Engine overheating?

[Steve]

I had some work done recently including an oil change. The mechanic said it took five quarts before I got a reading. Now the temp gauge tends to hover around halfway when I'm cruising, but if I sit idle (e.g. a red light) I see it climb higher and higher toward red. I'm used to it sitting below half all the time.

My first thought was to check the coolant; I saw that it was low so I filled it to the Max line. No change in this behavior, so I checked the oil and it was nearly empty. I put it two quarts about an hour ago and it was back to full, but the symptoms persist. Also, it tends to idle hard - the whole car can shake or shudder, but this goes away once I start moving again. The temp then goes back down too.

Any ideas of what to check for myself, or get looked at? This is a 1996 Honda Accord, 2.2L/4cyl, non-VTEC. 126,000 miles.

 

[Heisenberg]

Check to see if the radiator cooling fan is coming on when the temp starts to go above normal (I'm assuming it has an electric fan). Depending on what work was done, they may have unplugged the fan and forgot to plug it back in.

 

[Steve]

When I park the car there is a fan under the hood running, it usually does for five-ten minutes.

 

[Heisenberg]

And you're sure it's the radiator fan running? Will it actually climb into the red if you let it idle, or when the fan comes on does it cool it off to normal? Also, what else did you have done besides the oil change?

 

[Steve]

I'm drawing a blank (facepalm) because I can't remember what else I had done. I know there's a fan that comes on but it doesn't keep the temp from climbing into the red at idle (in Drive). It does stay running for a while after I park, but usually it doesn't even come on until a few seconds after I turn off the ignition. If that's not the radiator fan then I will ask them to reconnect it.

 

[Heisenberg]

Hmm. The radiator fan should come on when the temp climbs high enough, and turn off again when it cools off. On some cars it may run for a while after the ignition is off, but it should always come on while the vehicle is running when the temp climbs. It sits right behind the radiator so it's really easy to just look at see if it's running. Anyway, if it was okay before you had it worked on but now it's not, then I would certainly take it back and have them check it.

 

[AnnonUSA]

Check the Radiator cap..... More important...WTF is all your Oil going? You cannot displace that much oil without seeing where it is going....

 

[StageLeft]

You lost two quarts of oil and don't know where it went? Remember to check oil when the car is cold and on level ground so that your readings are consistent. If you do check the radiator cap, as mentioned, be damned sure the engine is NOT hot when you do it, or else you will have a boiling geyser in the face.

You shouldn't really ever lose coolant. If you lose any meaningful amount over time you have a leak. A slow one that doesn't increase in severity is not necessarily a major problem, though.

 

[Vette73]

Hondas were know to use oil if the PCV was stuck. So replace that, if you have not and check oil again.


For the over heating when was the last time your replaced the Rad cap and thermostat?

Start with the basic stuff first then worry about the rest after that. The majority of the time the basic stuff fixed most cars problems, and that was usually because maintaince was not kept up.

 

[SuperSix]

Check all spark plugs and wires. It may be missing, which will cause the symptoms you say. He may have jostled a wire or something.

And I wouldn't recommend going back to that oil change place. That motor take 4.5 qts at best, not 5.

 

[Steve]

The other work done was a complete tune-up, including replacing all the spark plugs and wires. I think I'll stop by there on my lunch.

 

[Zenmervolt]

Originally posted by: Marlin1975
Hondas were know to use oil if the PCV was stuck. So replace that, if you have not and check oil again.


For the over heating when was the last time your replaced the Rad cap and thermostat?

Start with the basic stuff first then worry about the rest after that. The majority of the time the basic stuff fixed most cars problems, and that was usually because maintaince was not kept up.

PCV valve would explain the hard idle. Marlin is, as usual, spot-on. Have the PCV valve checked and the entire PCV system cleaned.

