Head gasket or no?

[wwalter]

Spector,

Wow, that was a quick response--guess it's good to put up new topics around lunch time!

My understanding of the process is that, as the system cools down and the fluid returns to its usual volume, a partial vacuum will form in the cooling system and that this will pull fluid back from the expansion tank if everything's working well. The reason a head gasket leak can be a suspect in this case is that the vacuum may not form due to combustion gases keeping the C/S pressure too high (or, I guess, if the pressure does fall, it may pull air in from the combustion chamber instead of fluid from the tank--and similarly for a rad. leak, only the gas comes from the outside air.)

(All--I admit I'm a bit hazy on the above, so if I'm wrong about that, let me know.)

The overflow hose seems fine--I blew through it and there's no apparent obstruction. And there's certainly no problem getting the coolant *into* the tank.

As for the pump, it's a possibility, but nobody's looking in that direction, being convinced that it's the gasket.

Off to a meeting... Talk to you later.

Edit: Oh, and as for the overheating itself, I don't know--various people have just told me that it can be a sign of a bad head gasket. I'm not sure I know what the proposed mechanism behind that is... Maybe just the addition of excess heat from the c-chamber?

Andy

[ May 05, 2003, 02:04 PM: Message edited by: wwalter ]

 

[Smoky14]

With precious little info to work with, I would try a new radiator cap first. It is possible to have combustion chamber leak into the coolant without getting coolant into the oil btu it is rare.
Try a cap.

 

[Drew99GT]

Real simple to diagnose: either buy a leak down tester or have a leak down test performed by a competant mechanic. Or you can sort of make your own if you already have a compression tester. You can just use the spark plug fitting on the compression tester to rig up to an air compressor. Put each cylinder at top dead center and fill it with compressed air, with the radiator cap off. If any cylinder produces bubbles in the radiator, bingo, it's your head gasket. I'd just find the best mechanic you can to do the job; it's really freakin easy on a Honda 4 banger and mechanics like that!!!

If I were you, I'd just get the G35, but I would teach your wife to drive stick because those cars are bad *** with a 6 speed.

 

[wwalter]

Smoky,

I just did replace the cap, and it didn't have any effect on the expansion tank situation. I'm not sure if it helped with the overheating, since that's highly intermittent anyway.

Drew,

Yup, that test sounds like a useful one. I don't have an independent shop that I fully trust at the moment, and the dealership folks are already convinced by the HC... I'll follow up on this possibility, though.

Oh, yeah--I'm not mechanically competent, unfortunately, so I wouldn't trust my car in my hands, beyond the occasional oil change

In other words, I think I know what TDC, etc mean, but I would have no idea how to get a piston into that position (sweet-talking it

?)

Ya know, my wife has been fine not driving my current car, so... I like the 6-speed idea!

Andy

[ May 05, 2003, 04:31 PM: Message edited by: wwalter ]

 

[Drew99GT]

Hell, you may want to hit up honda-tech.com and see if there's any peeps in your area that would be willing to take a peek at your car for a case of beer or something. Seriously, some of those guys are the best mechanics I've ever seen; they KNOW the tips and tricks of doing extensive work on honda motors and they know how to do it right. If you go that route, you could do a bunch of stuff like new water pump/timing belt etc. at the same time as all the components needed for those changes will already be off the motor. And it would still end up being cheaper than going to a mechanic.

 

[labman]

My truck went several years not sucking coolent back into the radiator. Then the head gasket blew. With a new head gasket, it has gone several more years with the radiator staying full.

Note, the over flow tank is something I added years ago. I made it out of an old Prestone jug. Nothing but the best for my truck.

 

[Drew99GT]

In addition to a leak down test, a pressure test of the cooling system may also confirm the head gasket as being bad.

 

[wwalter]

All,

I'm trying to figure out if my head gasket is going bad.

Chief symptom indicating YES: Excess coolant remains in the expansion tank after the car has completely cooled down (overnight)--I have to pour it back into the radiator each morning. There's still some in the rad, too, but I get intermittent mild overheating at high speeds, and refilling the radiator seems to cut those incidents down quite a bit.

