TDI DIY coolant filter

[Shawn67]

My 2015 TDI clogged its heater core at 81k miles. I had flushed the system shortly before it clogged as part of a water pump replacement. After I put the new core in it clogged again in a few weeks. I removed the core and back flushed it with Preston radiator cleaner. I also flushed the system with another 2.5 gallons and put a temporary filter in the coolant return line to see if it would catch any junk in the coolant.

It did.

I cleaned that filter about 15 times and it was still removing material from the coolant. As such I decided to try adding up a more permanent filter. I bought a "Coolant Filtration System for 5.2007-2012 DODGE RAM 6.7L Cummins Diesel Turbo" on ebay for $49 and from the kit I really ended up only using the filter housing, filter and the mounting bolts.

I was considering drill the mounting holes in the filter housing all the way through so it could be mounted from up top but decided against it in case I screwed up the threads. Instead I made my own bracket from a cut down corner shelf bracket I had around.

The positioning of this is *tight*.

Test fitting...

I used 3/8" MNPT nut to 1/4"FNPT adapters and then 1/4" MNPT to 5/16" hose barbs for the housing.

For the inlet to the filter I took the hose from the coolant reservoir return off completly and connected the hard fitting on the engine to the filter with 5/16" hose.

As a test run to make sure it was flowing coolant I ran a clear tube from the outlet of the filter back into the reservoir and looped it so I could see it while it was running. Not a lot of flow at idle but it flows more once it gets above idle. This is the first run so the air is from the filter filling up.

https://flic.kr/p/2nXBTb3
From the engine side...

https://flic.kr/p/2nXAtuU
The dripping from the filter is due to the vinyl tube being too large so the barb wasn't right for it. This was just for a test.

Plumbed in for real with 5/16" hose.

Hopefully, as the coolant is circulated through this over time it will get any remaining or future gunk out of the coolant.

Concerns/areas of improvement...

To remove the fuel filter or to service the AC the coolant filter housing has to be moved. Also, to change the coolant filter the housing needs to come up as I don't think there is enough clearance to unscrew and remove it between the bottom of the filter and the AC lines.

Two mounting bolts for the housing and it is free. Ratcheting wrenches make install/removing the filter housing easier. If I had drilled it to be top mounted this would be easier still. I left extra slack in the hoses to make this easier.


The filter position is tight to the engine. I have about an inch of clearance between the bottom of the filter and one of the engine mounted hoses. Hopefully that is enough to account for engine movement. I am looking for a shorter coolant filter to get more clearance there and to also hopefully be able to change it without having to unmount the housing. This was the only space I could find for the housing, at least from the top of the engine. I didn't go looking above the splash guard. The filter housing can have the outlet on either side. It *might* have been possible to rotate this 90 degrees clockwise and have a 90 degree barb on the other side but it would be very tight that way too.

Shawn

 

[x1800MODMY360x]

What coolant are you running now? The G13 or G12?

 

[Shawn67]

I am using G13.

Shawn

 

[watatrp]

Very nice. I'm using a very similar setup on my 06 Ford diesel truck except I'm catching sand from the block left behind during casting. I'd much rather catch sand than the slime.

 

[Shawn67]

Thanks, I'm just hoping to get all the junk out of the system. I'm thinking about changing the filter out at a pretty low mileage and then cutting it open to see what ends up being inside.

Couple of little tweaks after a few test drives. The housing comes with a hex key plug installed on the opposite side from the outlet. Once the system was pressurized this plug had seepage around the threads. I took it out, cleaned the threads in the housing and tried resealing it but it still wept. I ended up replacing it with a different plug and now it looks good. Also added a little bit of vinyl pipe as a chafe guard from the inlet hose where it touches the fuel filter hex bolt.

 

[Tom in PT]

Thanks for posting this. What is the filter media - a metal mesh or a paper?
Also, so I am completely clear, you run the return hose that normally goes back to the reservoir first to the inlet of the filter, and then the outlet of the filter is plumbed to the reservoir return fitting?