The thermostat is also a very likely suspect. IIRC on older Accord I4 engines, the thermoswitch for the radiator fans is typically replaced along with the thermostat and when a thermostat fails it often takes that thermoswitch with it. (A similar issue happened with my '88 Accord a long time ago.)

The circuit that turns the fans on after the car is shut down is a separate circuit from the one that turns the fans on when you're idling and sitting still, so the fact that the fans come on after the car shuts off doesn't actually tell you anything.

Try turning on the A/C. The A/C circuit should force both radiator fans on at the high setting. If the fans come on when you switch on the A/C and the temp drops, the issue is definitely the thermoswitch that controls one of the radiator fan circuits.

ZV

 

[Steve]

I had the A/C on for my commute to work this morning. For most of the trip the temp stayed a quarter inch below half where I'm used to it, but for the last stretch it crept up and before long got to 3/4s. I didn't notice any fan coming on during the drive.

 

[Aikouka]

Yeah sounds like a thermostat issue... had it happen to me once. You'll have no problem while moving at faster speeds because you're pushing enough air through, but when you're stopped the fan would need to turn on to supplement the lack of air passing through.

 

[darom]

I used to own a 1996 EX Accord I4 and loved that car. Easy to work on it with the exception of changing the front rotors. The lack of low end torque wasn't fun while getting on the freeway. We had to turn off the a/c ('turbocharger' button) to gain a few more ponies.

With a/c on on a 100F+ day here in Bakersfield, CA I would get the temp gauge at 3/4 as well. It never reached that H mark.

You can buy an inexpensive laser thermometer and remotely check your engine temps. Point at different engine parts, intake, thermostat housing etc. This will confirm if your gauge is broken or if the engine is running hot indeed. If the temperatures are in the 220F+ range, I would say it is running hotter than usual.

Check your engine oil drain plug. One time a mechanic didn't tighten it, and my wife lost almost all oil on the way back home. Do you see any oil drips under your car?

 

[boomerang]

Originally posted by: Steve
I had the A/C on for my commute to work this morning. For most of the trip the temp stayed a quarter inch below half where I'm used to it, but for the last stretch it crept up and before long got to 3/4s. I didn't notice any fan coming on during the drive.

I'd be interested to know the speeds you typically drive on your trip to work. As has been said, at higher speeds airflow through the radiator, in conjunction with the fan or fans running (AC on), should be adequate to keep it cool. Was the last stretch at lower speeds?

I'm wondering if the car might need a cooling system flush. I have no idea if these cars are prone to problems in that regard though. This would be something to explore after dealing with the thermostat, PCV, etc. For the average Joe, the only way you're going to know if the fans are on while driving is to have a scan tool hooked up while driving.

Have you checked for something simple like some debris blocking airflow through the radiator? A paper or plastic bag or the like? Some cars are prone to packing leaves and crap between the condenser and the radiator. Could be they've reached critical mass.

No experience with Honda's so I'm just throwing things out there. I probably shouldn't because long distance diagnoses are difficult sometimes. I know it can get overwhelming with many responses and no common consensus.

Anyone know if these cars are prone to head gasket problems?

 

[Steve]

I have replaced the head gasket a couple times over the years.

That said, the problem turned out to be a cracked radiator. Coolant was leaking pretty badly. Got a brand new one and I'm back to normal.

 

[Arkaign]

Bleh. Plastic/Aluminum radiators. Their use is not confined to Honda by any means, but they aren't exactly heavy-duty units. You mention that the head gasket has been replaced twice (with only 126k miles? that makes me sad, the Hondas I've owned have never been so troublesome), which means that the radiator fluid was either contaminated or superheated, or both, which contributed towards this failure as well as the cheap design.

High quality aftermarket units that don't use plastic at all, and have precision welding are available, but usually at substantially higher than stock pricing.

This is an example : http://www.928motorsports.com/parts/alumradiator.php

I have a mechanic who always recommends a heavy-duty radiator for vehicles consistently seeing 100-110F outside temps and heavy use.