Rust

I am having some issues with my 1966 327 and I wanted to post here to see if anyone had run into this. I have been doing this since 1980 (messing with GS cars since I bought 4 new) and never had this before.

I have had to replace 3 water pumps in a month. The replacement one was returned to the vendor who sent me pics of it opened-up with brown spots all over it. He said it was from rust in the block.

SO, having drained and flushed the block twice recently--new radiator--and not seeing any rust, I was obviously confused. We purchased a rust product, let it sit in the block according to the directions, and flushed it out with hose water for about 5 minutes. We didn't see any rust, but used new coolant and installed the new pump.

About 50 miles in, the bearing is now making a loud noise again, so I am thinking it is the rust issue again. The only advice I received is that it is not uncommon on old engines that sit, but I have been driving it many times a week ever since I got it (@ 5 years) with the original water pump on it with no issues.

The ONLY major change was replacing the stock radiator with a new one that is made specifically for this car and has improved performance dramatically. It runs at 180 all day no matter how hot it is outside (I live in SO FL, so it gets HOT). The required coolant for this radiator is ZEREX G-05. It ain't cheep, but 2 full + 1 gal distilled water does the trick.

The advice I got said that I should remove a freeze plug and see if it is covered with goop, rust, etc. Not sure I can do this with the engine in the car--not much room to get a screwdriver and hammer in there, but we will try.

So, has anyone had this occur on a block that sat or even if it didn't? This is one of the weirdest things that ever happened to me, and NEVER with any 455 I have owned. Since we purchased the rust product and flushed it out before we installed this pump (and didn't see any rust, etc.) I am totally confused.

These pumps ain't cheep, and putting one on is a royal PIA.

Thanks!

 

My first question is did you use water only for a while or did you always use 50/50? Coolant is not only for freeze protection, it also will protect the metal surfaces from rust. However the rust protection does not last forever. Coolant needs to be changed from time to time because the metal protection additives do get used up.

 

Saw the title and thought maybe Alec Baldwin was going to the Hoosegow.

 

I haven't seen your problem before but wonder if the rust removal product you used is having a delayed affect. also, maybe the block is holding the rust in low spots and only distributing it at higher rpm . Just a thought.

 

Pull the screw in block drain plugs and blow water back through the block. I got a bunch out of one block that was used regularly after I used some acid cleaning product on the cooling system. The product must have disturbed the surface texture of the rust, causing it to keep coming loose even after the clean flush. You will have to take the starter off to access the other plug, if I recall correctly.

 

Typically if there is goop accumulated in the block down near the drain plugs and behind the core plus then the coolant will be brown and continue to be brown until you are able to flush the goo out. But seeing how you are using G-05, I don't know what I'd expect to see because I always use regular old green stuff in any old car. I'm not sure why the radiator maker would specify G-05. Green will work just fine but you shorten the service interval.

Rather than knocking out a core plug first, see if you have access to one or both of the block drain plugs. Core plugs are not a lot of fun on most vehicles, but maybe one or 2 have access. Getting the drain plugs out may be fun too, but if you can get 1 out, you can at least tell what your dealing with.

I've had several old cars in the shop with green (brown!) coolant. I was able to flush them 2 or 3 times per season for 1-2 seasons and they cleaned up. One was a 500ci Caddy, another was a 472 Caddy, and the 3rd was a 64 Dodge something-or-other. There were probably a few more in the last 15-20 years too. I don't recall any water pump issues on any of them either.

 

I’ll take a stab at this.
327, I’m assuming Chevy.
Their pump housings are iron, iron will rust. What the vendor was seeing was probably flash rust from the pump sitting in its box for who knows how long.
So I’d take the rust “issue” out of the equation and chalk it up to crappy rebuilds (bearings) as was mentioned.
You MAY want to check belt tension, pulley alignment, anything that can cause unusual stress on the bearing.
Like was mentioned, the water pump bearing is sealed, so any contact with coolant is a non issue.

 

G-05 was specifically designed for aluminum. There is a lot of difference between G-05 and the green stuff.


