[tonysilva530]

Specifically, how and what is the best way to clean out the engine block when someone has added some type of radiator sealant to the system?

When I feel the heater core hoses, neither one of them are hot. If one hoses was hot, it would mean the heater core is clogged.

But since NEITHER hose gets hot, I think the engine block is clogged with some type of sealant.

When I removed the radiator cap, I saw brown stuff caked on the inside of the radiator filler neck. When touched, it felt like soft, fine, damp, clay dust. I assume this brown stuff is some type of "Bar's Leak Radiator Sealant"

I intend to replace the radiator. I also intend to remove & clean out all coolant hoses as well as the water pump, thermostat housing and whatever else comes in contact with coolant.

I'm gonna pressurize the heater core to unclog it. If it leaks, I'll install a new one. I don't know the history of this truck. I don't know why the sealant was added. I've only had this truck for three days.

I'm going to order a top end gasket set including head gaskets with valve guide seals.

I only paid $650 for the truck, I don't mind spending some money on it, but I really don't want to replace the entire engine.

Besides the $650 for the truck, I spent another $25 for a new starter cable. The 1 year old Interstate Battery was dead/bad....so I took it to the Battery Store and (surprisingly) got a new replacement at no cost (thank you previous owner 🤷 .

So anyways, once the intake, heads, water pump & hoses are off the engine block.....how can I clean the water jackets in the block?

 

[tonysilva530]

UPDATE::

I pulled all the coolant hoses off the engine and smash them to break up the crust that was lining the inside of them. Rinsed out all the crust.

I tried to use water pressure to flush the heater core but it didn't work. I don't know how much psi a garden hose puts out but it wasn't enough pressure to pass thru the clogged heater core.

My brilliant brother suggested I pressurize the heater core with 150psi from my air compressor. I did that and it worked. I got blasted with poop colored rusty specks. Looked like somebody with a bad case of diarrhea pooped all over me.....but I was happy. 🤢

After multiple clasts of water & air the heater core is now cleared.

Oh, and the thermostat was rusted shut. I installed a new thermostat. The engine temperature is good now. Heater core hoses get nice & hot.

Next issues:

The air selection.......fresh air and recirculate air selection. It seems the HVAC is stuck on the recirculate setting. If I twist the knob to the fresh air setting, the door mechanism clicks, clicks, clicks........ So I guess I need to get a new actuator for that particular air door selection.

Another issue is that I hear the slight sound of rod knock. The rod knock is so slight and only occurs when holding the engine rpm around 1,800rpm with the transmission not engaged in any gear. I'm wondering if it's possible to replace the crank bearings without having to pull the engine? And if it's possible and the bearings are replaced.......what are the chances that new crank bearings will eliminate the rod knock.

I've been around the automotive-repair-block enough times to know what I'm doing....just don't know about rod bearings. In the past I'd either replace a knocking engine with a used engine or send it off to have it rebuilt. But this rod knock is so slight that I think the crank journals are still good and the soft bearing material is what is worn away.

 

[tonysilva530]

If replacing crank bearings......can the bearing shells be pushed up around to the top of the crank journals?

Obviously the oil pan will have to be removed to replace the crank journals but is there enough clearance after lifting the engine to remove the oil pan given the fact that the oil pickup tube drops down into the sump?

 

[tonysilva530]

What's the oil pressure? You may be hearing skirt slap.

You never gave us any engine info,

1997 GMC Sierra.
5.7L engine.
Automatic transmission.
2wd.
170,xxx miles.

 

[tonysilva530]

Ok, so.......

I got the engine block flushed out.

I replaced the recirculate/fresh door actuator. No more clicking when using the heater/air conditioner.

The oil filter housing.....it leaks oil. I bought a gasket kit to eliminate this leak. I removed the oil filter and noticed the oil is bad. The oil shows typical signs of coolant mixing so I guess one (or both) head gaskets are bad. I replaced the head gaskets. I haven't put oil in yet, but I'm hoping the bad oil was the reason the engine sounds like it's knocking.

Fingers crossed. 🤞