Does an mr2 overheat quickly?

[Adam Joo]

Ok i've been interested in mr2's and i was talking to a friend and he said that they overheat really quickly is that true?? If so how do you prevent that?

[MRH]

hahahahahah, sorry, I laugh at that statement. I'm sure if your fans are not working, and you spend 3 hours running hard on the track or driving for 6 hours straight through the mountains, I'm sure any car would have problems with that.

but the MR2 does lack the perfect cooling set up for the engine, but by no means is a bad one at all. just like any car, make sure you take care of it and it will take care of you.

-H

[Sang]

Originally Posted by MRH

but the MR2 does lack the perfect cooling set up for the engine, but by no means is a bad one at all.

Would love to hear your explanation of this..

[MRH]

defended by the statement "Nothing is ever perfect".

the "hose from hell" is probably my best defense. works great to cool the engine, pain in the butt to fix.

*edit*am I wrong?* please go on.

-H

[Jason.MZW20]

That, and the special coolant fill procedure, which can give some inexperienced people issues.

But, as long as the system stays pressurized and maintained, there's no issue. I do wonder where people get these ideas.

It's actually cooled more than your typical front engine car because it is both water and air cooled (via the side vents and vented engine lid; engine bay fans for the turbo also assist in clearing the engine bay of hot air from the turbo to prevent component heat soaking). The front mounted radiator is also less likely to heat soak.

[RePete]

Advice 'from a friend' stuff like this is rarely correct, especially if that 'friend' kept them in disrepair or never even owned one. He probably just has a bias against them or it's something he's heard from someone else.

The MR2 cooling system is actually very efficient, It works better than many cars of that era because of the long coolant route all the way from the front to the middle of the car. I've owned & traded 5 MR2s over the last few years and none of them have ever overheated - and I've given all of them regular 'canings' as I do my current turbo.

[como]

When I first was going to get mine (3,000 mile drive home) my boss told me to be weary of heat problems.
And, to his defense, I did have to pull over a few times due to heat-
However, I had two people (I was about 210lbs, passenger was about 150), and about 300lbs of gear. Since the cars weight capacity is 400lbs, and we were driving hard (7k rpm on the highway, in the mountains in 80 degree weather in the sun), I'm not too surprised.

Never had a problem since, and a few months later I did a coolant flush- I dont know how the engine ever cooled itself in the first place with the crap I flushed out of it.

The reason it's considered a "poor" cooling system is generally that the engine is in the back, and the radiator is in the front. The radiator vent fans blow directly into the front wall of the frunk. Just a poor setup overall imo, but I didn't have any heat problems after I ditched my passenger on that trip. (Well, she ditched me, but let's not talk about that- I still had the car)

[te51levin]

Originally Posted by como

The reason it's considered a "poor" cooling system is generally that the engine is in the back, and the radiator is in the front. The radiator vent fans blow directly into the front wall of the frunk. Just a poor setup overall imo...

If the system is properly maintained, any MR2 has more cooling capacity than it can use. I suspect your cooling system was not up to snuff if 80 degrees and a full trunk got the car hot. Aftermarket thermostat, perhaps?

We can eyeball it in the driveway and condemn the design all we want, but Toyota actually tests these things. They design them to work, and then they test them to make sure that they do. Fans blowing at the frunk has little bearing; at high speed, the fans aren't contributing anyway, and low speed, there's plenty of room for airflow when the fans come on.

No, MR2s don't typically overheat quickly, and I'd avoid getting any automotive advice from that friend from now on...

[Sh0ty]

Yeah, I've never come close to having heat issues with the car. I'd take any future advise from your friend with an entire shaker full of salt.

[efx]

I've had my mk1 for a few years after my rebuild and no problems with overheating so far. Still using the stock radiator. Oh yeah, the car got hit in the front when my dad was using it a while back and the radiator got bent a bit and I'm still using it. No leaks or anything it still running like hell. I did have to get another fan, one of them went out, but they're working again. So yeah like any car if the fans aren't working or you got crud in the water then yeah, any car may overheat. Or if you mess with your timing like I did one day, that would send your gauge up like a bat out of hell. Not a big deal, but I learned that really fast. It was a good experience because I know what not to do there.

So in short a huge misconception is that these cars cost more to work in because the engine is in the back. I say bull ****, the engine could be anywhere and you will still get your knuckles messed up no matter where it is. Don't get me wrong, if your car has more room for your hands, cool. These are just what they are. And that thing about these overheating, well I don't know what your friend was smoking, but they don't. Do keep in mind that any sports car does need a little more tlc than the regular sedan since you tend to push them a bit more. So this goes for any car, you give it the basic maintenance and treat it well, and it will last.

