300Tdi Radiator baffle, block or not

[TonyC]

Hi All,
I am having my 300Tdi 130 radiator re-cored.
Should I have the radiator shop block the hole in the baffle in the left hand tank.
I can't see any good reason to have it there, and if it's blocked off then I know that all the water is flowing though the core.

Thanks

Tony

[PAT303]

It's there to bypass the first pass through the core if the core is blocked,if you get the core flushed every year which should happen regardless you will never have an issue. Pat

[Bush65]

It's there to bypass the first pass through the core if the core is blocked,if you get the core flushed every year which should happen regardless you will never have an issue. Pat
I can't see the logic in that.

If the 1st pass is blocked, then bypassing won't do anything for cooling - it certainly won't allow flow through the 2nd pass.

And if the 1st pass is blocked it would not matter to the centrifugal water pump if there was a hole in the baffle or not (centrifugal pumps don't mind pumping into a dead end - in fact they consume less power), and there is still the bypass through the heater core to provide circulation through the engine, as that is it's what happens when the thermostat is closed.

I suspect the hole may be there to avoid an air lock below the baffle, but this is just conjecture. I remember there was an old thread where this was discussed and my memory is not perfect so I stand to be corrected, but I believe it was suggested that the hole should be blanked off.

[Tank]

I recently had my 300TDi radiator fitted with a new core, I asked the radiator bloke if he would block the hole in the baffle plate for me while it was apart.
He said he wouldn't do it and if I wanted it done, then I could come and p/up my radiator and have it done elsewhere. I asked him why and he said Land Rover knew what they were doing and he would leave it at that.
So even though I am a mechanic and have knowledge in this area I decided to take expert advise and leave the hole in the baffle, can anyone explain why they think this baffle should be blocked, Regards Frank.

[groucho]

I would say that the 200 TDI rad has the outlets at either end
so the water flows through the whole core .
The 300 TDI has the outlets on one side so the baffle is there
to make a double pass to utilise the whole core, or the water would not
utilise the whole area of the radiator.. Just my thought......Mark

In other words the water flows half the width
and twice the length...

[TonyC]

It's there to bypass the first pass through the core if the core is blocked,if you get the core flushed every year which should happen regardless you will never have an issue. Pat

Pat,
If the core is blocked it's blocked and will overheat!
Are you saying that if it's looked after, block the baffle and I'll never have an issues, or leave it and I'll never have an issue?


I recently had my 300TDi radiator fitted with a new core, I asked the radiator bloke if he would block the hole in the baffle plate for me while it was apart.
He said he wouldn't do it and if I wanted it done, then I could come and p/up my radiator and have it done elsewhere. I asked him why and he said Land Rover knew what they were doing and he would leave it at that.
So even though I am a mechanic and have knowledge in this area I decided to take expert advise and leave the hole in the baffle, can anyone explain why they think this baffle should be blocked, Regards Frank.


Frank,
I'm trying to work out why it's there in the first place, if it's to stop air an lock why so big.
The only other thing I can think of is to slow the flow through the core while keeping up the flow through the block.
The Rad Shop doing mine say the the LR radiator is the only one they have seen with a hole in this baffle.


I would say that the 200 TDI rad has the outlets at either end
so the water flows through the whole core .
The 300 TDI has the outlets on one side so the baffle is there
to make a double pass to utilise the whole core, or the water would not
utilise the whole area of the radiator.. Just my thought......Mark

Mark,
That is exactly why the baffle is there, but it has a hole in it, that allows some of the water to bypass the core.

Tony

[groucho]

Remember the oil cooler is there also and it aids in half the water to be able to warm the oil faster on cold start up ......

[cookiesa]

I look at it this way, it would be cheaper for them not to have it (1 less step i the process) so if they didn't think it was warranted they wouldn't do it.

[roverrescue]

I read it on the internet so it must be true...
"the baffle hole is a cold climate specification to prevent "overcooling" of coolant passing through the entire radiator."

