[Haza]

Recently I picked up a 2000 Suzuki Jimny got it to a rwc standard and am about to register it but from the test drives I've noticed it gets hot but the gauge is just under half. I researched the cars history and the head gasket has been blown 3 times, this last time it did the guy rebuilt the top with a full VRS and got the head machined tested and acid dipped.

To prevent it ever from overheating again I am looking for options to help make it run cooler than standard. Firstly I'm getting a K&N air filter and a Snorkel so no hot air comes from the engine bay. Secondly I am getting exhaust wrap and wrapping my extrators to restrict heat from them.

I need aditional ideas if possible its predicted to hit 45 - 46 degrees this year last thing I want is this engine damaged after all the work that has gone into it.

Thanks in advance.

[henno]

Haza wrote:

I'm getting a K&N air filter... Secondly I am getting exhaust wrap

If you are planning on taking the car offroad at all, I'd probably advise against both of those.
K&N "filters" are pretty shitty at actual filtering, and exhaust wraps get absolutely loaded with mud and dirt and water and muck and can cause premature rusting of bits and bobs.

[Haza]

I mainly brought the car to take my dogs to the beach im sure if i get the wrap dirty i can clean it haha.. im not a serious 4x4er. Why not use a K&N dont they have better airflow?

[Haza]

I did read some stuff on the K&N being quite bad for filtering, could you suggest any other filters as an alternative. The standard ryco seems to restrict my then it lets through.

[BoomBoom4216]

henno wrote:

Haza wrote:

I'm getting a K&N air filter... Secondly I am getting exhaust wrap

If you are planning on taking the car offroad at all, I'd probably advise against both of those.
K&N "filters" are pretty shitty at actual filtering, and exhaust wraps get absolutely loaded with mud and dirt and water and muck and can cause premature rusting of bits and bobs.

Assuming it's a panel filter in a box, just run a pre filter over the front of the air filter face. I've got a Tiffany Cloth which is a fibrous media (cleaning cloth), I run a piece of it for 15,000 km and replace it, keeps the K&N really clean!

Filters out a whole lot of crap and goes absolutely black with diesel soot from highway km's.

[henno]

Just run a stock paper filter.

[Haza]

What about other extra cooling mods im really paranoid about how physically hot these engine bays are.

[30ONA]

You can over cool an engine. Just make sure all the parts are working well. Fresh coolant. No leaks. No air in the system. No blockages in the inside or outside of the radiator. Hoses are nice and pliable.thermostat and radiator cap replaced every 100k as with the water pump. Clutch fan also replace at 100k. A bonnet vent may help but other than that should be fine. I and belts and idlers are good.

[fordem]

Let's go back to ...

Quote:

from the test drives I've noticed it gets hot but the gauge is just under half.

How do you know it's getting hot?
How hot is it getting?
How hot can it be getting if the gauge is just under half?

Yes - redundant questions - but the point behind them is to get you to understand that you really don't know what's happening, and until you do, you're not likely to achieve much.

The dash gauge is not a calibrated measuring instrument, it's there to alert you to an overheat condition without having you constantly worrying every time it moves up or down, so it'll sit approximately mid scale for surprisingly wide variations in temperature, but, if it's not moving up the scale, the probability is the engine is not, in fact, running hot.

If you want to be certain get an IR gun and make some measurements - start at the water outlet elbow.

Next - you do NOT want the engine running "cooler than standard" - engines are designed to run at a given temperature, run it lower than that and the efficiency drops, fuel consumption and wear rate increase - cooling systems are designed to allow the engine to operate within the optimum temperature range in a wide variety of conditions (that is what the thermostat is for), and in most cases, if the cooling system is properly maintained, it will have no trouble doing so - this does not mean that you cannot have a larger or more efficient cooling system, if you feel that the planned operating conditions warrant it.

[Haza]

I think Australia has above average conditions, most other countrys have winter but in central qld our winter is what i set my aircon to... makes me think i cant overcool the engine. Besides that after going on about 15 min drive in 36+ degree weather it reaches running temp quite fast, bonnet is quite hot, and my partner keeps mentioning a wierd burning smell, to me the smell smells like water, but i check my levels after every run and its fine. I plan on taking this car to the sand quite a lot since its 5 mins from my house, dont wanna get stuck out there with a over heating engine. Lol

[BoomBoom4216]

If you want to vent the engine bay without putting in vents at the top like scoops that require fair paced forward momentum to push hot air down through a engine bay, lift the actual bonnet by adding plates or washers to the hinge plate.

