What is this???
Thread Starter
Heel & Toe
Joined: Mar 2011
Posts: 23
Likes: 0
From: Conroe TX
What is this???
I was poking around my 89 the other night after FINALLY getting it to run (not perfect but acceptable) and found a small what apears to be water leak around the gasket where the hold down bolt is for the distributor. There is a small hose going to the heater core, so it obviously has something to do with the coolant system, but I don't recognize the part. Any ideas? I need to replace the gasket and seal it off, but it's a little difficult calling the parts store and not knowing what's needed...
Also, coolant related, I changed the temp gauge sensor and I'm still having issues with it jumping to 299 degrees. It starts out low like it should and will register normally for about 5 minutes and jumps to 299 and stays... Any clues? Wires all appear undamaged and clean...
Also, coolant related, I changed the temp gauge sensor and I'm still having issues with it jumping to 299 degrees. It starts out low like it should and will register normally for about 5 minutes and jumps to 299 and stays... Any clues? Wires all appear undamaged and clean...
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
I was poking around my 89 the other night after FINALLY getting it to run (not perfect but acceptable) and found a small what apears to be water leak around the gasket where the hold down bolt is for the distributor. There is a small hose going to the heater core, so it obviously has something to do with the coolant system, but I don't recognize the part. Any ideas? I need to replace the gasket and seal it off, but it's a little difficult calling the parts store and not knowing what's needed...
Also, coolant related, I changed the temp gauge sensor and I'm still having issues with it jumping to 299 degrees. It starts out low like it should and will register normally for about 5 minutes and jumps to 299 and stays... Any clues? Wires all appear undamaged and clean...
Also, coolant related, I changed the temp gauge sensor and I'm still having issues with it jumping to 299 degrees. It starts out low like it should and will register normally for about 5 minutes and jumps to 299 and stays... Any clues? Wires all appear undamaged and clean...
Sounds like you've got air pockets in the coolant system...which usually means you've got a coolant leak somewhere. If you car's coolant is hitting 299 F then you got big problems.
Pro
Joined: Feb 2010
Posts: 677
Likes: 3
From: Metairie LA
The hard line that comes off the rear of the TPI intake on the passenger side? Not sure of the official name. Sorry. I eliminated it when I went to the modified LT1 intake.
Which temp sensor did you change? The one at the front of the intake (2 wire) or the one in the passenger side head (1 wire)? The passenger head is for the gauge readout and the one on the front of the intake is for the ECM (and if you have one in the drivers side head that is for the secondary cooling fan). Make sure you don't use too much Teflon tape also.
The one for the ECM will make the car run like crap if it is bad - the ECM adjusts fuel for temp.
Which temp sensor did you change? The one at the front of the intake (2 wire) or the one in the passenger side head (1 wire)? The passenger head is for the gauge readout and the one on the front of the intake is for the ECM (and if you have one in the drivers side head that is for the secondary cooling fan). Make sure you don't use too much Teflon tape also.
The one for the ECM will make the car run like crap if it is bad - the ECM adjusts fuel for temp.
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Also, coolant related, I changed the temp gauge sensor and I'm still having issues with it jumping to 299 degrees. It starts out low like it should and will register normally for about 5 minutes and jumps to 299 and stays... Any clues? Wires all appear undamaged and clean...
My 89 went to 280 degrees for 5 seconds and I had to replace my head gaskets. If you are at 299 degrees I expect you might have some major problems ahead of you.
My 89 went to 280 degrees for 5 seconds and I had to replace my head gaskets. If you are at 299 degrees I expect you might have some major problems ahead of you.
- 1986 Original Owner -
Joined: Apr 1999
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From: North Yorkshire, England
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I'd be willing to bet a switch was installed instead of a sender. The switch is designed to close at a certain temp to run for instance the Aux Fan. If connected to the gauge it will read low when temp is low and the switch is open then when the coolant temp reaches the switch closing point, it grounds causing it to read 299. The sender that should be in the passenger head would have a somewhat linear resistance from something in the K Ohms when cold to something around 80-150 Ohms when at operating temp. It was a common mistake people made due to poor instructions when buying low temp fan switches where they'd get installed in the gauge sender location.
Thread Starter
Heel & Toe
Joined: Mar 2011
Posts: 23
Likes: 0
From: Conroe TX
The fan switch (single wire) was replaced as well as the sensor at the front of the manifold. I bought the sensor from Advance and it shows to be the coolant sensor and not a switch.
The car has not been close to 299 at anytime that I am aware of, unless it can jump to 299 in a matter of 10 minutes of a cold start... I have watched it to verify that the thermostat kicks in and the fan cycles on and off as it should. Prior to replacing the fan switch it did manage to get up to about 240 or so.
As far as the coolant leak, I want to replace the gasket to fix it, but I don't have a clue as to what part it is... It isn't a huge leak or anything, just noticed a little bubbling around the edges.
The car has not been close to 299 at anytime that I am aware of, unless it can jump to 299 in a matter of 10 minutes of a cold start... I have watched it to verify that the thermostat kicks in and the fan cycles on and off as it should. Prior to replacing the fan switch it did manage to get up to about 240 or so.
As far as the coolant leak, I want to replace the gasket to fix it, but I don't have a clue as to what part it is... It isn't a huge leak or anything, just noticed a little bubbling around the edges.
Burning Brakes
Joined: Dec 2008
Posts: 1,021
Likes: 7
From: Morgan Hill and Marina California
Does it go from some sensible temperature reading to
299 instantly? Or just very quickly (you can see the
temperature rising).
Also, when it's reading 299, pull the connector off the
gauge sensor. Does it still read 299? Then you have
short in the sensor wiring somewhere.
Too bad this isn't an OBD2 car, we could read out what
the ECM thinks the temp is and get a second opinion.
299 instantly? Or just very quickly (you can see the
temperature rising).
Also, when it's reading 299, pull the connector off the
gauge sensor. Does it still read 299? Then you have
short in the sensor wiring somewhere.
Too bad this isn't an OBD2 car, we could read out what
the ECM thinks the temp is and get a second opinion.
Thread Starter
Heel & Toe
Joined: Mar 2011
Posts: 23
Likes: 0
From: Conroe TX
From a cold start, it starts at "LO" and when it registers, it starts at like 158 or something, and within a matter of 10-15 seconds, it makes 3 or 4 jumps to higher temps and ends up at 299. It is a very fast change. Before this started, either the relay or fan motor had gone bad, so the car had gotten warm and it was a gradual rise to about 249. I replaced the relay, motor, thermostat and fan switch. Everything was good for a week or so until I changed the injectors. As soon as the injectors were replaced and the plenum was put back together, the problems started...
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Thread Starter
Heel & Toe
Joined: Mar 2011
Posts: 23
Likes: 0
From: Conroe TX
I'm pretty positive that the gasket is correct. I matched them to the bottom of the runners to make sure the holes and ports matched up correctly. Like I had said, the leak is at the bottom of the distributor around a plate that the hold down bolt screws into.
As far as the gauge reading, I'm pretty sure it's electrical, just have to I guess narrow it down and figure it out... I am going to try and unplug it next chance i get to spend some time in the garage and see what happens.
As far as the gauge reading, I'm pretty sure it's electrical, just have to I guess narrow it down and figure it out... I am going to try and unplug it next chance i get to spend some time in the garage and see what happens.
