Heat related loud noise Td5

[Charles]

Hi All,

I bought a Td5 which was showing early signs of head gasket failure ie pressuring header tank. Head gasket has been replaced plus new radiator etc. Thermostat not replaced. Condition of head was flat with some very minor corrosion pitting.

Car runs really well. However, when heatsoaked from 2 hr plus trip at 28 degree ambient, or shorter trip 35 degree plus ambient it makes a loud groan / vibration that is proving impossible (for me) to locate. It sounds like the noise and vibration a stalled out/overloaded hydraulic cylinder makes. Sound doesn't seem to be coming from header tank.

If I shut down, the sound stops immediately. On immediate restart it is absent then comes back quickly. If I leave car to cool completely it is absent unless car is fully heatsoaked again as described above.

Cooling system has been bled very carefully using various methods (RACE, Coke Bottle etc). Zero coolant use and no pressure in header tank after cooling down. Heater blows hot.

Any ideas are welcome as I am about ready to give up (or get divorced for buying another problem car...)

Cheers, Charles

[strangy]

So based on the story so far lets ignore cooling system for now.
I am thinking a bearing noise.
Idler, Water pump, Pwr Steering pump.

[Blknight.aus]

could be the centrifugal filter
could be any of the belt driven accessories
could be a mount collapsing allowing something to touch.

try warming it up, dropping the serpentine belt and seeing if it makes the noise while its warmed up without the belt there.

[Bohica]

So based on the story so far lets ignore cooling system for now.
I am thinking a bearing noise.
Idler, Water pump, Pwr Steering pump.

Yes, check everything that is run from the "fan" belt, assuming that the noise is there when stationary.

If you have a white, tundra D2a, we could swap utill the problem gets sorted. The wife may never know ;)

Julian

[Charles]

Hi Guys,
Have tried firing up without the serpentine belt plus all idlers & accessories spin fine without issues. Fan bearing was replaced - old bearing had stretched the bearing seat in the casting and new bearing needed loctite bearing "glue". Have checked and it is not spinning in the housing.

Crankshaft damper is in good nick and assembly hasn't rotated etc. New Crank bolt used on re-assembly and torqued to spec.

New genuine engine mounts.

There is a lot of visible turbulence in top of PS reservoir even at idle.

Biggest diagnostic drama is intermittent nature of problem and fact it only does it after a couple of hours on road or 35 degree plus day... seems to suggest it is temp related somehow.

Really appreciate the input.

Charlie

[Charles]

Blknight - That's interesting... When I changed the filter I noticed one of the cover retaining bolts had the thread stripped so it is not torqued fully to spec until I can fix it properly - not leaking though, so I figured was not an issue.

[Blknight.aus]

its not the cover bolts that cause the problem its the "bearings" in the filter itself..

the cheap ones do all kinds of wierd random noises, the geunine ones make a kind of protracted "whirring" noise on shut down that everyone imagines is the sound of the turbo whineding down.

[Charles]

Aaaahh... I heard that whirring on shutdown after a coolant bleeding session and thought "that's funny, haven't heard that before" and assumed it was the turbo (which wouldn't make any sense thinking about it...).

Assuming it is the phosphor bronze bush in the middle of the filter element "hat" could that produce such a loud noise as I am getting??

Thanks Dave - gives me somewhere to start looking.

[Charles]

Hi guys,

Don't think the centrifugal filter could be making the volume of noise or the vibration I am getting as the spin down whir that I heard was pretty low. Have disassembled the centrifugal filter and element looks fine with no marks etc on the phosphor bronze centre bushing.

I also pulled the fan hub again to re-check the bearing and it feels a little sticky in rotation. Not much but definitely a couple of very minor tight spots. As before, no sign of the outer race rotating in the housing.

Could a malfunctioning thermostat cause this sort of high temp groan / vibration? Mine was dry for a few weeks whilst everything was pulled apart (yep, grasping for straws).

[schuy1]

Is the vibration/ groaning constant once it begins? ie there all the while the motor is running? Unlikely it is the thermostat. I am thinking maybe the power steering box. They can make some weird noises and would fit your hydraulic sound. agitation in the reservoir is normal. Although after I fitted a brand new pump to mine there was less than before. After the noise arrives move the steering lock to lock and see what happens.
Cheers Scott

[northiam]

ACE pump or system? (if fitted)

[Charles]

Hi Guys,
No ACE so can rule that out.
Once the noise starts it starts and stops but with no particular rhythm or cause until the engine is shut down. Steering doesn't go heavy and winding lock to lock while groan happening doesn't have any effect. I have tried switching a/c on and off, heater from hot to cold etc all with no effect.
Thanks for the ideas though - they all help.
Charlie, going greyer by the day !

[Blknight.aus]

if its a manual it might be the dual mass fly wheel
if its an auto it might be a crack in the flex plate
it could be the coupling between the powersteering pump and water pump.

check the flex coupling and the security of the exhuast heat shield

[Charles]

Cheers Dave.
It is auto.
I am wondering if the slight notchiness in the fan bearing is the problem when it gets well heat soaked.
Is there any simple way to diagnose the ps / water pump coupling or does it need to come out?
Cheers, Charlie

[schuy1]

Hmm, This is getting beyond what can be diagnosed via the internet. Understand that noises can travel in cars. I think you really need to take it to some1 for a diagnoses .If it is bad that its a worry there could be something about to let you down in a big way!'

Cheers Scott

[discorevy]

Tend to agree with schuy1 , however I wouldn't rule out the thermostat , get it to make the noise then carefully with a rag place your hand on it, this would be easier with the fan removed though you may be able to get it from underneath

[Blknight.aus]

Cheers Dave.
It is auto.
I am wondering if the slight notchiness in the fan bearing is the problem when it gets well heat soaked.
Is there any simple way to diagnose the ps / water pump coupling or does it need to come out?
Cheers, Charlie

unfortunately it needs to come out.

the easy way to test up the fan bearing is to warm it up with a hot air gun, you need to heat it to about 120 deg C and then start the engine, if it makes noise and then quiets then becomes noisey again then its your issue.

[Charles]

Thanks Guys,
Will test fan bearing with heat and consider options.
Cheers, Charlie

[Charles]

When fitted how easily should the fan bearing spin?? Having removed the fan hub I can rotate the flange but if I "spin" it, it stops almost immediately (barely half a rotation). The old bearing spun very, very easily which I assumed was because it was totally knackered.

[northiam]

When fitted how easily should the fan bearing spin?? Having removed the fan hub I can rotate the flange but if I "spin" it, it stops almost immediately (barely half a rotation). The old bearing spun very, very easily which I assumed was because it was totally knackered.

My new front hub fan bearing doesnt spin like the old shagged one did, but it doesnt have any play in it like the old bearing did.

You could bypass the fan pulley bearing by removing the pulley and running a smaller drive belt to eliminate bearing noise.