Outer Limits 4x4 Board

I have prob with the 253 atm

When it has been running for a while (usually stationary) and I switch it off, I can hear a knocking noise (I can also feel it through the car itself).

I lifted the bonnet yesterday while it was making this noise and the water hose leading - into or out of - the intake manifold was "pulsing" in time with the banging noise.

The engine temp gauge was reading a little higher than usual.

Any thoughts ???????

possibly water pump

Check your thermostat , 10-1 its been installed upside down , thus your pulsing / knocking thru your hoses and car . Don't laugh I have seen it before on a Patrol !

Brad C wrote:Check your thermostat , 10-1 its been installed upside down , thus your pulsing / knocking thru your hoses and car . Don't laugh I have seen it before on a Patrol !

I have had the car for over a year. Why would it start now?

Not having a go at you, just curious

the pulsing hose and knocking and stuff after you have turned the car off is the water boiling in the hose. maybe you have lost some pressure of the cap? low on water? pump f*cked? hoses f*cked and the lower one may be getting sucked flat and stopping flow of the coolant.

I'd say that this is perfect justification for throwing the 353 in a bin..... if you know what's good for you......

I would say the thermostat has failed and is jamming closed at times.

Shorty40 wrote:I have prob with the 253 atm

When it has been running for a while (usually stationary) and I switch it off, I can hear a knocking noise (I can also feel it through the car itself).

I lifted the bonnet yesterday while it was making this noise and the water hose leading - into or out of - the intake manifold was "pulsing" in time with the banging noise.

The engine temp gauge was reading a little higher than usual.

Any thoughts ???????

on a holden v8 there are two things that cause this the number one cause is the water pump, you have to run a cast impellor pump the pressed steel ones are just crap and cavitate far to much, the other thing is the thermostat has given up and needs replacing, from experience i would say its the water pump. there are some other mods to do to holden v8's to help keep them cool here it is.
have you got a good clutch fan and shroud or thermofan setup,
next you can put coolant/steam bleeds from the high point on the manifold at the back by drilling and taping the manifold (one each side) and run it forward to the top of the thermostat or in to the top radiator hose (on the radiator side of the thermostat) each line only needs to be about 5/16, this works well i've done it on a 60thou overbored 351 cleveland with great results.
next underneath where the small hoses come out of the thermostat housing you need to get a piece of copper pipe that fits neat in the hole in the manifold and flare the end 45 degrees and countersink the hole in the manifold so the pipe will go unflared end first in to the manifold and the flare sit in the countersunk bit so when the housing goes on it holds the pipe there the pipe should be long enough so it is about 6mm from the bottom of the manifold.
the next thing you can get is a ECOtrans thermostat conversion system it moves the thermostat to the bottom hose and makes the cooling system more efficent the person you want to speak to about this is John Bennett at ECOtrans ph- (03) 9335 4344 at 23 webb road airport west victoria
i have read articles about this system that say it can keep a big block cool with a two core radiator. hope this helps.

how is it going Shorty40 any results yet???

mav wrote:how is it going Shorty40 any results yet???

Its in being looked at now. I'll let you know how it goes.

Thanks for all your advice

sounds like the top radiator hose is higher than the top radiator tank and it might have and air lock in the system...lost any fluid lately...

EA onward falcons
toytas alot of them
and some nissans suffer this drama..
given you have modeed your care..it may happen

Punchy wrote:sounds like the top radiator hose is higher than the top radiator tank and it might have and air lock in the system...lost any fluid lately...

Fluid loss..................yes (not much - but may be enough to cause an air lock) How do I remedy this ?

If the engine sits higher than the radiator fill cap then you need to either drill and tap an airbleed into the system somewhere on top of the motor or if you've got a heater set up then try undoing the hose and let the air bleed out from there.
John.

Punchy wrote:sounds like the top radiator hose is higher than the top radiator tank and it might have and air lock in the system...lost any fluid lately...

EA onward falcons
toytas alot of them
and some nissans suffer this drama..
given you have modeed your care..it may happen

most 40 series have the motor (v8 conversions) farly low compared to the radiator so the hoses usually run uphill to the radiator.