4.0 OHV top end redo

[Dantheman1540]

I've seen gritty, rusty coolant erode the water pump impeller and drastically reduce it's flow.
Not to nag but it still doesn't sound like you've pulled the block drains, without that you'll never get it cleaned out.

Block drains as in freeze plugs? If I was going to commit to that I’d just pull the motor that sounds like a miserable in truck task. If the motors coming out I don’t think I’d put a 4.0 back in.

The impellor issue on the water pump is a good one. I've never experieinced it but an impellor broken loose from the shaft and/or the impellor being so worn down that it doesn't move coolant is a thing.

While the 4.0 OHV engine isn't as finicky as the 2.9 with overheating, after you get the issue(s) figured out, you might want to consider getting the heads and block checked out for warping. More work, I know, but better to find out now than later when it's less convenient and will be more expensive.

Would be wild to see the water pump chewed up so quickly I don’t think it’s got much more than 5k on it. But I’ve seen jet engine blades chewed up by sand very quickly!

Again if the block is coming out a 4.0 ain’t going back in.

 

[Dantheman1540]

Well, I thought it was doing good with the new cap. I beat the snot out of it on the way home, even doing a 3rd gear pull from 2k-4.5k WOT the entire time up to like 75mph which is possibly the fastest I’ve ever had it. Truck didn’t seem to care at all and the needle hovered over the N. Then I turned down my sandy road and let it rip in 2nd gear through the sugar sand for a 1/4mile or so and it boiled over as I pulled into my driveway 100yards after the sandy road.
Not sure if the load is very different in the engine between the two, or if the long 3rd gear pull heat just hadn’t registered yet.

I added the coolant filter today spliced into both heater core hoses with Tees. I know it’s only a passive filter but it certainly can’t hurt.

 

[19Walt93]

The freeze plugs aren't the block drains. There will be a plug screwed into the block a little lower than the freeze plugs on either side. Sometimes they're allen heads, sometimes they have square heads or even hexes.

 

[Dantheman1540]

The freeze plugs aren't the block drains. There will be a plug screwed into the block a little lower than the freeze plus on either side. Sometimes they're allen heads, sometimes they have square heads or even hexes.

Oh I was not aware of that, I will look for those!

 

[Dantheman1540]

Got busy at work and took a break from messing with this thing for a few days but I’m back at it! I went to do a simple drain and fill and noticed the petcock was spraying funny like I often do with morning wood. So I stuck a piece of wire in it and some small rust pieces came out. I hadn’t considered there being so much crap at the bottom of the radiator that it would actually block the drain hole.
So I pulled the entire drain plug assembly out which probably leaves a 3/4” hole vs the 3/8” hole of the petcock drain. The picture is some of what came out in the initial opening of the bigger hole. Some pieces are nearly dime sized! I did another half dozen fill and drains and lots of rusty treasures came out. I will co time to do drain and fills every day until nothing at all is showing up in the bottom of the bucket.

 

[alwaysFlOoReD]

The side tanks are being emptied but the tubes between the tanks will still be clogged. On initial startup, after a few minutes, see if you can safely feel the fins and you will know which tubes are clogged. I would do a replacement if more than 1/4 are clogged.

 

[Dantheman1540]

The side tanks are being emptied but the tubes between the tanks will still be clogged. On initial startup, after a few minutes, see if you can safely feel the fins and you will know which tubes are clogged. I would do a replacement if more than 1/4 are clogged.

I will try to do that, went for a good long drive and it still got warm so you’re right it’s still clogged up.

 

[Dantheman1540]

Did a bunch more flushes including a rust dissolving one and here’s what comes out now. This was straight water only run for a 30min idle cycle with the heater on full blast.

I didn’t take a picture of what came out after the rust cleaner but it wasn’t as much yuck as I was hoping for. I’ll drive it around some the next few days and see if it gets hot, if it does I’m thinking it’s not the radiator and must be the head gasket or water pump. I’ll prob do another head gasket test tomorrow to totally rule that out.

