possiby head gasket blown

hi all,

i'm fairly certain that i'm having an issue with the head gasket, but not positive, so i wanted to get some opinions. my 1987 van has started to lose coolant at a moderate rate, but i don't see any leaks, cold or when it gets up to temperature. i had a leaky reservoir tank sensor, but i fixed that with permatex rtv water system sealant. a side note on that, no leaks so far. i pressurized the tank for a short period of time, and nothing came out the seal. so, with that taken care of, i'm still losing coolant.

i happened to notice today that the exhaust has a little bit of fog to it. i hadn't noticed this happening before, but wasn't watching for it. this fog occurs from the moment the engine is fired up. i held my hand in front of the exhaust for a while and it gets wet. i had previously ruled out the head gasket because the oil looks fine, no milky appearance. but now that i've noticed this, i'm wondering if maybe the gasket is damaged between the water jacket and a cylinder. can this happen without water getting into the oil. is this possible? this i my main question.

i was also wondering, is it possible to have water getting into the exhaust system at the exhaust valve, thereby not actually getting into the cylinder and not getting into the oil?

any thoughts on this or comments about similar problems are greatly appreciated.


thanks
clay

Only way I can think of on how coolant can get into the exhaust is a cracked cylinder head or a crack in it DON'T PANIC highly doubtful. BUT, to be sure that it maybe a head gasket issue you want to perform some tests such as a compression test; attach a pressure gauge (which you can rent from an autozone) to the spark plug hole and crank the engine, allowing it to turn over at less 5 to 6 times or for 5 seconds for each cylinder and write down the highest psi pressure it shows for each. Leak down test; you pressurize the cylinder with a air and listen for where the air is escaping with a stethoscope. Coolant system pressure test; probably the most simplest, :lol: you use a hand pump and pressure your coolant system and see if it holds the recommended system pressure usually around 13psi to 16psi whatever is written on you radiator cap, for a period of time around 5 to 10mins, if it doesn't you can source the leak while you're at it and if you can't see it on the outside around the engine,heater hoses, and heater cores, you may have internal problems. Also, have your heater switch for both front and rear set to full when doing this. Another one is get a head gasket testing kit that detects carbon dioxide within the coolant, which means that exhaust gases and fuel are getting in the coolant system meaning head gasket leakage. You can perform either one of these tests. Best start with the coolant pressure test.

Keep in mind that water is a normal byproduct of burning petroleum products (approx 1 cup of water for every gal of fuel), so seeing a light fog can be normal. Antifreeze has a distinct smell when it is expelled from the exhaust. To get an idea, open a jug of antifreeze and take a whiff. Coming from the exhaust the smell is very similar, but stronger as it will be atomized and mixed with exhaust.

Like Street said, the hand pump pressure test is the best way to identify leaks. It's not unusual to only have leaks for a short interval between cold & hot. Put about 13 psi in the system while cold and check for leaks. If you can't find any, start the engine and keep an eye out for them as it warms. Good luck. Tim

thanks for the help, i'm going to try the pressure test first. any suggestions on how to attach the pump? i'm fairly resourceful and can probably figure something out, but thought i'd see if there is a trick. keeping fingers crossed it's a small hole somewhere that i haven't noticed.

as you said tim, antifreeze does have a distinct smell and after reading this, i thought about that and remembered that my hand didn't feel sticky or smell funny (other than exhaust smell) while i was checking it or after it had dried. hopefully i'll get a chance to do the pressure test monday, as i'm taking it off and it's supposed to be nice (fingers crossed).

thanks again, i'll comment about how it turns out.

clay

They make a kit specifically for testing. Here's an example of one on Amazon: http://www.amazon.com/Radiator-Pump-...ressure+tester. If you don't want to spend $50 for the tester some auto parts stores rent out tools like this. It might be worth calling around to see who might have one.

