Thread: Will a bonnet scoop reduce heat in the engine bay?

how much?

Originally Posted by Eevo

how much?

About $200 for the Poison Spyder ones, but can only find on US sites and they want at least another $100 for shipping
Poison Spyder Vented Hood Louver - Black Powdercoat for 87-95 Jeep Wrangler YJ | eBay

The HyLine ones aren't bad either. They're $300 without shipping.

XJ-50HLP_(Use_As_Main).jpg

Gotta love so called 'heat waves'.

I've been keeping an eye on my 300 Tdi since last summer(acquired winter '16), and not been too happy with coolant temp running with A/C running.
First struck the heating up issue last summer on a trip to the high country, and had to manage the use of the A/C.

Tried various options to keep coolant temps from going sky high over the past few hot spells we've had, but overall the summer has been quite mild.

Generally when the coolant gauge reads 100+ C I'll chicken out and either back off, turn A/C off or both.
So far for keeping under bonnet temps in check, has been a new thermostat(from waxstat to tridon) which seems to open up a lot more, and more quickly.

then I did coolant flush, went for a drive up to central NSW, had a day or so of 40°C temps, D1 ran fine(up to 100°C) on a fairly easy run from Cobar to Broken Hill, pretty much flat all the way, mild headwind all the way too.
It generally ran in the mid 90's tho, just some very easy uphills maintaining my usual 95k/h. near Broken Hill, one last ascent saw EGT rocket to over 700C, so I backed off, but coolant only reached high 90's on that particular section.

Yesterday: 40+C drove around Melb a bit some clogged up freeway, a bit of inner suburbs driving .. coolant temps ranged in the high 90's when pushing hard in traffic, 105-111C on the clogged up freeway run back home A/C on all the way.
(actually turned off A/C at 110, but coolant still rose and momentarily peaked at 111)

Overall not happy with it's cooling ability in the heat with A/C. With A/C off, no problem at all. it'll settle to mid to high 80's once all that heat has dissipated. So the issue is A/C running, and really only on the highway or under engine load situatons.

So I've kept an eye on this thread due to my issue hoping an answer could be found for releasing heat from the poor ol 300 Tdi D1.

Don't have the time to muck about with additional venting, and suchlike, but today was another 42°C day, and it started early. Had to drive around Melb again today, a mix of freeway and inner city, all pushing to stress the coolant again, but this time with an eventual plan.
Basically I got the same or worse coolant temps as yesterday, and the issue is that the 300Tdi just works too hard. Mine feels like it's very good condition, runs smooth(for a Tdi) powerful enough .. etc.
On the freeway run out, I got a top temp of 101C, easy run, kept at 100k/h. the run on EastLink(southbound) also saw a very strong tailwind(northerly) that helped keep coolant temp at about high 90's(95-98C).
Obviously the engine load is the significant factor here. On the run back on the Monash(now heading NW) .. so not directly into the headwind.. I recorded a max of 117°C, and it rarely dipped below about 105 or so.
Only as I got to the turn off and backed down to about 80k/h did it cool down to about 100.

Got home .. thinking about vents and stuff.. thought easiest vent to manufacture without any mucking about was to remove the grille. ie. expose the rads to better fresh air .. even if that air is 42°C of dry filth!
So grille off, up for a freeway drive up north past Craigieburn(where it's usually a few °C hotter than inner suburbs Melbourne and bingo!
Coolant never rose above 103° pushing harder and harder, and only EGT kept me from pushing harder again.
I beat everyone to Craigieburn, except one chap in his tricked VR/VS/whatever ... V8 ute(no one was going to pass him no matter how many speed cameras he was up against! )
But that Disco 1 grille is a diabolical design, and adding into the mix the idiotic A/C apparatus blocking air through to the rads(receiver dryer placed in the middle of the rads!). Those dinky fans would be doing nothing other than restricting airflow themselves(even whilst running).

So that's my next plan ... replace those silly thermo fans for something less restrictive for when at speed. .. maybe just one larger one on one side ..
But, forget getting air out .. my next plan is to cut the grille to pieces and work out a way to fit a less restrictive mesh(Saudi Grille style) to allow air through to the rad.
At the moment I'm running without grille and the headlight trims cabled tied to the bull bar .. as they're needed to hold the indicators in place.
Massive difference tho without the grille. A min 10°C cooler running in my situation and on the run home (ie. with a tailwind now) had coolant temp drop to 87°C!! whoot.
And not only did the coolant run cooler .. AC definitely felt cooler out the vents too(which should make sense).

Hope that helps. Would be nice if someone else could try that as a test to confirm or debunk the grille being the issue.

Originally Posted by chillman

About $200 for the Poison Spyder ones, but can only find on US sites and they want at least another $100 for shipping
Poison Spyder Vented Hood Louver - Black Powdercoat for 87-95 Jeep Wrangler YJ | eBay

The HyLine ones aren't bad either. They're $300 without shipping.

XJ-50HLP_(Use_As_Main).jpg

Just look pretty rough

Originally Posted by AK83

Gotta love so called 'heat waves'.

I've been keeping an eye on my 300 Tdi since last summer(acquired winter '16), and not been too happy with coolant temp running with A/C running.
First struck the heating up issue last summer on a trip to the high country, and had to manage the use of the A/C.

