Thread: 1997 P38 4.6 Cooling system pull down

Good idea Peter, my 96 p38 was running a bit hot and would always climb up the guage on long hills so I had the radiator pulled down and rodded with good results. Now it never moves.I did fit a new thermostat as well but the rodding and clean out is definitely the way to go.

Getting the rad out is quite simple, its held in at the bottom by two bolts and just slides upward in a channel and out. If you remove the viscous fan it would make things easier but its not necessary, you just need to get the rad bottom outlet past the lower cowling with a bit of manoeuvring. When I took mine out one of the bolts was rusted and unable to get at the captive nut that was spinning I had to saw through it. Be careful of the suspension airlines that run under the rad as a slip could cause a puncture. Make sure the Rad shop knows what they are up to and can get spare tank clamps if required, maybe get a recommendation from the forum

Well another weekend of fun. Flushed the radiator and didn't see any crap in the flush, seemed to flow well. Pulled out the thermostat and tested it it all seemed to open and shut without any issues. Put it all back and read on rave to pull the drain pipe off the top of the radiator and blow thru to remove any residual fluid before refilling (to lessen air blocks). From the radiator side I couldnt blow thu the pipe whilst attached to the expansion tank. Is there a one way valve on that line in the expansion tank? I know the cap has a valve of some sort but is there a valve on that line, couldnt see as it all sealed but hope some one knows.
The other issue was whilst removing the line from the bottom of the expansion tank that runs over to the top of the engine ( near the air intake and now the line is snapped of course) somewhere I read that there is a ball bearing in there somewhere that gets clogged up and advises to remove the ball bearing. Does anyone know anything about this?
Also can I just run a rubber hose line to replace the hard brittle plastic broken one or is there some reason I must use the same.
Regards

The build up in the Rad is like concrete, I doubt a flush would clear much of it. Keep your eyes on that temp gauge and stop at any sign of overheating. For the sake of $100 odd dollars I would still get it rodded for peace of mind. Also when the car has been running a while have a squeeze of the top hose, make sure its not rock hard with pressure, a pretty good sign the rad is partially blocked

Thanks wayneg, I probably will pull it out and get it cleaned out but I am concerned that I cannot blow through the drain pipe through the expansion tank. I would have thought that fluid would go either way from the tank to the radiator but it seems that the fluid cannot flow from the radiator to the expansion tank in mine. I didnt check if it flowed the reverse way. Will do that tonight if I can. In addition when I last tested it all and the car warmed up I had a lot of noise in the expansion tank. sounded like there was a rock bouncing around in the tank. Have since taken the tank off and cleaned and found nothing. I am thinking there is a blockage in the pipe in the expansion tank unless it is only letting fluid flow from the expansion tank to the radiator and not both ways. If anyone knows the answer to this please advise

Hi Peter,

I am definetly NOT a mechanic, but logic (thanks Mr Spok) says it should flow both ways...

Sorry, no idea on the detailed stuff. Try giving the guys at AMV in Nth Ringwood Melb. a call (0398709904), they are generally very helpful and open with information/advice where they can be.

Hoo-Roo, Dave & the "pretty pig"

I can only comment on my Thor setup, the overflow pipe is just a pipe nothing more. Now when the expansion tank cap is on thats a different matter, It restricts the flow so blowing down the pipe from the rad it will appear blocked. I presume once the system is pressurised things open up but am not sure on that, maybe its a temp thing in the cap or pressure valve. On mine when the engine is running and the cap is off there is a constant small flow through the rad to expansion tank hose.
When you refill the system its a real pain to get the air out, the noise from the expansion tank could be that, air ( or probably steam ) forcing its way out. Try raising the front of the car when filling.
Whilst you are playing around there its a good thing to change the short overflow pipe from the expansion tank which dumps coolant just below the fuse box where corrosion will cause all sorts of gremlins. Renew it with a longer length and channel it down to the ground.

Thanks for your input, I was trying to clear it with the cap off but could not get any air through from the radiator to expansion tank direction. I will see tonight if it goes the reverse.