rented a coolant system tester, tested it out, it slowly lost pressure. about a lb. in 10 mins. not much but definitely a leak. i did the test a few times, taking off the tester, put it back on, just to make sure it was seating properly. after each pressurization, didn't see anything leaking below the van. tightened up a couple of band clamps that were loose, less pressure leaking but still there. decided to fire it up, was going to let it get up to temp, but then saw some dripping below the van. turned it off, dripping stopped. fired it up again, dripping started again. when i got down there, the exhaust pipe was wet, so i figured something was dripping onto it. fired it up and took a look. there was antifreeze spitting out of a weld joint where the two pipes become one. while pressurizing the system, i was dumping coolant into the pipe and it was pooling there. something i don't think was happening while it was running since such a small amount was leaking in, therefore i didn't see it dripping there before.

this leads me to believe the head probably has a very very small fracture in one of the exhaust ports, past the valve. i believe this is the case because there is no water in the oil or in the cylinders (i checked all the spark plugs and they were clean and identically tinted, didn't smell of antifreeze). this makes me sad because i'm going to have to pull the head and find a replacement. i had the opportunity to pick a head up at the auto recyclers in lake stevens a couple of months back (someone had already pulled it and it was sitting in the van) but i didn't and this makes me even sadder.

does it make sense to wait and find a used one at a pick and pull, or is it preferable to get a new head?

clay

Quote:

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Originally Posted by clay

does it make sense to wait and find a used one at a pick and pull, or is it preferable to get a new head?

clay

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That's a tough call. New stuff is nice, but anything in the affordable range is likely a Chinese reproduction. I got a new one on eBay a while back. It wasn't bad, but not what you'd expect for new. Here's a link to my evaluation of the head: http://www.toyotavantech.com/forum/e...Rebuild-part-2

I'm not sure what they'll charge for a used head, but if it's in decent shape and can be put right to work, then it can be worth while. If you go used, you will at least want to disassemble, check valve guides, valve surfaces, and replace valve seals. I just tore down a used head (150k miles on it) and it's in really nice shape. A couple exhaust valves need to be lapped in by hand, but guides are good. Roll of the dice either way, but probably more consistent results with new. Good luck. Tim

i want to thank you for your help and advice, both tim and street90. i really appreciate it.

i looked at a few heads on ebay, i might go that route. i need to take the head off first anyway, so i'll wait to purchase one until i see what the actual cause is first. might still be a gasket. either way, though, the head has to come off.

while looking at the heads on ebay, i noticed the same head was listed as both 3yec and 4yec. does this mean that a head off of a 3yec engine will work okay on my 4yec engine? just curious, because i might call to find out how much they charge at the p&p. if it's not too much, i might head over and get the one off that '85 there. tim, i think i read that you'd recently gone over to get something off that van. do you remember if the head was still on it?

again, thanks for all your help. i'll probably start blogging about the replacement of the head so i won't clutter this thread up. if i have more technical questions about this, i'll continue asking here if i can't find it somewhere in the forum.


clay

Quote:

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Originally Posted by clay

i noticed the same head was listed as both 3yec and 4yec. does this mean that a head off of a 3yec engine will work okay on my 4yec engine? just curious, because i might call to find out how much they charge at the p&p. if it's not too much, i might head over and get the one off that '85 there. tim, i think i read that you'd recently gone over to get something off that van. do you remember if the head was still on it?

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Yes, 3y & 4y heads are interchangeable. I've never compared them side by side, so not sure what (if any) differences, but suspect the 3y head may have slightly smaller intake ports. Lake Stevens is a couple hundred miles away from me, so no, I haven't been to the pick-n-pull there. Chester (member here) has been there a few times so you might PM him to see what he says. If you need a head, and have a choice between 3y & 4y, all other things being equal, I would choose the same as what originally belonged. Tim

Hey Tim,

Sorry for the confusion about p&p location. I live in Portland, and was referring to the p&p south Portland location. I mentioned the Lake Stevens one earlier because I had driven up to that one to get the sliding door off a van there and saw the head lying in the back.

Thanks for clarifying about the heads. Since the heads are interchangeable, I'm going to call p&p to see about the price. If it's not too much, I might go get it.

Oh, I just didn't read your previous post thoroughly. I haven't been to a Portland Pick-n-Pull since the last time they've had an 86 89 van (over a year ago). Due to the differences I usually don't get too excited about the 84 - 85 ones. Yes, some parts are interchangeable, but many are not. Since I'm not allowed to get complete vans anymore, the next time they get an 86 - 89 I plan to go there and strip it :yes:. Tim