Tracking down a coolant leak in an '03

[Kingfish]

Howdy all,

New to the forum and could use help in tracking down a coolant leak on my wife's '03 Sport w/105k miles. A few days ago she saw steam coming out from under the hood and got that awful coolant smell so I had a look. She said she heard a chime too, so I had her park the car until I could investigate. I saw coolant on the crossmember by the steering rack on the driver's side, but couldn't tell where it came from (top rad hose was dry). Last night I put in almost a gallon of Prestone 50/50 and still didn't have heat, so I added the rest and part of another gallon until the heat worked. I read on another thread here Prestone is no good because of phosphates, but couldn't find any mention of this on the bottle. I noticed a light brown foam in the overflow tank when I was adding coolant. What could that mean? This was obviously a decent leak, and my first thought was the rad sprung a leak somewhere, but then I read here it could be the water pump. What's the failure mode for both of those? I'm going to check the level after a short drive today then add more coolant. What's the best way to burp the system?

Thanks in advance for your help.

 

[CzarKJ]

First off. Regular coolant is the wrong stuff. These engines require a HOAT coolant (such as Zerex at napa) so once you find the leak you will need to have the system flushed with the correct stuff.

Places to check. Radiator on the top right side (driver side). That spot has a tendency to crack. All hoses look good? Water pump could also be the problem but I would think that is more noticeable.

Brown foam in the coolant. If oil is in the coolant or vice versa (check your oil dipstick) it could be a head gasket where a pressure test is needed.

I would not recommend driving this any further as when these engines overheat they have a tendency to throw rocker arms and do all sorts of bad things.

 

[Kingfish]

Thanks. The oil was down a quart, which is unusual for this car so there might be something ugly hiding. The 3.7 has alum heads and an iron block? How is pressure testing done to check head gasket integrity?

 

[uss2defiant]

i would pressure test the cooling system. You can rent one of those from your local autopart store.

If you can use a turkey baster or something similar to get some of that brown liquid for inspection that'll be great.

 

[teeje]

Howdy all,

New to the forum and could use help in tracking down a coolant leak on my wife's '03 Sport w/105k miles. A few days ago she saw steam coming out from under the hood and got that awful coolant smell so I had a look. She said she heard a chime too, so I had her park the car until I could investigate. I saw coolant on the crossmember by the steering rack on the driver's side, but couldn't tell where it came from (top rad hose was dry). Last night I put in almost a gallon of Prestone 50/50 and still didn't have heat, so I added the rest and part of another gallon until the heat worked. I read on another thread here Prestone is no good because of phosphates, but couldn't find any mention of this on the bottle. I noticed a light brown foam in the overflow tank when I was adding coolant. What could that mean? This was obviously a decent leak, and my first thought was the rad sprung a leak somewhere, but then I read here it could be the water pump. What's the failure mode for both of those? I'm going to check the level after a short drive today then add more coolant. What's the best way to burp the system?

Thanks in advance for your help.

That brown film is from the hoses breaking down over time. Wouldn't be a bad idea to change both. Get them from NAPA. Direct fit. Was there any coolant In the overflow?

Sent from my SM-G935P using Tapatalk

 

[GunnerSchenck]

But the heat did begin to work after you added the coolant? I'd be checking around the gasket on the water pump and be hoping for that..
Because as others already mentioned.. that brown foam is no bueno and I wouldn't drive it until you at least have the oil or coolant leak fixed and can verify the two aren't mixing.
could've been the colors of a correct hoat coolant mixed with a different color incorrect coolant in the right circumstance if the coolant was still hot i suppose..I'd hope..
You should post a picture of the brown liquid if possible..
Check the inside of the oil filler neck for any discolored sludge/foam.. then check the dipstick for any milky colored liquid.. if your oil isnt a clear variation of brown.. might be coolant there.
If none of these things show obvious.. you can get a decent pressure gauge set for not too bad of a price just about anywhere and hopefully are able to find a decent tutorial somewhere to walk you through it before and while doing the process..

 

[Kingfish]

I took the car to my favorite wrench, who pressure tested the system. Sure enough, the rad started ******* out coolant right where CzarKJ said it would. So they replaced the rad and overflow tank, and flushed the system to get the yuck out. I was still worried about the head gasket(s) but the engine was running great and no CEL so it was still sealing around the water jackets. Still can't figure out where that 2qts of oil went; that engine doesn't burn oil afaik and the oil on the dipstick looked good. I'm getting it back tomorrow & will have a chat with the mechanic about what's next. Hopefully nothing. Thanks to everyone for their input.

 

[HoosierJeeper]

Make sure they used HOAT coolant.

 

[GunnerSchenck]

Glad you found your leak! Hopefully all works well now

 

[Kingfish]

Post Mortem: It turns out the scummy brown foam in the puke tank was from corrosion inside the block. Apparently it was really bad, the mech told me. Kicking myself now for not having the system flushed years ago, esp because I had it done this summer on my Lincoln. Live and learn. I stll don't know where the oil went, but will be keeping an eye on consumption for a while.

 

[renegade 04]

You may have a loose oil filter, or you may be burning it either through the PCV system or in the combustion chamber.