 

[Shawn67]

Pretty sure it was paper or fiber based. I'm going to change the filter after a couple of hundred miles either with a cat coolant filter or a Napa 4070 coolant filter. I think they will both fit this base.

You have the plumbing correct. I pulled the original return hose completely and connected a 5/16" hose from the fitting on the engine to the inlet of the filter. Then a 5/16" hose from the outlet of the filter back to the reservoir return fitting. The kit I bought has a couple of ball valves included with it. Was thinking I might Y the fitting on the engine to both ball valves and then run one to the filter and the other to the reservoir with a Y there too. That would let me bypass the filter if I ever wanted to. If nothing else I am going to add one between the engine and the filter so I can close that off when doing a filter change to try and prevent any air from getting into the system.

 

[Andyinchville1]

HI,

I like the idea of a coolant filter ... I know some big rigs run them but never seen the idea gain too much traction on smaller vehicles ... I wonder why ? I suppose in theory it may help water pumps last longer (no grit messing up seals etc...)?

Andrew

 

[drew_t]

Good thread. It’ll be interesting to see what that filter catches.

 

[Tom in PT]

Is there any concern that the restriction presented by the filter might overly pressurize the rest of the cooling system? Just wondering if anyone has thought of that.

Also, it would be helpful if Shawn could post his suggested filter change interval (at least for his '15 at ~ 81,000 miles. Are you checking the pH of your coolant?

 

[Shawn67]

I thought a bit about that. The filter fits in a return to the reservoir, it is a small feed going to the reservoir, literally a 5/16" hose. Only a tiny portion of the coolant would flow through that. It it is really just a small bypass to let a portion of fluid get back to the reservoir and to give air a path out of the different coolant loops through the different valves in the system, several of which are closed most of the time. As such the restriction should be minimal. Of course that means it is filtering a portion of the coolant but over time it should eventually get it all, at least in the main loop. If the filter fully clogged that could make it harder for the engine to get air out. I mentioned the Y setup above. If that was in place one could leave a little bypass around the filter too to make sure that situation never happens.

As far as the filter change interval I don't know. When people add filters like this on the Powerstrokes and Cummings diesels it sounds like they change the first filter around 500 miles and then maybe a 1000 and then change it with the oil changes. Those engines end up with a lot of casting sand in their coolant loop though so it is a somewhat different situation. I will probably remove the filter this weekend and dump it out to see what it looks like and then decide if I am going to change it or reinstall it. If I change it out I will cut it open to see what is inside.

Shawn

 

[740GLE]

im more interested in knowing that there is flow at all.

My understanding is that's more of a vent to help bleeding, everything that sources that line has a check valve so it's a one way flow.

If there is flow on the line that may indicate that you have additional blockage/reduced flow in the system some other place.

 

[forrest resto`s]

Can some please assign what parts are the numbers are on that diagram please (some I identify with, others ?)?

 

[Shawn67]

im more interested in knowing that there is flow at all.

My understanding is that's more of a vent to help bleeding, everything that sources that line has a check valve so it's a one way flow.

If there is flow on the line that may indicate that you have additional blockage/reduced flow in the system some other place.

It could also mean that one of the valves is normally open under typical running conditions. Pull your return, it is easy to check for flow.

Shawn

 

[Shawn67]

Can some please assign what parts are the numbers are on that diagram please (some I identify with, others ?)?

 

[Tom in PT]

FYI I believe that is the diagram of the '15, the cooling system for '12-'14 years is totally different.
Anyway, I am thinking about the "Shawn67 Mod" but if I do it I am going to go with a clear housing type of filter so I can see what is going on.

I just did another drain of my radiator (G13 -> G12+) and I see a few very small black flakes of some dirt or something like that and no orange goo from G13 glycerin. I'll probably run the mod for a few thousand miles and then just go back to stock.

I also checked the pH of my coolant and its slightly acidic, so the flushes are probably a good idea anyway as it has been reported that an acidic coolant will eat away at the aluminum in the radiator and possibly start the clog process.