 

[SenorNoob]

Looks good. It is possible to have cleaned all the loose stuff out of the system and still have lined clogged in the radiator though.

 

[Dantheman1540]

Well I did two vinegar baths over the last three days. First one was just the radiator for 24 hours with white vinegar, which didn’t seem to change colors or get much contaminants out. Second one I actually drove to work and back with nothing but vinegar in the truck then drained it. That time the vinegar turned a light brown and had a decent amount of gunk in the bottom, not as much as I’d have expected but I’m hopeful.

So I flushed the system with water and I will thrash it tomorrow. I will note that with the system full of vinegar which had sat over night before I drove it to work. The gauge seemed to stay cooler than the day before, so maybe that’s a good sign. I know this picture is difficult to see but when looking down into the radiator it’s clean as can be, before you could see sand like rust particles gathered in the bottom. Also the gauge in the other picture was after an 11 mile drive to work.

 

[RobbieD]

That looks good. I think that you've got it as clean as it'll get.

I hope that you saved the vinegar, to make some pickles with.

 

[Dantheman1540]

That looks good. I think that you've got it as clean as it'll get.

I hope that you saved the vinegar, to make some pickles with.

Nope it ended up on some weeds next to my driveway lol. I’m just praying I don’t have to put a water pump in it because I’m lazy and just want to rip this thing on some trails again.

 

[Dantheman1540]

Alright I went and did a torture test and it’s doing better, but not good enough. So I pulled the rad, water pump, therm housing, and all the hoses for inspection.

The water pump looks fine to me, however I already ordered a new one and it will be here tomorrow. It was on sale a gates model for $43.

The thermostat neck is really corroded so I ordered a new one of those as well. The inside of the intake looks really good imo and besides being kinda stained orange there’s no flakes, sediment, or slime even when I rub it with a finger.

Hoses all look good, but I bought replacements for the heater core lines so I can remove the coolant filter I had spliced in. (More on that later). I also search through the auto parts store rad hoses for a better fitting lower hose and have a few options I’ll try out tomorrow when the water pump comes.

The rad does not look so hot. I could see small rust pieces stuck in the inner tubes by looking down the hose ports. I could lots of sediment still on the passenger side, and it almost appeared the passenger side had never been cleaned. Where the driver side which has the fill cap legit looks spotless, no sediment, no slime, just bright pretty AL. So I’m guessing the cleaners and vinegar never made it to the passenger side in full force due to the clogged passages. So I have it currently laying flat, ports up and filled to the brim with more vinegar. I already have it a two hour soak like that today and after wards I could no longer see sediment physically clogged in passages, but I figured letting it sit overnight would clean even more.

Lastly, I pulled the coolant filter honestly expecting not much since it was Ted in and more of a passive filter. Boy oh boy was I wrong! I wish I had taken pics but I recently ruined a phone case by touching it with chemicals and don’t want to ruin another. I used my filter cutter on it and it was slap full of sediment and slime! I’m very impressed with it although I’m not putting it back. The reason I’m not putting it back is because there’s not many good places to mount it, and I don’t want to have more coolant lines with more hose clamps running everywhere inviting possible leaks or blowouts on the trail. Instead I’m running an in-line filter that will go in the upper rad hose with a mesh screen and sight glass so I can physically see what’s happening. Plus being able to remove it easily in the trail and clean it out will be nice.

Oh and I tapped all the bad therm housing holes and cleaned the water pump mounting holes as well so it should be easy to install.

 

[Dantheman1540]

Well got it all back together and no better. I’m still waiting for the glass filter to come in so I’m gonna leave it as is till that shows up and see how much junk it catches. In the mean time I’m gonna play around with the idea of cutting and hacking a 34” 05 Silverado radiator and efans to fit. I just happen to have a very nice all AL setup laying around.

 

[Dantheman1540]

48 hours and 20miles of driving with the Evaporust has yielded these results. It turned from clear to straight black! I then flushed the entire system with water and added this nice jegs filter before the radiator to hopefully catch bits before it clogs further. Going to buy more evaporust tomorrow and I believe the new heater core is coming soon.