ok heres my deal... i have a 94xlt with a 351w and i have noticed that i have coolant that just disapears. so one day after driving it i opened the hood and noticed coolant on the outside of my overflow tank... like it came out of the fill hole. so i got on here and did a search and could not find anything to help me. i started it up and let it get to normal temp and tried to see if i could see bubbles or anything coming out of the tank and nothing happened.

i squeezed the upper hose and it was hot and had a lot of pressure to it. i dont have any coolant in my oil so it shouldnt be a gasket... i dont think. anyway if anyone can help i would appreciate it.

P.S. my temp gauge doesnt work... it only moves a little bit... like the very bottom line so i dont know if it is overheating either which could be a problem. since i bought it the gauge has never really work but when i had the engine rebuilt it worked for a couple months and then it stopped again. anyway if you need more info just ask

 

Same here..

I have a residue around the fill hole... it just started about 4 months ago.

Im filling it about every month or so.

 

Mine is doing the same, not a lot, just perplexing

 

I have been having the same situation for a number of years. I am assuming the fluid is sloshing around from movement of the vehicle and just an inadequate sealing cover on the reservoir. I have watched this over time and cannot figure out any other explanation. Would be interested in hearing from others on this.

 

96 XLT w/ 351W - same issue here

 

Coolant levels in the overflow tank when cold are at the 'cold fill' line or over? If over filled you could easily see some coolant come over the top as heat expansion kicks in. I have the feeling though that this might be a little too simplistic?

On my '94, I'm always adding a little to keep the overflow tank filled. Like Okacookie, I have yet to see any external leaks or coolant in the engine oil, from the heater, etc. However, I don't have any sign of a leak in or out of the overflow tank either.

I did just find myself wondering if there might be a very slow leak in the TB cooling path that would allow the coolant to be injested... or in some cases possibly adding pressure to the coolant system, resulting in the overflow?? Might try a TB bypass to test that theory... which is, granted, little more than a semi-SWAG.

Darn coolant has to go *somewhere* right??

Swit
'94 XLT 5.8 E4OD

 

I had this same exact problem, with finding coolant on the reservoir, for a number of months. I don't don't know if this had anything to do with it, but I had an itty bitty leak on my water pump seal. Not enough to drip, it just evaporated. When I was in an accident a couple of months ago, the rest of the seal went, and it started leaking all over the place. Well, part of the insurance settlement was to fix my water pump. Since that has been done, there has not been anymore coolant on top of the reservoir. Beats the hell out of me if these two things are connected.

 

I noticed the same thing and came to the conclusion that the coolant is coming out of the top from being sloshed around while driving. My temp gauge didn't work when I bought my 94 XLT, so I replaced the sending unit and it has been fine. Easy fix...

 

Yes, definately change your sending unit...and the gauge if you have to. They are a lot cheaper than a new motor. First check your radiator cap, if the seal is starting to crack or chip on it you may want to replace it, also could be that it is just bad... it's a $5 part and couldn't hurt to check. Also, check your T-Stat, could be sticking a bit or just letting the engine run too hott at idle (this can be caused by a bad fan clutch also)... either one could cause minor overheating and an overflow at the resoivor. The fan should turn by hand, but not spin freely, there should be a good amount of resistance there. The engine temp should also hold around 180-195.. anything over 210 or so could cause the overflow, the radiator cap only holds like 13 psi so if you go over that it will back flow into your resoivor. Finally, you may have a clog or a kink, I had a kink in a heater hose on my explorer that caused this same problem, finally figured it out and got a longer hose that eliminated the kink and problem solved and I believe a clogged heater core could cause similair problems... may not hurt to just flush the system. On the other hand it could just be sloshing... do you ever have low fluid levels in the radiator? If not you may try some sealant around the lid to the fill hole (or duct tape ) and just see if the problem persists.


Don't take any chances with the gauge, even with a working gauge I've lost motors to sudden overheating (stuck T-stats) but it can't hurt to have it working. I have an aftermarket gauge on mine, the sending unit screwed right in where my original was (with an adapter) and it had a bracket to mount it under the dash, but I found a good spot to the left of my stock gauges on the dash to mount it. It gives actual temp in degrees instead of ( H - NORM - C )... and it was under $20 and took less than an hour to hook up.

Good Luck.

 

Hmmm...Have you thought about a leaking head gasket which is pressurizing your system? I couldn't tell from your original post how often you are replacing your coolent and as no one else had mentioned this I thought I'd throw in my 1/2 cents worth. Myself I HATE stuff like this BUT when I get it fixed I feel like I AM DA MAN. My wife is very quick to remove that feeling but there for 30 seconds or so...it's nice. ;-) LOL

 

Try replacing the radiator cap with a new OEM one. I hav eseen the springs get weak and allow the over flow bottle to fill up during driving. make sure it is the correct "Lbs" cap for your truck.

 

I took the liberty of roughly tabulating vehicles and symptoms with what I could pick out of the text... I tried to avoid assumptions of details, hence the "?". I'm curious to find what is common, and isn't, what has been changed or 'fixed' on the coolant systems below that had or didn't have an effect. Granted these vehicles are mostly 10(+) year old buggies and can easily have more than one cause for the symptoms... or not.

Here's what I've tabulated so far. Under the Coolant heading are three symptoms; "atop Res" is 'residue on top of the resovoir', "Res Low" is loss of coolant from the resovoir either emptied or nearly so. Finally, "Rad Low" is a loss of coolant from the radiator... ie a bit low on a regular basis or needs to be topped off to keep it filled regularly.

Though it is folly to do so, I'm assuming that there are no external leaks found on the vehicle... water pump, thermostat housing, heater... etc.


Name Year Engine Coolant
atop Res Res Low Rad Low

Okacookie 94 5.8 yes yes ?

AYoungbld 90 5.0 yes ? ?

Dhelper ? ? yes ? ?

Scionti 94 5.8 yes ? ?

Kaised 96 5.8 yes ? ?

Swit 94 5.8 not yes yes

NHHottie 95 5.8 yes ? ?

Jbondi 94 ? yes ? ?



Hope this helps some/all of us a bit!!

I'll edit my prior post as changes are added with results.. and will invite y'all to do likewise.

 

As I mentioned in another thread, my 95 EB 351 is doing the same thing. I had a new radiator installed earlier this year, so when I saw the little green drip a couple of weeks ago, I was not happy. I noticed that I had coolant on top of the reservoir, and level in bottle was down a bit, but not too bad. When engine is cold, level of fluid in radiator is full to the brim. When running, temp gauge stays in low end of normal range, so assume the t-stat is fine.

Took it back to shop that installed radiator, and they seem to think there is a small drip from lower hose area. Tightened clamp and added a second clamp, and put on a new radiator cap. Just got it back a couple of days ago, and haven't really had time to look at top of reservoir. However, there is still a slight drip below. I think they are going to replace the radiator again (under warranty of course).

Kevin

 

My 96 Bronco does the same thing. I can't explain it. I have a KN FPK kit installed and thought maybe some of the coolant was coming out the top and being ingested into the air cleaner (open gauze) but its not obvious.

 

Appreciate all the insight and possible culprits. After carefully perusing each of the "Possibles", I am lead to believe that the residue around my fill cap on the reservoir is simply a bad design of the cap itself. Sloshing of anti-freeze inside of reservoir ends up on the interior of the cap, and eventually escapes to the top flat exterior surface of the reservoir. This is a great site and appreciate all the responses