Overheating issues

[Michael Fenimore]

Hey guys. I have a 1995 Eagle Talon (2.0 Esi non-turbo) that when idling it overheats.
When I get up to speed, usually 40+ mph, the temp will SLOWLY return to a somewhat normal level.
But as soon as I slow down it rises to the point of almost being scary.
Also, I have to add anywhere from 1 quart to 2 quarts of water even after the shortest drives. Work is only 8 miles away!
There doesn’t appear to be any obvious leaks, like from under the water pump or hoses. But the overflow tank “bubbles” with the excessive hot water from the engine.

I purchased this vehicle about a year ago and had receipts for: water pump, timing belt, radiator and other sundry items (hoses, etc.) I contacted the original shop that did the work, but of course since ownership has changed, they won’t cover any warranties. Go figure.

It has only been doing the overheating thing about the last 3 months.
My question is: Could this be a faulty water pump? A head gasket?
I have replaced the thermostat already.
There are other performance issues with it, but those can wait until I resolve this overheating problem. Especially with the HOT days of summer approaching.

Any info or advice would be greatly appreciated.

Thanks!

PS, Love your channel Eric.

Topic

[Michael Fenimore]

There is a brand new thermostat. New radiator cap too.

[college man]

If you turn the heater on full blast does the temp
return to normal? also is there good heat when the
heat is used?

[Michael Fenimore]

When I turn on the heater there is very adequate heat.
The temp gauge does drop a bit, but never really back to a normal level, unless I’m driving at around 45mph or hold the RPM up to 3500-4000 RPM

[college man]

You may have a radiator problem or water pump
issue. usually when you turn the heat on for an
overheat and it brings the temp down. That would
indicate radiator trouble. Try lowering the coolant
level and look inside the radiator and see if there
is good flow.Also look inside the radiator for heavy
calcium.

[Michael Fenimore]

[quote=”college man” post=68242]You may have a radiator problem or water pump
issue. usually when you turn the heat on for an
overheat and it brings the temp down. That would
indicate radiator trouble. Try lowering the coolant
level and look inside the radiator and see if there
is good flow.Also look inside the radiator for heavy
calcium.[/quote]

According to the guy I bought it from last year, the radiator, water pump, timing belt and hoses were all replaced at the same time.
I know that doesn’t mean anything, but I am leaning toward the water pump. :unsure:
The radiator appears to be in decent shape on the outside. When the level is right and it’s cold, I do see a good amount of flow.
As far as calcium build up there isn’t any. I’ve gone as far as removing the lower radiator hose when I was flushing the system and peeked inside the radiator. No build ups or sediment to speak of.

But at the same time with the issues I’m having as far as the engine running right, I’m wondering if that could also play into this mess.
Here’s a list of things I know I have to take care of soon.
1- Alternator – major squealing when cold. Minor squealing when under load. Output is within range.
2- Catalytic converter – Excessive leak. (Could this have anything to do with the performance issues?)
3- Replace A/C radiator fan – On order and should arrive in a couple of days.

So as you can see, I have my work cut out for me. And none of it cheap.

Once again, thanks to everyone for their input with this nightmare of mine. banana: :pinch:

[Michael Fenimore]

UPDATE # 2

I finally got the NEW fan yesterday and installed it last night. This morning I drained the coolant system of the distilled water that was in it and proceeded to perform a bleed of the cooling system.
After letting the car run at idle for about 45 minutes I still saw some very minor bubbling going on.
The temp gauge stayed pretty much in the normal range during all of this.
Then I took it for a test drive of about 20 miles. Local driving with speeds at 45-50mph.
Stopped for gas and noticed a very slight overflow but nowhere near what I was experiencing before. In the past when I would stop after a drive like this, it would be bubbling/boiling over from the overflow canister. Since I topped off the overflow canister prior to the test drive I attributed the coolant I was seeing as an equalization of fluids. (I could be wrong lol)

Got back on the road and took it out on the highway. Speeds of 55-65mph. Temperature was normal for the 8 miles. When I got back onto local roads the gauge rose a little bit. Again, nothing like it did before. But it rose all the same.
When I parked the car in my driveway, after about 3 minutes, the gauge rose to a very high level. However, there was no boiling or bubbling over at the overflow bottle. (This has always been my indicator of issues in the past.)

