Coolant Rust

[chadzeilenga]

I used a thermal imaging camera to take some pictures of the inlet & outlet coolant connections. From a cold start I let the vehicle idle up until the thermostat opened.


This was the thermostat housing. Temp at the cross-hairs was 185F, but max temp in the image is 194F per the autoscale on the right


This is the water pump inlet from the lower radiator hose. Cross hairs are 175F, so only a 10F delta between the two. I'll take another round of shots after I have driven on the highway and all of the items are all up to temperature.

 

[Toasty]

Nice! That would suggest your engine runs on the cool side of operating temps which is common for a 12v 3.0, thanks for sharing! Looking forward to the next set of images. This stuff really interests me.

 

[mike5]

I used to get muddy looking coolant after a flush. Long story short, went to an old school radiator shop, had them remove the end tanks, clean up the radiator and weld it all back together. They also performed a flush service on the entire system. After that it stayed green.

 

[chadzeilenga]

Friday night I took a 4hr round trip on the highway. Ran cool for the first half of trip, but off highway at idle the temp gage was climbing to between half and 3/4. I think those rust clumps were clogging my tubes in radiator.

Started out the day with a back flush of the coolant from the heater core. Could only run 5 gal through got a good amount of rusty coolant out.

Then 1/2 cup of liquid cascade dishwasher detergent to get any old oil out from Previous owner HG issue. Ran on highway for 30min and let cool & drain

The rust was more muddy, so I drained and refilled, ran for 10 min and cooled/drained again.

Making progress.




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[chadzeilenga]

Well that didn't quite turn out how I had hoped... After refilling, I took the fam out for some ice cream so that I could run the Montero some and continue to stir up that rust to drain out.

While cruising on the highway at 65mph my temp gage was at halfway mark. I put the defrost on to hold the temp and when I got there let it idle in parking lot, but engine was running rough and temp gage was at 3/4 and coolant coming out of the overflow bottle. Full on overheat...

Let it cool down and topped off radiator and got some white smoke out of the exhaust so it looks like I'll be doing the head gaskets on this. Since there's a fair amount of prior examples I'll be reading up on what others have done and I can't wait to dig in and find all of the PO's handiwork while I'm in there... I'm wondering if the junk that I've been getting out of the radiator was sealing up the HG.

The one thing I'm on the fence about is whether to go all in with the bottom end. When I did plugs a few months ago, I was getting a consistent 120psi on a warm engine for each cyl. Although pretty even, that is the minimum spec per the FSM. Anyone have experience with compression this low?

 

[jeep-N-montero]

Sounds like the headache is not worth the investment at this point, I would just sell it and buy something in better condition unless you prefer spending time tinkering than doing other things.

 

[chadzeilenga]

Sounds like the headache is not worth the investment at this point, I would just sell it and buy something in better condition unless you prefer spending time tinkering than doing other things.

I’m planning to fix it. The rest of it is in too nice of shape. Just trying to determine whether I just do the HG and get it running while I look for a spare motor to rebuild or go all the way now.

Reflecting, I think the issue started during my drive on Friday and then just got progressively worse while I was doing the flushes. I never did overheat on Friday so I’m not sure what the trigger was. Ran great on highway but when slowed down to idle, my temp gage was climbing from 1/4 to ~1/2, but then would go right back down once I was moving. I thought fan clutch, but it has resistance to it when cold.


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[Salonika]

At this point I’d be rigging up an external pump so you can flush that sucker all night long vs driving around or idling to get the job done. Pull the thermostat so you get full circulation.

 

[chadzeilenga]

Good idea, once it get it all back together I’ll set something like that up.

I was able to do some inspections on it tonight:
- pulled all plugs and only #3 cyl was wet with water

- all cylinders checked out to be 120psi, same as prior test when I did plugs about 3k mi ago. Unfortunately this was on a cool engine. I wasn’t comfortable running for very long with the noise in the heads.
- the engine was about 1qt low on oil. I noticed that the oil had sprayed down the firewall on the passenger side and had coated some of the undercarriage. Not sure of the source of this yet.
- drained the oil and some presence of water, but not a milky color yet. Maybe it was better that I was running straight water due to flush and not coolant. I’m reading that coolant is worse on journal bearings. Didn’t see any metallic material.

Overall, at a minimum the heads need to come off. What I’m still trying to determine whether there is any damage to the short block. Are there any more in-vehicle inspections I can do?

 

[chadzeilenga]

I was able to get down to the timing belt and remove upper intake. I’m keeping a list of missing parts and found 2 stripped bolts in the fan bracket and lower intake, so it’s been worthwhile.

Also, there are some hoses which are not in the best condition so I can replace them and the band clamps from the PO.

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[Salonika]

What year is your truck again? What motor is that?

 

[chadzeilenga]

It's an 89 LWB 3.0L.

I have the heads off and am taking to shop to have inspected. Not sure how much was taken off them by the PO. For the overall height in FSM, what is the other measurement plane? Is it the valve cover gasket surface?



Nevermind, I found it is to the valve cover gasket surface.

 

[BayMonty]

It's an 89 LWB 3.0L.

I have the heads off and am taking to shop to have inspected. Not sure how much was taken off them by the PO. For the overall height in FSM, what is the other measurement plane? Is it the valve cover gasket surface?

View attachment 473128

Nevermind, I found it is to the valve cover gasket surface.

I know it's been a while, but any update on this?

 

[Superduty]

Thermocure works miracles! I tried multiple products, flushes, parts on my 73 dart, this stuff cleared it out in one pass.

I would agree that Thermocure is a great product. I have tried many different radiator/cooling system flushes and cleaners in my 98 Jeep. Thermocure seems to have done the best job. However, my system is still not completely clean. Over time i start seeing rust remnants in my radiator.

bajavanadu - did you do anything special with the Thermocure besides follow the directions?


Thanks.

 

[kalieracer]

thermocure is the way to go here. It will require some leg work. I got a 20+ degree drop in my 99 after using it. You will have to be super diligent and use the block drains and really drail it out Make sure to use distilled water for the whole process. Mine were so clogged with rust a pick was needed to open them up.

Thermocure works miracles! I tried multiple products, flushes, parts on my 73 dart, this stuff cleared it out in one pass.