3rd Heater Core Plugged In 6 Months...

[Exhaustgases]

Next time, get the tech or manager to allow you or them to open up the failed heater core, on the spot.
It could be a defect and something is coming apart and blocking it inside. But then I guess more trucks would be showing up with the problem. Could be a bad hose somewhere in the system feeding the heater? Or someones over use of RTV.

 

[JWC86]

Next time, get the tech or manager to allow you or them to open up the failed heater core, on the spot.

How do you suggest I do that?

 

[Joba27n]

Next time, get the tech or manager to allow you or them to open up the failed heater core, on the spot.
It could be a defect and something is coming apart and blocking it inside. But then I guess more trucks would be showing up with the problem. Could be a bad hose somewhere in the system feeding the heater? Or someones over use of RTV.

Thats also most likely a no-no. Warranty parts have to be returned intact

 

[JWC86]

Update:

At some point after my last heater core I decided I would install a coolant filter if/when my heater core plugged again OR if it wasn't plugged by the start of this winter I would do it then.

I had the truck in the shop a bit ago for some warranty work so I just had them install the filter, the heater was blowing good heat so I figured it must not be plugged. The coolant filter is a bypass style, its plumed into the heater core supply where it steals some of the flow and goes through the filter and returns it to the overflow tank.

The unit came with a Wix filter that seemed ok so I left it on for the first interval. I picked up a 6 pack of Donaldson filters to go back on.

I was doing a oil change on the engine last night so figured I would pull the coolant filter and have a look at it. It had 150 hours on it. (About 3,000 miles)

There was easily twice as much sediment as what is shown in the pictures that got poured out and a bunch of sludgy coolant also.

I put in a Donaldson filter and will run it for longer than the 150 hours I ran this one for, not sure how long... maybe 300 hours?

 

[KrisZ]

Why on earth would the cooling system have so much sand in it? Good call on installing the filter, but Ford simply builds junk, this level of quality is simply unacceptable IMO.

 

[Fordiesel69]

Problem found, but not solved.

You sir fell victim of an engine that was not properly washed after its casting. Jeep 3.7L engines had this. The factory had improper rinsing techniques and that was the result.

The solution is a new engine unfortunatley. Or you will need to strip the engine down to the block and remove all the freeze plugs and have a mahine shop hot tank it. Then re-assemble.

Very sad. I would be very bummed.

 

[JWC86]

Problem found, but not solved.

You sir fell victim of an engine that was not properly washed after its casting. Jeep 3.7L engines had this. The factory had improper rinsing techniques and that was the result.

The solution is a new engine unfortunatley. Or you will need to strip the engine down to the block and remove all the freeze plugs and have a mahine shop hot tank it. Then re-assemble.

Very sad. I would be very bummed.

Seems a bit dramatic or I'm I crazy? I have 5800 hours on this engine already. If I continue to filter out the sand I should be ok?

 

[zzyzzx]

He doesn't think the tech did much of a flush despite what he wrote in his notes.

Fixed:
He doesn't think the tech did a flush despite what he wrote in his notes.

 

[zzyzzx]

I would ask for your old heater core back. I'd like to see it. Sand, scale, sludge what is plugging it. That will tell you what to do next.

For warranty work they aren't going to do that.

 

[CDX825]

I figured it had to be casting sand. There is probably a bunch of it laying in the bottom of the cooling passages in the block. Pulling the block drain plugs and flushing would help a lot.

 

[BC1]

You should be fine now with the filter. This sand was not uncommon on the 7.3s as well. I still see it in my overflow tank every few years when I do a coolant swap. Thankfully it has not caused an issue.

 

[KrisZ]

Seems a bit dramatic or I'm I crazy? I have 5800 hours on this engine already. If I continue to filter out the sand I should be ok?

Yes what you're doing is fine, but this is bitog where spending someone else's money is always easy in order to fit an arbitrary definition of "doing it properly".

