Hz oil leak question

[Sethsquatch]

Just bought a 1991 hzj77. PO put a turbo on it. Drives amazing. Has an oil leak I'm trying to get sorted. It's coming from the back of the engine, up top, almost looks like where the head bolts to the block. 😳
I know the valve cover could be a culprit and I read about the half moon thing under that. Hoping for some wisdom.
I tried to get a scope back there and took a picture.
The other thing it might be, which I noticed is one oil line for the turbo runs back there and maybe it's rubbed a little hole in it. Will be replacing it as well.
I have a valve cover gasket, and a new half moon on order.

So question is, would it be possible for oil to seep out of the head gasket at the rear?
Also, the oil is super black despite only having 2k miles on the engine. The oil looks like ink. Is that something to be concerned about?
Thanks for any help!

 

[sodafeld1]

she dribbled at the mouth a little but her body was perfect..well done mate!

diesel engine oil gets dirty very quick from carbon, it is across the board on diesels. I change oil every 5000km. Only way to minimise that is ultra fine bypass filters combined with a centrifuge oil spinner and keeping revs at/over 2000rpm. Idling in city traffic is a killer.

A little unlikely head gasket is leaking oil, water or combustion gasses are more likely. She probably wouldn't run well with a head gasket leak.
Sometimes rocker gaskets, especially non ome ones can cause little leaks. ome rocker cover gasket is heaps better rubber. I hope and suspect rocker from here.

I buy 20l containers of brake cleaner, crc (like wd40), also use a water based degreaser aquaclean. Heaps cheaper, lasts yonks. When I get a brand new second hand, pull out batteries, check for corrosion there, pull out everything easy and clean everything.

Best way to find leaks.

You are going to love her!

 

[mudgudgeon]

Give it a really good degreasing, and then see where it appears from.

Agreed with above. Change the ticket cover gasket with new OEM. The rubber hardens send over time they are gonna leak
It's an easy job to change them, reseal that halfmoon while you're there.

Be real careful not to go strongarm on the rocker cover bolts. Doesn't take a lot to snap or strip them.

 

[Sethsquatch1]

she dribbled at the mouth a little but her body was perfect..well done mate!

diesel engine oil gets dirty very quick from carbon, it is across the board on diesels. I change oil every 5000km. Only way to minimise that is ultra fine bypass filters combined with a centrifuge oil spinner and keeping revs at/over 2000rpm. Idling in city traffic is a killer.

A little unlikely head gasket is leaking oil, water or combustion gasses are more likely. She probably wouldn't run well with a head gasket leak.
Sometimes rocker gaskets, especially non ome ones can cause little leaks. ome rocker cover gasket is heaps better rubber. I hope and suspect rocker from here.

I buy 20l containers of brake cleaner, crc (like wd40), also use a water based degreaser aquaclean. Heaps cheaper, lasts yonks. When I get a brand new second hand, pull out batteries, check for corrosion there, pull out everything easy and clean everything.

Best way to find leaks.

You are going to love her!

Thanks for the kind words! I am glad to hear it's not likely the head, it had me worried. I have genuine Toyota valve cover gasket and new half moon on the way. Hopefully that resolves it...

 

[RangerDownUnder]

You may not need to replace the half moon unless it's damaged. Make sure you scrape all the old liquid gasket off the cover and the head and put new liquid gasket on in the places indicated (and on the half moon).

 

[Sethsquatch1]

You may not need to replace the half moon unless it's damaged. Make sure you scrape all the old liquid gasket off the cover and the head and put new liquid gasket on in the places indicated (and on the half moon).View attachment 3194774

Understood, I did read about that and ordered a new half moon with my gasket.
Where is that image from? It looks helpful!

 

[Sethsquatch1]

Update:
Drive the cruiser a little yesterday maybe 50 miles. And woke up to a huge puddle underneath it. I pulled the oil supply line, hoping it was the culprit, but no dice.
If it is a valve cover or half moon, is it typical to get that much worse after one drive? It doesn't make sense to me.

 

[Nemesis1207]

I think you're wrong about where the leak is coming from. Rear main oil seal maybe?

 

[Sethsquatch1]

I think you're wrong about where the leak is coming from. Rear main oil seal maybe?

It's supposedly brand new. I did pull the oil line to the turbo, I didn't see a hole, it's steel braided, and there's oil all over it like in the braids. I hope that's it, I'll be replacing it. So annoying, I want to drive my new rig!

 

[sodafeld1]

is it engine oil or transmission oil?, the smell will tell you. Keep it topped up at all times, if you have to use it.