Keith

 

I'll pile on about the water pump bearing. Unless the seals are bad the bearing should never see coolant. I remember a Dodge 318 that was so rusty that we had to remove all of the side core plugs to scoop the rust out. It had the consistency of mud. We then pressure washed the cooling passages in the engine as best we could, then gently flushed the heater core and cleaned the radiator (Our shop had a dedicated radiator section with a guy that did radiators). after we chemically flushed the cooling system one last time we filled it 50/50 with Ethelene Glycol anti-freeze and water and sent the guy on his way with a warning that he might have heater core issues. His check didn't bounce and the Dodge full-size Van never came back for cooling system issues. We never touched the water pump, and it survived the whole mess.

 

I have pulled freeze plugs on several old engines and there is ALWAYS rust in there. This doesn't affect the cooling system or the water pump at all.

Maybe the belt is being installed too tight? Sorry if this is a stupid suggestion.

 

And the green stuff is compatible with aluminum too. G05 is a hybrid OAT. Green is OAT.

 

Surface rust is different than goo. And an overtight belt or a fan balance problem are two water pump killers for sure.

 

Traditional green coolant uses silicates for metal protection. It is not OAT. G05 is a hybrid OAT or HOAT. It has low amounts of silicates (as compared to the green stuff). Dex-cool is a true OAT. OAT has no silicates for engine protection.

John is right, the only way the pump bearing will see coolant is if the mechanical seal is puking it onto the bearing lip seal. With a new pump that is not leaking any noticeable amount coolant, there is no way contaminated coolant is having any effect on the pump bearing. Unless of course the lip seals on the bearing are garbage to start with.

 

My bad - old green is IAT. I stock 16-17 different coolants at my shop and have given up trying to re-invent the wheel. 2 of my 455's use AL radiators, one is a Tomahawk, and they both get green and serviced every 3-4 years.

 

All my "hot rods" and classics have aluminum radiators, and my daily driver F100 is aluminum everything except for the block (radiator, water pump, heads, intake), and I still use green in everything myself....One of my Cadillacs would squeal like a piggy after I changed the pump, and a little WD 40 behind the pulley while it was running would silence it immediately. Ended up rebuilding the factory pump with a kit and solved that, the squealer rides in the trunk as a backup for road trips now....as was stated, the rust should never get to your bearing in the first place. With new/replacement parts, you just can't trust them anymore, unfortunately. Even stuff straight from mother gm at the dealership here, sometimes it'll take 4 or 5 new whatever sensors, gear sets, water pumps, fuel pumps, hubs, what have you before you get a good one. It's a frustrating mofo to diag anything anymore.

 

That is absolutely maddening.

 

Did anyone mention heater core? Does the car have one? You flushed the block but ...

 

First, THANKS to everyone who posted. I really appreciate your help and experiences. FYI, the DeWitts Corvette radiator is close to $1000.00, so I use the coolant he says to use...

SO, I called the pump provider and he is sending me another one. We discussed EVERYTHING in the above posts and we have determined to do two things:

1. Check the belt for the right tightness. It COULD be that we tightened it too much. My car has factory A/C, and the entire front of the engine is a major pain to take off and re-install, so that will be job one.

2. Remove the pump, remove the back, and check for 2 things: is there rust in the pump? If so, use THERMOCURE from CRC (spoke to Scott over there and he knows what is what) and flush the block again. Do not remove freeze plugs unless I want a total rebuild, which I cannot afford, and anyway I wouldn't give an engine to anyone in FL to even pack up much less work on. As for block drains, try to keep from messing with them if possible.

3. After removing the pump, pull off the back and see if the bearing area is pulled to one side and is leaking lubricant. If so, belt is too tight, and if no rust, that is the problem.

SO, that is the current plan. I asked the pump vendor about shelf-rust and he said no, that is not what it is. NOW, he recently bought out the man who was doing this for many years and retired, so I am a bit skeptical, but when we take off the back of the pump, we shall see. The good news is that he is NOT going to charge me for a 3rd pump, and I agree that if a new pump is damaged due to my engine rust, it is definitely not his fault.

SO, I will be taking this one off and checking it when the new one comes in from Arizona. By the way, even though I don't show, he always supplies correctly dated pumps for the car because he can.

I will post again when we have more data.

Thanks again to everyone who posted. Forgive me not answering each one individually. I read and learned from each of them.

Cheers!