That'll lift up the back end creating a gap at the back allowing hot air to escape naturally. A lot of milk bottle racers do it and the heat that escapes is pretty noticeable.

You can findo me on any given hot day or on a way home with my bonnet cracked to allow more air into the engine bay, certainly drops the overall heat generated and trapped in the engine bay.

[Gwagensteve]

There's nothing above average about Australias conditions. Many, many places have higher ambients (and higher ambients with higher humidity) than Australia.
The factory cooling system if in good condition is perfectly adequate. The Jimny was engineered for the world market. Engineers are fully aware of the temperature and humidity ranges around the world and actually test vehicles in these conditions prior to release.

You need to be able to answer fordem's questions.

Engines are supposed to get up to temperature quickly, because that's when they work properly. That's why cars have a thermostat. This is even more critical with EFI cars where the engine will run rich if it's below operating temperature.

I don't want to take this discussion off topic, but if the head gasket has failed three times there is likely to be another underlying issue. It is definitely not due to inadequacy in the factory cooling system. Perhaps the second repair was associated with poor workmanship the first time around, or perhaps the cause wasn't ever identified. Block and heads cracks are not unknown in the Jimny.

A noticeable coolant odour when the car is in use isn't a good sign and in my opinion needs investigation. Putting an inefficient filter or adding a snorkel won't make any meaningful difference. Lowering intake temperature a few degrees won't lower engine operating temperature a few degrees - that's not how it works.

If you're curious, get an inside/outside thermometer and put the "outside" probe it in the intake air flow to the filter. You'll be surprised how close to ambient the intake air is once the car is in motion. All cars "heat soak" if they are idling with hot engine bay.

Also, you need to ensure the radiator isn't blocked with mud, you don't have a bar, winch and lights blocking flow - all the normal things.

[30ONA]

Think about the engine running temps. in a logical fashion. Engine coolant temps are often ideal at over 100deg. from the factory, is an extra 10deg. ambient really going to do anything when the system is designed to maintain say for example 100deg? even at 110 you are not going to cook the engine. You will get a problem is the system is not working in all respects and the temp start to climb

As above why do you think the engine is hot?

Are you loosing water, even very slowly? Coolant leaks are sweet smelling, different to just a hot engine.
If your getting smells inside the car and no visible leaks you could have a leaking heater core or AC expander/evaporator in the dash. Coolant runs through these and if small leaks develop it will burn on the heat of the core inside your dash and vent into the car. I've had this in two cars. Sometimes they go dramatically but in one case it was very slow till I found it.

As above, if the factory system is working 100% you shouldn't need anything else.

[alloz]

Holy smoly you guys are serious into worrying.....I live in Indonesia & am in a very active katana club & we punish these little beasts in HOT Temps all day & night. The bonnet is ALWAYS TOO HOT TO TOUCH (please read that twice, I'm sure you yeah yeah whatevered the 1st time). We love our zooks & reward our little buzz boxes with NO thermostat, quality coolant, good hoses & electric thermos fans. I have never experienced such hot donks in Australia in the Mallee or The High ontry of Victoria, where I also have a Sierra (presently in storage), but Java is hot & i have no drama. Go out to your garage & tell your zook you love her & then go drive her like the bush explorer you want to be & stop fussing about like an old woman.

[shep]

Haha wot he said. If the gauge isn't moving into the red then it isn't hot.

[Gwagensteve]

I'm not sure that no thermostat and thermo fans are a "reward" but I do broadly agree with your point.

[alloz]

@ Hillbilly......brother zooker, I'm just putting it out there that different folks in different countries have the same passion & to your mind, rudeness or ignorance of all systems proper. Chill bro (pun intended) Don't get as hot as your donk. I will let you all know the minute one of our 80 club cars blows up & i will await your "i told you so" & cop it on the chill without retort (read:name calling). For the record, none of my 7 (seven) previous 4wheel drive vehicles i've owned & USED has ever had the thermostat removed as an answer to an overheating problem, BUT here in Java, I do as the Javanese do ! (don't hate me, embrace me as a fellow offroader, as I do to you all) XX alloz, apparently --> the ^^^^clown. PS. I am Australian not Indonesian (NB:in case your jibe was racially based,you can apologize now)

[henno]

Hillbilly isn't talking to you. He wrote that in another thread and Steve has simply copied it into his signature.

[Gwagensteve]

All right all right. I've changed my signature. That's the third noob it's offended. Alloz, Hillbilly was talking about ME and I was quoting him because he doesn't realise how funny he is.

