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| Engine temps all over the place (Page 8/9) |
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Cliff Pennock
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JAN 16, 01:46 PM
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Just an update, in the past two weeks it has only overheated once. I have no idea why - it just stopped overheating. The single time it happened, I wasn't driving the car differently than normal. It just heated up until the overheating light came on, after which temps dropped to normal within seconds.
It is still loosing coolant somewhere though. But it's just weird the overheating stopped.
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cebix
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JAN 16, 03:11 PM
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Do you have means to log in data from the ECU?
You can wire up a quick signal converter shown here with a RS232>USB converter of choice. It worked for me even on Windows 10 with WinALDL.
https://www.techedge.com.au.../aldl160/aldl_hw.htm
I believe I had the same problem as you or at least something very similar. I posted my readings somewhere on this board of some drives. Will post them here if I find them. I have a 2.5L though and the problem is still really unresolved... I believe it's either an intake manifold gasket leak or a head gasket leak.
EDIT: If I remember correctly I actually had to flip the signal, I think this was the proper circuit:
https://www.techedge.com.au...ldl160/160serial.htm
EDIT2: Here's my thread:
https://www.fiero.nl/forum/Forum2/HTML/143849.html[This message has been edited by cebix (edited 01-16-2023).]
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Cliff Pennock
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JAN 20, 09:01 AM
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Just another observation: I noticed the other day that, after having driven the car for an hour or so, the radiator cap was still cold. And I mean outside temperature cold. It's currently 38F outside now and that's how cold the radiator cap feels.
So I've been checking this for the past few days and it's always cold, it never heats up.
If I feel the top of the radiator, that's cold too and it feels warmer the lower I check.
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ArthurPeale
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JAN 20, 12:53 PM
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| quote | Originally posted by Cliff Pennock:
Just another observation: I noticed the other day that, after having driven the car for an hour or so, the radiator cap was still cold. And I mean outside temperature cold. It's currently 38F outside now and that's how cold the radiator cap feels.
So I've been checking this for the past few days and it's always cold, it never heats up.
If I feel the top of the radiator, that's cold too and it feels warmer the lower I check. |
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do you have, or have access to, one of those touchless temperature reading devices? I got one of Wish years ago and it's handy for being able to read surface temperatures easily.
Sounds like you've got some kind of block in the lines.
Here's what I would do - drain the system as best you can. Pop off the thermostat housing cap. Remove the drain from the pipe on the opposite side of the car. Get a hose, put it in the thermostat housing opening, and turn on the water, nice and gentle. Watch to see what happens. If water starts coming out of the drain, block shouldn't be from where you're pouring water, down to where it's coming out.
Or, pull the radiator, and start pouring water down from the outlet, it should come out the inlet easily.
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sanderson231
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JAN 20, 07:39 PM
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Could be the impeller in the water pump corroded away ------------------
formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged
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Patrick
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JAN 20, 09:35 PM
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| quote | Originally posted by Cliff Pennock:
If I feel the top of the radiator, that's cold too and it feels warmer the lower I check.
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It's been mentioned at least once before (but I don't believe you addressed it)... are you absolutely positive that neither one of the two stainless steel coolant pipes that run the length of the car has been crushed?[This message has been edited by Patrick (edited 01-20-2023).]
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sanderson231
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JAN 21, 10:50 AM
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After thinking about this some more, I urge you to make sure that the coolant system is properly filled per the procedure I posted previously and also do the sniff test to make sure that there are not exhaust gases in the coolant system. ------------------
formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged
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Raydar
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JAN 22, 02:52 PM
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I'll jump in here and drop my two pence, FWIW.
I had installed a remanned 3.4, and was doing the "drive it easy to break it in" thing for 500 miles.
I suddenly started losing coolant. (I forget what the gauge was doing, but obviously it was doing something strange. Not important to this post.)
It got to the point that I could top off the coolant, warm it up, let it sit in the garage and idle, and it would behave normally.
As soon as I drove the car and stomped the gas to accelerate, it would blow massive quantities of coolant out of the overflow.
A compression test showed all cylinders within spec. Then I hit on a method...
The hose from my compression tester was threaded the same size as my air tools. I was able to attach an air tool fitting.
I removed all the spark plugs, and started with #1 at TDC. I removed the thermostat cap and thermostat, and made sure the cooling system was full.
My plan was to plug the compression gauge hose into each cylinder, and then hit all the cylinders, in order, with the air compressor, moving each piston to its compression stroke before connecting.
When I connected to cylinder 1, I got lots of bubbles from the thermostat housing. Good enough. Engine had to come out, anyway, and go back to the rebuilder. But at least the mystery was solved.
(Ended up being a broken head bolt, that allowed the gasket to blow.)
At first, I questioned the wisdom of hitting my cylinders with the full pressure of the compressor, but then I remembered that the compression test produced more PSI than my compressor did.
To do this outside of a garage, you'll either need a portable compressor, or a portable air tank. But it should be do-able.
And since yours seems to act up when it's cold, it shouldn't be a problem to test it the same way.
(Not that I agree that you have a head gasket issue. Just another way to rule that out, if nothing else works, first.)
Good luck.
Note: my problem did NOT get better as the engine got warm. It got worse, as expected.[This message has been edited by Raydar (edited 01-22-2023).]
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sanderson231
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JAN 22, 03:47 PM
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Raydar
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JAN 22, 05:04 PM
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| quote | Originally posted by sanderson231:
What Raydar described is similar to a leakdown test:
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That is where I got the idea. My test didn't "measure" leakdown, exactly, but it did tell me that compression was leaking into the water jackets, which is what I had to find out, and already suspected.
Once I described what I did, and the results, the vendor (The Fiero Factory) warrantied the repair.
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