I have the modified Fiero thermostat housings for 3800. The one I have is the WCF version. It was originally installed with a rubber gasket that went in the intake manifold. The rubber gasket had a modified thermostat (i.e., guts removed) to hold it in place. It started leaking. After examining the gasket and housing I can see a problem. The original 3800 housing is flat. The Fiero house is notched the full circumference. It looks like the notch allows the rubber gasket to move up and leak. There is all most 1/8” difference between the original housing and the Fiero housing. I tried using a paper thermostat housing gasket from the auto parts store and sealer and it is leaking also.
So what is the best gasket to stop the leak?
Thank Frank
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I am using a Fiero thermostat. Here are a few pictures I took of the original 3800SC thermostat housing and a Fireo housing. I included a picture of the orignal thremostat gasket with a modified thermostat to hold the gasket in place.
Top is the Fiero housing, bottom is the 3800SC housing
This shows the different in diameter between the two housings
This is the 3800 gasket with the modified thermostat.
This is the 3800NA gasket
I am going to try the 3800NA as soon as I get a chance to work on it.
Frank
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11:18 PM
Sep 27th, 2011
Dennis LaGrua Member
Posts: 15528 From: Hillsborough, NJ U.S.A. Registered: May 2000
Have been using a modified Fiero thermostat housing just as a high fill point while retaining a 180*F 3800 thermostat (w a 1/8" anti-cavitation hole) . I never liked the Fieros fragile, easily bent, pull out thermostat. Never had an issue with leaks. Try replacing using a thin coat of Permatex water pump and thermostat housing RTV.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, ZZP Intercooler, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
So my thermostat has a tall frame to stabilize it. The frame hits the cross bar, in the thermostat housing.As seen in the pic above . What am I doing wrong? Am i suppose to break it off?
So my thermostat has a tall frame to stabilize it. The frame hits the cross bar, in the thermostat housing.As seen in the pic above . What am I doing wrong? Am i suppose to break it off?
are you using a fiero v6 tstat? sounds like your not... Fiero v6 tstats load from the top, under the cap...
So my thermostat has a tall frame to stabilize it. The frame hits the cross bar, in the thermostat housing.As seen in the pic above . What am I doing wrong? Am i suppose to break it off?
Are you putting it un upside down...The tall frame goes upwards...
It is spring down and frame up, but as you can see in the pic the housing has a bar in it that blocks the frame from going thru. Is that bar suppose to be there