Makes sense if its sub zero outside, thermo will open as water in head is >80degrees water will enter rad and then come out super cooled due to low ooutside temp... baffle hole allows some hot cold mixing?

Its not like the 300tdi is over-endowed with cooling capacity... anything to reduce that seems counter productive in a hot climate.

FWIW my current rad is 4 core 4pass (ie two full baffles) with oil cooler an external unit.

I can still get my coolant temp up to 105degrees!

S

[PAT303]

I can't see the logic in that.

If the 1st pass is blocked, then bypassing won't do anything for cooling - it certainly won't allow flow through the 2nd pass.

And if the 1st pass is blocked it would not matter to the centrifugal water pump if there was a hole in the baffle or not (centrifugal pumps don't mind pumping into a dead end - in fact they consume less power), and there is still the bypass through the heater core to provide circulation through the engine, as that is it's what happens when the thermostat is closed.

I suspect the hole may be there to avoid an air lock below the baffle, but this is just conjecture. I remember there was an old thread where this was discussed and my memory is not perfect so I stand to be corrected, but I believe it was suggested that the hole should be blanked off.

The coolant goes throught the first pass to the opposite tank,turns and passes a second time,if the first pass is blocked,coolant can then go through the hole,through the bottom part of the core at back around. Pat

[PAT303]

I read it on the internet so it must be true...
"the baffle hole is a cold climate specification to prevent "overcooling" of coolant passing through the entire radiator."

Makes sense if its sub zero outside, thermo will open as water in head is >80degrees water will enter rad and then come out super cooled due to low ooutside temp... baffle hole allows some hot cold mixing?

Its not like the 300tdi is over-endowed with cooling capacity... anything to reduce that seems counter productive in a hot climate.

FWIW my current rad is 4 core 4pass (ie two full baffles) with oil cooler an external unit.

I can still get my coolant temp up to 105degrees!

S
There is alot of unknowns with how the cooling works,just fitting a bigger rad won't stop overheating.The way it works is air flow through the rad into the engine bay then down under the vehicle,with almost all modern vehicles the engine bay is insulated to keep down NHV levels so the bay is sealed,air then hits the front of the vehicle and into the bay where it can't get out therefore pressurising the engine bay so the air then takes the path of least resistance and flows around the bay not through it,that is the reason why most vehicles run fine at lower speeds then as soon as you hit 105-110 the temp goes up as the air flow through the rad stalls and the bay becomes a heat sink.If you look at high speed vehicles,Astons,mercs you'll notice vents in the bonnets,with Range Rovers they have very large vents at the firewall,they are put there because those area's are low air pressure area's so they cause suction to help draw air through the bay and through the rad.Regardless of what vehicle you have you MUST have a rad shop flush and clean your cooling system every year,no question. Pat

[TonyC]

I read it on the internet so it must be true...
"the baffle hole is a cold climate specification to prevent "overcooling" of coolant passing through the entire radiator."

Makes sense if its sub zero outside, thermo will open as water in head is >80degrees water will enter rad and then come out super cooled due to low ooutside temp... baffle hole allows some hot cold mixing?

So block the hole and cover part of the radiator when I'm playing in the snow.


Its not like the 300tdi is over-endowed with cooling capacity... anything to reduce that seems counter productive in a hot climate.

FWIW my current rad is 4 core 4pass (ie two full baffles) with oil cooler an external unit.

What is your logic of using a 4 pass radiator and wouldn't that need 3 baffles 1 in the right tank and two in the left (hose) tank?

Is the external oil cooler is to remove heat load from radiator or for extra oil cooling?


I can still get my coolant temp up to 105degrees!

S

Thanks

Tony

[TonyC]

The coolant goes throught the first pass to the opposite tank,turns and passes a second time,if the first pass is blocked,coolant can then go through the hole,through the bottom part of the core at back around. Pat

I can't see your logic Pat.
If the top half of the core is blocked, the water will go through the hole and straight out the bottom hose, there will be nothing to make to go through the bottom half as there will be equal pressure over the whole thing.

