Gunk under oil cap

[Jacksna]

Hi guys I'm recently purchased a 97 collectors edition and have been fixing surprises daily since. I am doing all the work myself and learning as I go. I randomly checked the oil cap yesterday and found an interesting white substance under it and the ledge right below it in the hole.

Background.

After driving it off from the previous owner it over heated 30 min into the drive. I found tons of stop leak clogging everything related to cooling. I changed the radiator, thermostat, water pump and a few hoses. On top of that I flushed the heater cores, block and radiator two days in a row earlier this week. I alternated between water hose and compressed air. A great deal of stop leak came out both times and I plan to do it again once the temp gets over 35 degrees outside.

Good news is that it doesn't over heat anymore, even when pulling a 16ft trailer. Also the front heater finally work, but back is still cold.

A friend suggested the sludge was coolant and a head gasket leak. What are your thoughts? I Don't want to pay a mechanic so I need all the help I can get diagnosing this stuff.

1997, 202,xxx miles.

Your help is greatly appreciated.

 

[scrowley]

Send your oil out to Blackstone lab for analysis. Then you will know for sure

 

[94SRUNNER]

What's the weather been like in your area?

In cold weather (as I am seeing now in my area) and shorter drive cycles, I will see similar "gunk" under my oil cap. Once the truck has completely warmed to operating temps and I have driven more than 20-30 miles the gunk is gone.

Not saying that is your situation, but it is one possibility.

 

[Jacksna]

I'm down in Dallas and it went from 65 to 35 in just two days with the cold front coming in. Maybe that's has to do with it? Thanks for help guys

 

[fj80pb]

X2 with @scrowley. Do the analysis and get hard evidence of what's going on.
Since it would appear still you have a few flushed ahead, FWIW, I recently did a major overhaul of the cooling system. Before putting the new hoses, I did several (meaning a lot!!)flushes to both heaters (much simpler when everything is disconnected and without risking putting contaminants back into the system). Perhaps you want to consider this.
Good luck
Cheers

 

[94SRUNNER]

I would certainly monitor your coolant levels and engine oil. As scrowly said a oil analysis may be a good idea as well. They are reasonable priced and provide useful information.

 

[Kuneefay]

Looks like headgasket time. Oil change and keep an eye on coolant levels and overheating issues. A temp gauge is an amazing investment. Like the other guys said lab test.

 

[SUMMIT CRUISERS]

Looks like headgasket time. Oil change and keep an eye on coolant levels and overheating issues. A temp gauge is an amazing investment. Like the other guys said lab test.

Looks the same to me. You might try Blue Devil head gasket sealer if the Antifreeze starts disappearing. We used it in a Ford 5.4 work truck and the the disappearing of Antifreeze stopped. It's a clear liquid, unlike the Bars leak products (that didn't work) and it has been about 3 months now. How long will it last? Permanent fix? Probably not. Just a thought...

 

[S.CarolinaFZJ80]

The gunk is moisture mixed with oil vapor.

This is a common mixture.
As your engine burns more and more oil between oil changes. Some of that burned off oil is replaced in volume with the water from the condensation process.

I used to see it in aviation reciprocating engines often dripping off oil breather tubes. As the air cools in your engine after shutdown, condensation forms on the inside of the components. As the engine warms up on subsequent short trips the water in the nasty mixture turns to vapor and since it's a closed system the vapor has no where to go but up to the cap where it condenses after the engine is shut down and cools.

Now wether the moisture is from normal condensation forming in the engine then mixing with the oil OR from an external source via a head gasket leak is the question.

I see this in my, seldom driven 80's oil catch cans and occasionally under the cap as you did, only not to that extent. All the stop leak that you flushed is a good indicator as to the maintenance history of that engine. You've got some PM catchup to do & the oil analysis can't hurt.

Good luck with your trouble shooting and welcome to the 80 owners club.

 

[Offroads4x4]

X2 with @scrowley. Do the analysis and get hard evidence of what's going on.
Since it would appear still you have a few flushed ahead, FWIW, I recently did a major overhaul of the cooling system. Before putting the new hoses, I did several (meaning a lot!!)flushes to both heaters (much simpler when everything is disconnected and without risking putting contaminants back into the system). Perhaps you want to consider this.
Good luck
Cheers

X3

It sounds like you need to play catch up on the maintenance since it appears the last guy put out flames (maintenance as it showed) with quick fix maintenance and didn't do much preventive maintenance.

1- Send off a oil sample to Blackstone. Tell them this is a first baseline sample. They will give you a good idea of what's going on.

You mentioned your flush helped with keeping it running cooler but the rear heater was still not working. You still have gunk in your system that needs to get out. When you flushed the system it may of just moved it from one area to another and blocked of an already restricted rear heater core with more gunk.

