New Mechanic

[monroe74]

I want to echo Gary's concern, but also offer an encouraging anecdote.

Yes, overheating is a Very Bad Thing. Running without coolant and/or running without oil are two excellent ways to ruin your motor. And it can happen very quickly.

But sometimes you get lucky and a motor is incredibly resilient. Once when I was 17 I borrowed my dad's 1962 Studebaker Lark. 4 doors, straight 6. Automatic, I think two speeds.

I visited some friends about 30 miles away. I got into a collision. Basically head-on, at fairly low speed. Just enough force to crunch the grill and the radiator. Some damage to the hood. The radiator was totally ruined. It completely lost its ability to hold water. It was Swiss cheese. But other than that, the car was very drivable. Just enough space left between the radiator and the fan for the fan to spin with no interference.

My options were very limited, and I decided to drive home. It was summer. I prepared by putting lots of water jugs inside the car. I started by pouring a bunch of water in the radiator, even though it immediately started leaking out from a dozen holes. I jumped in the car, started the motor, and started driving. I drove for 5-10 minutes, and watched the temp gauge rise rapidly.

I ran the heater full blast, to help cool the motor. The heater would get very hot, and then it would quickly turn cold. I knew this meant that there was no water left in the cooling system. I did a last burst of acceleration, and then I did some EOC.

I drove with the hood partially unlatched, in order to ram some cool air over the engine.

I coasted to the side of the road, and raised the hood. I could feel waves of heat radiating off the engine. There was hardly any steam, because the water was all gone.

I poured some water directly on the engine. I knew I could crack it this way, but I tried to be careful, and I figured it would help. The engine was so hot that the water sizzled off instantaneously. The engine seemed to be almost red-hot.

I stood there and stared at it for a while, and then I repeated the routine. I think it took about two hours to get home.

You know the rest of the story: I gave the car a radiator, and I did some bodywork, and then we drove it for years, with no sign of any engine damage whatsoever.

I hope you'll be this lucky. I guess the odds are 50/50.

[Ford Man]

It would probably be to you advantage to have the mechanic drain the oil and check it for water before doing any repairs. If there is water in the oil you definely have a blown head gasket. If not maybe you got lucky. An oil change won't cost you much more and might save you a bundle. Good luck.

[mrmad]

Originally Posted by Ford Man

It would probably be to you advantage to have the mechanic drain the oil and check it for water before doing any repairs. If there is water in the oil you definely have a blown head gasket. If not maybe you got lucky. An oil change won't cost you much more and might save you a bundle. Good luck.

Since the Honda engine is an open deck design, you can have a blown HG without coolant in the oil. So having the oil clean does not mean the HG is not blown

[Otistheminivan]

Okay im going to chime in hear. As some that runs a Radiator shop. If you were to bring the car to me. Let me break it down. Rad $157, T-stat $15, Labor $171.35 2.3hrs, $15 Anti-freeze sub-total 358.35 tax 29.07 total $392.42.

From where Im sitting 500 bucks is kinda high. But we are all in the business to make money and I will be the first person to tell you that you can save a bunch of money if you can do it yourself. But from some of the issues that you have told me the first thing I would do was to verify that the motor is still good. Anytime the end of the hose falls off the neck of the rad the little lip of neck is melted or broke off. Then after the next overheat the rad is leaking from the fillcap area. I would say the car got low enough to make steam and these type of failure are called steam errosion. Normally when this happens the car is stupid hot 275+ give or take. Engine head gaskets/heads dont last long with type of heat.

As some of you suggested that he should do a compression test, but he should also use a quick test called a block test. This is a simple test with a blue fluid that changes to yellow in the pressence of exhaust gass. Ive had too many car through the door with no issue and find that it fails the block test. If you have water in the oil or bubbling during a compression test, these are REALLY bad signs. But many car dont show this until they get really bad.

John

[R.I.D.E.]

Just hook up the radiator hoses to the new radiator, fill with coolant and pressure test the system, for a few hours. You dont even need to finish the radiator installation. If the system won't hold pressure, pull the plugs and look down into the cylinders to see if there is any water in the cylinders.

If the system holds pressure, follow my previous advice. If it wont hold pressure and you see water in the cylinders, I would seriously consider replacing the engine with one of those used engines from Japan, Thats what I would do if it was my car.

regards
gary

[Ford Man]

Originally Posted by mrmad

Since the Honda engine is an open deck design, you can have a blown HG without coolant in the oil. So having the oil clean does not mean the HG is not blown

I didn't mean it would assure there was no problem, but if there is water in the oil there is a problem. Any water could have also evaporated from engine heat and went out the tail pipe as steam.

[bowtieguy]

Originally Posted by Otistheminivan

As some of you suggested that he should do a compression test, but he should also use a quick test called a block test. This is a simple test with a blue fluid that changes to yellow in the pressence of exhaust gass.

John

thanks for confirming my thought. couldn't be cheaper or simpler IMO.

[1993CivicVX]

Gary: you are not coming across as an Ahole at all (I don't understand why you would think this) You've been very generous with your time and experience weighing in here and I appreciate it. My mechanic made it clear to me that fixing the rad/thermostat and cap was a diagnostic step and I could be sunk. I'm being optimistic that I'm going to get lucky.

Monroe: the last time the motor overheated it wasn't even that hot. I didn't feel heat coming off of it. I only waited a few moments before removing the rad cap. All the times I removed the rad cap after overheat, it never did anything too bad.. little steam or so at the worst. Gary mentioned minutes overheating to do permanent damage. I don't think my engine suffered more than seconds. I'd say 10 seconds max in the red zone (and I doubt that long). But that's not including when my friend borrowed the car. No idea how long he was driving around with needle in the red, but I would hope he would notice that? All he said was that the motor was smoking when he pulled into the driveway and he didn't notice the temp gauge (he didn't think to look!???). I consider him a fairly intelligent bloke and to be mechanically minded (at least in theoretical terms) But he was rather cavalier about the whole thing which was odd to me. Any rate I am hoping he wasn't completely out to lunch. The other reason I'm optimistic is that I drove 55 miles after the last overheat and was able to keep the temp from hitting the red line again the whole ride there--so can my car be all that damaged? But I'll know on Tuesday. I feather foot it and EOC like a champ (although EOCing a lot doesn't allow the coolant to do its job properly) I did run the heater on hot and high all the times it overheated.

[monroe74]

Originally Posted by 1993CivicVX

I did run the heater on hot and high all the times it overheated.

OK, that's a very interesting thing to know. I think it's smart and important that you did that.

Did you notice how the air felt? Did it ever get extremely hot? (I notice that my heater produces very hot air, and I know my engine runs at a normal temp, so hot air is normal. But I wonder if it ever got much hotter than normal.)

More importantly, did the air ever start very warm, and then gradually (or suddenly, for that matter) turn cool? That situation, with an overheating engine, would indicate that the cooling system has become essentially empty, and useless (useless for cooling the engine, and useless for carrying engine heat into the heater).

I think that would tend to be a bad sign. On the other hand, if you always had hot air coming out of the heater, I think that would tend to indicate that the cooling system was never completely empty. So I think that would be a very good sign.

[1993CivicVX]

it started off cool even though it was quite warm out. It took awhile (couple minutes engine running interspersed with a minute or two here and there of EOC) to get hot--but when it got hot it was very hot to the point it was burning my ankles so I put it on defroster. I imagine it was hotter than normal--this was on the 55 mile drive to the mechanic.