 

[Shawn67]

Yes, that is the EA288 cooling system, which is what I have. The problem with most of the clear filters is they aren't really built for pressure or temp as they are typically for fuel lines, at least the locally sources ones I found where. They also had little filtering area, the one I rigged up temporarily was clogging up quickly and stopping flow. Summit Racing has a clear filter that is said to be for coolant but it doesn't have a lot of filtering area either and it cost more than the kit I bought.

 

[Shawn67]

After inspecting this yesterday it was still slightly leaking so I took it apart today. Think it was leaking at the filter seal itself, I probably didn't tighten it down enough. Changed the hose barbs to 3/8 MNPT to 90 degree 5/16" barbs using high temp thread sealant so I need to let that cure for a few hours. The 90 degree barbs up front will clear the fuel filter now.

The Cat filter I bought also arrived, it does fit this housing and is a little bit shorter.

That will give more clearance to the engine and I think will be enough to be able to change the filter without unbolting the filter housing.

I dumped the filter into a bucket but couldn't get a good photograph, so I poured it into a ziplock. Wiping the bottom of the bucket with a paper towel yielded this:

And then letting the coolant in the ziplock settle for a bit had a lot of debris at the bottom as well as a cloudy layer of coolant which I think is maybe captured sludge?

" https://flic.kr/p/2nYAeL2 "

This was after only 100 or 150 miles so it is certainly filtering.
(Edit)
Cutting open the filter I found more of the grit and such that I had been getting out with the temp filter.

and that grit was in most of the pleats too but not a huge amount.

 

[forrest resto`s]

Thanx!

 

[Shawn67]

The Cat filter does fit in a bit better and the 90 degree barbs make it look a bit cleaner.

 

[calimustang]

hows the car so far?

 

[Shawn67]

The little leak I had let air back into the circuit and it ended up clogging the heating core again. I am now just about positive the main problem is if any air gets trapped in the heater core that leads to problems if the car is shut off while in a regen cycle. I believe the v488 heater support pump keeps running to keep coolant flowing through the EGR cooler if the engine is turned off while in regen. If there is air in the top of the heater core it probably isn't able to keep coolant flowing after shutdown and that is where the coolant gets cooked and then clogs the core.

I used a fluid transfer pump connected to the return hose going to the expansion tank and then pumped the old coolant out while refilling the expansion tank when it got low. After pumpiong out a few gallons I then kept pumping the fluid back into the expansion tank as it was clearly pulling air out. After doing that till I wasn't see the bubbles any more I started the engine and did the bleed procedure in VAG-COM a couple of times. Then drove it for a few hundred miles to filter the coolant again and then replaced the core.

After replacing the core I rebled it again. First pumping coolant using the transfer pump to pull air out and then using VAG-COM a couple of times. It has been good now for a few tanks and I did end up having to shut it off during a regen without issue.

Shawn

 

[JELLOWSUBMARINE]

Thanks for the time to write it up. Nice install. I have this filter set up but have been leery to install for just the reasons you experienced. Odd issues. Like the trapped air plugging the heater core. Sounds like your good now? Any more problems (where its tied in etc...) please post.

 

[Shawn67]

I likely had air trapped in the heater core before I put the filter in too though. Pretty sure that is why it clogged the first time after changing the water pump. I hadn't used the pump to bleed it then. After that last change out and serious bleed it has been good so far. I will likely change the filter again in a few hundred more miles.

 

[lemcc]

I've often debated on going down this track and adding a coolant filter after going through two broken heater hoses and a clogged heater core last year. I definitely think it's on the right track, of course just identifying the root cause would be the most beneficial for all of us. Lots of theories out there, some more solid than others, but no concrete answer from VW. Seems it's mainly just a 'we fixed the emissions and now the EGR boils off the coolant and causes silicates to wreck havoc since they aren't suspended'

Some tips that may help you out on getting down to the coolant system woes:

