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Lex3486

93 Overheating

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My car has begun overheating recently and I can't figure out why. I replaced the radiator a few months ago and ran strait water in the system for a couple hundred miles, to flush the system out some. It never overheated in the summer when I had just water in it. When I drained the water out, it looked sorta rusty, but nothing terrible. I put the orange Dex-cool antifreeze in it and it drove fine for quite a while. The temperature when workin right, is right above the second line on the guage; right at halfway. Recently, I can drive it for a while (usually 30 minutes or so) in the city, on backroads, the highway, wherever without any trouble, but eventually the temperature begins to rise. Usually it'll go back down momentarily, indicating the thermostat opening and closing I suppose, but after a while of this, it will go sky high at which point the system can't recover and I have to stop and let it cool down. I've visually checked the thermostat and gasket, as well as tested it and it works just fine. The cooling fan also appears to work alright (it runs continuously at a slow speed and speeds up as temperature goes higher. stays on full blast when it gets really hot). The cooling system has no leaks, and as I said earlier, the radiator is new. One thing I've noticed is that when I very first start the car, I can hear the sound of rushing water behind the dash (possibly air in the cooling system moving through the heater core my dad says). Also, as the car is running, the coolant overflow tank will slowly fill up above the full line till it's almost full, but the temperature is still normal. Performancewise, the car still drives 100%. It does smoke some on initial startup, but it's not white smoke and doesn't smell of antifreeze. It's more bluish and smells of gas, so...but it is an older car, so I don't think this is any major concern. My dad used to have a Toyota Supra which did almost the same exact things, except his antifreeze began to get oil in it (hasn't happened to me); he had a blown head gasket. We're thinkin what's happening with my car is that I've got a slow leak somewhere, either a head gasket or cracked head/block, which is slowly as you drive pressurizing the cooling system causing it not to work correctly and overflow and/or cause the thermostat not to work as it should. I know this isn't unheard of on an ES, and I was just hopin to hear some symptoms from people who have had this problem so I can determine if it's head gaskets, cooling system, etc. <!--emo&:wacko:-->wacko.gif<!--endemo-->

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first thing I would do is when the car is cool check both radiator caps and fill to the neck. Do this over a period of few weeks. I had overheating prob on my 93 ES300 also. It takes a few toppings to fill the system correctly.

FYI...The rad. fan is propelled by your power steering fluid.

Otherwise you may have an internal leak. Have it pressure tested for leaks at any shop.

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I've been doing that but it doesn't seem to make much of a difference; once the car heats back up, it just boils whatever I've added back outta the reserve tank. <_< I'm REALLY hopin that it's not as serious as a head gasket, but it could be. One thing I'm still worried about is the coolant; I'm using that orange dex-cool stuff and I'm not sure if I should be. I've seen many an argument here about this in the past, but have never seen a real solution...I bought a jug of the OE Toyota red stuff-what came outta the car when I first replaced the coolant way before I had to replace the radiator. I don't think I'd mixed the red and orange together b/c I ran straight water in the system for some time before puttin the orange in. I just don't wanna put the expensive Toyota antifreeze in it if I know that it's just gonna overflow; it's like flushing money down the toilet the way I see it, unless the stock antifreeze has such a large affect on the system that if I used it, all my problems would be solved, which I highly doubt. Another thing I forgot to mention was that it never once has "overheated" (i.e. steam and water boiling outta the radiator or engine). It just sorta spews randomly fluid outta the reserve tank and gets really hot. Power steering fluid is normal, and no noises coming from the pump when I turn. I'm pretty sure the fan system works a.o.k. I think the next step is to replace the radiator caps; I used the one off the old radiator and had some trouble gettin it off and onto the new one, but it never once has leaked any antifreeze. After that, I guess I'll have the pressure in the coolant system checked. Keep the suggestions comin! I need all the help I can get, b/c I can't trust the car to drive right now, and I really need to fix this ASAP!! ;)

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well, try the cheap wal-mart $4.xx/gal and mix 50/50 with distilled water...to see if that helps to solve your problem...

also, when the car is heating up, try to feel the lower radiator hose to see if it is as hot as the upper hose...this will tell you whether your thermostat is working or not...

another way of overheating is timing...if your timing is more advanced/retarded than it should be...it will overheat your system...

btw, turn heat on to full blast should delay over-heating.

