Georgia Fiero Club Forum
All Things Fiero => Tech Tips, Tech Questions => Topic started by: Fiero GTB on August 30, 2011, 09:53:45 pm
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As too many of you know, I've had relentless overheating problems with my 308 re-body (w/ 87 V6 and what appears to be an 84 radiator and fan).
WhoDeanie has replaced the temp switch, thermostat, etc. Water pump's fine. Still on really hot days, it overheats.
Anyone ever used this stuff (or similar)?
http://www.redlineoil.com/product.aspx?pid=74&pcid=10 (http://www.redlineoil.com/product.aspx?pid=74&pcid=10)
Also, any experience with R134a "booster" refrigerants for the A/C ?
Thanks,
Fiero GTB
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Have you tried a thorough flushing of the system?
A properly prepared AC system will cool quite well. No need for any special additives. But if the system is "iffy", they do help some.
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First, are you absolutely sure you're overheating. A simple test would be to leave the AC turned off, start the car and let it sit and run. Raise the front hood and watch for the cooling fan to come on. When it comes on, look at the temp gauge to see if it's up in the 220-230 range. The cooling fan should quickly bring it back down, but the important thing is where the fan comes on relative to the gauge reading. It could simply be that your temp sensor circuit is giving an erroneous reading. If it all turns out to be correct, then try removing the thermostat for a while and see how it reacts. We can check it out at the meeting or maybe this weekend if you'd like.
Second, one of the common problems with 134a conversions on the Fiero is that people tend to put in the same amount of 134a as was originally required of R12. The expansion rate for 134a is much greater than the R12 and the same volume of 134a into a Fiero system will overpressure and reduce cooling efficiency. It could possibly even damage a weak system. You should use only 80% the required R12 refrigerant when converting to R134a. The system required 32 oz. of R12. Multiply that by .80 and you get 25.6 oz. So, 2 12 oz. cans is very close. Not enough difference to open a 3rd can in my opinion.
After experiencing poor cooling on my 87 which was filled using a gauge, I slowly drained it, being careful not to loose any of the oil. I then put 2 cans (total 24 oz) of 134a back into the system and it cools just great.
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Thanks: WhoDeanie has done all the work, so I trust that everything was done correctly, I just figure that because of several other factors (my car having an '84 radiator/fan coupled to an '87 V6 on an '86 SE chassis, etc.) and the extra weight of the 308 re-body, all topped off with the high weather temperatures (90s) we've been having, that I might need to try some different tricks.
Radiator system fluid looks really good, but will try a flush just before next summer; and maybe even some of the Water Wetter. Next meeting would be fine to check it out per FF's suggestions.
As far as the A/C goes, WhoDeanie just completed a total rebuild of the system and it blows cold; I just see these ads for the R134a "boosters" that claim colder air (up to 18 degrees) up to 50% quicker and wondered if they actually work...
Thanks!
Tim
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i've used something similar in a big block corvette that kept running hot and worked very good.
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When I first got the 4.9 and was trying to get the swap sorted out, it would occasionally run a bit warm.
Water wetter seemed to help a bit. It sure didn't hurt.
Having said that...
If you have an 84 radiator, it's designed for a 4 cylinder.
My 4 cylinder 88 radiator was significantly thinner than the same year V6 radiator.
A new replacement V6 radiator from one of the local vendors keeps even my air conditioned 4.9 quite cool.
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Thanks, guys!
I feel a new radiator assembly coming on... (Are ya listenin', The Don?)
Best,
Tim
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Noted ;D
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When I first got the 4.9 and was trying to get the swap sorted out, it would occasionally run a bit warm.
Water wetter seemed to help a bit. It sure didn't hurt.
Having said that...
If you have an 84 radiator, it's designed for a 4 cylinder.
My 4 cylinder 88 radiator was significantly thinner than the same year V6 radiator.
A new replacement V6 radiator from one of the local vendors keeps even my air conditioned 4.9 quite cool.
Radar... can you recommend the vendor where you bought your new radiator, or anyplace else? How about the cooling fan? I was thinking of also replacing the stock fan with a 'double' from Summit or somewhere...
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Tim I have an like new V6 radiater if interested call or email me can bring to the next meeting !