88 Camry: is engine cutting out from overheat?

The water shooting out of the radiator is a bad sign I'm afraid to tell you. It only happens when there is compression leaking into the water-jacket, pressurising it and then under this extra pressure, the water literally tries to get out where ever it can, and an open radiator cap is where it will gush out.

The water-pump is designed to *circulate* or move the water around the cooling system. In a normal cooling system, bring the engine revs up will actually cause the coolant in the radiator to drop slightly as the water cools more and the water reduces in volume.

As to the engine itself, the fault maybe a blown headgasket, and-or a cracked head. If the compression loss is great, the level of coolant in the overflow storage resevoir will fill up when the car is running, and then drain itself back into the motor to replace loss coolant which has been sucked into the cylinder. A blown head-gasket works both ways ie on the compression stroke, compressed air/fuel and exhaust will be forced into the coolant on the compression, power and exhaust stroke while on the intake, coolant will be sucked into the cylinder concerned causing a miss if the amount of coolant is great enough.

Just to confirm, your engine should be losing significant amounts of coolant? And running hot once the coolant level drops sufficiently. It should also be losing power and running rough? The pump bearing may well be noisy and should be replaced while doing the head-job.

Jason

How does the oil look is it milky from water, is any water vapor comming from the exuast To loose power when hot sounds like it is loosing compression or as Jason said water might be getting in a cilinder

The oil is not milky, it looks like honey, like new oil. See no water contamination in it. There is not water coming out of tail pipe, or steam. It runs perfect for a while, all cylinders firing OK, plenty of acceleration, for the first 5-10 minutes or so. Today, when I drove it around, it was fifteen minutes before it lost power, and I noticed the temp higher than normal. There might be some tiny coolant leak, but I haven't had to add water. As I watch engine at idle, once every few seconds a puff of white smoke or steam is coming off the exhaust manifold....like there is a slow drip of either water or oil onto it. When my van blew a head gasket and was leaking water into one of the cylinders, it would run very badly from the very start, and there was lots of water and steam at the tail pipe. But if it turns out that the head gasket is blown or the head cracked, then Ill have to turn right around and sell it as is, cause it doesn't make any sense to get a loan to put a new engine in an 88 model.

Well, when the engine is cold/ firsat started, and the thermostat is closed, wouldn't that ALSO force water out of the opened radiator cap as you rev the engine?

Does the computer maybe cut back fuel and revs when it senses overheat?

Thanks!

On Sun, 16 Apr 2006 20:43:59 -0500, snipped-for-privacy@webtv.net (m Ransley) wrote:

The thermostat starts to open about 10F below its rated figure of operation. If its not open, revving the engine will produce little reaction while viewing the radiator water thru the cap-hole. The reason is, all the heat is generated in the block and head waterjacket, not in the radiator *until* the T/stat opens allowing hot coolant to flow thru the radiator.

Not in Camrys. Some Fords limit the number of cylinders in use under an overheat condition.

I realise its difficult sometimes to diagnose cooling system problems. But taking into acct the previous owner replaced the radiator, then you are left with the t/stat and the head-gasket and-or head cracking. As the car is old, I'd be tempted to remove the t/stat and take it for a longish run. If it remains cool over say 50 miles, then it's a cautious bet the removed t/stat maybe unserveable. They can remain only partially open after long service. Water-pumps almost always keep pumping except inrare cases where the pump's impellor free-wheels on its shaft. See how the car runs without the t/stat before it overheats, if it overheats.

Jason

Does it run on 4 cilinders when it slows down or is it missing.

I think all four cylinders are still Ok even when it has lost power down to walking speed. There is not a roughness like only a couple of cylinders firing, it just has no power. And like I said, my little ignition-tester is still showing a strong/normal voltage pulse on each spark wire. Its like the fuel is being cut back. I tried to remove the thermostat today, in order to run the car a while without it.... but was unable to. I did find that with all the run time put on the car yesterday, that the water level did not drop the slightest amount. The system is tight in spite of it running quite hot. I am guessing the temp needle should not have gone over about mid-scale, at least that is the case with all the cars I have owned. Someone told me that their Camry did the same thing as far as losing power after a few minutes....turned out it was a bad computer. But they didn't say anything about it also running hot.

