My stepson’s 2004 Honda Civic (~250k miles on the clock) has a teeny-tiny leak in the cooling system. We notice no water in the oil, nor any oil in the water, but he’ll lose coolant over a few days. We can drive the car, just have to add water about every other day. My SS tells me that on long (>3hours) trips, the car will begin to overheat, but around-town trips are manageable with his diligent and daily attention to the radiator’s water level. It was assumed that the coolant was leaking into the combustion chamber; we do not find it pooled on the ground or on the engine.
2 weeks ago, his dad took the car to his mechanic, and was told that there’s a leak at the head gasket. The mechanic would need ~US$2000 to do the job, yet he advised against putting more money into this engine.
We’re all considering finding a new ride for him. Buuuuuuut, they (stepson and his dad) are thinking of trying this fix, specifically the BlueDevil brand. I’m torn on how to handle it. The reviews on the web are mixed. There are enough “yes” votes to make it sound intriguing, but also an adequate number of “no” votes to scare me.
Coupla things…
If you’re losing water and you think it may be getting into the oil, you’ll find water in the oil, but not necessarily oil in the water. I don’t know if you said that backwards by accident or if you haven’t checked the oil yet.
A very small leak can make it into the combustion chamber without your car looking like a cloud factory.
Similarly, if water is leaking to the ‘outside’, it’s common for it to burn off or blow away before you see it.
If you really want to figure out where it’s going, add some dye to it, drive it around for a few days and check under the hood (at night) with a UV light*.
You can also get a combustion leak tester (some places rent them). It tests for exhaust in the cooling system and is about as easy as a test as you can do. But, again, coolant leaking to the combustion chamber doesn’t guarantee combustion by products making it to the cooling system.
My only other question is, did the mechanic verify the leak or just assume it was a blown head gasket? I’d hate to dump that stuff in the cooling system if the mechanic is just guessing based on experience/symptoms. I’d verify it myself.
And, finally, at 250,000 miles, he might be best off just topping off the coolant every few days and keeping his eye out for a new car or consider swapping the engine for one with less miles. There’s not going to be any shortage of Civic engines floating around.
it’s a band-aid which is only meant to get you as far as the nearest shop to get the actual problem fixed. it won’t take too long before it collects somewhere in a narrow passage and clogs up the works.
[anecdote] I tried one such product on an old Buick with more than 300k miles on it. To the best of my knowledge, it did absolutely nothing, good or bad, to my engine or the leak.[/anecdote]
[personal opinion] It’s worth a shot but at best, your engine is on borrowed time. Even babying the engine, sticking to local trips and watching the fluids like a hawk, it’s going to fail sooner rather than later. Start saving money for a replacement.
If you’re fairly handy with a wrench, this isn’t that complicated of a DIY repair. If we assume that it’s actually a blown gasket rather than the head itself being warped or damaged*, then it’s not a bad weekend project. Go to ALLDATA, get the info and make a judgement call. There are certainly pitfalls and you may end up having to pay someone to tow it straight to the scrapyard but you also might turn a $2000 repair into one costing a few hundred. [/personal opinion]
(* It’s a dangerous, highly speculative assumption. It’s a roll of the dice and your odds get worse the longer you let this continue. Overheating or contamination of the oil with coolant will kill this engine in short order.)
If he’s watching the coolant level, longer trips may be preferable. If the coolant is making it’s way into the oil, you need the engine to get up to temp so the oil can boil the coolant off instead of it sitting in there causing problems.
Also, if he’s topping it off, he should be sure to do so with antifreeze and water. Whether he just eyeballs it each time or makes up some 50/50 and keeps it in the car. Antifreeze not only keeps the coolant from freezing, it also raises the boiling point (so it doesn’t flash into steam) and IIRC contains rust inhibitors.
That’s a fair point and the periodic longer run to boil off any water in the crankcase is helpful. At the same time, the engine is going to fail sooner rather than later in rather ugly game of “Pop Goes The Weasel”. Do you want the engine to detonate two miles from home or two hundred? Make a choice and play the odds.
IME, and this was with just one vehicle that had other issues, it just continued to run worse and worse. It’s not that it threw a rod.
At work, our forklift is typically run for less than 5 minutes at a time. When the forklift guys come to do periodic maintenance, the oil looks like something you’d get from Starbucks.
We try to, let it sit and idle for an hour here and there, but we very rarely actually do it.