But it's also academic as with a 50% blocked core it will overheat.

Tony

[groucho]

Good debate.......
If You think about how the show works
Water pump is pushing from right to left. so the baffle is there to slow down the water movement. the slower the water moves across the core the better cooling affect and uses the whole of the core coming out of the left hand bottom hose.
The water can only go one way with the water pump doing its job. You can not get water going back towards the inlet with the flow volume going the opposite way.... .Some are getting confused with 4 core or tubes. extra tubes more cooling. Like every thing else they are made to a minimum standard to to the job......... over

[Bush65]

The coolant goes throught the first pass to the opposite tank,turns and passes a second time,if the first pass is blocked,coolant can then go through the hole,through the bottom part of the core at back around. Pat
I'm afraid you are wrong! That is not possible.:wallbash:

[Bush65]

Good debate.......
If You think about how the show works
Water pump is pushing from right to left. so the baffle is there to slow down the water movement. the slower the water moves across the core the better cooling affect and uses the whole of the core coming out of the left hand bottom hose.
The water can only go one way with the water pump doing its job. You can not get water going back towards the inlet with the flow volume going the opposite way.... .Some are getting confused with 4 core or tubes. extra tubes more cooling. Like every thing else they are made to a minimum standard to to the job......... over
No, it doesn't.
The hot water from the engine enters the top of the left tank on the radiator.

The left tank has a baffle at about half height so the hot water flows through the upper half of the core (that part which is above the baffle) to the right tank. This is the 1st pass through the radiator core.

The water then travels from the right tank, through the lower half of the core, to the lower section of the left tank. This is the 2nd pass.

The water pump draws the now cooler water from the bottom of the left tank.

Now, all of the water, no more and no less, that flows into the right tank (1st pass through the upper half of the core), must flow out of it.

But some water will flow through the orifice in the baffle that is in the left tank and will not pass through the radiator core.

The dimensions of the orifice and the pressure difference between the upper and lower sections of the left tank will determine the flow rate of coolant that is not cooled in the radiator core. Obviously this will increase as resistance to flow in the core increases due to partial blocking in the core.

[PAT303]

I'm afraid you are wrong! That is not possible.:wallbash:

If the core blocks on the first pass how does the coolant get through to the rest of the rad?. Pat

[groucho]

But some water will flow through the orifice in the baffle that is in the left tank and will not pass through the radiator core.

So where dose that water go. just stays there?
the inlet and outlet must be flowing at the same rate
It works on flow......
The water pump is pushing the same volume as it pulling.
It can't push more than it can suck.......
Thats why they are called a Cross flow radiator
they are more efficient than a down flow radiator

[groucho]

You are right i am wrong they go in and out the same side....
getting confused with 200 and 300's......

[justinc]

I know it isn't extreme in temp department down here in Tas, but I am working on a full size (width) rad for the 300Tdi and a full width IC as a cure all for the 300Tdi cooling system and IC shortfalls because we do send a few clients up to the mainland touring etc. Only if it is cost effective, BUT most want to upgrade the IC at some point anyway, so why not do it once?:twisted:

JC

[TonyC]

I know it isn't extreme in temp department down here in Tas, but I am working on a full size (width) rad for the 300Tdi and a full width IC as a cure all for the 300Tdi cooling system and IC shortfalls because we do send a few clients up to the mainland touring etc. Only if it is cost effective, BUT most want to upgrade the IC at some point anyway, so why not do it once?:twisted:

JC

:mad:So my radiator is "in the shop" in bits, the new core is on back order due Tuesday, and my intercooler is leaking again, and your working on a fix.:mad:

The mad smilies are of course in jest.

When do you think you might have this Radiator Intercooler ready to go?
Do you have a prototype you'd like me to fit and test:D

Do you have an opinion re the hole in the baffle plate.

Thanks

Tony

[justinc]

:mad:So my radiator is "in the shop" in bits, the new core is on back order due Tuesday, and my intercooler is leaking again, and your working on a fix.:mad:

The mad smilies are of course in jest.

