oil heat exchanger cleaning
 

Thought I'd share my latest mad scientist project. I've never reused an OEM oil/water heat exchanger after any sort of bearing damage, due to the unknown amount of contaminants remaining in it. Due to their ~$300 cost, used units are usually your best bet, but there's gotta be a better way! I was gifted a '99 block with thrust washer damage, and I thought, why not make a fixture to clean these? So here it is. Old head galley plugs used for plugging the mains, OP port, along with some smashed oil jets. Head feed and oil pump feed got NPT threads for the NPT to -6 adapter, with 5/16" barb to -6 adapters on those for the fuel lines headed to the fuel jug where the pump is. Old but functioning Lexus GS350 battery on a 6amp charger provided the power, and when I upgraded from a Walbro 190 to a 255 recently, so that provided the fuel pump. Only expense in the project was the $4 filter.

I recently lost ~.003" off the top of one of my rod bearings, so I was confident the oil cooler didn't have much material. Ran this setup for 20 minutes just to be sure before reusing it.

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It might not be clean even yet Sir.
This IS something I have a shit load of experience with.
I clean out air conditioning systems. If I leave any of the microscopic dust in the system I get to warranty my new system in a year, 18 months tops...
Your rig is AWSOME, only way to have a snowball's chance...

You absolutely have to "pop" the system. After your done with which ever liquid you are using you hit it with air (I use BIG air here) A 80 gallon two stage compressor with 15 CFM at 175 psi is the MINIMUM for AC core cleaning.
Blast air till no more liquid come out then hold your thumb over the end of the exit hose for a split second and release. More liquid will come out. Do this multiple times till the "pops" are basically dry.
Reverse your liquid flow, do it again.

I flush with 3 chemicals for AC systems.
First is Berryman's B12 in liquid form for the big trash. It's three time cheaper than AC flush.
Then I use AC flush, only one brand. I've tried them all and like one brand best. This stuff is expensive
Then I finish with alcohol. Tons of it. Alcohol is cheap and it clears all the nasty chemicals I just used.
I go "both ways" with all three fluids. I catch it in a WHITE 5 gallon paint container.
I am not finished till 8 ounces of alcohol can be sent both ways with no color change or debris. I use a bright light to check for glitter
This is for flushing a system that just has debris...

It's not been baked of with engine heat. It never has hydrocarbon build up.

It's much easier to clean than a integral oil cooler...

The guys at ATS performance (serious MR2 shop) up in Denton have gone round and round with cleaning these little coolers.
They came to the decision that the little plate coolers were "un-cleanable" at least to the point that they were happy with them.
They made a small rig that they could just bolt the coolers up to. Using a whole block was their first attempt.

After you think that it is clean put it in a ultrasonic cleaner. Crap will continue to come out.
They tried pretty much everything including boiling the shit out of the coolers. Nothing really worked...

Hope this helps...
I am NOT trying to step on your toes

No worries at all, It's far from a perfect system. I head the SLIGHTEST knocking sound on my car and drove it less than a mile after that to my house, then trailered it to the shop to tear down. Every bearing looked perfect except for #3 rod bearing, like I said only .003" difference in bearing thickness between all the good bearing and the #3 bearings, so very little metal was present. I flushed it with 2-3 bottles of brake clean before this process.

I would never expect this to work on a catastrophic engine failure. If this was anyone's but my own, I'd follow the same process, but use multiple fluids such as mineral spirits, air, and an ultra sonic cleaner.

Here's where I'm going to piss on your fire again, sorry!
The guys at ATS tested "clean used" and found debris.
They found debris is EVERY one they tested.
This little critters are $400 from Toyota.

I've seen the coolant path get gummed up as well. Little tiny flow paths here.
SO even if the oil path is clean the coolant path can be trashed.
They need to be thrown away, replaced with new, or adapted OUT of the system.
OUT of the system is "THE WAY"...

I love this setup. No experience as to effectiveness, but everything about it just looks "highly danger." I assume that the fuel pump with no fuse is submerged in a flammable liquid with a low flash-point as the cleaning agent?

Want to go down this rabbit hole further talk to these guys, bunch of car crazies. one of them runs an MR2 on the street with 900whp. They talk "shop" just fine
Home - ATS Racing

Want to actually have a chance of getting these critters clean talk to these folks. I don't know them, I've never spoken with them, but they DO know how to clean stuff.
They have a $10K plus AC refrigerant flushing system that I would LOVE to own.
I'm not going to be able to "sell" it to my Wife until hell freezes over...
HECAT Home (hecatinc.com)

Try it with explosive chemicals that are INSANELY flammable...
When they burn you CANNOT see the flame in bright conditions...
Welcome to my world Joe Perez!

One of the single best features of the HECAT 1000 series AC flushing machines is they have 0% flammability...

I have a lot of experience with air-cooled Porsche engines. They don't have coolant and use a dry sump oiling system with about 12 quarts of capacity. Typically there is a small oil cooler attached to the engine as well as a much larger front mounted cooler. These oil coolers range from $500 to $1,000 each. In the past I have had the oil coolers ultrasonically cleaned. They come back with a little baggie containing the debris that was removed. They're supposed to get all the debris out and be safe for reuse.

After talking to a few respected engine builders I don't reuse the coolers anymore. If there has been any kind of engine failure or debris risk the coolers get trashed. The engine builders had examples of contaminated oil causing issues after having all the coolers and lines flushed and ultrasonically cleaned. The engines are just too expensive to risk it.

I once had a set of the oil lines front to back on a 964 redone by a hydraulic hose shop near me. $175 for new rubber on both.
The new hoses from Porsche were over 2K! Porsche crap is WAY TOO expensive.
Kim's International was the single best hose shop in the world and I didn't know it till it was gone...
The guy who ran it was OLD, like 90 years old. When he finally "retired" his kids took it over, sold all the priceless weird fittings he had for scrap and disposed of the property in a week.
Kim's vanished OVERNIGHT!
I am still looking for a decent hose shop 10 years later...