I have very recently bought a BJ74 3.4 Diesel with 220,000km on the clock. i am unsure of the history of it but seems in good condition, clean all round. The problem is when i switch the engine off the coolent overflows out of te top of the expansion tank.
bj74 overheating
- Thread starter jono
- Start date
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Welcome to MUD!
So...is your truck actually overheating or is the coolant just spilling over? Have you tried just adjusting the level of the coolant? It's supposed to be below the MAX line on the reservoir to avoid spilling over when the engine is hot...basic, I know, but it's worth a shot.
Is the coolant just spilling over after you shut off the engine, or is it doing it while you're driving around without you noticing? Are you having to add coolant at all (is it really low in the reservoir or rad after it's cooled down)?
It could be a head issue.
Oh yeah...those are great points. A faulty rad cap that doesn't allow the system to pressurize will allow the coolant to boil over at a lower temp. Might as well replace that on a vehicle of that vintage if it's not a recent one.
Oh yeah...those are great points. A faulty rad cap that doesn't allow the system to pressurize will allow the coolant to boil over at a lower temp. Might as well replace that on a vehicle of that vintage if it's not a recent one.
x2 A radiator shop run by an honest man told me a lot of his competitors run up $500 bills on customers cars for want of a radiator cap
ding... ding... !! --->> go with this as your first option. I have seen many bad rad caps lately.Also, make sure you're running your coolant at 60/40, or better - 70/30. I know 50/50 is the usual recommendation... but it's just not enough corrosion protection and I'm seeing too many problems with overly dilute coolant.
if the rad cap is good, then spray a little water on your rad and see if it's evaporating and if all the rad clears of the sprayed on water - where the water stays, the rad is likely blocked (if the coolant level is good and your thermostat is opening properly).
hth,
~John