Was prevented from taking thermostat housing loose from the block by that 15 mm bolt projecting back from the top of the AC compressor, and the oil filter. I am @#^%$@#&^@#$&^#$#^% with this engine...it seems that you can't do much of anything on it, not even remove the filter, without a special tool. Where can I get an oil filter removal tool for it? THis filter is like half the normal size of a filter!

Thanks, Geronimo

On Mon, 17 Apr 2006 07:19:02 -0500, snipped-for-privacy@webtv.net (m Ransley) wrote:

Maybe a bad fuel pump, but how could it relate to overheating?

Um, you've never replaced the oil filter?

Car temp-gauges are not what you would call precision-calibrated thermometers,..they are at best an indication which you refer back to if the gauge is reading differently. Having said that, 99% do not read in the "red" when the car is normal temperature.

Headgasket leaks which allow coolant to get sucked into a cylinder (s) and vice versa allow compression to super- pressurise the water jacket,.*vary* from a very small leak to a catastrophic leak. Some engines will go for a long time with a small leak, but, they always get worse.

If you fill your radiator with water when its cold, leave the cap off, start it, then let it idle for 15 minutes. In that time some water will spill out due normal expansion. What you look for after the heat-up, is any gushing of water out the radiator cap-hole when you lift the revs to 2000 rpm. Sustain those revs for a minute,..if there is a leaking or cracked head'gasket, the water will keep pushing out the radiator in relatively large amounts.

If the fault IS the thermostat and not the head/gasket, then the water will get very hot and start to blow out under steam pressure. Great care needed not to get burnt.

If you still want to try removing the T/stat,..its not a hard job. There are inexpensive oil-filter removal tools which accomodate the smaller filters. You should have a new gasket or a tube of silastic to reseal the t/stat housing when putting it back. Its not a big deal, and if you are just starting to work on cars, this job is one of the easier ones. A set of cheap sockets and wrench will suffice for this job.

Jason

"geronimo" wrote: "After about ten minutes of driving the engine loses power." ======================== Sounds to me, like the coolant temperature sensor may be malfunctioning. There are actually two sensors. One sends data to the temperature gauge on the dash, and the other (the one you're looking for) sends information to the engine control computer to regulate fuel delivery. If the engine runs fine when cold, but loses power as soon as it warms, I suspect that temperature sensor. Should be on the water outlet near the head with a green color top near the connectors. Check for linear change in resistance over a temperature range - like with an ohm meter while heating in a pan of water on the stove. No need to boil the water, you're looking for a range from room temperature to 180* F.

Got a oil filter wrench for this oil filter, and once off, was simple to get the thermostat removed. Yep....it was a thermostat stuck closed that was causing overheat. Now the temp gauge never goes over about 1/3 of full scale. For 20 minutes at a high speed, car not moving, engine stayed at constant temp, so a new thermo will fix overheat problem. But....I then drove it a couple of miles, and engine cut back to walking speed again. It wasn't the overheat causing it at all. But I think I know what it may be. The starter would not engage when I first got the car. Had an idea it was a bad neutral start switch. So I have temporarily removed the neutral (actually PARK) safety switch, and bypassed the two large contacts at the conn. for the safety switch function. This fixed the starter problem...it is the starter lockout contacts that were bad. I took apart the switch and all the contacts were darkened and coated with black grease. I cleaned them up ....nice and shiney again...so I think the neutral start switch will work again fine. But I don't have it reinstalled yet. So the question is.... there are other lower-current contacts on the switch which I think tell the computer what gear the tranny is in. Maybe, in addition to the starter lockout contact being bad/open, the contact for the "tranny in drive" signal was bad/ open, too? And since I haven't jumped any of the gear position contacts, the computer is still not getting the "tranny in drive" signal, maybe causing the loss of power after driving for a little while? Would the computer do this? Funny thing is that there is no check engine light coming on.

If its not related to the missing gear position switch signal, then there is some serious problem. Maybe computer IS bad, or car is losing fuel pressure. The spark, I found out, is remaining strong.

Thanks, Geronimo

On 18 Apr 2006 06:34:12 -0700, "Daniel" wrote:

At this stage, given the difficulties of communicating via the Net, your theory should be pursued. He did say the gauge was near full scale, and despite him also saying the water gushed out of the radiator,.I'm not all that sure he has a genuine overheat. Further however, if there are 2 sensors, one for the gauge and one for the Computer,..why would both fail at once? Its possible I guess.