Chief sign indicating NO: Recent oil analysis showed no convincing signs of water or antifreeze and reasonable levels of NA and K for the oil used. See the report in the used oil analysis section, topic Red Line 10w30, 94 Civic, 260K

Supporting evidence for YES: Dealership looked for hydrocarbons in the coolant and found a low amount. They now believe the head gasket is an issue. Question: I recently added some Red Line WaterWetter to the cooling system to bolster its cooling ability when I forget to refill the radiator; I threw away the bottle, but I wonder if the product contains petroleum distillates or any other compound that may be detected as hydrocarbon. I'm trying to contact RL as well, but I'd appreciate any info.

The dealer also says "it may run another 100K that way," and I'm wondering how likely that is. Maybe I should wait a couple Kmi and retest the oil before deciding. I'd hate to have the head gasket replaced unnecessarily--it involves rental cars, mucho dinero, and my wife's objections (She'd prefer a new car with automatic, so she can drive it. We're both tempted by the Infiniti G35, but my cost-conscious side just won't play along.)

I'd also appreciate any tips on what to do if this last hope doesn't pan out and I do need a new gasket. Bror Jace, I know you had such a problem recently, and I seem to recall the car was never "right" again... Any details of your experience: cost, time, any warpage or other damage to the head, what wasn't "right," etc.??

Thanks,
Andy

 

[Spector]

The very strange part of your description is that the overflow tank is not sucked dry by morning but the radiator is not completely full when you pull the cap. This implies that the overflow hose may be plugged, problem with radiator (possible leak) etc. A bad head gasket would not cause the overflow tank to remain full after the engine has cooled off, it should drop back down to the cold level. Certainly another analysis is less expensive then a head gasket which may not be worth the cost depending on value etc. Also, overheating implies a pump issue, radiator issue etc. not a head gasket leak.

[ May 05, 2003, 12:51 PM: Message edited by: Spector ]

 

[wwalter]

Update:

I had the head gasket replaced yesterday. Sure enough it was bad--and in more than one spot, they tell me. The head itself was fine--no warpage or other problems.

Apparently, early-mid '90s Civics had an issue with the HG and many have needed new ones at unreasonably low mileages (140-150K). I'm not at all upset that, at 260K, mine finally went up.

For what it's worth: The techs were impressed with the condition of the engine and, I think, its cleanliness also. I had just finished a 2nd course of Auto RX before taking it in, and that may have contributed. Service writer ventured an unsolicited guess that the engine might be good for 400K.

I'll be continuing for now with the conventional oil they put in as part of the 270K service (had this done while they were in there), and may use my last bottle of Auto RX as a final flushing of any gunk that may have resulted from the HG leak(s). Then I'll go back to Red Line 10w30 and try another analysis around 5-6K, both for curiosity and to be sure the twain (oil & coolant) haven't met again.

Oh, and I asked them about the 5w20 oil now recommended for new Hondas. They never use it; strictly 5w30.

quote:

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Labman: Note, the over flow tank is something I added years ago. I made it out of an old Prestone jug. Nothing but the best for my truck.

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Why do some systems not find it necessary to have the tank, anyway? Anybody know?

Andy

[ May 14, 2003, 04:38 PM: Message edited by: wwalter ]

 

[RussellA]

quote:

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Also, overheating implies a pump issue, radiator issue etc. not a head gasket leak.

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Actually exhaust gas in the coolant system can cause an airpocket to form at the thermostat which acts as an insolator and makes it close, thus leading to overheating. Unfortunately I've had this happen to a car.

 

[labman]

I think they skipped the over flow tank for the same reason it had breaker point ignition, rubber floor mats, AM only radio, vinyl seats, etc. It was a cheap 77 truck.

I have made several upgrades, but still have the breaker points and carb.

 

[Drew99GT]

So you found a mechanic that you trust? It's good to hear!!

 

[Drew99GT]

quote:

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Originally posted by RussellA:

quote:

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Also, overheating implies a pump issue, radiator issue etc. not a head gasket leak.

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Actually exhaust gas in the coolant system can cause an airpocket to form at the thermostat which acts as an insolator and makes it close, thus leading to overheating. Unfortunately I've had this happen to a car.

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Plus, if your cooling system doesn't hold pressure from the head gasket, it will lose efficiency like crazy, leading to overheating.