 

[Fabulous50s]

Thank you for all the updates, and keeping this going!

Did you ever see any of this rusty sand collect in the degassing (expansion) tank? That is crazy, the dealer just keeps replacing the same part u der warranty, never getting to the bottom of it until now. After 2nd heater core, you'd think a filter and some investigation as to what the root cause would have happened. Rather than rinse and repeat the same story.

You'd think Ford would have had some say in it rather than pay for heater core R&R over and over.

 

[JWC86]

Did you ever see any of this rusty sand collect in the degassing (expansion) tank?

No, none in the expansion tank and the coolant actually looks very clean surprisingly.

That is crazy, the dealer just keeps replacing the same part u der warranty, never getting to the bottom of it until now. After 2nd heater core, you'd think a filter and some investigation as to what the root cause would have happened. Rather than rinse and repeat the same story.

You'd think Ford would have had some say in it rather than pay for heater core R&R over and over.

You have more faith in auto manufactures than me...

 

[Fabulous50s]

I've never had much faith in dealer techs. Likely because I was an independent mechanic for years.

I guess I just assumed a manufacturer/ dealer would red flag something and try and avoid spending more $ and time on a problem child.

 

[nthach]

I know in the Jeep community if OAT and HOAT are mixed there are all kinds of problems, with things plugging up. I wonder if there is a compatibility problem with the wrong coolant being mixed in?

Prestone “claims” that their xOAT coolant can play nice with IAT and HOAT like G-05/48. I don’t believe it but in the real world where people are topping off their cooling systems with whatever coolant they can find, there hasn’t been widespread reports of issues.

 

[nthach]

Problem found, but not solved.

You sir fell victim of an engine that was not properly washed after its casting. Jeep 3.7L engines had this. The factory had improper rinsing techniques and that was the result.

The solution is a new engine unfortunatley. Or you will need to strip the engine down to the block and remove all the freeze plugs and have a mahine shop hot tank it. Then re-assemble.

Very sad. I would be very bummed.

Yea, if it was coolant incompatibility, the forming residue wouldn’t be rusty. It’ll be more clear or gel-like or a different color. That stuff looks like Dex-Sludge - which was poor design/QC, not because of 2-EHA(which did attack the IMGs GM used at the time).

 

[JWC86]

Just had the 4th heater core replacement done, no surprise given what we saw in the filter.

This time they also replaced the radiator, pulled the block heater and flushed block with the pressure washer, new degas bottle, new thermostat and new block heater.

Coolant filter was replaced, I have a oil change in about 150hrs so I'll cut the filter open then and see what we see.

 

[JWC86]

So 200hrs later after the 4th heater core and new radiator I changed the coolant filter mostly because I wanted to see what was inside it.

I poured the filter out onto a rag.

More casting sand.

Maybe I'm overreacting but I'm starting to agree with the previous member that said a new engine is the only way to solve this mess.

If this was just a regular truck for me I would sell it and buy another but I've spent a significant amount of time and money outfitting it for my work so that's not a option. I would pay out of pocket for a motor before I did that.

Here's what I'm thinking for a plan:
- Reach out to ford to see if they will replace the motor(yeah right) or extend the warranty for this problem(doubtful)
-Install a full flow filter inline of the heater core but I would be worried about heater performance in very cold temps (sub -20), I guess I could have a bypass for really cold temps but now were talking more plumbing and space in the engine bay isn't unlimited.

 

[Fabulous50s]

Thanks for the C&P on that filter.

FWIW, I dont think your heater performance would change much with a full flow filter ahead of it. It takes a surprisingly small flow of coolant to make heat, even at -20F.

I would pipe in the filter housing with a bypass valve just in case its really cold and you notice the heater not keeping up. Open the bypass slightly if you need to.

Ive found ¾" crimp pex ball valves to fit perfectly with ⅝" heater hose. Buy spring clamps for all your connections, they wont leak in the cold like worm clamps can.