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I've done all of the above, and nothing has really helped; tested the thermostat, and it works fine. I can let the car idle up to operating temp. and the upper hose eventually gets hot, signifying the thermostat allowing the system to circulate as it should. I wouldn't imagine that it has to do with timing; the car idles and runs smoothly; revs quickly, not indicative of timing problem I don't think. It's always driven fine up until about a month ago starting with transmission problems, which I believe a simple fluid and filter change seemed to have fixed, and now this... <_< Any more suggestions anyone? I'm thinkin as I said head gasket problem or even possibly a cracked block or head; this could be it in that as the engine heats up (driving it for a while) the crack gradually expands and forces air into the cooling system and fluid outta the overflow tank. Air in the system could throw off the operation of an otherwise properly functioning thermostat as well...

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I've been finding all over the web people with the same problems, and everyone tells them the same; head gasket or cracked head/block... :unsure: I was hopin for an easy fix. <_< Any more suggestions are still welcome! Speak your mind! I need some help here! :rolleyes:

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Ok.... the BOTTOM hose is the one that tells you if your thermostat is working, not the top one.

When is the last time you changed your water pump? - could be a problem.

To check the water pump, get engine to normal temp and squeeze the top hose. If you feel a

pressure surge as you release the hose, then the pump is working fine.

Also, if you had the green stuff in before without any problems, then you should have stayed with it.

I also read all of the posts on the debate over antifreeze, but I've had the green stuff in forever

and it never has done me wrong. I have a 92 - same engine as yours. The orange stuff works better

in the 94 and later model engines as they are aluminum, not steel like ours.

Only other thing is to get it pressure checked and looked at by the dealer. Good luck!

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if you have a leaky gasket...it can be checked with compressed air...

method:

* remove spark plugs

* set cylinder to TDC

* use an adapter and thread it the spark plug hole, and force in the compressed air

* listen to see if you can hear anything in the exhaust manifold...and if you do...you have bad

lucks (either the rings or gasket or valve is your problem.)

and, if you don't have access to compress air, the least you can do is do a

compression test....that will tell you if you have a leak or not too...

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Thanks a ton guys; I'll try that stuff out soon, and yes su24 you're right about the hose being the lower one. I haven't checked the pipe itself, but I have removed and tested the thermostat against a new one and it works just fine; within specs too, so I doubt that it's it. And it had the red Toyota longlife antifreeze in it originally, which I have more of but am afraid to use b/c it'll just boil over..I'll try the compression tests and see what I come up with.

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Your problem may be that your power steering pump may be going bad or leaking.Your probably asking yourself what does the power steering pump have to do with the cooling system. Strangely enough Lexus has the power steering pump and your cooling fan connected together. My return hose on my power steering pump was leaking and it was causing the fan to not spin fast enough to cool my car down, therefore the temp gauge would fluctuate, but not overheat. Usually the gauge would rise when I am driving at low speeds or stopped and the gauge would go down when driving at high speeds. I replaced the thermostat, radiator cap, water pump, heads inspected for crack head, and a rebuilt power steering pump. To check for leaks locate your power steering pump and make sure its not leaking. If it is not leaking then the problem is most likely with the hoses. I ended up having to replace my return hose which cost 100 bucks and only Lexus sells it.

Layne

To get rid of that white smoke replace your valve seals and adjust them while your at it.

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LBINH posted-FYI...The rad. fan is propelled by your power steering fluid

This is not true, fan is propelled using Power Steering Pump.

