This is my second season with my '84 Allegro. Bought it with a blown engine. Put a Craigslist-found 454 in it (truck spec GM Performance crate engine). When I got the engine home, put it on a stand and turned it upside down a bunch of rusty water came out of it. An alarming amount actually.
With the water pump off of it I ran water through it until it came out clean. Last year was the first camping season with it. It ran great, though on the warm side.
This year, on my last trip out, it overheated pretty bad. I could not get it to cool down.
Yanked the radiator and brought it to a local shop to be rebuilt. For a significant sum of money, I'm getting an all-new radiator custom built. The rad shop called me today and said my problem was that there was a baseball-sized chunk of rust clogging the inlet side of the radiator. The radiator was toast anyway, but they advised me to figure out why this happened otherwise the new radiator will meet the same fate.
So - I need to clean the block out some how. On the one hand I'd like to think the many heat cycles have dislodged most of the rust in there. Upon removing the radiator the lower hose drained clean. I took the thermostat housing off and hosed out the engine - came out clean too. But how can I be sure?
The radiator guy suggested yanking out the drain plugs and seeing whats in there. He suggested pulling out the freeze plugs too.
So....does anyone have any advice that's different than this? Ideas would be appreciated.
With the water pump off of it I ran water through it until it came out clean. Last year was the first camping season with it. It ran great, though on the warm side.
This year, on my last trip out, it overheated pretty bad. I could not get it to cool down.
Yanked the radiator and brought it to a local shop to be rebuilt. For a significant sum of money, I'm getting an all-new radiator custom built. The rad shop called me today and said my problem was that there was a baseball-sized chunk of rust clogging the inlet side of the radiator. The radiator was toast anyway, but they advised me to figure out why this happened otherwise the new radiator will meet the same fate.
So - I need to clean the block out some how. On the one hand I'd like to think the many heat cycles have dislodged most of the rust in there. Upon removing the radiator the lower hose drained clean. I took the thermostat housing off and hosed out the engine - came out clean too. But how can I be sure?
The radiator guy suggested yanking out the drain plugs and seeing whats in there. He suggested pulling out the freeze plugs too.
So....does anyone have any advice that's different than this? Ideas would be appreciated.
Thanks all for the replies.
As mowermech implied, if I had the time and money to "do it right", I would have :). Naturally I wanted something reliable, but not break the bank (the motorhome cost me $200). The engine was allegedly low-mileage, and an internal inspection verified this. I purposely got something that wouldn't (or shouldn't) need rebuilt. The rust in the block was a bit of a curve ball. Now that I've paid almost as much for a new radiator as the engine itself, I need to take some extra measures.
I'd like to think that it's cleaned itself out and deposited all the rust in the old radiator. Based on all the conversation here I think I'll pull the drain plugs and rinse it out to see what happens. If it's clogged up (won't drain, or ugliness comes out) then I'll run something like Evapo-Rust through it.
As mowermech implied, if I had the time and money to "do it right", I would have :). Naturally I wanted something reliable, but not break the bank (the motorhome cost me $200). The engine was allegedly low-mileage, and an internal inspection verified this. I purposely got something that wouldn't (or shouldn't) need rebuilt. The rust in the block was a bit of a curve ball. Now that I've paid almost as much for a new radiator as the engine itself, I need to take some extra measures.
I'd like to think that it's cleaned itself out and deposited all the rust in the old radiator. Based on all the conversation here I think I'll pull the drain plugs and rinse it out to see what happens. If it's clogged up (won't drain, or ugliness comes out) then I'll run something like Evapo-Rust through it.
dodge guy wrote:
I'de pull the most accessible freeze plugs. You'de be surprised what can hide at the bottom of a block! When I had my Dodge conv. van with the 5.9 I had a freeze plug start to leak (rusting from the inside out). I pulled all the plugs and flushed the block from the front to back and back to front. Installed the new freeze plugs and fresh coolant. That alone dropped the coolant temp about 15 degrees. After that I installed a new radiator and fan clutch and it again dropped a bit more. The engine always ran about 210 when I got it. After all that even when towing it took a lot to get it to break 200 deg.
Thanks. I turned it upside down for a few days to try to get the junk to move out.
Rusting from the inside out is a pretty good indication that there's junk stuck in there.