• Check PH of coolant. Should be ~ 8.5 if it's G13. Anymore acidic and you'll be open to corrosion.
• Rig up a closed loop flush, ensure to get some hose clamps and pinch off the proper circuits and flush the system properly. VW Service Guide recommends 2 liters per circuit, I flushed closer to a gallon per circuit.
• Use Vacuum Lift tool to check system for leaks. Essentially once you put the coolant circuit under vacuum, as long as it's holding vacuum, you should be leak free.
• Maybe try a 55/45 coolant/water mix. This should raise the boil protection temp as well, so it may help with the EGR boil off issue. (Shooting in the dark here, someone may come in and be like 'don't be stupid' which I'm guilty of from time to time.)
• Remove silicate packets/tube from reservoir tank. They burst and wreck havoc on the coolant system, clog heater cores, etc. Those are there to add silicates to make the coolant 'lifelong' but as long as you monitor ph and freeze protection and/or flush coolant every 5 years or 100k, the silicate packet won't make a difference.

I read where another TDI owner rigged up their own coolant filter as well. They also opted to flush all the G13 coolant out of the car and go for a silicate free coolant. @767wrench was the guy: https://forums.tdiclub.com/index.php?threads/coolant-filter.457119/

Any who - keep us posted how your coolant filter setup works out! Curious to see how it's working!

 

[740GLE]

yeah most of that junk has to be from that silicate packet/rod.

 

[Shawn67]

I've often debated on going down this track and adding a coolant filter after going through two broken heater hoses and a clogged heater core last year. I definitely think it's on the right track, of course just identifying the root cause would be the most beneficial for all of us. Lots of theories out there, some more solid than others, but no concrete answer from VW. Seems it's mainly just a 'we fixed the emissions and now the EGR boils off the coolant and causes silicates to wreck havoc since they aren't suspended'

Some tips that may help you out on getting down to the coolant system woes:

• Check PH of coolant. Should be ~ 8.5 if it's G13. Anymore acidic and you'll be open to corrosion.
• Rig up a closed loop flush, ensure to get some hose clamps and pinch off the proper circuits and flush the system properly. VW Service Guide recommends 2 liters per circuit, I flushed closer to a gallon per circuit.
• Use Vacuum Lift tool to check system for leaks. Essentially once you put the coolant circuit under vacuum, as long as it's holding vacuum, you should be leak free.
• Maybe try a 55/45 coolant/water mix. This should raise the boil protection temp as well, so it may help with the EGR boil off issue. (Shooting in the dark here, someone may come in and be like 'don't be stupid' which I'm guilty of from time to time.)
• Remove silicate packets/tube from reservoir tank. They burst and wreck havoc on the coolant system, clog heater cores, etc. Those are there to add silicates to make the coolant 'lifelong' but as long as you monitor ph and freeze protection and/or flush coolant every 5 years or 100k, the silicate packet won't make a difference.

I read where another TDI owner rigged up their own coolant filter as well. They also opted to flush all the G13 coolant out of the car and go for a silicate free coolant. @767wrench was the guy: https://forums.tdiclub.com/index.php?threads/coolant-filter.457119/

Any who - keep us posted how your coolant filter setup works out! Curious to see how it's working!

Thanks, interesting idea going back to G12. As an update I changed the filter again after a few thousand miles and cut it open. There was still a little debris in it but not much. Going forward I'm likely going to swap the coolant filter when I do oil changes unless something obvious happens like the core clogs again.

 

[Shawn67]

yeah most of that junk has to be from that silicate packet/rod.

I don't think so, both packets were completely intact with no holes.

What I got out of the heater cores when I back flushed them and what I filtered out wouldn't have all fit in those two packets. This is something beyond that.

 

[danmin]

Quite a few shops have coolant filters for powerstroke and cummins trucks. found a full kit for $50. I’m sure cheaper are out there.

Labwork New Coolant Filtration Filter Kit 3Filter For 03-07 Ford 6.0L Powerstroke Diesel

Description 100% Brand New Made of the high quality? You will use three filters inn the first nine months,once the initial none months has passed, you can only

labworkauto.com

 

[eugene89us]

I have never seen a silica bag or any bag in my coolant take since my car was new. I am surprised to know that is even a thing, I thought you all were nuts!