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Coolant leak, starter soaked


sierra99
01-11-2010, 05:34 AM
Hey all again. I have a 99 silverado 4x4 5.3l, 155k miles, that has a coolant leak on the passenger side only, that is soaking the starter. I can see clan coolant on the passenger tranny bolts and the starter is soaked. I cannot tell where it is coming from. I have checked the oil stick and the oil filler cap for coolant contamination, the good news is that it is clean. I have read about the water pump gasket going bad on these, but I do not see anything dripping from the water pump area. I do park my truck (front downward) on a small slope, and the only signs of loss is from the passanger rear side of the motor. I have looked at the rear of the heads, but do not see anything, so from the heads and up are dry.
I will check the heater core drain tube for coolant lthere. It may be my heater core, but I nerver smell coolant in the cab.

I have already replaced the intake gasket (due to the truck throwing a code). but this engine does not have any coolant through the intake or gasket. I can put in some dye, but would like to get some other info before I do that. Are there any other problem areas on this truck that I should look at? I was reading about some coolant drain plug above the starter that needs to be re tightened, does this affect this motor??

Thanks in advance...

j cAT
01-11-2010, 10:57 AM
this is usually the heater core hoses...get a white cloth and using a rod probe for where the leak is...I have had good success when the engine has started to cool down to probe for leaks...

don't need dye unless your running pure water...

the heater core if it is leaking will cause you to smell antifreeze in the cab..

the coolant drain plug is just above the starter. you must remove starter to get to it. you will need a 7/8 allen to rotate..
this part is steel, so it is possible it is corroded...if it is I suspect the coolant has not been properly maintained...

sierra99
01-12-2010, 07:40 PM
Thanks Jcat, I used your advise and put some white wipes around everything in the passenger side of the engine compartment (but not touching the motor or exhaust). It ended up being the quick connect going to the heater core (neutral color). It must have been going for a while and had dry rotted over the past 10 years. It was very brittle. I removed it but did not have a replacements quick connect, so I used a 3/4 to 5/8 plastic adapter and bought 6 inches of 3/4 pipe and attached it that way with a hose clamp at the heater core. I called a dealer and they want $36 for the new quick connect. WOW. Can I get this anywhere else other than the dealer? I will replace the hose also. Or can I leave it this way, with the clamp and the adapter.

For those of you who cannot find a leak but keep loosing coolant, this may be a place to look. My truck has been losing coolant since summer. I could not find where it was going. But it was dripping on my starter or exhaust and evaporating.

Oh yeah, be careful around this quick connect, it was very brittle and almost fell apart when I touched it. Hard to believe that it did not break under the pressure of the coolant system.

Napa has the quick connect for a 5.7 but not for a 5.3.

Thanks guys.



Thanks to all...

j cAT
01-13-2010, 08:10 AM
Thanks Jcat, I used your advise and put some white wipes around everything in the passenger side of the engine compartment (but not touching the motor or exhaust). It ended up being the quick connect going to the heater core (neutral color). It must have been going for a while and had dry rotted over the past 10 years. It was very brittle. I removed it but did not have a replacements quick connect, so I used a 3/4 to 5/8 plastic adapter and bought 6 inches of 3/4 pipe and attached it that way with a hose clamp at the heater core. I called a dealer and they want $36 for the new quick connect. WOW. Can I get this anywhere else other than the dealer? I will replace the hose also. Or can I leave it this way, with the clamp and the adapter.

For those of you who cannot find a leak but keep loosing coolant, this may be a place to look. My truck has been losing coolant since summer. I could not find where it was going. But it was dripping on my starter or exhaust and evaporating.

Oh yeah, be careful around this quick connect, it was very brittle and almost fell apart when I touched it. Hard to believe that it did not break under the pressure of the coolant system.

Napa has the quick connect for a 5.7 but not for a 5.3.

Thanks guys.
Thanks to all...

anyone who has this fitting must be inspecting for leaks there...getting too common.. good luck ...

Bob B
01-13-2010, 09:12 AM
Hi,
I got my replacement quick disconnect at Kragens (O'Reilly).
They had two of different quality and price.
Bob B

sierra99
01-13-2010, 06:04 PM
FYI:
Dealer has 2 different quick connects for this truck

1. white or clearish white, towards the motor for $36
2. Black outer, towards fender ........................$18 (slightly smaller inner diameter)

Oriely says that their part is a replacement for both, it is NOT. I needed the white one for $36. Bought the other from oriely just to see if it would fit. It is too tight. Do not try to push this one on the inner heater core fitting. I then tried the oem from the dealer and it fit perfectly.

Just some info.

wagslick
11-28-2010, 10:37 AM
Thanks Jcat, I used your advise and put some white wipes around everything in the passenger side of the engine compartment (but not touching the motor or exhaust). It ended up being the quick connect going to the heater core (neutral color). It must have been going for a while and had dry rotted over the past 10 years. It was very brittle. I removed it but did not have a replacements quick connect, so I used a 3/4 to 5/8 plastic adapter and bought 6 inches of 3/4 pipe and attached it that way with a hose clamp at the heater core. I called a dealer and they want $36 for the new quick connect. WOW. Can I get this anywhere else other than the dealer? I will replace the hose also. Or can I leave it this way, with the clamp and the adapter.

For those of you who cannot find a leak but keep loosing coolant, this may be a place to look. My truck has been losing coolant since summer. I could not find where it was going. But it was dripping on my starter or exhaust and evaporating.


Ok, I've got the exact same symptoms. I've been looking from the top down and can't find anything wrong. Looking from underneath the truck, my starter is soaked with coolant and the stuff drips in my face but I can't find the source. I'm not the most mechanically savvy but where is the heater core and which hose did you replace? Aren't there a bunch of hoses?

j cAT
11-28-2010, 12:55 PM
Ok, I've got the exact same symptoms. I've been looking from the top down and can't find anything wrong. Looking from underneath the truck, my starter is soaked with coolant and the stuff drips in my face but I can't find the source. I'm not the most mechanically savvy but where is the heater core and which hose did you replace? Aren't there a bunch of hoses?


on the fire wall passenger side engine compartment 2 hoses go into the fire wall this is where they usually leak, as the other forum member discovered... the hoses are not the problem but the hose connects to the heater core are..need tool to remove..some bypass these and just hook up a hose with a section of piping to allow connection..this is a good area to place a reverse flush setup..

replacing hoses would be good , less trouble but more expensive..

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