My question now is this: Since this overheating has been an issue for me over the past 2-3 months, is it possible that the temp sending unit has been stressed due to overheating so many times, therefore not communicating to the ECU properly?

I am feeling better about it than in the past. At least it’s not acting like a teapot within the first 10 minutes.

Thanks for any and all replies.

PS
Previously I stated that the fan needing replacing was the secondary A/C fan. I was WRONG! It was the MAIN cooling fan that went bad. So for all this time the secondary A/C fan was what was trying to keep this thing cooled down. Lesson learned!

[Its me]

To answer your question about the sending units. There should be two sending units, one for your gauge and one for your ECU. There may be an issue with the sending unit that is sending information to the ECU… A good scan tool would help tell you exactly what the temperature the ECU is reading, but since this is a 1995 you probably don’t have ODB II to pull the information easily… ODB II did not become mandatory until 1996 (but 1995 Lexus ES300’s had OBD II, so maybe…)

The two inputs about temperature are the following… Different manufacturers may call them something slightly different:

The Coolant Temperature Switch sends information to the gauge.
Coolant Temperature Sensor sends the information to the ECU.

You could have a bad Coolant Temperature sensor for a variety of reasons. If this is reading wrong, then the fans may not come on at the proper time.

-Karl

[Michael Fenimore]

[quote=”ToyotaKarl” post=68948]To answer your question about the sending units. There should be two sending units, one for your gauge and one for your ECU. There may be an issue with the sending unit that is sending information to the ECU… A good scan tool would help tell you exactly what the temperature the ECU is reading, but since this is a 1995 you probably don’t have ODB II to pull the information easily… ODB II did not become mandatory until 1996 (but 1995 Lexus ES300’s had OBD II, so maybe…)

The two inputs about temperature are the following… Different manufacturers may call them something slightly different:

The Coolant Temperature Switch sends information to the gauge.
Coolant Temperature Sensor sends the information to the ECU.

You could have a bad Coolant Temperature sensor for a variety of reasons. If this is reading wrong, then the fans may not come on at the proper time.

-Karl[/quote]

Thanks Karl.
My car is a late 95 and does have the OBDII diag port.
This past week I purchased an el-cheapo bluetooth OBDII ELM327 device that interfaces with my Android phone using Torque Pro which arrived today.
My initial tests are not very hopeful. lol

Bled the coolant system for about the 100th time. While sitting and at idle the coolant temp was fairly normal I think. Ranged from 190F to about 209F.
But during a test drive the temperature rose to about 211-220. Coming to a red light it rose to close to 245!!
Back into driving mode (40-50mph) the temp naturally dropped but nowhere near normal. Best temp achieved was 216F.

What has me puzzled and what makes me think it is a head gasket issue is that when I start the car up initially the coolant “shoots” out of the fill (radiator cap) hole. (Mine is not on the radiator but on the engine. It is the thermostat housing.)
After it gets to “normal” temp, fans kick in, temp drops fine back to around 185-192. But even during this period the water pulses up and out of the housing. Temps stay fairly normal. It is only when I begin driving that the issues really start.

I will have to take it back to my garage friend and have a pressure test on the system WHILE the engine is running.
For now I’m going to just keep adding fluid after every stop. I can’t take this car off the road for more than a couple of hours since it is my only working vehicle. (At least for now … 01 Saab 9-5 coming soon.)
Once I have another car then I am planning on stripping this Eagle down.
Water pump, timing belt, head gasket, etc etc etc.

Thanks to everyone for their input and advice.

[Author]

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