99 Honda Accord temp gauge question

99 Accord 4cyl, auto, 105k miles. Had the rubber band changed a couple months ago, shortly before the weather got cold. Also did water pump at the same time (since they had it apart anyway), and changed plugs, wires, etc.

Since then, at cold start, the temp needle takes forever getting off the peg. At highway speed, it drops down to just above the peg, and only shows in what I consider the 'normal' range (1/3 to 1/2 of scale) when driving in town in stop and go traffic. Engine seems to run fine, and MPG is still mid-20s in town, and a hair under 30 on highway.

Do I have a problem? If I take it back to same shop, what do I need to ask them to check? Bad sensor? Bad gauge? Wrong T-stat?

Any ideas appreciated- I haven't done any wrenching to speak of since carburetor non-computer days. Hate to just throw parts at it, since Honda parts cost twice what normal cars do, it seems. The shell is still clean, so I was hoping to get another 5-6 years out of this thing.

Reply to
aemeijers
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Thermostat.

Reply to
JRE

If the engine runs then it will generate enough heat to overheat in short order. If it is overcooling than you have a bad thermostat. Or you've somehow recalled the laws of physics.

Reply to
AZ Nomad

Sounds like an open or missing thermostat. Not an uncommon thing to have them bad out of the box. One of the reasons I test all the ones I buy before they get installed.

If they are a good shop they will throw a scan tool on it before they pull it apart. The tool will show if the gauge is correct or if it really is running cold.

Reply to
Steve W.

Why is it you think the car might suddenly acquire the wrong thermostat? If changing the thermostat was part of the recent maintenance work, go back and complain.

What you describe is exactly what happens with an stuck open thermostat or perhaps even no thermostat. Probably it is stuck open (unless for some reason they removed it). Extremely unlikely that the gauge or sending unit is bad. Its pretty close to impossible, given your precise description of what its doing, that it could have a properly working thermostat and a bad gauge or sending unit.

-jim

Reply to
jim

Appreciate all the replies, everyone. I was hoping it was something minor like that. Unless we get a warm spell, guess I need to take it back to the shop. :^(

Reply to
aemeijers

One further question - does the heater output coincide with the temp gauge? That is - does the heater take forever to get warm and only put out warm air or does the heater seem to work as it should? If the heater is working normally, the best guess would be either the sending unit or the temp gauge. If the heater isn't working as it should, then the best bet is the thermostat.

DaveD

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Reply to
Dave D

aemeijers wrote in news:G-- dneWEt7IIMIzWnZ2dnUVZ snipped-for-privacy@giganews.com:

I'd suspect the T-stat.it's probably stuck open. I doubt they changed it during the timing belt service.

Reply to
Jim Yanik

...or they removed and never replaced it..

JT

Reply to
Grumpy AuContraire

(snip)

Tested that today, by driving the car to work. Heater seems to work fine, and blows warm within a couple blocks, and very warm within a mile or so. (Car lives inside the attached but unheated garage, so the start temp is warmer than a car that lives outside. Has to be subzero for the garage to freeze hard.) All this with temp gauge on or slightly above the peg. Gauge does still move a little, if car is stopped and idling.

Still too sniffly to get out there with a flashlight to see if I can get to the temp sensor, with all the other crap in the way. No hurry at this point, I guess- I can wait for a warm day, especially if the snow they are forecasting for later this week actually happens. This is my road trip car, and I don't have one of those for awhile.

Reply to
aemeijers

Toss a scan tool on it and see what the sender is telling the computer. If it is OK then ignore the gauge. May be possible to borrow one from some of the parts places. Just ask them if it will read live data as well. You could have a bad sender to the gauge OR a bad connection or even a bad gauge. A quick scan and you would know if you can just ignore it until better weather.

Reply to
Steve W.

Oh where are you located? If you are nearby I could scan it for you easy enough.

Reply to
Steve W.

aemeijers wrote in news:8Z6dnW63frarxInWnZ2dnUVZ snipped-for-privacy@giganews.com:

If the heater appears to work fine, then the gauge is suspect. You need to aim an infrared thermometer at the upper rad hose outlet from the head. If, fully warm, you get much less than about 205F, then the engine is running too cool. If, fully warm, you get about 205, then the gauge is faulty.

It's a one-wire connector that's usually right under the distributor. Should be easy to get at.

With the infrared thermometer showing about 205 at the "sweet spot", unplug the sender's wire and push it aside. Using a VOM, connect the sender's contact to a good engine ground. At full-hot, you should see 35-32 ohms. If you see significantly higher than that (like 140 ohms), then the sender is bad.

Reply to
Tegger

"Steve W." wrote in news:hf1nb2$uar$ snipped-for-privacy@aioe.org:

I'm sure you're referring to using the scan tool to check the ECT sender, not the gauge sender.

Honda coolant-temperature-gauge senders (really just a variable ground) go bad far more often than the gauge itself.

An infrared thermometer and a VOM are invaluable tools for solving this problem.

Reply to
Tegger

Yep,

Sort of like other breeds. EXCEPT the damn stepper motors GM stuck in some vehicles....

True, just figured the scan tool was a "clean hands" option.

Reply to
Steve W.

"Steve W." wrote in news:hf1ndl$uar$ snipped-for-privacy@aioe.org:

He's in the San Francisco area. Bit of a drive from the Birthplace of Baseball...

Reply to
Tegger

Just a bit. I don't think the cable will reach either ;-) Oh and don't believe that drivel about Cooperstown...

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The first recorded game of baseball in US history officially took place in Hoboken in 1846 between the Knickerbocker Club and The New York Nine at Elysian Fields.

Reply to
Steve W.

Now if I only HAD an IR thermometer.... :^(

Reply to
aemeijers

Oh, that's only about 14 hours away, if I cut through Canada.... :^/ But thanks for the thought.

Reply to
aemeijers

???? If you are referring to me (the OP in this thread), where do you get SF out of anything I have ever posted? I'm in Baja Ontario, aka southern peninsula of MI. (not a lot of Honda mechanics around here for some reason...)

Reply to
aemeijers

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