When do you think you might have this Radiator Intercooler ready to go?
Do you have a prototype you'd like me to fit and test:D

Do you have an opinion re the hole in the baffle plate.

Thanks

Tony

Tony,

I have experienced no issues with 300Tdi rads UNLESS they are blocked, even 20% will make them overheat that is why I wanted to fit a full size 3 row and move the IC to the front. SO, the baffle plate hole IMHO isn't really an issue, just keep the rad core tubes clean and free of obstruction and they'll work OK.

I am still waiting for prices etc SO a long way off I'm afraid:(

It won't be cheap though, so I don't anticipate selling too many. Mostly to serious travellers towing vans, boats or campers.

I'll obviously be keeping all here informed of progress:)

JC

[PAT303]

The reason for the hole is just like I said,to bypass the first pass.The reason for that is if the rad gets blocked and they all do over time the flow is slowed or stopped altogether and you get the same situation as a closed thermostat in that the engine is boiling but the temp gauge reads good.The hole is there so that regardless on the rad condition coolant is allowed to flow through the cooling system and past the temp sender with enough flow to operate the guage. Pat

[justinc]

The reason for the hole is just like I said,to bypass the first pass.The reason for that is if the rad gets blocked and they all do over time the flow is slowed or stopped altogether and you get the same situation as a closed thermostat in that the engine is boiling but the temp gauge reads good.The hole is there so that regardless on the rad condition coolant is allowed to flow through the cooling system and past the temp sender with enough flow to operate the guage. Pat

...And like you said Pat, 300Tdi systems need to be in tip top condition.

JC

[PAT303]

...And like you said Pat, 300Tdi systems need to be in tip top condition.

JC

I'm glad some one listens:angel:. Pat

[roverrescue]

Just to answer TonyC
the reason I went 4 pass was the rad was in the shop to get its yearly clean (as per PAT303!!!)
Was speaking with radman about getting hot issues when heavily loaded (3/4 in tray towing a tonne) up hills... so was just some experimentation while the tanks were off. Yea you are right will be 3 baffles in there to get 4 pass. The oil cooler was moved as there is no tank for it now. The 4 pass hasnt been the silver bullet I was hoping, but it was a first step before going to a full size radiator.

And PAT im certain you are onto something with regards to the air speed. I can drive at 80-90 or low range slow speed, stupidly loaded with the temp reading 85-95 degrees... but then when I push it up to the 100 mark even a moderate hill will see the water temp climb up to 105...

Steve

[pk.hoarder]

G'day Tony

Hobbo from Lynda's Landrovers told me the same as roverrescue said, the hole is there for cold climates where the radiator can freeze - the hole provides some water flow while the radiator is thawing out (I'm not sure how the radiator could freeze without breaking something, maybe the coolant takes care of that... :confused: ).

Our 300Tdi radiator was cleaned & the hole blocked around 10K ago & so far so good, including a hot summer with the a/c running pretty much non stop. :)

I'm told that it's worth getting the radiator cleaned & inspected (that is, partly dismantled & properly looked at) every 80K.

Hope that helps

[PAT303]

That makes no sense hoarder. Pat

[pk.hoarder]

Pat, I've never pulled one apart but the way it was explained to me was like this:
the hot coolant from the motor enters at the top & flows across to the opposite side of the radiator, where it can get past the baffle & come back through the bottom half of the radiator to return to the motor. The hole in the baffle allows some flow in the event that the core is frozen - water flowing through the hole bypasses most of the radiator. This is to give the motor some coolant flow (& provide some hot coolant to thaw the frozen parts of the radiator) just after start up.

Before the hole in ours was sealed, the heater used to blow warm air pretty much straight away on a cold morning. Now it takes almost 10 minutes to warm up enough to blow warm air. It seems to drive much the same though.

[PAT303]

The right anti-freeze anti-boil solution would stop that from ever happening. Pat