Perhaps he can get a replacement from a breakers (wrecker's) yard to try...

Jason

Daniel has mentioned a second coolant sensor which feeds temp info to the computer. I'd leave the T/stat out for the moment and pursue his remarks.

Cant see how this would effect the injector shutdown condition. Have you read Daniel's remarks? Its possible you have 2 faults. We can assume for the moment, the overheat has been bandaided by removing the t/stat. Now can you replace the sensor Daniel mentioned? Do you have access to a wrecking yard?

Also back to the t/stat for a moment:

All automotive thermostats will be closed at ambient temperatures, such as removing it from your car. You need to heat it to check its performance.

You can test that thermostat by heating it in water on a stove. As the water starts to reach 200F (water boils at 212F), bubbles start forming in the saucepan. The thermostat should have started to open well and truly by this point. If it hasn't, it is stuffed.

It might be the computer or another electronic component since nothing else sounds like it would affect what you describe, ive had similar electronics fail only when the motor and everything is fully hot

Well, I am really in a bad spot now, then. Something has to be shutting down the fuel flow when the car has been driven around for a few miles, and you say that the absence of the "drive is selected" signal (neutral safety switch is not installed) won't cause the computer to shut down fuel like this....so it looks like I need to try a new computer. I had already been running the engine for 20 minutes at high speed, and temp had stabilized as high as it was going to go, no matter what RPM you ran it...before taking off on a short test-drive. So the cutting out happened well past the point when it had reached operating temperature! A new/rebuilt computer costs about $200, and may not be the fix. How can I try one from the wrecking yard, when it is totally unknown if its any good? So I spend $200, which I don't have now, and could find that it is money thrown away, still have a broken down car. Does the fact of not getting any check engine light (although self-test when turning on power is good) when the engine cuts out point to a bad computer? Wonder if AUtozone can read the codes for Toyota Camry, as they do for free for many cars? Nope...can't do that...it wouldn't go that far and is unregistered, too. NOT GOOD!

On Tue, 18 Apr 2006 17:24:02 GMT, "Jason James" wrote:

Maybe they can let you borrow an OBD reader.

Can you call them / ride there in another car / get a ride?

When the engine loses power, does it do suddenly or does it come on gradually? If it comes on gradually, there maybe fuel delivery issues like a blocked filter or crud in the tank.

Next time it dies,..remove one battery cable for 20 mins, to see if a computer reset does anything. I assume that will reset the computer?

Jason

I have NO real Idea what your issue is and am not saying its the computer, I would not just buy a computer, I would figure out the issue. A 50$ test on scope by a mechanic might find it. My issue with a computer was simply not firing a cilinder. You dont describe it well, do you just loose power, or does it run rough-miss firing cilinders? How much power does it loose, when does it come back? Does it run smooth when power is lost? Does the motor seem to have power but the trans might be the issue? I have had motors nearly shot that loose the last part of their compression when warmed fully, loosing power, what is your compression hot and cold.

Can a Fuel Pump when warmed up loose power? Probably, the bearings or a bad winding in the pump motor might do this. You could check fuel output of the pump cold and when this occurs, there is a Gallon per minute output rating, and a minimum needed, also a lb. output.

Does enging timing remain the same hot and cold, this "might" be possible by the computer retarding timing when hot but I dont know if it could have the negative effect you experiance. retarded timing will reduce power but not make a car powerless. Loosing power could be fuel pump, coil-maybe-slightly, Differential, transmission, air control valve, emmission system, [ maybe computer] but only to do this when fully warmed? Id look into compression, and fuel pump first. Talk to a Toy mechanic, I am not one. Buying an old car is " buying someones headache" .

I would first try the fuel pump output pressure and flow, then compression, then??.

As far as the symptom: over the space of perhaps 1 minute, it is going along with full power...then you notice it gets jerky/intmt cutting out when you are accelerating from a stop, and in about a minutes' time you are crawling along and only have walking speed with the accelerator floored. So it is not exactly instantaneous. If you then turn the car off and sit for 10 minutes, it will then start up normally and have full power again, but for an even shorter time before it loses power again, I guess because it is still warm.

I bought a fuel pressure gauge not too l> I have NO real Idea what your issue is and am not saying its the