Coolant leak left rear side of block

[Fast_Z71]

Just replaced my waterpump and now there’s coolant coming from the lower rear left side of the block. Any thing can help, I haven’t changed the intake gaskets yet thanks.

 

[Jerryred94silvy]

Freeze plug maybe?

 

[PlayingWithTBI]

Left side - looking at it from the steering wheel or from in front? If looking at it from in front, check your Knock Sensor too, just above the starter.

 

[Fast_Z71]

Left side - looking at it from the steering wheel or from in front? If looking at it from in front, check your Knock Sensor too, just above the starter.

The drivers side

 

[Schurkey]

Just replaced my waterpump and now there’s coolant coming from the lower rear left side of the block. Any thing can help, I haven’t changed the intake gaskets yet thanks.

WHAT ENGINE? WHAT MODEL? WHAT YEAR?

Most likely a core plug, intake gasket, or cracked casting.

 

[HotWheelsBurban]

If it's a vortec, it's likely the intake manifold gaskets. On vortecs you need to put aviation permatex gasket sealer on the pump mounting bolts. Some of them go into the water jacket and it WILL LEAK if you don't. Also use the same sealer on the pump gaskets, and be sure to check the rear plate bolts on the Chevy water pumps. I've seen them new with loose bolts.....

 

[Fast_Z71]

WHAT ENGINE? WHAT MODEL? WHAT YEAR?

Most likely a core plug, intake gasket, or cracked casting.

98 Vin R Vortec 350

 

[Fast_Z71]

If it's a vortec, it's likely the intake manifold gaskets. On vortecs you need to put aviation permatex gasket sealer on the pump mounting bolts. Some of them go into the water jacket and it WILL LEAK if you don't. Also use the same sealer on the pump gaskets, and be sure to check the rear plate bolts on the Chevy water pumps. I've seen them new with loose bolts.....

I did the permatex sealer on the waterpump gaskets I also put GM pipe sealant on the bolts. The truck has had the intake gaskets done 20 years ago by the dealer so it might be time to change them lol.

 

[Fast_Z71]

Update two of the freeze plugs, the knock sensor, and the intake are leaking. The intake the worst out of all of them so I guess I’ll changing those out sometime next week.

 

[Schurkey]

If that were mine, I'd do a compression test and a leakdown test on all eight cylinders, and take inventory of how old the distributor, starter, alternator, and spider injectors are. In short--an assessment of what's likely to be a problem in the next few years.

Then rip the engine OUT, replace ALL the core plugs. They've all been bathing in the same acidic coolant. It's not worth popping the two leaking plugs, and leaving the rest of them; and it's easier to do them on the stand than in the chassis.

With the engine on the stand, I'd re-gasket the whole assembly.

Check the timing chain while the cover is off. Pull a main cap or two to verify the bearings while the pan is off.

Depending on the results of the compression and leakdown tests, we might be talking dingle-berry hone, rings, bearings, valve-job, perhaps even more extensive work. Or maybe not--those engines have a long service life. Point being, all the diagnostics is done BEFORE you yank the engine; you can have a "plan" in mind, and you can fix everything likely to be a problem for the next three-four years or more.