Found Silver "Sludge" In Coolant
- Thread starter bandit25
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I would think the same. Some sort of "stop-leak" residue. Have you inspected the radiator for any wear signs? System flushed? I would start there and get it cleaned up before you have an issue on the trail!
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I'm actually planning on replacing the radiator (along with rad cap and thermostat) because I've been having some bad overheating problems this summer. Already modded the fan clutch, which helped, but not enough.
Since I'm planning on replacing those with new and flushing the coolant, if it was a stop-leak, could it cause any performance issues with the engine block?
Since I'm planning on replacing those with new and flushing the coolant, if it was a stop-leak, could it cause any performance issues with the engine block?
It can definitely cause a clog/partial clog somewhere in the system. Any signs of a blown head gasket?
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- #6
The overheating used to be both on the highway (uphill, AC on) as well as idling (AC on). I modded the fan clutch (45mL of 20k cst oil) and that seems to have resolved the issue while on highway, but I'm still overheating while idling with the AC on. And by overheating I mean ~225, just enough for the AC to kick off but not enough for it to reach the reds.
The previous owner told me that he did blow the head gasket and it was repaired. Now that I'm seeing this silver sludge I'm getting pretty concerned... However, I am not seeing any signs now of a blown head gasket.
The previous owner told me that he did blow the head gasket and it was repaired. Now that I'm seeing this silver sludge I'm getting pretty concerned... However, I am not seeing any signs now of a blown head gasket.
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This is about the temp that mine was running when my HG was blown. I would really suggest getting a Blackstone OA before throwing $$$ at the radiator.
Hey @bandit25, did Mike tell you that the HG blew when he owned it? If so that would be news to me.
The known history on this truck is:
1) My very good friend bought it from the original owner in ~2015. He owned it for probably 6-12 months and in that time did the suspension, tires, ARB, paint and head gasket. The HG was done by a reputable local mechanic we have both used with 100% success for 30 years.
2) I hooked Mike up with my buddy, who purchased it. I continued to fix things and did the routine maintenance. He never complained about overheating to me. I never suspected the HG to be blown either. That being said, I don't think I saw the truck for the last 6-8 months he owned it.
I think if anyone had used stop leak or anything like that, it would have shown up a whole lot sooner than now? Not sure. It looks pretty new to me.
What is the mileage on it now?
Here's the old for sale ad FYI:
forum.ih8mud.com
The known history on this truck is:
1) My very good friend bought it from the original owner in ~2015. He owned it for probably 6-12 months and in that time did the suspension, tires, ARB, paint and head gasket. The HG was done by a reputable local mechanic we have both used with 100% success for 30 years.
2) I hooked Mike up with my buddy, who purchased it. I continued to fix things and did the routine maintenance. He never complained about overheating to me. I never suspected the HG to be blown either. That being said, I don't think I saw the truck for the last 6-8 months he owned it.
I think if anyone had used stop leak or anything like that, it would have shown up a whole lot sooner than now? Not sure. It looks pretty new to me.
What is the mileage on it now?
Here's the old for sale ad FYI:
For Sale - (SOLD) 1996 FZJ80 - Super clean - Deflared, New Factory Paint - San Diego
SALE PENDING. THANK YOU FOR YOUR INTEREST. 1996 FZJ80 Moonglow Pearl - 233,000 miles - NO LOCKERS - $11,750 OBO. Solana Beach, Ca. (North County, SD). JT3HJ85J8T0129046 My buddy bought this car last year with a blown head gasket. He had a Toyota specialty shop in Mira Mesa rebuild the top end...
forum.ih8mud.com
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- #9
Not a bad idea. I'll look into this!
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- #10
Hey @bandit25, did Mike tell you that the HG blew when he owned it? If so that would be news to me.
The known history on this truck is:
1) My very good friend bought it from the original owner in ~2015. He owned it for probably 6-12 months and in that time did the suspension, tires, ARB, paint and head gasket. The HG was done by a reputable local mechanic we have both used with 100% success for 30 years.
2) I hooked Mike up with my buddy, who purchased it. I continued to fix things and did the routine maintenance. He never complained about overheating to me. I never suspected the HG to be blown either. That being said, I don't think I saw the truck for the last 6-8 months he owned it.