On this forum the users avatar is on the left, not the bottom of each post. I'm going to assume that's the reason for the confusion.

There was no slur directed at you, racial or otherwise.

I still, however, can't see any reason to remove a thermostat, I don't care whether the Japanese do it or not. They don't have a monopoly on good ideas and removing the thermostat does't magically improve cooling capacity or efficiency. At best it's having no effect at all. At worst, it's increasing the speed of coolant flow in the radiator, reducing cooling effectiveness*. If it was effective and was lowering the operating temperature of the engine it would be unhelpful in an EFI engine in any case, increasing idle speed, running the car rich and generally not helping anything at all.

In case you wondered, it gets quite hot in Australia. Much of the country was hotter than 45˚C today. Removing the thermostat isn't considered as a means of improving cooling here.

*Amongst other things I'm a journalist. I was writing an article on an off-road race car recently and the owner was having trouble keeping the car cool. Following conventional thinking, the owner fitted a much larger radiator. It didn't fix the problem - it still overheated. Eventually, they put a restrictor in the cooling system to slow the flow of coolant through the radiator, and the car now runs cool.

Steve.

[losfer]

FWIW , i read a lot of Steves posts and sometimes i dont agree (but cant be bothered arguing the point) with what he says but on this topic i 100 % agree.

Ive built a lot of BIG HP engines and have never used anything but the FACTORY radiator. if all the components are operating correctly then there should be no reason for an overheating problem.
Also agree with removing the thermostat is a bad idea , it regulates the flow so the radiator can cool efficiently as steve pointed out but also help with the ecu to improve fuelling . The coolant temp sensor enriches fuel when the engine is cold , running too cold all the time will cause poor fuel economy. it will also damage the catalytic convertor.
Engines that are front wheel drive regulate the temperature via ecu , unfortunately jimny and most north south engines that use a fixed or viscous hub fan rely on the fan to regulate the temp. In a fwd the ecu switches on the thermo fan at approx 94 degrees and turns it off at 89 .

In a jimny the ecu knows the engine temp has reached 94 but has no way of controlling the viscous fan so most overheating is caused by poor airflow over the radiator at low speeds caused by a shitty viscous fan or blocked radiator . too many accessories in front of radiator can also affect airflow over radiator , ie lights etc

[fordem]

Since no one else has mentioned it, let me do so - one of the other issues with running the engine with no thermostat is that the engine takes longer to come to operating temperature (if it ever gets there) and the end result is a significant increase in wear on the cylinder walls & rings.

[jdk81]

If you require extra cooling, turn the heater on full.
Sure it proper sucks on a hot day, but adds extra cooling capacity.

Re Steve's sig, that was kinda funny.

Re no thermostat
As above, it sucks arse and causes more problems than it fixes.

[Gwagensteve]

Interesting note JDK - I noticed when I was in Bali a couple of years ago that all the local spec Japanese cars (corollas, Kijangs, APV's etc) had no heater installed at all, from factory. No temp dial - just air blend and fan speed. There's obviously a tropical 3rd world spec.

Not suggesting Alloz car has no heater, but it wouldn't surprise me.

I didn't notice if that was the case for Indonesian spec Sierras - those I saw all had good-as-opaque window tint.

Steve.

[Marko_SJ]

Gwagensteve wrote:

I still, however, can't see any reason to remove a thermostat, I don't care whether the Japanese do it or not. They don't have a monopoly on good ideas and removing the thermostat does't magically improve cooling capacity or efficiency. At best it's having no effect at all. At worst, it's increasing the speed of coolant flow in the radiator, reducing cooling effectiveness*. If it was effective and was lowering the operating temperature of the engine it would be unhelpful in an EFI engine in any case, increasing idle speed, running the car rich and generally not helping anything at all.

It didn't fix the problem - it still overheated. Eventually, they put a restrictor in the cooling system to slow the flow of coolant through the radiator, and the car now runs cool.

Steve.

Pretty sure I read a thread about this exact thing with TD42 patrol engines. People removing thermostats make the problem worse.

[alloz]

Yeah so........I actually took a spanner & looked & there IS a thermostat where the locals told me there wasn't, it turns out that when they remove the thermostat "IT MEANS" they have removed THE ORIGINAL spec unit & replaced it with a slighty higher temp one. Ive only been living abroad here for 2 years & comprehending the local meaning AND what they actually mean is 2 different things. I sympathise with you all suffering 40+ degrees & hope the breweries don't go on strike ! (btw : I am a white Australian born 55yrs ago in Victoria & my 1984 sierra here is called a Super Jimny & has no heater fitted)