I posted a similar threadin the tech section if anyone has a chance to look for it. Basically car was running hotter than usual Friday, air temps in the 90's. Car didn't overheat or run too hot but I was getting a coolant smell, which I can still smell with the hood open. The floor is dry and the engine compartment, too. No loss of coolant is noticeable either. Any ideas? The only thing I noticed is that the lower hose feels slightly damp and sticky, but I didn't see any leaks or drips.

 

you have a minor leak. water pump would be my first suspect simply because it's where most cooling system leaks come from. you can try and trace down where the sticky on the hoses is coming from

old hoses sometimes seep at the ends. if you haven't replaced all your coolant hoses they really should be. even the newest c5's are due for replacement from age

also, when is the last time you removed the radiator for a good cleaning? not related to the coolant smell but it is to the running hot factor

 

As far as cleaning the radiator is concerned I usually do that once a year around the beginning of summer. I spend way too much time cleaning it to get it as clean as humanly possible. It does make a big difference. As far as hoses are concerned I've been thinking of replacing then anyway, couldn't hurt. Years ago I had a Z28 which blew a hose in a parking lot away from home just as I shut off the engine.

Anyone have experience with those silicone hoses and are they worth the money, aside from the looks?

 

I agree with racebum. If you can smell it, there probably is a leak and from what you said, it sounds like a it's a hose. Those silicone hoses are really nice, but they are expensive!!

 

Do they hold up and last that much better? Not so sure I need more color on my engine. BTW, I cleaned everything up as well as possible. There was a sticky coolant film on alot of components in the thermostat area. I will keep tabs on it to see if I can track where it starts from, but it does seem like it could be coming from the hose ends. Nothing of the hoses are actually leaking and the thermostat and pump seemed dry, so it might just be time to replace all my hoses. The car is an '03 and I don't think I've ever replaced any hose, not even the main upper and lower hoses even though I have done coolant changes.

 

A pressure test kit something like this should take the guess work out of it.

http://www.harborfreight.com/radiato...kit-69258.html

 

I've been losing some coolant lately too and cannot find where it is leaking. At least nothing obvious yet. Probably will have to resort to a pressure test etc.

 

I'd suggest checking the coolant overflow tank for a crack where the hoses connect to it, both top and bottom. I had a similar smell not long ago and found a crack where the upper hose connects. Another place to check that is common is the seams on the plastic sections on the side of the radiator. Both the overflow tank and the plastic part of the radiator are very common leak points.

 

I just replaced mine. Was leaking from a small crack in the plastic. Was barely noticeable, but the smell was there after every drive. Amazon has them cheap..

 

C5 coolant tanks are notorious for failing where the hoses connect. It took me a while to figure out my coolant smell and loss because it was such a small leak and it was coming from underneath the nipple so you could not visibly see it but can smell it.

 

cooling system in general seems to have a ten year life. when i picked up my 02 i knew i needed to troubleshoot the cooling system. what i found was a pump seal was leaking allowing coolant to run down the hoses and appear as if a hose was leaking. i also found a crack in the plastic coolant tank. putting A+B together i realized that the radiator while not leaking now, probably would be before long. it was also jam packed full of that gritty road sand

here is a list of parts for the cooling system. most you can find great deals via amazon but the part numbers will let you search anywhere

Ac delco 20889 radiator $188.16
Ac delco water pump 251-744 $177.61
Ac delco water pump inlet w/ stat 15-11057 $29.30
Ac delco 18021L hose $27.52
Ac delco 24388L hose $25.35
Ac delco 24458L hose $14.59
GM hose 10229491 $24
Gates 18127 $12.62
Gates 5/8” heater hose {runs small} 2ft section
GM coolant tank 10430189 $69.95

also note, there is a 2ft section of straight hose that runs into the coolant tank. it's not actually 5/8" hose, more like 9/16 which is not made by anyone other than GM at $10/ft if you can even find it. i measured various 5/8" hose and the particular batch of 5/8 gates was actually .5mm smaller than the OE hose i brought with me. was a nice tight snug fit and even let me use the constant tension clamps since the OD was also the same

 

Good stuff Racebum....thanks!

 

Is the hose and overflow wear based on usage/miles or age?

My 2004 is pretty much a weekend driver, however next year for it's 10th birthday, I plan to swap out all of the engine rubber, i.e. hoses and belt as well as the spark plugs/wires.

I'm also thinking about the silicone hoses or braided hoses. Should I be concerned about the overflow tank or the actual OEM plastic radiator/fans as well?

When the time comes for a new radiator, I do plan on installed a Dewitt's aluminum one.

 

age

seals & rubber are age items.

your radiator might be alright if it's really low mileage. typically heat cycles and debris are what shorten the life of those

hoses and water pump are age items though. the seals and the rubber rot. there's actually quite a bit on cars that are age related more so than mileage. it's also why you can look at value books like NADA and only see a 2000-2500 difference between a 40k mile 2002 car and a 100k mile 2002 car

 

Thanks for all the input. I've cleaned up anything I can find that I think is suspect. There was some messy wetness in spots but no definitive place where I can see the seepage starting from. I'm planning to drive it Tuesday to work and keep an eye on it so maybe I can track down where it first starts from. It is supposed to be considerably cooler air temp wise so I don't know if I'll find anything out. I had no symptoms until the first time I drove it when it was in the 90's last Friday and I got stuck in traffic. Idling in traffic I got a high temp of 234. I know that's not too hot but it was the first time it got that hot since last summer driving. I drive my car alot year round. Its got 115k miles.

 

Great info racebum, thanks.. I believe I have a small leak in my coolant tank, so for $55. I just went ahead and ordered a tank.