FIRE UP wrote:
Turbo,
Just a word here. While water pumps do a fair job of moving water/coolant throughout the engine, they do have a hard time "removing" debris/sand/large scale deposits/etc. that is lodged down in the water jackets and cylinders and block walls, way down low in the water jackets. I proved that many-a-time when I had the blocks out and on a stand, and even in some chassis that I did "in-chassis" rebuilds.
Now, again, that was way back then. I have no idea on how well the later engines are prepped for assembly these days. You're replacement is close the year/models I worked with . And, it did not matter what maker. I had the same results from tear-downs on Ford, Chevy, Dodge, AMC, Ford Courier, and more. Good luck on your venture.
Scott
It's one of the last Mark IV big blocks manufactured with a 1990 date stamp. I'll see what I can do to get it cleaned out as much as possible. I'm hoping I don't find anything significant when I pull the drain plugs. Yeah, I should have done that while it was on the stand in the driveway (note the rusty puddle):
But it's in there now - waiting for that radiator!
turbojimmy wrote:FIRE UP wrote:
TurboJimmy,
Long, long ago in a far away place, (Star Wars stuff, remember?) I used to rebuild engines for side job. When I pulled them and put them on stand to perform surgery on them, I'd take them all the way down to a gain as much access to any portion of the block I could get my little hands on.
Every single time, I'd pull every freeze plug and drain plug. You'd be surprised on how much SAND I'd find in there, big chunks of black carbon, solid chunks of pure rust etc. I'd have to pry much of it out and or, use a chisel and break much of it up to be able to remove it through the freeze plug holes. Once all the debris, sand and other big stuff was removed, then I'd hit with special, long nosed nozzle that I had for my garden hose. You'd still be surprised at what came out as a result of using that nozzle.
That was then, (from about '65 to, oh around '90 is when I quit that non-sense) and this is now. Unless it's an old hot rod, i.e. '60s Chevy etc., I won't even think about pulling an engine in a motor home. But, back to your issue. Yep, pulling the freeze plugs is the least you can do to get the closest inspection at the cheapest cost. Freeze plugs are cheap.
If you have one or, have access to one, you can use an "Inspection camera" to get into many tight places, inside the water jackets of that block. You know, the kind that Home Depot, Lowes, and other tool places sell. I got mine from Costco quite a while back and, it's not the best but, it sure works for getting into very tight places and seeing what's in there. Good luck.
Scott
Thanks! I'll start with the drain plugs, assuming I can free them up. If it looks bad, I'll start pulling freeze plugs. I'm hoping that the problem was the clogged radiator and not clogged coolant passages - maybe the gunk made its way through the block and accumulated at the radiator inlet. The rad shop told me that the stock high efficiency radiator is made of many smaller tubes rather than some smaller amount of larger tubes. Smaller tubes clog easier. Dunno.
Yanking the engine out isn't really that bad. On the '84 there's not a lot to unhook. The 454 comes out the door easily without the exhaust manifolds on it. Everything is easy to get at. Not that I want to do it again, but far better than replacing the TCC solenoid on a FWD Northstar Cadillac, for example (top of the list of things I will never do again).
Turbo,
Just a word here. While water pumps do a fair job of moving water/coolant throughout the engine, they do have a hard time "removing" debris/sand/large scale deposits/etc. that is lodged down in the water jackets and cylinders and block walls, way down low in the water jackets. I proved that many-a-time when I had the blocks out and on a stand, and even in some chassis that I did "in-chassis" rebuilds.
Now, again, that was way back then. I have no idea on how well the later engines are prepped for assembly these days. You're replacement is close the year/models I worked with . And, it did not matter what maker. I had the same results from tear-downs on Ford, Chevy, Dodge, AMC, Ford Courier, and more. Good luck on your venture.
Scott
FIRE UP wrote:
TurboJimmy,
Long, long ago in a far away place, (Star Wars stuff, remember?) I used to rebuild engines for side job. When I pulled them and put them on stand to perform surgery on them, I'd take them all the way down to a gain as much access to any portion of the block I could get my little hands on.
