housing without major spills.

[pmesfun]

Originally Posted by bcsbadboys

Tested the Temp sender (when grounding the connector the gauge does not peg all the way to hot)

I remember when applying ground, it should go all the way to hot.

[bcsbadboys]

fenixus- I agree with that. These engines usually reach operating temp fairly quickly. I may have just gotten a bad one out of the box. I'll go with OEM + gasket and try again.

pmesfun- what would it indicate if the gauge did not peg all the way to hot when grounding the sending unit connector?

[pmesfun]

Maybe a broken connection in the wire, I'm guessing. Not to good with electrical.
+1 on the thermostat, I had this problem also.

[fenixus]

before replacing thermostat again (OEM this time). try this first.

warm up the car enough, so you get the hot air from vents, that usually corresponds to dash gauge between Cold and Normal (middle) position. shut the car off. unplug ECT connector and measure resistance between its terminals.

make sure the ECT sensor shows COLD reading (resistance) pretty much same as the dash gauge.
if ECT says WARM while dash gauge still says completely cold then the problem will be the dash gauge sender (or wiring).

[bcsbadboys]

This is where it gets and holds steady. Is this normal or low for the 5SFE?



The vents put out HOT air and everything runs properly. I'm just uncertain why it takes so long for the gauge to show proper operating temperature. It's been staying down by the C for up to 10 minutes before moving.

[fenixus]

if dash temp gauge sender works correctly then it looks like a stuck open thermostat or wrong thermostat type (.e.g no jiggle valve) or improperly installed.

example of WRONG type thermostat below:


example of CORRECT type thermostat (with bottom bypass valve):

[wave180]

I had the same issue, I changed the thermostat with Stant's supersat from Pepboys. So far so good after about 700 miles.

[Mister_Perkins]

Make sure your Jiggle valve is angled correctly too!

[JohnGD]

Yeah, the jiggle valve helps burp the system of air. And OP's temp looks on the low side. It's also possible that a lower 170 deg thermostat was installed.

With the car warm, measure the resistance of the ECT sensor (2-wire one, not the 1-wire gauge sender). And we should know.

[JohnGD]

I can't believe any competent mechanic would waste time putting in stat like this:

Originally Posted by fenixus

example of WRONG type thermostat below:

[Mister_Perkins]

Its hard to find competent mechanics these days

[fenixus]

Originally Posted by JohnGD

I can't believe any competent mechanic would waste time putting in stat like this:

most of them will do anything do earn extra few bucks and make you come back in future

BTW, Hey the OEM Toyota thermostat I got from dealer is the Kuzeh (82C) with jiggle valve. Funny thing that in shape it looks more similar to the cheap (Wrong) type of STANT thermostat hehe:

[bcsbadboys]

Conclusion!

Why I always troubleshoot before throwing parts at something:

The thermostat was new. The temp sensor tested GOOD. I grounded the sending unit and it did not peg the gauge to HOT. So...I pulled the instrument panel out and tightened the 3 screws for the temp gauge. Now this AM, the gauge responds quickly. Must have been a poor connection at the gauge.

Always check connections and test stuff before replacing parts. Thanks everyone for the help!