Ferrari 308 GT4 radiator repair

Warm spring weather 22° and after a long run spotted the main radiator leaking in two places at the top along the soldered joint - boo.


Removed the radiator by firstly removing the front bumper and fog lights then drilling out the pop rivets that hold the skid plate onto the front wings. This gives access to the bottom radiator hose. Had to disconnect the air-con hoses, noticed a lack of coolant in the A/C system.

Sent radiator to Dixon Radiator Repair in Denton, Manchester (0161 336 2705) - £40 for the resolder repair. Top and bottom front hoses in poor condition. Replaced with new 40mm ID silicone ones - £20

Cooling fans seem slow and wires are in poor condition. Stripped both fans down and rewired them. Fitted auxiliary fan cut in switched wired to fire the fan relays in the fuse box – simply earths the relay coil in the same way as the temp sensor switch.

Stripped down front bumper and paint and waxoyled behind to protect. Added stainless fasteners where removed.

Refitted the radiator, filled and bled the system – no leaks. On the test drive the car ran lumpy but fine after a stop and warmed up. Running hot at 95° on test run and it turned out that both fans were running but the wrong way! Re-connected them the correct way and problem solved.

Removed the rear bumper and painted and waxoyled as per the front.

Ferrari 308 fusebox problems

Main auxiliary fuse (indicators, etc.) #1 melted after a run out! Not the conductor but the plastic part of the fuse due to excessive heat across it caused by resistance at the terminals.


Example melted fuseblock - picture from www.birdmanferrari.com

Researched this on http://www.ferrarichat.com/ and it is a very common problem with the fuse box. Especially on the high current / always on applications such as aux systems, fuel pump! radiator fans. The fuse holders are riveted onto the spade terminals and the physical connection through the rivit deteriates. This encourages corrosion which in term increases resistance to cause a downward spiral of your 308 electrical system

Ordered myself a pair of famous Birdman fuse blocks with the glass type fuses and non riveted connections which took a few days to arrive and about 30 minutes to fit. Never seen an electrical gremlin since!

Also repaired O/S heater duct flap which stopped working, inner cable stiff. Dash removal easy, but access to cable and clamps difficult.

Replacing the oil pressure sender on my 308

Replaced engine oil pressure sender unit (similar if not the same as Fiat 124) with new non genuine from Superformance.

Did not need to remove the oil filter or housing as expected. Removed the oil cooler hose and brake vacuum hose and ground down a spanner to undo the oil pressure sender unit and retighten the new one. No oil came out of the system at all, so it was a pretty easy job in the end. New reading on the dashboard gauge is now smooth and by the book 85psi at temp and revs :)

Ferrari Dino 308 GT4 slow electric windows

Fitted relay circuit to N/S door to solve slow window problem. Routed new power feed from heater rear window fuse – same as for O/S. Used the two relay method instead for a neater solution:

Ferrari Dino 308 GT4 slow electric windows

Solution to slow electric windows found on FerrariChat.com. Need a relay driven circuit to reduce the wire loop length in the power window circuit. Eliminates long wires and poor earth connections.






Fitted four Maplin relays to driver’s door motor circuit which solved the problem – see diagram:

























New power feed to relays from the rear heated window fuse. Wired routed along dash board and through to the door. Found a new two-relay solution afterwards using SPDT – will try that on passenger side.

Ferrari 308 GT4 Fuel filler and heater blower repair

Fitted a new fuel filler neck by removing n/s rear wheel and inner arch liner – quite easy job. Easy access to n/s engine bay through rear arch.

Removed front bonnet plastic liner to investigate the poor heater output from o/s heater port. Heater matrix and duct pipes appear fine, water valve opening fully, but heater control flap lever for o/s is stiff and doesn’t open properly. Fixed that but no extra output. Removed front o/s wheel and blower access panel. Removed blower motor – very tight fit in valance. Stripped and cleaned it nothing wrong with it, but realised it was wired in reverse! Wired it correctly and now get full flow on both heater blowers.

First run out in the GT4

Spent some time to assess car went on a run, cold day took a while to warm up. Filled with Shell V-power.

• Right-hand heater blower poor performance
• Both electric windows very slow
• Replaced all visible steel fasteners with stainless-steel ones
• Notice fuel filler hose was perished. Available from Superformance £25
• Erratic oil pressure readings – probably sender, available from Superformance