Tried various options to keep coolant temps from going sky high over the past few hot spells we've had, but overall the summer has been quite mild.

Generally when the coolant gauge reads 100+ C I'll chicken out and either back off, turn A/C off or both.
So far for keeping under bonnet temps in check, has been a new thermostat(from waxstat to tridon) which seems to open up a lot more, and more quickly.

then I did coolant flush, went for a drive up to central NSW, had a day or so of 40°C temps, D1 ran fine(up to 100°C) on a fairly easy run from Cobar to Broken Hill, pretty much flat all the way, mild headwind all the way too.
It generally ran in the mid 90's tho, just some very easy uphills maintaining my usual 95k/h. near Broken Hill, one last ascent saw EGT rocket to over 700C, so I backed off, but coolant only reached high 90's on that particular section.

Yesterday: 40+C drove around Melb a bit some clogged up freeway, a bit of inner suburbs driving .. coolant temps ranged in the high 90's when pushing hard in traffic, 105-111C on the clogged up freeway run back home A/C on all the way.
(actually turned off A/C at 110, but coolant still rose and momentarily peaked at 111)

Overall not happy with it's cooling ability in the heat with A/C. With A/C off, no problem at all. it'll settle to mid to high 80's once all that heat has dissipated. So the issue is A/C running, and really only on the highway or under engine load situatons.

So I've kept an eye on this thread due to my issue hoping an answer could be found for releasing heat from the poor ol 300 Tdi D1.

Don't have the time to muck about with additional venting, and suchlike, but today was another 42°C day, and it started early. Had to drive around Melb again today, a mix of freeway and inner city, all pushing to stress the coolant again, but this time with an eventual plan.
Basically I got the same or worse coolant temps as yesterday, and the issue is that the 300Tdi just works too hard. Mine feels like it's very good condition, runs smooth(for a Tdi) powerful enough .. etc.
On the freeway run out, I got a top temp of 101C, easy run, kept at 100k/h. the run on EastLink(southbound) also saw a very strong tailwind(northerly) that helped keep coolant temp at about high 90's(95-98C).
Obviously the engine load is the significant factor here. On the run back on the Monash(now heading NW) .. so not directly into the headwind.. I recorded a max of 117°C, and it rarely dipped below about 105 or so.
Only as I got to the turn off and backed down to about 80k/h did it cool down to about 100.

Got home .. thinking about vents and stuff.. thought easiest vent to manufacture without any mucking about was to remove the grille. ie. expose the rads to better fresh air .. even if that air is 42°C of dry filth!
So grille off, up for a freeway drive up north past Craigieburn(where it's usually a few °C hotter than inner suburbs Melbourne and bingo!
Coolant never rose above 103° pushing harder and harder, and only EGT kept me from pushing harder again.
I beat everyone to Craigieburn, except one chap in his tricked VR/VS/whatever ... V8 ute(no one was going to pass him no matter how many speed cameras he was up against! )
But that Disco 1 grille is a diabolical design, and adding into the mix the idiotic A/C apparatus blocking air through to the rads(receiver dryer placed in the middle of the rads!). Those dinky fans would be doing nothing other than restricting airflow themselves(even whilst running).

So that's my next plan ... replace those silly thermo fans for something less restrictive for when at speed. .. maybe just one larger one on one side ..
But, forget getting air out .. my next plan is to cut the grille to pieces and work out a way to fit a less restrictive mesh(Saudi Grille style) to allow air through to the rad.
At the moment I'm running without grille and the headlight trims cabled tied to the bull bar .. as they're needed to hold the indicators in place.
Massive difference tho without the grille. A min 10°C cooler running in my situation and on the run home (ie. with a tailwind now) had coolant temp drop to 87°C!! whoot.
And not only did the coolant run cooler .. AC definitely felt cooler out the vents too(which should make sense).

Hope that helps. Would be nice if someone else could try that as a test to confirm or debunk the grille being the issue.

Well as mentioned, Saudi grill is just mesh on disco

Originally Posted by blackrangie

Just look pretty rough

Yeah they’re not pretty but I reckon they’d reduce under bonnet temps.

Found a nicer one that is designed to reduce water intake which I’m going to buy. About $100 just waiting on shipping costs

Originally Posted by chillman

Yeah they’re not pretty but I reckon they’d reduce under bonnet temps.

Found a nicer one that is designed to reduce water intake which I’m going to buy. About $100 just waiting on shipping costs

Twas one i found back in the day too..good find, best one to stop water.

Still a little bulky for my liking, hence the custom scoop..mould for RRC should be ready in a few days, disco done

Originally Posted by blackrangie

Well as mentioned, Saudi grill is just mesh on disco

AFAIK, only available for the D2 .. and quite an expensive lil tacker at that too.
Don't know of a version for the D1(as this is a D1 query).

I suspect that the D2's cooling is slightly better designed too, with just the single A/C thermo fan only covering one half of the condenser and a more open design for the thermo fan too.
And they placed the dryer to the side, as I suspect most makers did/do. Why in the centre of the cooling area on a D1 .. makes no sense at all.