Radiator cowling - is it necessary?

Post by **camfairweather** » Fri Jan 06, 2006 5:31 pm

A few months ago, I went a little mud crazy and managed to get pretty much everything covered in in a fine layer of mud (broke the altinator - but thats a different story).

Somehow, while playing in bog, I sucked a peice of wood into the cooling fan area. This bit of wood broke into several small peices and flew into the fan cowling, smashing it in 3 areas. A couple of other people in my 4wd group said the cowling wasn't neccesary and it was really only there for saftey reasons. I took their advice and removed what bits of it were left.

I've since had overheating problems which I put down a dirty radiator. After removing it and giving it a decent clean, the problems seemed to go away - at least on the shortish trips I usually go on.. Recently, I went on a bit of a road trip and after about 4 hours driving at 100kph on a highway the overheating problem returned. Looking at the radiator, I can see it's still possible to clean it further (I waould say it's about 90 - 95% clean).

So, before I spend 1/2 day removing, cleaning and reinstalling the radiator - how important is the cowling? Would all my problems be solved if I ordered a replacement part?

Thanks for any help you can offer.

Post by **Bowhunter** » Fri Jan 06, 2006 5:55 pm

My roza fan has no cowling and I only get the temp going up when fanging in 2nd gear low range in the fluffy stuff on the beach for an extended period

I've never, apart from that, had any dramas with temp in mine and I've had it well loaded up on long hauls on numerous occasions

Sorry that's not much help but at least it's a bit of a reference point

Luke

Post by **Goatse.AJ** » Fri Jan 06, 2006 6:35 pm

Prolly won't find your cowling makes too much difference at highway speeds, so I'd be looking for the cause of your overheating.

However, in heavy traffic, it WILL make quite a difference to cooling efficiency.

Post by **Mudsierra** » Fri Jan 06, 2006 7:08 pm

Cowling?? as in raidator shroud?? Is that what u guys talking about??

Post by **RockyF75** » Fri Jan 06, 2006 9:49 pm

MudRoza wrote:Cowling?? as in raidator shroud?? Is that what u guys talking about??

Yep, think so

What have you got camfairweather rocky/roza/year?? My F75 gets pretty hot on extended highway driving, not to the point of boiling over but up past 3/4 on the dial. Had to slow down to 90kph a few times on my last holiday, and when going up steep hills it also does this. I think its just normal but I could be wrong. Mine gets to 1/2 way in less than 20 mins, but takes about 1/2hr-1hr of 100kph or a reall steep (like 2nd gear) hill to get close to the red.

Edit- and i have the cowling - plastic shieldy thingo, if thats what it is

Post by **camfairweather** » Sat Jan 07, 2006 6:37 am

> What have you got camfairweather rocky/roza/year??

Sorry, I should have said. It's an f-300s.

> Edit- and i have the cowling - plastic shieldy thingo, if thats what it is

Yup - not sure what its officially called, but that's the one.

Post by **drewe** » Sat Jan 07, 2006 9:34 am

I don't have the cowlin g on mine in QLD and it is fine. However.

The purpose of the cowling is to force the fam to suck air through the radiator when car not moving. Now cowing means the fan sucks air from around the top of the radiator - not through it. So it plays an important role in slow speed or idling....

Drewe

Post by **HotFourOk** » Sat Jan 07, 2006 9:35 am

As said, the cowling wont play a part at high speeds... only at lower speeds or when your stopped, when the fan itself is pulling air through the radiator. It just makes sure the entire radiator is being used.. not just the section in front of the fan.. it distributes the air flow over the entire radiator...
So i think your problem at 100km/h is due to a dirty radiator still, or some other issue rather than the cowling.. Coz at 100km.h it gets full flow through the lot.. cowling or not.

Good luck mate

Website · Post by **murcod** » Sat Jan 07, 2006 11:12 am

The cowling would still help at 100km/h IMHO.

Could be a case of your radiator being on the way out. I bought a new replacement for mine recently and it runs a lot better now.

Post by **Sweeney** » Sat Jan 07, 2006 10:48 pm

In actual fact, the radiator cowling is required and I wouldn't remove it!
Air is lazy, in order for fans to work properly (efficiency) they require cowlings. Without the cowling the fan loses efficiency due to turbulent air at the tips of the fan blades. Fan Cowlings reduces this turbulence. Even after-market thermofans have a cowling!
I tight confines of engine bays where air flow is hindered, manufacturers put a radiator cowling around the fan in order to ensure maximum airflow through the radiator. This is even required at highway speeds sometimes.
Fitment of bull bars, spotlights, screens (to stop grass seeds) and even the grille reduces clean air getting to the radiator.
I have seen cases where the radiator was in good condition (or even new) where the overheating problems where traced to the fact that the fan cowling had been removed.

Toyota HZJ75's Landcrusiers can over heat when the radiator cowling has been removed or the fan-clutch is not working.

Overheating cleck list:
Radiator in good condition (core intact, clean, etc...)
Fan in good condition (No broken blades, fan-clutch working)
Head (head gasket intact, head not cracked)
Fan/Radiator cowling present and intact
No leaks/System pressurising/No loss of coolant

Post by **runnin4life** » Sun Jan 08, 2006 8:16 am

yes the fan shroud is needed basically it makes the fan suck the air through the radiator

if its not there its starts to suck the air from around it and not through the radiator

a mate of mine had a 2.4 td surf he has spent more money than the vehicle was worth to try and fix this over heating problem

when all it took was for me to notice that there was only one half of the fan shroud fitted

cheers
elliot

Website · Post by **murcod** » Sun Jan 08, 2006 10:16 am

Sweeney wrote:Overheating cleck list:
Radiator in good condition (core intact, clean, etc...)
Fan in good condition (No broken blades, fan-clutch working)
Head (head gasket intact, head not cracked)
Fan/Radiator cowling present and intact
No leaks/System pressurising/No loss of coolant

I'll add a couple:
Water pump / fan drive belt correctly tensioned?
Water pump serviceable/ working?

Post by **camfairweather** » Mon Jan 09, 2006 5:28 am

Thanks for your input.

Seems opinion is a little devided on whether I need the shroud or not.

Only one way to find out - I'll install a replacement part and see if my problems go away.

Will let you know the result.

Cheers again

Post by **tufferoza** » Tue Jan 10, 2006 11:43 am

the cowling on mine was busted (only one section left hanging there) when i bought it. i removed it completely and havnt had any issues with overheating at all.
though i'll need to get another one (or make one) before i change my rego over to WA, by law i think it's gotta be on there.

migth even go the thermo route...

Outer Limits 4x4 Board

Radiator cowling - is it necessary?

Radiator cowling - is it necessary?

Who is online