rebuilt motor in the vl about 2 years ago, done about 3000kms running perfect, car was running a manual box, took car of the road to put in a powerglide, got it running again but it strangely starts to overheat now after around 5mins gets to 100degrees slowly and keeps rising slowly using the same radiator, same clutch fan, water pump was new when the motor was rebuilt done **** all work, changed thermostat to a brand new one. i felt the blades of the pump whilst spinning the crank, the pump is def spinning. could it be that tune (Autronic SMC) was to suit manual and now its auto with 5grand stall could it be lean or something? Also when first started the car wasnt pumping water through like it had a massive air lock, bleed the cooling system with a funnel sitting in the radiator, took multiple attempts to get all the air out of the system. Wtf is going on, im about the burn the bucket of ****, any ideas?

thermostat installed backwards? auto box o/heating causing high engine temp: are you using the auto trans cooling part of the radiator to cool the p'glide ? are you using the factory fan shroud? does it o'heat while driving or while started but stationary?

installed thermostat the same way as the original when the motor was built that wasnt overheating runnning a massive b&m supercooler infront of radiator for auto not runnng like original setup, Running clutch fan and shroud from before whilst driving its ok for a bit then starts to overheat after idiling and cruising for a bit but temP wont come back down

coolant system not bled properly?

Put another sensor in see what that does??

def overheating its boiling

my 25/30 had the same problem when it was done i left it sitting for 5min from cold and it would boil, i had the radiator flushed out i put a new thermostat in and got a bleed valve welded on the inlet manifold as the motor sat higher than the radiator as i was having trouble getting the air out, doing all that seemed to fix the problem... Are you running a genuine water pump?

blocked rad.?

yeh could be blocked radiator as you've had it sitting around for some time, may be worth getting it serviced also airflow to the radiator may be blocked or severely decreased due to auto trans cooler you describe

siezed thermostat possible?

Put in a new thermostat, Will try get the radiator flushed tomorow forsure spose the cooler could block airflow but it is finned so air could def get past it ---------- Post added 26-01-11 at 21:11 ---------- Grunter did you try bleed the coolant system with a funnel in the radiator first? that bleed hole things sounds like a good idea but inlet Manifold is diff to 25 head

Sound to me like its due to having an intercooler and big trans cooler in front of the radiator. That by itself would proberly cause overheating problems let alone the amount of heat that Trans fluid carries an all the air passing through that is going to be heated up and pushed onto the radiator.

So you made NO other changes to the car besides the Auto conversion? You didnt touch the motor at all?

Is the thermostat opening? Keep the radiator cap off and bring it up to temp and check that the water in there gets warm - this means the thermostat is working. I know you said it is new but they're a cheap part that might not be working. Does it cool down if you drive it or continue to get hotter?

no other changes to the motor apart from the auto conversion everything is the same as before and was running perfect, yep the thermostat is def opening, its running through, i pulled off the top return hose and its pumping hot water through, apparantly there is a bleeder on the the rb26, in a diff spot to the rb25 head and rb30 head, in the pic its on that rail thing directly above the third intake runner from the back of the head, i thought the plug was just something to do with vacumn i will try this tonite hopefully it will help and will get a taller funnel so its def way above the head. ---------- Post added 27-01-11 at 13:38 ----------

If nothing else has changed, its unlikely but possible that the addition of the transcooler could be partly to blame? Can you move the trans cooler to one of the inner guards, behind the bar? May also (if you cant sort it out with this bleed valve) be worth putting it on the dyno just to check A/F, the extra revs from the 5000 stall could also be adding to the extra heat but it sounds like its getting hot just sitting there?? Could your clutch fan have sh1t itself?

alrite been playn around with it some more, radiator wasnt blocked def got all the air out of the system fans working sitting there idling doesnt overheat stays at perfect temp only starts to overheat when accelerating, whilst coasting temp comes back down spoke to tuner he seems to think the extra load from the converter is making the tune lean so hopefully the tune will fix it

Hey, did you open the bleeder bolts when you put the funnel in the rad? Or just let all the air come out the funnel?

yeah open the bleedeer bolts aswell, theres def no air in the system

I thought fitting a transcooler in front of a radiator was always a big no-no in a turbo car.( i could be wrong) As the air has to already travel through intercooler/transcooler/radiator. And those transcoolers have to shed of alot of heat(they sit around 200+ degrees don't they) especially with a big converter the oil gets much hotter as on the street they never lock up. I always have put one in the guard, and 1 in each guard this time. might be you prob, might not be to good luck cheers darren