Thread: 300 tdi engine temps

I have played with my 130 radiator in all ways
It currently is running as 4 pass (ie water crosses from left tank back and forth four times before exiting)
No difference still can get it up to 115 up the byerstown range in midday summer
(oh and this is of course on an engine with no head troubles etc etc sorted that )
In honesty the trouble is the aero design of the fender. Up to about 90km/h you get good airflow across the radiator.
Over that speed and the air stalls

When it is hot (as in road temps over 35 and high humidity) the fender is at its cooling limits

I take solace in the fact that glycol+water at 15psi wont "boil" until 130 degrees so despite perhaps a little pump cavitation as long as temps stabilise after hills I just keep plodding.

But if your head/ gasket or cooling hoses are suspect then the extra pressure wont help!!

Talk of whacking holes in the side guards to better airflow has been made

Honestly might be better just to disconnect the temperature guage.
The factory gauge is normalised between 80-110 ie it wont start moving till your up over 110

maybe some logic in that - don't sweat that which you cant change!!!

S

Originally Posted by roverrescue

I have played with my 130 radiator in all ways
It currently is running as 4 pass (ie water crosses from left tank back and forth four times before exiting)
No difference still can get it up to 115 up the byerstown range in midday summer
(oh and this is of course on an engine with no head troubles etc etc sorted that )
In honesty the trouble is the aero design of the fender. Up to about 90km/h you get good airflow across the radiator.
Over that speed and the air stalls

When it is hot (as in road temps over 35 and high humidity) the fender is at its cooling limits

I take solace in the fact that glycol+water at 15psi wont "boil" until 130 degrees so despite perhaps a little pump cavitation as long as temps stabilise after hills I just keep plodding.

But if your head/ gasket or cooling hoses are suspect then the extra pressure wont help!!

Talk of whacking holes in the side guards to better airflow has been made

Honestly might be better just to disconnect the temperature guage.
The factory gauge is normalised between 80-110 ie it wont start moving till your up over 110

maybe some logic in that - don't sweat that which you cant change!!!

S

I've wondered how close I'm getting to the limit, but you can hit 115 coolant temp and no apparent issues to speak of? From all the reading on here, it seems to me if the factory gauge moves, you will end up with head gasket issues. If the factory gauge is normalised to 110, then I can't see 110 being safe. Thoughts?

Would a disco have the same air stalling issues? I heard the p76 had a simlar issues at speed when the shape of the car at certain speeds created some sort of positive presure area and would then get hot

-generally the factory gauge moves BECAUSE you have a head gasket problem
-It has been years since I tested factory against VDO but from memory it was 110 before the factory went up
-If I hit 110 going up a range with stupid heat and humidity (good examples are Byerstown near Palmer or Bamboo range north of Laura) the temp will settle back to mid 90s once power comes off or get to top of the hill.

Im not advocating pushing an alloy head that hard often but I guess I have not had super problems.

Also having said that some people are scared of 300 head gaskets. This plays into the fears of temps? Last change out I did of a 300 head started at 830am and was drinking beer by 1100am on a Saturday morning... Id take a head gasket change over doing the swivel hubs or control arm bushes for example?

Maybe Im too blas? but if the temps start to fall as soon as the noise comes off and then stay down until the next big engine load well then Im okay with that?

If you drove your 300 powered defender at 85km/h or less everywhere I doubt you would ever get much over 90... I think it was Rick (rick130) who did some aero testing and found the air stall speed was about 90-95km/h - once you hit that the only cooling you are getting is via the viscous fan drawing air over the rad.

s

No issue doing heads gaskets just think they run a bit hot is all and if I can improve it for not much money I think it makes sence not that I can see any sure fire way of geting them to run cooler

From what I have seen the only way to get them running cooler will be an alternative to factory rad however space is not your friend or whacking some big holes down your guards so that the stalling air can flow when at highway speeds

Other than that call it a design feature from colder climates!

Originally Posted by roverrescue

-generally the factory gauge moves BECAUSE you have a head gasket problem
-It has been years since I tested factory against VDO but from memory it was 110 before the factory went up
-If I hit 110 going up a range with stupid heat and humidity (good examples are Byerstown near Palmer or Bamboo range north of Laura) the temp will settle back to mid 90s once power comes off or get to top of the hill.

Im not advocating pushing an alloy head that hard often but I guess I have not had super problems.

Also having said that some people are scared of 300 head gaskets. This plays into the fears of temps? Last change out I did of a 300 head started at 830am and was drinking beer by 1100am on a Saturday morning... Id take a head gasket change over doing the swivel hubs or control arm bushes for example?

Maybe Im too blas? but if the temps start to fall as soon as the noise comes off and then stay down until the next big engine load well then Im okay with that?

If you drove your 300 powered defender at 85km/h or less everywhere I doubt you would ever get much over 90... I think it was Rick (rick130) who did some aero testing and found the air stall speed was about 90-95km/h - once you hit that the only cooling you are getting is via the viscous fan drawing air over the rad.

s

Interesting first point. You could be right - or at least some of the cases happen that way around. I know my case was definitely in order of overheating, then head gasket soon after.

I hear you on the temp dropping back after coming off the power. My VDO gauge hits 105*C, but as soon as I'm over the hill the needle drops at rapid speed.

BTW, mine is a Disco, so it may not have the same airflow problems?

See mines mesureing head temp not water and that may be why its taking so long to come back down on the gauge