Clean her absolute, to find where it leaks.

If it stops leaking when not using it, a bit of a good sign.

Don't worry, they are very fixable. Do you have a jack and tools?

 

[Sethsquatch1]

is it engine oil or transmission oil?, the smell will tell you. Keep it topped up at all times, if you have to use it.

Clean her absolute, to find where it leaks.

If it stops leaking when not using it, a bit of a good sign.

Don't worry, they are very fixable. Do you have a jack and tools?

Yes definitely oil, I pulled the braided supply to the turbo, and I think that's the culprit. I had a new one made but unfortunately I'm out of town for a week so I won't know until next weekend. Appreciate the advice! Going to put the new line on and take to a car wash and flush the old oil off to see if it's leaking.

 

[ATL Cruiser]

Finding oil leaks is pretty straightforward, especially one this massive. Go buy 4 cans of brake clean and empty all of them cleaning until the engine is dry.

Then, fast idle the truck for an hour, checking on it every now and then. You'll find it. If that doesn't work, you can add UV dye to the oil and get under there with a black light. That is probably overkill, though.

 

[mudgudgeon]

I pulled the braided supply to the turbo, and I think that's the culprit

Post a pic of how it's connected to the turbo?
It's it directly threaded into the turbo? Or adapted somehow.

I had a hard pipe oil feed to a turbo crack once. Crack was small, but it puked a lot of oil out fast.

Puddle on the floor looks distinctly black like diesel engine oil. Light reflection makes it a little hard to be sure.

If it's not the oil feed, is also suspect the rear main seal.
Even if the PO says it's new. They may have fúcked up the install, or it may not be new at all.

This is a 5 speed manual? Can't remember

 

[sodafeld1]

I think you shall be fine in the long run, just persevere. Start with the most obvious until you find the next thing..

 

[Sethsquatch1]

Post a pic of how it's connected to the turbo?
It's it directly threaded into the turbo? Or adapted somehow.

I had a hard pipe oil feed to a turbo crack once. Crack was small, but it puked a lot of oil out fast.

Puddle on the floor looks distinctly black like diesel engine oil. Light reflection makes it a little hard to be sure.

If it's not the oil feed, is also suspect the rear main seal.
Even if the PO says it's new. They may have fúcked up the install, or it may not be new at all.

This is a 5 speed manual? Can't remember

Yeah the oil line came from the oil sending point to the turbo. It went around the back of the block and that's directly where the leak is from. I am pretty sure it is this line cause it seems worn and the braids were impregnated with oil.
If the rear main is bad it wouldn't just exponentially leak worse after a drive right? It seems weird. Much more like a hose getting worse.
Black diesel oil for sure, no chance it's something else. It is a 5 speed manual

 

[mudgudgeon]

Sounds like you're on the right track.

Get some spiral nylon hose wrap to wrap the new line in to prevent abrasion.

Braided hoses are good at holding pressure, but can rub through fast.

Pic of from Amazon. Available in different colours, and for different size hoses

 

[Sethsquatch1]

Sounds like you're on the right track.

Get some spiral nylon hose wrap to wrap the new line in to prevent abrasion.

Braided hoses are good at holding pressure, but can rub through fast.

View attachment 3195362

Pic of from Amazon. Available in different colours, and for different size hoses

My man! Purchased it as well with the hose. It's a thermal and rub resistant tape!

 

[RangerDownUnder]

Understood, I did read about that and ordered a new half moon with my gasket.
Where is that image from? It looks helpful!

It's from the 1HZ/1HD-T/1HD-FTE engine repair manual. You should be able to find a PDF version online. Or you can buy the Haynes or Gregorys equivalent at auto parts stores.

 

[mudgudgeon]

It's from the 1HZ/1HD-T/1HD-FTE engine repair manual. You should be able to find a PDF version online. Or you can buy the Haynes or Gregorys equivalent at auto parts stores.

FSM - 1PZ, 1HZ, 1HD-T ENGINE REPAIR MANUAL

ENGINE REPAIR MANUAL for 1PZ, 1HZ, 1HD-T engines.

forum.ih8mud.com

HD-FTE manual is in the resources section also

Understood, I did read about that and ordered a new half moon with my gasket.
Where is that image from? It looks helpful!

 

[franklin40]

i have a major oil leak on my 1hdt that produces that size of a puddle. mine is leaking from the interface between the girdle and main block. get a good clean around that interface and see if it get wet there after a short drive.

it looks like im going to have to pull my engine to fix this issue. 😩. i hope yours is an easier fix