[Tyler H]

Compare the huge radiators in MR2s to a 95 Honda Civic. The Civic radiator looks like a postage stamp by comparison. MR2s have more coolant on board, also.

A healthy MR2 just flat out won't overheat in any natural environment or operation condition.

I did 140 track miles in 100 degree heat one day with my Gen3 swapped NA and it never got hot. I had a passenger too.

Maintenance is always a good idea, but I find that these cars tolerate a high degree of neglect and still soldier on. I bought several that looked like they had coffee for coolant.

[Sang]

Originally Posted by MRH

defended by the statement "Nothing is ever perfect".

the "hose from hell" is probably my best defense. works great to cool the engine, pain in the butt to fix.

*edit*am I wrong?* please go on.

-H

So you basing the MR2's ability to overheat by it's maintenance procedure? Of which, that $5 hose surpasses 100K miles or close to it.

Your logic seems sound to me...

Fact of the matter is, the MR2 has exceptional cooling as explained by previous posters.

[traintech86]

really, if there was problems with over heating, these guys in AZ would be able to let us know. the only issues i had with over heating was when i went out to va beach to hang with someone from the forums. we looked in my coolant to see the level and i didn't click the cap on all the way. all my coolant evaporated out and my 2 over heated. i felt like a morron and was worried i might have seriously broke something. my buddy brought me some coolant and we waited for it to cool off. we bleed it and she turned over just fine. i can't believe that it put up with my ignorance. i was on the freeway when this happened and i am amazed that nothing else went wrong from it.

your friend must not know anything about 2's because if properly bled, it makes sense to me that the radiator being up in front of the car, out of the engine bay, would perform better. tomarrow i am going to get some of that toyota red with some oil and i am gonna treat my 2 right heh.

[mr2_mk1.5]

I full heartedly agree with everyone that says the mr2 is highly prone to overheating. I have an 86 with a full out race engine(3sgte) that I swapped in and all I did was build a duct that forces all the air through the intercooler radiator and engine radiator with a couple of 10" spal fans and I forgot to put the fuse into the fuse holder so I had no power going to the fan relay and I was pulling full boost runs at 17+psi boost hard and constant and in 80-100 degree priarie weather I wasn't running more then 3/4's the gauge even at idle and low speed without fans

[traintech86]

is it just me or is this last post confusing? i think he is saying that they don't overheat even when you have a mk1.5 lol

[te51levin]

Originally Posted by mr2_mk1.5

I full heartedly agree with everyone that says the mr2 is highly prone to overheating.

You mean you disagree, not agree, correct? From the sounds of it, you haven't had any overheating problems yourself despite putting a lot more load on the cooling system than it was intended to handle.

[MRH]

yeah, pretty much saying if you don't take care of it, it will be more likely to break. lol, just like anything. tell you what though, I saw an evo with the exhaust manifold touching the radiator hose, they had that thing heat wrapped with duct tape :/ I hope it works out for them. I'm glad my radiator is 2 firewalls away from my engine.

-H

Originally Posted by Sang

So you basing the MR2's ability to overheat by it's maintenance procedure? Of which, that $5 hose surpasses 100K miles or close to it.

Your logic seems sound to me...

Fact of the matter is, the MR2 has exceptional cooling as explained by previous posters.

[mr2_mk1.5]

to clear that up, i meant to agree that they don't overheat easily except if you don't mantain them or have air in the system

[Adam Joo]

Thanks everyone for all the posts now i know not to trust my friend and just ask people on the mr2 forum :]!!

[lsgheero]

Originally Posted by traintech86

really, if there was problems with over heating, these guys in AZ would be able to let us know.

LOLOLOLOLOLOL

speaking of which I just happen to live in phoenix az :P so I will chime in...

As others have mentioned these cars cooling systems are more then adequate for what most peeps use them for. I have ran my mk1 with minor internal engine upgrades on the stock cooling system for 2 years without any issues. all the cooling parts on my car with the exception of the thermostat are the original parts from 1988.

Now as others have also mentioned that while these cars will take a ludicris amount of abuse and keep on ticking regular maintainence is always a good idea. As the few bucks/hours you will spend yearly to keep everything in good condition is much less than letting them decay and become the serious problems your friend and others mention (this applies to any car not just the 2).

The only other thing I will tell you is that IF you have air in the system then yes they will overheat/appear to overheat very quickly as the temp gauge does not like seeing air lol. But just check your levels once a month and do proper maintainence and you will be fine.