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318 water leak/foam in radiator

01-02-2010, 01:35 PM
i originally posted a few days ago about water in the oil, now there is no water in the oil(i drained off about 1/2 qt) the engine does not smoke. i was checking all of the things about water in the oil and engine continues to run fine and does not overheat. the van sat for two days and now there is water dripping out or down from the back of the block on the drivers side. it is a puddle for sure about a drip every 5 seconds. the coolant is a little low. when i started the engine and revved it up for a minute or two then went to check the dip stick to see if there was any foaming, i pulled the radiator cap and there was white foam. i let the engine idle for a while and things settled down but when i revved up the engine it foamed up again. the engine fires right up and runs good for its age. once in a while i have a little bit of slow idling but a tap on the gas gets it back going and like i said it is only once in a while. i cannot see exactly where the water is coming from but the back of the block is damp. i pulled all of the plugs and 7 are grey, one is a little tan. but they are very clean and dry. i believe the thermostat has been removed as the water is really moving thru the radiator. any suggestions?

01-02-2010, 09:15 PM
On the back of each cylinder head is a freeze plug. There are also two freeze plugs on the back of the block that can only be accessed after the tranny is out. Lastly, the back of the intake gasket could simply be leaking.

Did you take the engine cover off to look for the leak on the back of the engine? If you did and could not see any leak, then it's probably one of the two hidden freeze plugs that you have to pull the tranny out to get at.

01-02-2010, 11:00 PM
i did remove the engine cover and do see some wetness but not enough to assume this is the area. dont know what to do about removing the tranny to check the others you speak of, but would this cause that frothy appearance in the radiator? i also believe you mentioned the possibility of the intake gasket on my water in the oil post. but as i stated for some reason there is no more water or foam in the oil. are the freeze plugs on the bottom back of the block under the tranny bell or the top. just wondering if i do unbolt the tranny how far back i have to move it and where to look.

01-03-2010, 01:04 PM
Here's an image of the rear of the block with the flywheel removed. You can see the two freeze plugs. Ignore the plug at the top center. That is not a freeze plug, but rather is a plug for the back of the camshaft bore.

01-03-2010, 01:30 PM
thanks for the photo. i see it would probably be impossible to slide the tranny back a few inches to see them. i wonder though how this relates to the foaming. if these are leaking would it actually be sucking air in thru them? is it possible to add some type of dye to the cooling system to identify leaking areas without damaging the cooling system itself?

01-03-2010, 01:37 PM
Yes air being sucked into the leak would cause a foaming effect, and yes they do make a dye that can be added to find leaks.

01-03-2010, 01:42 PM
thanks for the quick reply, will try the dye and watch it overnight.

01-06-2010, 02:07 PM
i finally got around to get back to look at the radiator. i took cap off and started engine, took picture. see foam everywhere, after a few minutes it settled down but still looked foamy inside, see second photo. outside temp around 48 deg F. see mild smoke out exhaust, this has never been there before and i assume because it was cold out?

01-06-2010, 03:35 PM
Oh wow, that's some real serious foaming. I figured you were talking about a few bubble. I'm assuming you don't have a prankster around that would drop some alka-seltzer tablets in there, just to mess with you?

After seeing that picture of the inside of the radiator I'm gonna say blown head gasket or cracked head. The heads will have to come off to determine which it is.

01-06-2010, 03:51 PM
pretty sure no prankster. as van is in garage and parked for days at a time. i hate to think what its going to take to get the heads off a van block, without pulling the motor i cant see how this can be done. its so weird to think about blown gasket or cracked head when this thing runs so well. cant decide to start wrenching or start shopping

01-06-2010, 04:40 PM
It's actually easier to remove the heads than it looks. I'd say the worst part is deciding to get started. :)

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