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djlai,

Just curious, what powers the power steering pump then? :huh:

Another leak check is to see if your oil has a milky appearence. Check the dipstick or check the oil on your next oil change if you can wait that long. It may signal a gasket leak or engine block fracture. Otherwise get a coolant pressure test for peace of mind. Good luck LEX3486. I have been there as you with the cooling system problems on my 93. :cheers:

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Lbinh,

I was just being more specific to the actual part because it may cause some confusion and the user may only replace the fluid.

layne

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I was just being more specific to the actual part because it may cause some confusion and the user may only replace the fluid.

Hey, no probelm, I don't mean to sound rude Layne. I was implying that there could be a P/S fluid leak and to check the P/S pump's operation. Always good to be specific though.

:cheers:

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The power steering has always had a sorta constant "whine" to it, but it's not the sound that they make when the fluid is really low. It's not quite that loud, but it never goes away. Also, in corners, I've noticed the steering has the slightest fluctuation in it; by this I mean that you can just very slightly feel it shaking, and every once in a while the steering upon cornering feels like it's almost locked in one position, but I think this in particular is the feeling of slight understeer, something I'm sure we're all familiar with. I've noticed this same noise and feeling on my moms' 96 also, so I assume it's normal...? I know my 92 didn't do that. Visually, I'm havin a hard time tellin if the pump is leakin for two reasons; one is that there's antifreeze all over everything on that side of the engine on account of the overflow tank overflowing, and two, it's extremely hard to see anything in there in general, especially on that side of the engine. But I haven't ever noticed the car leaking anything of any kind nor is the fluid level low. The fan runs at a pretty good speed right now when the car's just idling; I assume this speed is normal b/c it's not too fast but it still moves a good amount of air at idle speed, plus the fan operates faster when it begins to overheat, so I guess I'm assuming that it's workin right. Is there any way to test if the fan is operating at the right speed? As for the oil, it's perfect; no condensation on the dipstick, no milky appearance. I haven't replaced the radiator caps, and yes there are two. I guess that's the next step really, but I'm extremely doubtful, reading other people's experiences here as well as other places, that this will solve anything. I guess it's still a good idea; just another step in the elimination process I suppose. I'm just lucky that I've got the Land Cruiser to drive!! :D But I still wanna fix my car ASAP <_<

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Well, I started the car for the first time since Monday today (had to charge the dead battery-another problem I've found) and it didn't run worth a :censored: . It idles terribly rough, as if it has a miss, and it's started smoking white smoke, which smells an awful lot like antifreeze, and spitting large amounts of fluid outta the tailpipe when I rev it up, this fluid smelling suspiciously like antifreeze. Yep, don't think there's much doubt at this point what my problem is... <_<

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if there is lots white smoke...then your oil is milky...then sure you have a bad gasket....

but some white smoke is probable if you car has sat for a few days...and it is wet and cold outside...

car may also idle poorly if bad battery/ground/alternator....

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Well it was cold out but the car was driven around for a while before, so as to warm the engine up, and it still smoked; the smoke not only has a white color but smells like antifreeze to some extent. Also, when I let it idle for a while, I get lots and lots of condensation on the bumper, signifying lots of moisture in the exhaust gas, and the pipe starts to spit water out when I rev it too. The miss doesn't seem related to the battery b/c it was fully charged for a day or two before I noticed it, so...I'm just gonna have to tear it down and see what's up. I'll keep everyone posted, and thanks for all the help so far! Please stick with me as I tear it apart, as I'm sure I'll have more questions once I get into fixin it. :ph34r:

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Maybe i can get you a smoking deal from this local guy on a engine and tranny as he has tons of 92-93's and it would be cheaper on labour as you wouldn;t have to use a hoist and support the engine to remove the tranny .

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Well actually, we were hoping that it could be done without pulling the motor; mcelligott sent me pics of his while it was being rebuilt and it was done in with the engine still in the car. I know it'd be much harder to do, but it just seems like less work, plus I'd be sorta wry of replacing the entire engine with one that may develop the same problems over time...I'll keep that in mind though. If I were to do that though, I'd wanna go ahead and make it a manual...I think I'll just fix what I've got for now and eventually get a SC300 5 speed; I'd rather do that then invest in making the ES a manual. B)

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