Temp Indicator way to high

Reply Subscribe

Thread Tools

Search this Thread

Dec 29, 2003 | 07:57 AM

broncoray

Thread Starter

Junior User

Joined: Nov 2003

Posts: 85

Likes: 0

From: Switzerland

Temp Indicator way to high

Bronco 4x4 2.9L 1988 95.000 miles

I still have a problem with my engine temperature, today they told me that the Viscous-Fan is not working properly, it always blows at maximum speed even when the engine is stone cold.

I changed the thermostat, temp-sensor, new radiator, radiator cap, flushed the system and still the temp indicator goes up to the red line.

The coolant in the radiator is not getting hotter then about 65°C, the hoses from the heating system that goes into the cars compartment are hot but can still been toughed.

The ford mechanics says that the temp indication is way of and claim that the engine is not overheating, is there an other option to measure the coolant temp?

Can it be that if the fan is always turning even now with outside temps of -5°C that the thermostat feels when opening this gold coolant and then closes again so the radiator fluid is never reaching the normal temp?

Ray

Dec 29, 2003 | 09:27 PM

Ultramagdan

Post Fiend

Joined: Feb 2000

Posts: 11,496

Likes: 6

From: Kansas

Re: Temp Indicator way to high

Quote:

Originally posted by broncoray

Can it be that if the fan is always turning even now with outside temps of -5°C that the thermostat feels when opening this gold coolant and then closes again so the radiator fluid is never reaching the normal temp?

Ray

You have had quite a struggle there. It's possible, but I would expect it under more extreme conditions then just -5 C. Waterpump may not be moving enough coolant to push it through the system. (I know I keep coming back to that..)

Dec 30, 2003 | 04:24 AM

broncoray

Thread Starter

Junior User

Joined: Nov 2003

Posts: 85

Likes: 0

From: Switzerland

Yes I now, I just don’t now how to test this in a simple way.
Because the thermostat is never opening full and the test to squeeze the upper host to the radiator is not working then.

They tray to block the cooling fan when the engine was heating up and this was impossible, it can not been blocked at all.

Im waiting for a new visco clutch and we see what happens then.

Ray

Jan 3, 2004 | 12:12 AM

biz4two

Lead Driver

Joined: Sep 2003

Posts: 5,844

Likes: 6

From: Albuquerque

I run an electric fan setup on my 390FE and the only way to dial in the temp is to use an Infrared Thermometer with Laser Pointer. Mine is a Craftsman from Sears. These devices range in price from $15-$100+. Depends on your needs and budget.

What I do is let the truck get to operating temp and point the device using the laser pointer at the thermostat housing. This gives me the temp reading that I need to adjust for winter/summer seasons. Works extremely well!

As for the problem, I would say it could be the water pump too. But there is a slight possibility that the system has "air" pockets. Did you bleed-off the system properly?

Another test to try and this is really a "cheap" test...to verify that the "fan" is the problem put a large piece of card-board in front of the radiator. Since we know the fan cools the radiator pulling air threw it and not really cool the engine. This will test the theory of the fan being the problem. My guess...it isn't!

Good luck and please report back what the fix is...

Jan 3, 2004 | 04:36 AM

broncoray

Thread Starter

Junior User

Joined: Nov 2003

Posts: 85

Likes: 0

From: Switzerland

Hello biz4two,

Thanks for your interesting replay, this makes sense to me.
How do you bleed-off the system properly? How shut I procede.

(Another test to try and this is really a "cheap" test...to verify that the "fan" is the problem put a large piece of card-board in front of the radiator. Since we know the fan cools the radiator pulling air threw it and not really cool the engine. This will test the theory of the fan being the problem. My guess...it isn't!)

This I will test to.

Thanks, Ray

Jan 3, 2004 | 08:31 AM

broncoray

Thread Starter

Junior User

Joined: Nov 2003

Posts: 85

Likes: 0

From: Switzerland

So today I went to a friend of mine ho had a Laser Temperature gun.
We measured the temp on the Thermostat housing and it was about 89°C after driving the car for 20 minutes. The temp indicator gauge in the car showed almost HOT. The gauge stopped ad 2 mm under the red line.

So this wood mean that the new temp sensor I already built in is also faulty.
Are there different types so the give me the wrong one for this 2.9L engine?

In my Haynes manual I do not find a table with the resistances the Temp sensor shut give, thus anybody knows what this shut be.

Ray

Last edited by broncoray; Jan 3, 2004 at 08:37 AM.

Jan 4, 2004 | 11:10 PM

biz4two

Lead Driver

Joined: Sep 2003

Posts: 5,844

Likes: 6

From: Albuquerque

Does seem as the temp sensor is at fault. Not totally sure if their are different ones...sorry. Might want to post that question in the engine groups.

Part stores usually sell the air purge kits. Usually it installs in place of the radiator cap. Follow the instructions that come with the kit...as they are all a little different.

Good luck...and please post back any results.