coolant leak, passenger rear of engine compartment, 96 Suburban

[jrsavoie]

coolant leak, passenger rear of engine compartment, 96 Suburban

The sensor at the back of the head is wet. The leak seems to be above the starter.

Any likely suspects?

There are a lot of coolant lines in that neighborhood. I'm hoping that as apposed to a head gasket or something else more serious.

I couldn't see anything top side. But it looked like it was wet as high as eye could see from underneath.

It didn't seem to be in the right area for it to be one of the front heater core lines.

 

[buddy]

All of these engines have a coolant blockoff plate on both sides on the rear. Its just like on the front where the t-stat x-over mounts. Some PCM grounds attach to a stud on it. If you messed with grounds likely loosened the blockoff. Or the heater hose quick connect can be bad if still there and travel back on heatsheilds and what not that takes coolant to the starter.

 

[jrsavoie]

The leak seems to be on the other side of the bhead from the ground stud.

I first thought it might be the overflow tank. Still could be related but it seems to be lower.

 

[jrsavoie]

I looked lard yesterday and it didn't look like the block off plate.

The sensor at the back corner of the head, the one closest to the firewall and the coolant reservior was wet.

Coolant is dripping around the base of the starter but that tells nothing about where it is coming from. I'll get it up on a lift someplace next week where hopefully I can see better.

It probably won't make any difference on what I have to take apart to fix the problem but it sure does make life easier.

Sometimes you're just as well off to start ripping and tearing. Usually once you're into it things go better and faster anyway. I just wasn't in the mood after thinking I was done for a while - With that vehicle anyway.

 

[88gmctruck]

Mine was loosing coolant and it ended up being the pass blockoff plate leaking very slightly.

 

[zielinski.family]

My wife's suburban (gasser) had a bad antifreeze leak on that side. I thought the same thing that it was either water pump or head gasket. Come to find out there are two 3way valves for the rear heat on that side down low. They are made of cheap plastic that breaks down due to the heating/cooling cycles. This leak was elusive because it only leaked when it was under preasure at operating temps. When I began investigating the valce broken into pieces. I changed it and leak dissappeared. I would check those valves.

 

[JMJNet]

My wife's suburban (gasser) had a bad antifreeze leak on that side. I thought the same thing that it was either water pump or head gasket. Come to find out there are two 3way valves for the rear heat on that side down low. They are made of cheap plastic that breaks down due to the heating/cooling cycles. This leak was elusive because it only leaked when it was under preasure at operating temps. When I began investigating the valce broken into pieces. I changed it and leak dissappeared. I would check those valves.

x2. It is actually not a valve just a plastic tee at least it is in the diesel not sure for gasser.

Another place will be the quick connect after the t-stat. It has the same behavior as the tee very elusive. You can put your finger underneath it to feel it before it evaporates.