Tiny bubbles and coolant loss with new rad. dont think its a blown HG. what to do??


Just a good ole boy...
Hey guys,

as some of you may recall, a month or so back i did the f-body radiator and ramchargers dual fan swap on my 85 hotair GN. The car ran great, and MUCH cooler. Since then, I've noticed though that it seems to be consuming coolant (actually just distilled water, no green stuff for me) and if i check the rad soon after the car has been running, there is a lot of foam, or tiny little bubbles in there. At first i thought it was air trapped in the coolant system finding its way out, since it had been sitting draining for weeks in my driveway, but after a few times of filling it with water I realized that wasnt the case. Next thought was of course a blown headgasket, but theres no oil in the water, and when i changed the oil last week, it looked just fine, didnt seem to be any water in it. Then yesterday I put the old compression tester on all cylinders to see if one wasnt holding pressure, but they all seemed to be pretty darn good. the numbers looked something like this


driver side-----passenger side


Now thats a little bit more of a gap between lowest and highest than i'd like, but not too shabby, and theres none that are drastically lower as i would expect to see with a headgasket blown.

Now, I didnt hit any higher boost, or drive the car any harder after the rad changeover than I did before, so i dont know what would have blown the gasket. Combine that with the decent compression test numbers, and im thinking its not that. Is it possible to develop a small HG leak, that wouldnt really affect the compression numbers, but would cause the issues im having? Or could there be a leak in the intake manifold somewhere? Im definitely losing water, with no observable leak (no drips or streams when running) so i assume its leakin interally somewhere?

The problem isnt too dramatic; the car still drives fine (no noticeable loss of power), and i only have to add maybe a half gallon of water every other day or so, but I would like to fix whatever it is before it gets any worse. Plus knowing something is wrong with my car and not being able to fix it is driving me crazy.

One last thing, i only noticed this problem after the rad/fan swap, is there any way i could have done something wrong in the process that would have caused this? Oh, and in case this is a clue, my heater only works intermitently, sometime blows hot, sometimes not. Dont know if its always done that, or if that started with the other problem, as this is the first time since ive had my car its been cold enough to need the heater.

Sorry for the long post, I'm just dying to figure out what is wrong with my baby and get it fixed, and I figured I'd give all the info i had available to help you help me If you have any other questions, please feel free to ask. thanks is advance!!!
This is one sure way to determine if you have a bad hg.
With the engine warm and the radiator cap off, use an emmission sniffer at the radiator neck.
Granted, you will have to find someone that have access to a sniffer.
It will tell you in a heartbeat if you have exhaust gases in the radiator.

There is another tester (forgot name & brand) that will sometime work right.
It uses a liquid in a cylinder and you draw air out of the warm radiator and the liquid changes color if exhaust gases are present. This type didn't work for me but the emmission sniffer sure did.

I had 165 to 170psi compression on all 6 cylinder but all 6 had a exstreamly small hairline crack going into the water opening.

Bad water pump. Check that - it could be seeping externally most likely when you are at higher rpms than idling because that is when it builds up more pressure.

The hot/warm/cool heater air is a big clue in my view. My money is on a bad water pump.

Edit: One other thing regarding the hot/cool heater - do you have a scan master or other temp gauge to tell you the actual coolant temp? It's possible you have more than one issue - perhaps you have a faulty thermostat that would be 'cycling' causing the heater temp but it's not that likely. Just a possibility. That was the case with my car but then again, I live in Ohio and it got down to 2* above zero last night. Brrr!

Good luck.
I've got a scanmaster, and the thermostat is new as of a few weeks back. its a 160* unit, and my temps (according to scanmaster) cycle between about 160 and 170.

Would a bad water pump be causing teh aeration/bubbles/froth in the water that I am seeing? I think the guy i bought it from in march said he had the pump replaced pretty recently, and i think i ahve a recipt for parts/labor showing as much, though I'll have to check on that... I hadnt relaly considered the possiblity of a leaking pump, but I'd much rpefer that to having to pull the heads!
My money is on h/gasket. Not a big leak but enough to cause bubbles.

I'd bet that some water is being burned and in this weather, you would'nt notice.

Take it out for a good beating and pull over right away. If it's bubbling into the overflow, well. :(

Those compression # should be higher on all cyls., like 150psi.

Pull the intake. Bet you find a coolant trail down the lifter valley.

Ask me how I know. :frown:
What about the possibility of a leaking heater core? Any wet carpet inside? Does the radiator hoses hold pressure or does presure bleed off really quick?
Hey Corey, if you can't find any external leaks, it's probably a seeping HG. Just go to discount and throw in a can of metallic block seal. Follow instructions and you should be fixed. ;)
Basics first

The first thing a professional auto technician would do is use a radiator pressure tester. $15 to $20 charge is about right. See if the cap holds at designated rating and then on the radiator (cooling system) itself. Watch to see if it holds pressure or slowly leaks down. If not holding, get a good flashlight and look everywhere: all hose connection points, radiator seams, evaporator case drain, inside car-passenger side under dash, water pump from underneath, back of the block, etc. You get the idea. Half a gallon every other day is quite a bit of coolant loss to me. It has to be going somewhere. Hopefully on the ground and not from inside your engine. NAPA sells a fluoroscent dye for coolant that will show leak under ultraviolet (black) light. Look especially close at your hose clamp connections. Could just be slightly loose and seeping coolant. Good luck.
On my old car I used that dye. It worked great. I found a small leak that trickled down the water pump. I was in a spot that you just wouldn't be able to see with out the glow of the dye. Neat stuff.
I meant to say that its leaking about a half a QUART every other day, not half a gallon, my bad :redface: ASf ar as external leaks, would they cause the bubbles/froth i see in my car when i check immediately after its been running, especially if i have been driving it hard? In my mind that suggests a head gasket? I may try a bottle of that leak-stopped stuff you see in the autoparts store, as John and others suggested, and see if that helps any. If not, I guess ill try a pressure tester, or something else to try and fiure out where exactly all this is going.
So does an bubbles in the oil mean HG blown? I had some bubbles a couple of times, does this mean no more HG?
us the carbon monoxiide sniffer. you pull the level down in the radiator so the tool wont suck up water, pump it a couple times to let the air in the radiator into the tool. the blue fluid will turn green if any CO is in there- if its bad or if you rev it itll usualy turn yellow indicating a large amount of CO in the coolant system.


Part#: AC560000

Price: $62.50