Every single time, I'd pull every freeze plug and drain plug. You'd be surprised on how much SAND I'd find in there, big chunks of black carbon, solid chunks of pure rust etc. I'd have to pry much of it out and or, use a chisel and break much of it up to be able to remove it through the freeze plug holes. Once all the debris, sand and other big stuff was removed, then I'd hit with special, long nosed nozzle that I had for my garden hose. You'd still be surprised at what came out as a result of using that nozzle.
That was then, (from about '65 to, oh around '90 is when I quit that non-sense) and this is now. Unless it's an old hot rod, i.e. '60s Chevy etc., I won't even think about pulling an engine in a motor home. But, back to your issue. Yep, pulling the freeze plugs is the least you can do to get the closest inspection at the cheapest cost. Freeze plugs are cheap.
If you have one or, have access to one, you can use an "Inspection camera" to get into many tight places, inside the water jackets of that block. You know, the kind that Home Depot, Lowes, and other tool places sell. I got mine from Costco quite a while back and, it's not the best but, it sure works for getting into very tight places and seeing what's in there. Good luck.
Scott
Thanks! I'll start with the drain plugs, assuming I can free them up. If it looks bad, I'll start pulling freeze plugs. I'm hoping that the problem was the clogged radiator and not clogged coolant passages - maybe the gunk made its way through the block and accumulated at the radiator inlet. The rad shop told me that the stock high efficiency radiator is made of many smaller tubes rather than some smaller amount of larger tubes. Smaller tubes clog easier. Dunno.
Yanking the engine out isn't really that bad. On the '84 there's not a lot to unhook. The 454 comes out the door easily without the exhaust manifolds on it. Everything is easy to get at. Not that I want to do it again, but far better than replacing the TCC solenoid on a FWD Northstar Cadillac, for example (top of the list of things I will never do again).
turbojimmy wrote:
This is my second season with my '84 Allegro. Bought it with a blown engine. Put a Craigslist-found 454 in it (truck spec GM Performance crate engine). When I got the engine home, put it on a stand and turned it upside down a bunch of rusty water came out of it. An alarming amount actually.
With the water pump off of it I ran water through it until it came out clean. Last year was the first camping season with it. It ran great, though on the warm side.
This year, on my last trip out, it overheated pretty bad. I could not get it to cool down.
Yanked the radiator and brought it to a local shop to be rebuilt. For a significant sum of money, I'm getting an all-new radiator custom built. The rad shop called me today and said my problem was that there was a baseball-sized chunk of rust clogging the inlet side of the radiator. The radiator was toast anyway, but they advised me to figure out why this happened otherwise the new radiator will meet the same fate.
So - I need to clean the block out some how. On the one hand I'd like to think the many heat cycles have dislodged most of the rust in there. Upon removing the radiator the lower hose drained clean. I took the thermostat housing off and hosed out the engine - came out clean too. But how can I be sure?
The radiator guy suggested yanking out the drain plugs and seeing whats in there. He suggested pulling out the freeze plugs too.
So....does anyone have any advice that's different than this? Ideas would be appreciated.
TurboJimmy,
Long, long ago in a far away place, (Star Wars stuff, remember?) I used to rebuild engines for side job. When I pulled them and put them on stand to perform surgery on them, I'd take them all the way down to a gain as much access to any portion of the block I could get my little hands on.
Every single time, I'd pull every freeze plug and drain plug. You'd be surprised on how much SAND I'd find in there, big chunks of black carbon, solid chunks of pure rust etc. I'd have to pry much of it out and or, use a chisel and break much of it up to be able to remove it through the freeze plug holes. Once all the debris, sand and other big stuff was removed, then I'd hit with special, long nosed nozzle that I had for my garden hose. You'd still be surprised at what came out as a result of using that nozzle.
That was then, (from about '65 to, oh around '90 is when I quit that non-sense) and this is now. Unless it's an old hot rod, i.e. '60s Chevy etc., I won't even think about pulling an engine in a motor home. But, back to your issue. Yep, pulling the freeze plugs is the least you can do to get the closest inspection at the cheapest cost. Freeze plugs are cheap.
If you have one or, have access to one, you can use an "Inspection camera" to get into many tight places, inside the water jackets of that block. You know, the kind that Home Depot, Lowes, and other tool places sell. I got mine from Costco quite a while back and, it's not the best but, it sure works for getting into very tight places and seeing what's in there. Good luck.
Scott
