3800 S2 blown head gasket? (Page 2/2)
Frenchrafe JUN 14, 10:19 AM
OK, 3800 heater return blocked off (still have my turbo water feed, but it's small diameter tube):



Put back the heater return pipe as original:



And made a 5mm restrictor to go in the heater feed hose. (I use a tee at this point to fill my coolant system as it's the highest point):




Everything is back together and purged now. However, it's Sunday afternoon and there is nobody making any noise like lawnmowers, DIY work, etc... so I can't annoy the neighbours with the Fiero idling in my garage! I'll be the only one making noise pollution.

I'll start it up and run it to temperature tomorrow...

Regards,
Rafe

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"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

[This message has been edited by Frenchrafe (edited 06-14-2020).]

Frenchrafe JUN 15, 08:15 AM
Problem solved!

And I'm a numpty, plonker, wally and twit all rolled into one!!!

Everything is circulating as it should. The car gets to temperature quickly and then stays there.
Fans come on at 87°C (189.5°F) and then the temperature drops as it should.

How this poor engine kept cool before, with my crappy hose routing, is anybody's guess? I recon air flow while driving and just convection in the cooling system kept it just about OK, except for the hard days at the track or when the air temps were very high.
(Like when I got the shutdown that started this thread - the ambiant air temperature was at 30°C. Very hot for the saison here in northwest France!)

Best regards,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

Gall757 JUN 15, 09:28 AM


Can't quite picture what went wrong. Did your coolant go through the water pump but not the block?

[This message has been edited by Gall757 (edited 06-15-2020).]

Frenchrafe JUN 15, 10:48 AM

quote
Originally posted by Gall757:

Can't quite picture what went wrong. Did your coolant go through the water pump but not the block?




Yes, the water pump was pushing nearly all through the heater matrix with hardly any flow through the block.
The 3800 seems to have a very free flowing circuit for the heater! It seems the fluid dynamics preferred the easy route!

Regards,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

Gall757 JUN 15, 11:23 AM
Maybe the radiator is getting more restrictive. Corrosion?
Frenchrafe JUN 15, 11:44 AM
Yes, that as well.
That's why I stripped down all the system and did a chemical and pressure flush on the radiator to hopefully eliminate some of the corrosion and/or deposits in the radiator.

Regards,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg