1993 Honda Civic overheating

[arthurwait]

Just to clear something up for a couple of posters. Yes a lean mixture will cause an engine to run hotter, but not hot enough to blow a head gasket or crack a head.

Overheating after 15 mins from cold sounds like a faulty thermostatic fan switch not bringing the fan on.

Glad all is well eventually.

http://www.enginebuildermag.com/2009/10/uncovering-the-culprits-that-cause-head-gaskets-to-fail/

http://www.aa1car.com/library/gasket_failure.htm

http://www.ask.com/technology/causes-blown-head-gasket-b05975f2a2183236#full-answer

http://www.doityourself.com/stry/5-causes-for-a-blown-head-gasket

[ClareQuilty]

Been driving the car a great deal the last two days, and I can say it seems very good. Funny thing is, it takes a very long time for the car to get warm now.. I guess he may have overdone it a bit, perhaps a lower temp thermostat or something? Now it takes about 5-6 kilometers of driving before the temp gauge even budges at all from cold. It eventually gets to normal operating range, but only after driving a lot.

I'm happy with the repair so far.. if it holds up a couple-few years I'll be very happy. The car's a joy to drive compared to my Soluna.

[JAS21]

Been driving the car a great deal the last two days, and I can say it seems very good. Funny thing is, it takes a very long time for the car to get warm now.. I guess he may have overdone it a bit, perhaps a lower temp thermostat or something? Now it takes about 5-6 kilometers of driving before the temp gauge even budges at all from cold. It eventually gets to normal operating range, but only after driving a lot.

I'm happy with the repair so far.. if it holds up a couple-few years I'll be very happy. The car's a joy to drive compared to my Soluna.

I very much suspect that there is not a thermostat fitted AND from reading previous I also suspect that there never was a thermostat fitted either. I suspect someone removed it in an attempt to stop the overheating ... get it checked and get one fitted.

[ClareQuilty]

I very much suspect that there is not a thermostat fitted AND from reading previous I also suspect that there never was a thermostat fitted either. I suspect someone removed it in an attempt to stop the overheating ... get it checked and get one fitted.

Oh, I didn't know it was possible to do without one. The car warmed up correctly before the repair - that is, during the few weeks I had it before it overheated, it warmed up quite quickly and then held at normal operating temperature, so I'm pretty sure it had one at that time. Perhaps he removed it during the repair.

[WarpSpeed]

Just to clear something up for a couple of posters. Yes a lean mixture will cause an engine to run hotter, but not hot enough to blow a head gasket or crack a head.

Overheating after 15 mins from cold sounds like a faulty thermostatic fan switch not bringing the fan on.

Glad all is well eventually.

I agree with that, for my part though I confirmed the question of the poster who questioned, I believe it was Author, never said it could get hot enough by itself from being too lean, it can however cause the engine itself to over-heat, lose water, continue to get hotter if not replenished and THAT can cause the head to warp or crack (though as I mentioned earlier and it turned out to be the case that it wasn't cracked as it is less likely with an aluminum head because they flex more being softer metal hence the more likelihood of warping instead). All damage is always a series of several events in a chain reaction and it's the forensic process that eventually gets to the actual culprit. Lean mixture for a long time can also burn the exhaust valves however.

Edited May 17, 2015 by WarpSpeed

[WarpSpeed]

Been driving the car a great deal the last two days, and I can say it seems very good. Funny thing is, it takes a very long time for the car to get warm now.. I guess he may have overdone it a bit, perhaps a lower temp thermostat or something? Now it takes about 5-6 kilometers of driving before the temp gauge even budges at all from cold. It eventually gets to normal operating range, but only after driving a lot.

I'm happy with the repair so far.. if it holds up a couple-few years I'll be very happy. The car's a joy to drive compared to my Soluna.

Should be to temp before you drive it 5-6 kil. Meaning you should be waiting for it to warm up properly, but in much of Thailand most times of the year you don't really even need a thermostat except to create turbulence in the water to help with heat transfer. In our stock based racing engines, running in Thai atmospheric temps, we just used the outer portion of an old thermostat to impede the flow a little and cause some turbulence, we never used thermostats, so they're not really even necessary in most of that climate except maybe the more extreme northern provinces in winter and even then not so much. I'd not worry about it, just give it a few more minutes to warm up first before driving it.

Edited May 17, 2015 by WarpSpeed

[ClareQuilty]

I'm going to sort of take both Jas21's and WarpSpeed's advice - I'm too broke now (unsurprisingly after a 14,000 baht repair) to do anything more, and the car is going OK in the current extreme hot weather. However, I'll certainly replace the thermostat by about October when we begin to have quite cool temperatures at night up here in Isaan. It can get down to 15 or even less many nights during the 'winter', and I tend to drive the car more at night than during the day.

[DavisH]

The mechanic.

A head has to be removed and refitted in sequence and stages with a torque wrench or it can bend.

Seems odd they wouldn't know about that - they do these head jobs at least once a month: I've seen them doing them, and had friends who had them done there..

It's very easily done if you get slack or try to rush it.

I keep telling the missus that but it just falls on death ears

Edited May 19, 2015 by DavisH

[Lancashirelad]

Just to clear something up for a couple of posters. Yes a lean mixture will cause an engine to run hotter, but not hot enough to blow a head gasket or crack a head.

Overheating after 15 mins from cold sounds like a faulty thermostatic fan switch not bringing the fan on.

Glad all is well eventually.

http://www.enginebuildermag.com/2009/10/uncovering-the-culprits-that-cause-head-gaskets-to-fail/

http://www.aa1car.com/library/gasket_failure.htm

http://www.ask.com/technology/causes-blown-head-gasket-b05975f2a2183236#full-answer

http://www.doityourself.com/stry/5-causes-for-a-blown-head-gasket

Don't have time to read all those linked articles in detail but on a quick scan through they all seem to be saying the same thing, namely that blown head gaskets are often caused by overheating. I fully agree with that and have replaced many on customers cars in the past.

What I said was a lean mixture alone will not cause the engine to run hot enough to blow a gasket and/or warp a head. What it might do is cause pinking (pre detonation) which in the longer term can cause other damage such as a blown gasket and as Warpy says, receeding exhaust valves.

[arthurwait]