244-Overheating above 105 degrees Topic is solved

[jimmy57]

I see no burping coolant out of tank as a result of this.
Still can be the slight problem making the gauge reach that extra signalled degree that sends gauge up drastically.
Grounds need to be checked. Batt neg post to block and to body. Block to body also. Alternator case to block too. All these as voltage readings when it idles and everything is on.
The electric fan may be the load that causes a voltage drop that is giving a sending unit offset. That car uses the one wire sender. The two wire senders on newer models is to address this very issue of sender signal bias due to voltage differences in ground between engine and cluster. Two wire systems read sender isolated from the engine ground.

NEXT: what is the true idle speed when this happens?
If the throttle and microswitch need attention and idle speed is low as a result, BINGO! you may have a fix with that being addressed.

Cars of your model and year operating locally here in north and west TX where it is not that much cooler have not had issues like this that can't be resolved.

One more question: The electric fan is triggered by what? Is it using A/C high pressure switch from factory or was another control system added? If it is temp triggered then what temp triggers it to run?

[Rob1]

Thanks for all the help.

Lummert - in answer to the question: What brand and temperature rating thermostat are you using?
I do not know. Mechanic put two different ones in but I am told it is working. But, I will talk to him today.

Jimmy57. I believe all the grounds have been checked but will see if I can find out. We may recheck.
Do not know what triggers the electric but it appears to run all the time. Will find out.
Idle speed will check.

I hope, I have not missed any questions.

Will not be until next week before, I update again.

Thanks & Take Care!
Rob O'Halloran

[Rob1]

Mechanic removed & cleaned the idle control motor. Tested the throttle sensor which tested "OK" and adjusted the idle speed up by 50-75 rpm when the A/C is running and vehicle is idling.

Guess, I wait until the next hot day 110 + to see if it works.

Thanks again for all your help.

Take Care!
Rob O'Halloran

[MoVolvos]

Mechanic removed & cleaned the idle control motor. Tested the throttle sensor which tested "OK" and adjusted the idle speed up by 50-75 rpm when the A/C is running and vehicle is idling.

Guess, I wait until the next hot day 110 + to see if it works.

Thanks again for all your help.

Take Care!
Rob O'Halloran

You've really done a lot of work thus far and have not found any issues or parts that may have caused the high temperature. As I mentioned earlier and jimmy also that the car may be exceeding it capability to cool and or is just an issue that can't be solved. My suggestion is to replace the Thermostat(s) with an OE and check its function before installation. You can also compare the 2 while you are at it. It is the cheapest part and one you have not checked.

If that solves it you know the cause as you have eliminated as much as possible quite a few if not all the factors. I don't believe the added idle RPM is the problem nor will it help out a great deal. Keep an eye on it either way. A couple years back a Head Gasket job done by a supposed reliable and reputable shop only lasted 2 years. You may also have your timing checked out as that can cause your car to overheat especially at it's limit of performance.

Blessings,
BKM
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[jimmy57]

I guess he ran the throttle stop screw in to get you more idle speed. How fast is out gear now?

[Rob1]

Update:

I am trying to locate a mechanic who previous worked on the vehicle. When he worked on it. It ran great and sounded like a sewing machine.

Here is what I am looking at; Having him reset the idle back to where it should be. In my opinion setting the idle up is not solving the problem.

Am in process of checking with manufacturers on the gpm / flow rates of their water pumps. To see how much difference their really is. They do not want to release or are slow in releasing information.

Have been looking at Davies Craig electric booster pump that will activate when the water temp exceeds a preset temp. Like when the car is idling. Parts cost would be in the range of $250 - 420 depending on the pump selected. www.daviescraig.com.au Have looked at other manufacturers of pump but they do not seem to have a temp sensor that you can preset based on water temp.

But, I want to be sure something else is not causing the problem.

If I can find the above mechanic. Then will get his opinion. If this mechanic is not available then will enter the lottery of picking a another mechanic.

Will update when I have something definite.

Thanks
Rob O'Halloran
Phoenix, AZ

[Rob1]

Problem was solved by bypassing the radiator pressure switch on the pusher fan in front of the intercooler. So, that the pusher fan runs "all" the time instead of being activated by the pressure switch and running intermittently.

Long story short it was an air flow problem but we ( mechanic & I ) wanted to be sure we had solved the problem and tested it before I answered with an update.

Thanks for all the ideas and help.

Take Care!
Rob O'Halloran
Phoenix, AZ

[billofdurham]

Thank you for the update.

Bill.

[Rob1]

We solved the problem by putting in a Ron Davis Radiator. Expensive yes but not as expensive as blowing a head gasket and a new head. So far the car has not overheated sitting in traffic at the outside temp of 110 degrees plus. An added benefit is the air conditioner seems to work better. Here in Phoenix new vehicles driven off the showroom floor overheat at those temps and alot of car dealers do not stand behind their cars. My recommendation if buying a new car in Phoenix is to pull the radiator and install a radiator plus a condenser that will do the job in extreme heat conditions.
Thanks for all the help and recommendations.
Rob

[93Regina]

We checked all the fans and they are working.

I acquired a 240 radiator, which may have come from a turbo volvo; it has a thermostatic switch mounted on it.

I had this radiator cleaned, and mounted it on a 1993-240. 240 came with an AC fan, so I hooked up a relay on ground side to this thermostatic switch, and removed stock fan. It works fine, but I may reinstall stock fan someday.

I think this radiator is a triple core