So my Fiero died... (Page 8/12)
Cliff Pennock AUG 10, 05:37 AM
I checked the hose I'm using now and it's SAE J30 R6/R7.

Don't know why but i can't find any place in the Netherlands that sell SAE J1532 hose.

I did find other hoses with no SAE labeling, but with the following specs:

Working Pressure: 20bar
Burst Pressure: 60 bar
Temperature range: -58F to 176F (some specify -22F to 200F)
For use with: oil, lubricants, diesel, hydraulic oil, water, coolant, compressed air and inert gases
Wall thickness: 3.2mm (1/8")

Would that work?
Cliff Pennock AUG 17, 05:55 PM
AliExpress granted me a partial refund!

I asked for a €30 refund (I figured that was the cost of the extra parts needed to make the radiator work), they actually gave me €40.

But BUYER BEWARE. When buying a radiator on AliExpress, always double check they will send you one with the proper fittings...
theogre AUG 17, 06:53 PM
Temp swings can be many things. Only some common items covered in cave in coolant section.
Worse, You can't get Super Stat since motoraid buyout so even w/ 100% good system, you see temp swings on Fiero and more so w/ cool/cold weather. OE type T-stat was made for FWD and Front Engine that only handles ~ 6-7 quarts of coolant and =ize way faster then 14.x quarts in Fiero.

Even then GM had to push TSB saying Fiero and others are going to see temp swings on dash gauges.


quote
Originally posted by Cliff Pennock:
I checked the hose I'm using now and it's SAE J30 R6/R7.
I did find other hoses with no SAE labeling, but with the following specs:
<snip>
Would that work?

Likely no better then the fuel hose you have now. maybe worse.

Next time you drive 1/2 hour or more in City so TC stays unlocked a lot read temp @near the new hoses.
If near the top of range, hoses likely won't last long. If over temp, definitely won't last long.

Even then may not last long carrying AT oil because of above.
Cliff Pennock AUG 18, 05:12 AM
If I disregard the overheating for a moment, the engine runs a lot cooler than before. Before, the fan would come on even during short trips. Now, the fan only comes on as a result of the overheating. If it doesn't overheat, the fan seldom comes on.

I checked the temperature of the transmission hoses (by hand) and they felt warm, but not hot. I will check using my IR thermometer soon, but if I would have to guess, I would say the hoses were no warmer than about 140*F.

But I received the hydraulic hose, and I also found a 90* fitting so I will replace the current hose with those.
ArthurPeale AUG 18, 12:02 PM

quote
Originally posted by Patrick:


I've always thoroughly burped the coolant system (using This method) in any of my Fieros after doing any work on their cooling systems. I've never experienced coolant temperature swings after doing so. However, after repairing a coolant leak in my Formula, as reported in This thread, I purposely did not burp the system. I simply topped off the coolant at the thermostat housing, ran the engine for half a minute, topped it off again, ran it for another half a minute, topped it off again. I made sure the coolant reservoir was also filled to the proper level.




That's essentially what I've done, and I haven't had a problem. I've done it twice. I mean, the system is essentially a big loop-ish. Making sure it's more-or-less filled seems to take care of the issue.
Raydar AUG 18, 01:35 PM

quote
Originally posted by Cliff Pennock:
...
I also found a 90* fitting so I will replace the current hose with those.




I'm not sure about in Europe, but in the US it's sometimes called a hose barb. Yeah. I was surprised too, the first time I heard it.

Glad you found one in 90 degrees.
sdgdf AUG 18, 02:57 PM

quote
Originally posted by Cliff Pennock:


First filled overflow tank to "Min" level.

Fill it to the top at the t-stat housing, open radiator cap until all air is out, top it off at t-stat housing.

Repeat until level no longer drops at t-stat housing. Start engine, let it run for a few minutes, then repeat all steps.

This is how I've always done it. I still haven't checked for crushed pipes yet since I will have to jack up the car for that.

BTW, the new radiator does cool a lot better than the old radiator.



Run it with no thermostat and a really aggressive fan switch? Just keep that fan on. If it still has temperature swings with that it seems like you have some other kink in your system.

[This message has been edited by sdgdf (edited 08-18-2023).]

sdgdf AUG 18, 03:02 PM

quote
Originally posted by ArthurPeale:


That's essentially what I've done, and I haven't had a problem. I've done it twice. I mean, the system is essentially a big loop-ish. Making sure it's more-or-less filled seems to take care of the issue.



I get big swings but that's because of my t-stat, my fan, and the gigantic amount of coolant in the Fiero system. First few times it gets hot enough to open the t-stat it'll crash from 210 down to like the 1/8th mark on the gauge.

And my fan is set for like 140*F, it just about always runs unless starting a cold start.

When I got the car it had no t-stat and would basically never get above 160F. I had trouble in winter with it, the oil would never warm up so I felt bad about going WOT until I put a stock t-stat in it.

[This message has been edited by sdgdf (edited 08-18-2023).]

Patrick AUG 18, 04:40 PM

quote
Originally posted by ArthurPeale:

That's essentially what I've done, and I haven't had a problem. I've done it twice. I mean, the system is essentially a big loop-ish. Making sure it's more-or-less filled seems to take care of the issue.



What is "That's"?

You referenced a post of mine, but because you only quoted part of it, it's rather confusing. The point I was making was because I didn't follow my entire burping procedure, I experienced (and as it turns out, continue to experience) wild temperature fluctuations. Just topping the coolant off at the thermostat housing after the system has been drained (or is low by a few litres due to a leak) does not work in my experience. The radiator cap needs to be removed beforehand to ensure there isn't an air pocket trapped up front.
Cliff Pennock AUG 19, 04:07 PM

quote
Originally posted by sdgdf:

Run it with no thermostat and a really aggressive fan switch? Just keep that fan on. If it still has temperature swings with that it seems like you have some other kink in your system.




I've ran it without thermostat before, and that made no difference. But today I had to make a longer trip than normal (about 80 miles both ways, mostly highway) and on the way there I had huge temperature swings for the first 20 minutes. Temperature rose to beyond the red in about 10 seconds, stayed there for another 10 seconds, then dropped to about 160*F in about 2 seconds. And that repeated itself for 20 minutes after which the temperature stabilized at around 175*F. The temperature light came on each time the needle was past the red and turned off when temperature was dropping (but still in the red)

But on the way back, things got really weird.

First of all, it never stabilized during the 1.5 hour trip. It kept fluctuating between beyond the red and about 160*F. But it looked like the temperature light was living its own live. Sometimes it came on when the gauge was showing 220*F* (but slowly rising), stayed on and wouldn't go out until temp dropped all the way to 160*F.

Then as soon as I got off the highway and drove with speeds of around 30mph, temperature dropped all the way down to something ridiculously low and stayed there:

PS: my temp gauge is in Celcius. 40*C = ~100*F, 105*C = ~220F, 125*C = ~260*F


As you can see, it shows around 56*C or about 133*F. But oddly enough the radiator fan was on, even though the gauge showed such a low temperature.

So I'm not entirely sure when the temperature warning light comes on (what does it measure? Coolant temperature or oil temperature?).

And apparently, there's a huge difference between the sensors for the temperature gauge and the radiator fan.