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Overheating? NOT?; Phantom overheating
Topic Started: Sep 13 2017, 03:04 PM (602 Views)
Foster
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I've been on here before with this question, but this time I think I have checked everything and the problem still exist.
The Car: 1995 Suzuki Swift, Hatchback,4 Cyl, 1.3 Lt. 5 speed manual transmission. NO A/C
The problem: when ever the air temperature is over 80 degrees and I am going up a long incline, the temp gauge will start climbing. If the incline is long enough or the air temp. high enough, the gauge will red line. Going downhill or on level grades the needle will drop to the normal midpoint of the gauge. I can drive around the city, with stop and go traffic, in 100 degree weather, no problem, needle stays at midpoint. I can do 75 on the interstate in 100 degree weather, and as long as there are no long inclines, no problem. When the air temperature is 75 degrees, I don't have any of these problems.
What I have done: Flushed the radiator & engine, changed the thermostat (195 degrees), changed the coolant, replaced the temp sensor at the thermostat housing and even replaced the instrument panel (in case the temp. gauge was messed up) & a new radiator cap.
Now here's the kicker, I have checked the coolant, in both radiator and expansion tank, for the last month, and I have NOT LOST 1 OZ. OF COOLANT!
To top it off, I have been carrying an Infra red thermometer with me and I have never got a reading higher than 209 on the engine side of the thermostat and on the radiator side the max has been 205. The engine never has that overheating smell that you get when the engine is really stressed.
I am out of ideas :banghead and am hoping a Geo Guru on this forum has a bright idea. I'm down to swapping out the ECU, though I don't know why that should make a difference or swapping out the engine.
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suzukitom
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Tom

Sure sounds like just low coolant level to me. Does turning the heater temp lever to hot on a hill cause the temp gauge needle to fall rapidly?
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Moringa
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Living BOT

Engine flushing in general, is a bad idea. The potential to loosen large particles which plug up the radiator, and/or heater core, is a high probability. One test you could try, is to drive at freeway speeds, and check the temp of the top of the radiator, compared to the temp of the bottom. There should be a significant drop. You would need to stop the car and check it ASAP. The longer it idles, the more compromised the test becomes. You could shut off the motor immediately after stopping, to help get accurate results. If you want to safely flush your cooling system, put about a level tablespoon of TSP into your cooling system, and drive it for about a week. I've always used straight water for this, and don't know if coolant plus TSP will accomplish the same thing. You do need to thoroughly flush out the TSP afterwards. Leave it in for months, and it will start to eat the engine aluminum.
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ptcapboy


I think I mentioned this before when you posted this problem-my car did the same thing but at maybe 20 degree cooler temperatures-a new radiator solved the problem-I had previously tried the flushing, thermostat, etc-by the way that was over 5 years ago and my 40 dollar ebay radiator is doing fine-
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Dystopiate666
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Yup, use your infrared to scan the whole radiator after its warm. Look for cool spots, when I bought my 98 it had pretty much the same symptoms....it would hang out in the "ok" zone (higher than I liked, but still not really close to red), until I went up a hill, then it would get close, until I turned on the heater full blast, kept the rpms low and putted up the hills.....when I scanned the radiator one half was only reading 80 degrees....changed it out and no more problems.
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Foster
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Lot of good suggestions. Turning the heater on does not cause the needle to drop drastically. The temp. goes down as slowly as it goes up. I have not tried TSP (maybe as a last resort) Checking the radiator surface to see if there are cold spots is brilliant, will do that tomorrow. A new radiator is a cheap fix. Will let you know what I find. Thank you everyone
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JellyBeanDriver


Agree about getting a new radiator. Sounds like a classic 'the radiator can't keep up' likely due to buildup.
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freegeo
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Is your fan running at the time the gauge shows it getting hot?
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Foster
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Yes the fan is running when it shows hot on the gauge.
Took it out for a spin, isn't as warm as has been so no overheating on the gauge, but when I put the IR thermometer on the surface of the radiator I did find several cool spots, especially at the sides. Not just a couple of degrees cooler but 20+ degrees cooler. When I ran the IR up the radiator on the same line, it got 40+ degrees warmer and when I went down, the same thing. I did not have that kind of disparity in the middle of the radiator. Gonna check over the next couple of days, see if this stays the same. Might be on to something.
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freegeo
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What type of bumper and grill is on the car? Is it open like the guppy mouth type (95 - 97 metro) or something different. If the readings were taken right after driving the air flow could be effecting it. You may want to take some readings when the car is sitting still at a idle and compare the difference. You want to try and get readings on it as the engine temps come up to fan temps.
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Foster
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It has the Guppy mouth and should have good air flow. Will do temp checks as you suggest.
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davegran
Old Fart w/Wrenches

Make sure that your ignition timing isn't way advanced. :popcorn
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Foster
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Ok, put 200 miles on the car today and did 4 temp checks on the radiator. Not only did I find a cold or cooler (more than 20 degrees) differential on one side, at least a 1/4 of the radiator, but I found another just off the center of the radiator. All together, this make up 1/3 of the radiator. Gonna buy a new rad, can't be worse than I'm experiencing now. Will let you know how that works out. Good suggestions Dystopiat666 and Jelly Bean Drive,
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freegeo
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If you are going to do a system flush make sure you do it before you put the new radiator in.
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Dystopiate666
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:thumb
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