I think if anyone had used stop leak or anything like that, it would have shown up a whole lot sooner than now? Not sure. It looks pretty new to me.
What is the mileage on it now?
Here's the old for sale ad FYI:
For Sale - (SOLD) 1996 FZJ80 - Super clean - Deflared, New Factory Paint - San Diego
SALE PENDING. THANK YOU FOR YOUR INTEREST. 1996 FZJ80 Moonglow Pearl - 233,000 miles - NO LOCKERS - $11,750 OBO. Solana Beach, Ca. (North County, SD). JT3HJ85J8T0129046 My buddy bought this car last year with a blown head gasket. He had a Toyota specialty shop in Mira Mesa rebuild the top end...
That's interesting... Maybe I'm misremembering what he told me, but I could have sworn that he said "it blew the head gasket but was professionally repaired". Maybe he was just referring to the prior owner (ie your mechanic)?
I don't routinely check the coolant at the cap, so it could have been there for longer, I'm really not sure. I'm not even sure that it IS a stop leak! I just can't think of what else it could be. I've never added anything to the coolant myself.
Thank you for the additional notes! Mileage now 268,600.
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- #11
Here's the old for sale ad FYI:
For Sale - (SOLD) 1996 FZJ80 - Super clean - Deflared, New Factory Paint - San Diego
SALE PENDING. THANK YOU FOR YOUR INTEREST. 1996 FZJ80 Moonglow Pearl - 233,000 miles - NO LOCKERS - $11,750 OBO. Solana Beach, Ca. (North County, SD). JT3HJ85J8T0129046 My buddy bought this car last year with a blown head gasket. He had a Toyota specialty shop in Mira Mesa rebuild the top end...
Oh apparently the radiator is relatively new? This mentions a new Koyo radiator, which means that it probably only has 40k miles on it? Hmm...
Here is the link to my original thread when I was having this issue. There are some really good troubleshooting tips in there that would be worth a try. For example, it could be something as simple as air in your system and it needs to be “burped.”
Regardless, the OA is cheap and will give you a great baseline as to what’s happening on the inside. Mine ended up being the HG and I went on a 5 year adventure of rebuilding a donor engine (long story). Feel free to PM if I can help further.
forum.ih8mud.com
Regardless, the OA is cheap and will give you a great baseline as to what’s happening on the inside. Mine ended up being the HG and I went on a 5 year adventure of rebuilding a donor engine (long story). Feel free to PM if I can help further.
Running warm, looking for theories
Okay all, I will try to be as detailed as possible. I am a new 80 series owner; I took delivery of Mountain Girl , a 1995 80 series, in November with 251,000 miles on her. PO had used as a daily driver. Since then I have put MAYBE 100 miles on it. The first thing I noticed when I drove it home...
forum.ih8mud.com
I'd assume he was talking about the HG when my buddy bought it ~5 years ago. He did a full head and valve job. The mechanics brother owns a machine shop so he would have ensured the head did not have cracks or any deformations.
The radiator in the for sale ad states that the radiator is in fact new (well not any more I guess ; )). I would give it a once over and make sure it's not clogged with dead insects, dirt, etc. Are you using a scan gauge or ultra gauge for temp readings, or an analog style gauge with temp sender?
Make sure that the radiator cap is Toyota for sure, I can't recall what was on there. Check to see if thermostat is Toyota as well. See if there is any gunk in the housing there. 225F, even in Yuma is a little bit too hot...
The radiator in the for sale ad states that the radiator is in fact new (well not any more I guess ; )). I would give it a once over and make sure it's not clogged with dead insects, dirt, etc. Are you using a scan gauge or ultra gauge for temp readings, or an analog style gauge with temp sender?
Make sure that the radiator cap is Toyota for sure, I can't recall what was on there. Check to see if thermostat is Toyota as well. See if there is any gunk in the housing there. 225F, even in Yuma is a little bit too hot...
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- #14
Here is the link to my original thread when I was having this issue. There are some really good troubleshooting tips in there that would be worth a try. For example, it could be something as simple as air in your system and it needs to be “burped.”
Regardless, the OA is cheap and will give you a great baseline as to what’s happening on the inside. Mine ended up being the HG and I went on a 5 year adventure of rebuilding a donor engine (long story). Feel free to PM if I can help further.
