Ok, having gotten that out of the way....

 

The car is a 1988 GL wagon, SPFI, Auto. Recently swapped in a motor with about 130k or so on it. Got the engine in and running. When we added coolant and let it run up to temp the first time, we found that the upper radiator hose was showing signs of high pressure, but didn't feel like a lot of flow. Recently, when I run it up to temp the first time of the day, it will blow bubbles in the catch can when I shut it off. Now, I might think this is a sign of blown headgaskets except there are NO other signs of headgasket failure. No crankcase milkshake, no cloud of steam following me around, nothing. It doesn't seem to do the bubble blowing thing unless I let it cool all the way down.

 

Any thoughts?

Engine installed backwards? Next time, use a better mechanic.

 

We never checked the lower hose for pressure/temp, did we? Top of my list would be thermostat... I don't remember touching it. Plugged radiator comes to mind, but the radiator worked with previous engine...

 

(FWIW, I did HGs on an XT and it did some of this same weirdness. Didn't figure it out before I had to move on to my next crisis.)

Yeah, I don't know what I was thinking taking it to that guy. What a tool!

Ok, having gotten that out of the way....

 

The car is a 1988 GL wagon, SPFI, Auto. Recently swapped in a motor with about 130k or so on it. Got the engine in and running. When we added coolant and let it run up to temp the first time, we found that the upper radiator hose was showing signs of high pressure, but didn't feel like a lot of flow. Recently, when I run it up to temp the first time of the day, it will blow bubbles in the catch can when I shut it off. Now, I might think this is a sign of blown headgaskets except there are NO other signs of headgasket failure. No crankcase milkshake, no cloud of steam following me around, nothing. It doesn't seem to do the bubble blowing thing unless I let it cool all the way down.

 

Any thoughts?

 

Kinda sounds like the cooling system may have a vacuum leak that allows air to enter instead of just coolant from the overflow bottle when shut down.Sometimes these leaks are one-way(no coolant loss)

 

I would heat up the engine w/the rad cap off,shut down and reinstall the cap,and then attach a vacuum pump and gauge to the overflow to see if the system holds vacuum.

 

Or,just disconnect the overflow bottle and put the gauge(only) at the end of the tube.

It should pull and hold vacuum as it cools down.

 

 

Or, just tighten the hose clamps.

Edited December 23, 201015 yr by naru
easier method

How much water did it take to fill? Just sounds like a big-o air lock in the system. Running up to full temp with the radiator cap off change any thing?

Was the themostate checked or changed? Did you have full heat while running the engine at full temp? If you had low heat temp. it is just an air lock and low on water in the system.

It took nearly 2 gallons of pre-mix but the engine we put in was not completely empty. It sloshed a bit. I'll try purging it again.

I'd suspect the thermostat-start with the simplest thing.

weak radiator cap? or am I missing something here?

weak radiator cap? or am I missing something here?

 

Maybe this?

 

"It doesn't seem to do the bubble blowing thing unless I let it cool all the way down."