No leaks or drops on the ground but you are losing water. Try a new radiator cap. Sometimes they get weak, won’t hold pressure, and let water out.
If the water is going into the combustion chambers you should see white smoke coming out of the tail pipe. If it is going into the combustion chamber and the radiator is holding pressure then what can happen is hydro-lock. After you turn off the car the coolant system is still charged and putting water/coolant into the cylinder and then it won’t turn over when you try to start it because the water doesn’t compress. You can also pull the spark plugs to see if one looks different than the others.
Answer to OP question. I have never found any of these stop-leak products that will fix a head gasket. Some will temporarily fix a small radiator leak. And if the mechanic recommends not putting money into the car, listen to him.
Something else. Make sure when he fills the radiator, he tops off the overflow tank as well (might as well fill it all the way up). That’ll buy him some time between refills since each time the car cools it’ll suck some of that water back in.
Thanks for all the replies! He changed his oil last week and it was water-free. I submit that just to say that it appears the water is headed into the combustion chamber and not the crankcase (via oil passages). I’ll talk to him and his father this evening to confirm, but I think they (mechanic) performed testing to confirm the leak. I’ll try to gather more info.
Also, we replaced the rad cap over the winter. A cheap, though fruitless, investment.
Something else you can do, for free, is go to Autozone/O’Reilly (or whatever you have around) and rent a cooling system pressure tester. It’s free and if it’s leaking to the outside, it’ll be really easy to spot. Plus, it’s easier to look for leaks when the engine isn’t running and hot.
Probably because if you overfill the overflow tank, the surplus will simply spill out onto the road. It’s not a mechanical problem, it’s just a waste of coolant.
True, but in this case I wouldn’t worry about it. Not only because it sounds like excess coolant is going somewhere else, but also because it’s that much extra coolant you have as a reserve.
As long as it’s just a band-aid, he could even fill the overflow with just water so it’s not a waste.
ETA, it should be noted that getting water all over the engine does make finding a leak a bit more challenging.
I’ve had close-hand experience with “stop-leak” stuff twice, and both times ended poorly. The first time just made a progression of leaks develop in the radiator core - the first leak was plugged, then the next weak spot popped and filled in, followed by another…
The other time was about a year ago. Same deal - leaky radiator and a friend just wanted to keep the car running to next payday when they could get the rad replaced. I guess the stuff clogged up the entire radiator as the top “tank” exploded and the car shuddered to a final halt.
the other thing is a lot of modern cars now have the de-gas bottle/expansion tank as part of the pressurized system (see here). the “radiator cap” which controls cooling system pressure is now on the de-gas bottle; it’s not easy to see in that photo but the cap has a “hot liquid” warning symbol and is marked “21 psi/144 kPa.” over-filling that thing at minimum risks making a mess from excess fluid being pushed out, but can also contribute to overheating since it won’t help de-aerate the coolant properly anymore. and if your head gasket failure has combustion gases being forced into the coolant passages, even more so.
and if you have stop-leak gunk in there, it can clog the pressure regulating parts of the cap and now something can potentially burst.
One way to save a fair bit of money would be to buy the concentrate instead of premix. Saves $5-8 per gallon and requires very little work. Save one empty coolant jug, pour in half the coolant from the new jug, fill both up with water and you have basically doubled your money. Heck, if it were my car going through coolant that fast I’d likely mix it 4 parts water to one part coolant.
After all, it’d be pretty hollow praise for the mechanic to say “Yep, that engine’s shot. Head gasket went. But man, ain’t it rust free inside!”
You’re making the dubious assumption that the internal coolant leak into the oil gallery or cylinder is faster that the rate at which the expanding coolant is forced into the overflow reservoir. I promise you, if your pushing that much water into some place in the engine internals where it doesn’t belong, you’ll see the evidence in a big hurry. Even if the leak is external with coolant being pushed out of the engine entirely, with an overfilled overflow tank, you’re going to lose the vast majority of that coolant before you lose much through the leak.
Just for the sake of argument, lets assume that the cooling system works as you seem to thing it does.
By refilling with plain water, you’re trying to dilute the coolant blend and making it more likely to boil over.
OP, fill the cooling system with a proper 50/50 blend to the proper, marked level and no more.
Not sure if an '04 Honda qualifies as a modern car by this metric but thanks for the tip.