Running warm, looking for theories
Okay all, I will try to be as detailed as possible. I am a new 80 series owner; I took delivery of Mountain Girl , a 1995 80 series, in November with 251,000 miles on her. PO had used as a daily driver. Since then I have put MAYBE 100 miles on it. The first thing I noticed when I drove it home...
Great read! Thank you for linking this. I think I will do a Blackstone OA but from what my symptoms are, I think a blown HG is very unlikely. I went ahead and hooked up my "burp coolant funnel" thing and ran the engine for ~30 minutes with heater on max and rear heat on. Revved to 2500rpms a couple times. Absolutely no air bubbles.
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- #15
I'm glad to hear that! Makes me feel a bit better, but still confused as to what these silver floaters are.
I took a good look at it and the radiator is pretty spotless. I pressure washed it (as good as I could without removing anything) a couple months ago and it's still clean from that.
I'm using a scan gauge with the Torque app.
The radiator cap is NOT Toyota. Not sure about the thermostat.
So just thinking outloud here, trying to diagnose the overheating:
Radiator - Unlikely. 40k miles old, clean/straight fins. No signs of leaking. Coolant looks clean.
Rad Cap - Possible, because it is not OEM. However, a failed cap can lead to low system pressure which can cause the water pump to cavitate, introducing air into the system. I just "burped" my cooling system but there was absolutely no signs of air bubbles/pockets. This makes me think that there is no cavitation, and so the cap is probably fine?
Thermostat - Very possible, have not inspected/tested, but this could explain my overheating. Any idea if this was replaced during the HG repair?
Water pump - Very possible, have not inspected/tested, but this could explain my overheating. Any idea if this was replaced during the HG repair?
Coolant - Levels are good, no signs of air. It is green instead of red, but that shouldn't cause 225-levels of overheating. Apparently the coolant has 40k miles on it. Might be time for a flush, but again, probably not bad enough to cause 225-levels of overheating.
Thoughts?
Nice work! Thermostat could be the cause...I hadn’t the opposite issue in an old ‘88 Toyota van - thermostat was staying open so the car wouldn’t get to correct running temp. Yours could be stuck more closed than open - sometimes they seize up from contaminants
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- #17
Drained the coolant and thoroughly flushed everything. There was absolutely no gunk or sludge anywhere (except a bit of dirt dislodged from backflushing the heater core). Replaced the thermostat and gasket with new (OEM) after testing/verifying it in a hot water bath. Also replaced radiator hoses and a few heater hoses while I was there.
Filled with distilled water and went on a test drive.
Temps at idle, in the shade with AC on, reached 208. So it's better, but still not great.
Temps while moving (55mph) stayed solid at 190.
Ambient temp was 105.
The fan roars thanks to the 20k cst oil, so I think my issue is somewhere else... I'll replace the radiator cap next just because it's cheap, but I'm starting to think the issue is with the radiator.
Filled with distilled water and went on a test drive.
Temps at idle, in the shade with AC on, reached 208. So it's better, but still not great.
Temps while moving (55mph) stayed solid at 190.
Ambient temp was 105.
The fan roars thanks to the 20k cst oil, so I think my issue is somewhere else... I'll replace the radiator cap next just because it's cheap, but I'm starting to think the issue is with the radiator.
Hate to say it, but I had almost all these symptoms on my '97 Cruiser when the HG blew and was pushing exhaust into the coolant. It would run fine, then occasionally hot (over 208*F). Finally one day it blew the gasket enough that I felt a stumble at idle and scan gauge went to 220*F and I shut it off and water was coming out from around the CAT area.
Are you consuming water? Do you lose water from the overflow over a week or so? Do you get bubbles in the overflow after the truck is warm and you shut it off? You should be able to hear them if its quiet around you.
The sludge in the coolant makes me think there was stop leak in the system at some point and there is still remnants left. Once it's in the system, it will pretty much always be in there.
Are you consuming water? Do you lose water from the overflow over a week or so? Do you get bubbles in the overflow after the truck is warm and you shut it off? You should be able to hear them if its quiet around you.
The sludge in the coolant makes me think there was stop leak in the system at some point and there is still remnants left. Once it's in the system, it will pretty much always be in there.