2- Repeat your flush of the cooling system. Make sure your dash heater temp is set to max heat to open the heater control valve. Flush in a backwards direction with fresh water then air then water then air.
A- Pull the block drain plugs and thermostat to flush your block.
B- Pull your radiator drain plug.
C- Start your engine just long enough to help move any coolant in your water pump and inlet/outlet areas. (Don't let it warm all the way up 1-2 minutes.)

Next isolate each part of your system to be flushed.
A- Block, radiator, main heater core and rear heater heater core. I'd pull your overflow bottle and flush it as well as the over flow hose.
B- Flush each as a stand alone. For the rear heater you may want to remove the pass seat and remove it to flush it out easier. If your radiator or rear heater core appear to be blocked or restricted you could send them out to a radiator shop to be cleaned.

3- Flush any hard lines (rear heater lines, PHH line ) it's a good time to replace all your heater hoses and radiator hoses .
A- You should replace your PHH hose (Small 3-4" heater hose at the back of the block just above the starter on the driver side.). Check search for PHH replacement. It's best to use the blue silicone hose or gates HD green stripe hose using HD compression hose clamps. This a pain to replace but it's most likely one of the best cooling system PM's. You don't want to have to replace this one on the trail.
B- Replace your thermostat (Many of us will drill a 1/8 hole in the thermostat to help burp any trapped air out of the system even though factory thermostat has a brass burp built in it.)
C- Don't forget to replace your block drain plugs, radiator drain plug.
D- Replace your radiator cap.

4- Replace coolant using distilled water and anti-freeze. (I always fill the over flow with pure anti-freeze.)
A- Check all hoses, plugs, clamps and lines for leaks after putting coolant back in the system. Start your engine leaving the radiator cap off. This will let it run up to temp until the thermostat opens to burp out any trapped air. Then top off as needed.

Remember Toyota parts are usually almost always best as apposed to most parts store replacements.

Just some thoughts.

 

[fj80pb]

Excellent & quite didactic write up @Offroads4x4. Congrats!. Basically that's what I did. I should've mention that I flush my rigs every 25K or so (always with distilled water), I've never had gunky stuff or build ups, therefore it's quite easy to keep it clean. Also, I only use Toyota's coolants.
@Jacksna, Looks like you should print out @Offroads4x4 "flushing manual"
Cheers

 

[Mighty690]

With the overheating included, I'd bet it's head gasket time. I wouldn't even fart around thinking about it, beyond getting confirmation with a $25 oil analysis. Potassium comes in coolant, and it's a clear marker.

 

[MedicineMan]

Wow this is exactly what I have been looking for. Just bought my first FJ62 a couple weeks, this is my first post here..an old thread but hopefully someone will see this. I could only find one post about this issue on the 60 series forums and there wasn't nearly as much information as there is here. Mine is not overheating but is getting a nasty buildup under the oil cap like I've never seen.

Does everything @Offroads4x4 say apply here even though it's a different model? The guy I bought it from has been helpful but he said he never saw it as bad as the picture I sent him (can't figure out how to post it here). He said it was due to the condensation from only driving it on short trips (just to and from work everyday..about 15 mins one way.

He had a new head gasket and new radiator put in just a few months ago so he is thinking that if it continues I should try replacing the vacuum hoses.

I'm up for trying to flush the system myself if someone can direct to some easy-to-follow pictures or videos

Never heard of getting an oil analysis done before..does it really provide worthwhile information? Thanks in advance!

 

[Gabriel 71]

Headgasket i had a hard time trying to diagnose mine. didnt do blackstone ,didn't have to smoke out exhaust dead miss in cylinder 5 tear down confirmed it was cylinder 5 also had water in the cap mine wasn't as bad as your pictures show. good luck

 

[Offroads4x4]

Wow this is exactly what I have been looking for. Just bought my first FJ62 a couple weeks, this is my first post here..an old thread but hopefully someone will see this. I could only find one post about this issue on the 60 series forums and there wasn't nearly as much information as there is here. Mine is not overheating but is getting a nasty buildup under the oil cap like I've never seen.

Does everything @Offroads4x4 say apply here even though it's a different model? The guy I bought it from has been helpful but he said he never saw it as bad as the picture I sent him (can't figure out how to post it here). He said it was due to the condensation from only driving it on short trips (just to and from work everyday..about 15 mins one way.

He had a new head gasket and new radiator put in just a few months ago so he is thinking that if it continues I should try replacing the vacuum hoses.

I'm up for trying to flush the system myself if someone can direct to some easy-to-follow pictures or videos

Never heard of getting an oil analysis done before..does it really provide worthwhile information? Thanks in advance!

The post I wrote above on flushing will work for any model or brand. Isolate each part of the system when you flush. This will also give you a better idea where you system is plugged or restricted. If it won't flush out on the heater cores or radiator have them cleaned by a radiator shop or replace as your $ allows. I've had radiator shops build custom new ones as well making them bigger but still fit in the factory locations, (more core rows or wider adding more area).

Happy flushing.