Engine runs hot at times, do I need to change the oil?

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Nov 30, 2005
Senoia, GA
I've got a daily driver of a 95 Honda Accord, 4cyl VTEC. I am thinking I need a new radiator as the temp gauge will climb 1/2 way between normal and hot on these hot afternoons with the A/C running in stop-n-go (mostly stop) traffic. After I get it going down the road (or shut off the A/C, it will cool back down to normal.

It's been hot 4-5 times like this, for about 4-6 minutes at a time.

4,700 miles on the current oil. It's a mix of 2-1/2 quarts of M1 and Havoline 5W30, with about a quart of makeup oil.

I was hoping to run this out to 7500 miles, but should I go ahead and change it?

Car has 147,700 miles on it.
If you're concerned that because it ran hot it ruined the oil, consider that dashboard temperature gauges are usually not precision instruments. So it may not have been as hot as you think.

I've seen the temperature guage on my car go up further than it usually does and when I check it with the Scangauge, the temperature is no higher than 205-210F. The Scanguage reads the actual coolant temperature sensor reading from the computer.
If the coolent is 210F then the oil would be hotter, the coolent wouldn't be the exact temp as the engine, the engine would be definatly hotter...by how much I'm not sure.
I'd forget about the oil now......look into why it's running hot. Rad fans not turning on high? Condenser plugged with bugs and rocks?
Your oil will usually only suffer a breakdown if the car gets REALLY hot....to the point where coolant boils and you have steam and boiling water coming out of the reservior. Like mentioned above..the temp guages are kinda inaccurate and a small temp increase can make them appear to jump way up, when it may just be a 10-20 degree increase due to weather or other conditions. My roommate's 99 Explorer's needle rarely moved very far off "C" no matter how far we drove, even though I knew the engine had to be fully warmed up. It's Texas, after all. :)
Get yourself a digital meat thermometer and stick it in the overflow tank. If it's over 197F - you got problems. Of course it would be nice to have one of those laser gun thermometers. Check to make sure the fans are on full time with the A/C on.
I've got the same car as you, and my coolant gauge is weird. I can drive HARD and it won't budge at all. I drove over Blewett Pass which was at least 5 miles of steep windy uphill road at 4500+ rpm in 3rd all the way (70-90 mph). It was 95°+ and I drove hard enough to get the oil to 245°. The temperature gauge didn't budge.

On the other hand, when driving at night on open freeway between 60 and 70 mph in 5th gear the gauge will start to rise on long hills. I drive these same hills many times during daylight or at higher speeds and the temp gauge doesn't budge. At 80 mph the temp gauge won't budge, at 60 in 3rd or 4th gears the temp gauge won't budge. On hot days at 60-70 mph with the same throttle opening the gauge won't budge. The only time it EVER moves is under moderate throttle in 5th gear at night between 60 & 70 mph.

Be very careful about overheating the F22B1. I was stuck in traffic idling with the A/C on for 45 minutes or so in 98° weather last summer. The temp gauge climbed about 3/4 of the way to the hot mark but no higher. According to the gauge I still had room before overheating. According to every UOA I've done since then, I've now got a small coolant leak. I'm guessing that the halfway overheating did a little number on my head gasket.
Thanks Palut.

My gauge has climbed to the 3/4 mark twice.

I'm thinking about getting rid of this car anyway.

The coolant is new. New Genuine Honda coolant.

The hoses and T'stat are new.

I know one of the fans does not work. I also suspect that the radiator is getting ready to fail. Probably clogged.
That does sound like a clogged radiator to me. I've run into that situation before thanks to neglect on the part of the PO and found that chemical cooling system flushes were useless. I think you're looking at a rad swap if you're going to keep it. I wouldn't worry too much about the oil under these conditions, but I wouldn't run that mixture 7,500 miles either. It's really up to you as to what you do.

Originally posted by thooks:

I know one of the fans does not work.

There's your problem
W/O airflow the best radiator in the world won't work.

Your symptoms sounds like a cooling issue to me. IF you want to keep this car may I suggest the following:

(1) chemically flush and refill your rad with quality coolant

(2) check all your coolant hoses for rot and collapse.

(3) check and replace your thermostat if possible.

(4) check and clear any obstructions on your radiator and such

(5)make sure that when you flush and refill your cooling system, purge the system to rid of air pockets. There's a small nipple like screw on the top of the thermostat housing which will let you do that.
Yea, a non working fan would explain the hotter running in slow traffic, but a plugged rad would also explain the hotter running while climbing grades at speed.
I vote for the non working fan being a problem. A plugged radiator could also be a problem. Heck, it might even be a little of both.

Back in the day of using my Datsun King Cab diesel to haul horse manure onto my property as landscaping mulch, I developed a fly problem. I never could figure if they were there because they were attracted to it or whether they were breeding in it.

I finally decided it was a little of both.
Is it your driver's side fan that failed? That's the A/C fan. Trim levels without A/C don't even have that fan. It supposedly only comes on when the A/C is on. It's failed on mine too. I discovered that it didn't work after my little overheating incident. Just sitting in traffic w/o the A/C on won't cause any overheat. Just having the A/C on for a long time while not moving will do it.

No, the driver's side fan is the one that works. And no, sitting in traffic w/o AC won't get the temp gauge to move.
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