Finding internal coolant leak

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
I mentioned it in another thread, but I found coolant in the oil of my silverado. It is a 2002 with the 5.3L and 150k. What is the best way to find out where its coming from? It drives fine, no CEL or anything. Im thinking the 2 options are water pump or head gaskets, yeah? No visible leaks on the exterior.
 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
Anyone care to point me in the right direction? Should I do a coolant system pressure test first?
 

ilikemtb999

I eat dirt
Donating Member
Joined
Oct 24, 2007
Messages
69,196
Reaction score
350
Location
Denver, CO
The tool is free to rent so might as well. When you have water coming out of your dipstick you know the test is complete.
 

Turbocharged400sbc

Welllllllllll ya knowwwwwww.....
Joined
Jun 16, 2007
Messages
26,499
Reaction score
12
Location
hangover park IL
whats your leak rate? (how much ya add and how often?)

if its an internal leak the best option is to pressurize it and wait till the coolant level stops dropping and that will give you an indication of the leak elevation. at which point you can listen for a hiss and see if you can locate the leak point
 

EineKatze

No Stress
Joined
Oct 27, 2012
Messages
98
Reaction score
0
Location
Joliet
I would be willing to bet you have either slightly degraded a gasket (most likely in the valley, as its common on these trucks) or you have something as simple as a small gouge in a coolant passage allowing the coolant to sneak past. As 400sbc said, pressurize the sucker and see what you get. If you coolant level drops drastically you have blown through a gasket, if it trickles down I'd check your mating surfaces for imperfections. Hope this helps, now time to look for some info on preferred tubular k members...
 

ilikemtb999

I eat dirt
Donating Member
Joined
Oct 24, 2007
Messages
69,196
Reaction score
350
Location
Denver, CO
You could do a compression test too and see if you've got a dead cylinder/bubbles coming out of your cooling. Spark plug condition would help too
 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
Not sure, very slow, as the coolant reservoir was barely low and the last time i filled it was when a flush was done about a year ago.
 

ilikemtb999

I eat dirt
Donating Member
Joined
Oct 24, 2007
Messages
69,196
Reaction score
350
Location
Denver, CO
If its not leaking very much chances are its probably not the head gaskets then. I'd start with the coolant pressure tester first. Easiest first
 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
OK ill change the oil and see how much is in there and test the pressure on Saturday. Thanks guys.
 

PANDA

Well-known member
Joined
May 24, 2007
Messages
34,323
Reaction score
111
Location
FRG
u just see some coolant looking stuff under the oil cap or dip stick?
 

PANDA

Well-known member
Joined
May 24, 2007
Messages
34,323
Reaction score
111
Location
FRG
My GTP had the same issue before, in the winter. I'm like oh shit I got problems. James said it was just because of the fluctuating temperatures causing moisture to form at the cap. I changed the oil anyway and it was perfectly clean...

 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
I dunno, i have never seen this much and the same color as the coolant. It was down in the filler neck as well. Ill take a closer look and change the oil before anything else.
 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
Guess I should have specified, the low oil level light popped on and when i went to top it off, until i can change it, I saw it on the cap and neck.
 

Wild White Pony

Well-known member
Joined
Oct 13, 2012
Messages
1,101
Reaction score
0
If it's just in the valve cover I wouldn't sweat it. If you have cream in the oil pan start sweating. My valve cover and filler neck has the condensation puss all the time, but I have no water in the pan and the oil is clean. Can you show us a pick of the oil on the dipstick?
 

PANDA

Well-known member
Joined
May 24, 2007
Messages
34,323
Reaction score
111
Location
FRG
I dunno, i have never seen this much and the same color as the coolant. It was down in the filler neck as well. Ill take a closer look and change the oil before anything else.
My dads durango had the same issue as you explained also in the winter. This was MUCH worse then the picture I just posted. It looked like someone yacked a pound of green barf down the oil fill. I have pictures just not here. Also normal apparently. The same shit was also all in the PCV lines.
 

ktraver97ss

I say what everyone thinks
Joined
Aug 29, 2007
Messages
13,449
Reaction score
37
Location
Roselle, IL
No pics, trucks at home. Weird I would not have noticed it before. Hopefully im a jackass and that is all it is.
 

ldyzluvdis06

Supercharged C5
Joined
Sep 30, 2008
Messages
5,797
Reaction score
19
Location
Jacksonville, IL
My GTP had the same issue before, in the winter. I'm like oh shit I got problems. James said it was just because of the fluctuating temperatures causing moisture to form at the cap. I changed the oil anyway and it was perfectly clean...

x2...i had the same issue happen once. just change the oil and see what's going on there.
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Top Bottom