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gregp553

Oil Leak - Head Gasket or ??

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I searched the topic and read dozens of opinions. My oil leak can be seen here, looking down at the block, along the upper left corner of the head if you were standing on the passenger side of the vehicle. The shiny stuff above that hose clamp (circled) is fresh oil on the block. Second photo is zoomed out so you can see the head bolt. I cannot find any leak from the valve cover gasket (replaced it with no change), no oil is dripping from the distributor housing or distributor that I can see, it doesn't drip onto the exhaust, it's not coming from the upper manifold bolts. There's no water in the oil. Is there any way this is not coming from the head gasket? What I've read says there should not be oil leaking from that area from the head. But there it is. If I wipe off the oil, it's wet again after a drive. Drips once or twice onto the ground as it travels down the transmission housing right where it meets the block. Am I destined to replace the head gasket? I bought this car recently and was told it has 87,500 original miles. Possible the motor has never been opened up. Thanks for the input.

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The distributor housing above that could be leaking oil, have you made sure it's not coming down from there?

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I wouldn't jump to HG so quickly.

 

The distributor housings are pretty common leak points, and there's a bolt back there that requires a special crush washer you shouldn't reuse (but can...unless it leaks when you do).

 

Oil can also get blown down the length of the motor from wind/ the radiator fan and pool in the back, so it could be coming from a poorly sealed, or failing seal on your upper timing cover. 

 

Mine weeps a bit from the breather-hose on the valve-cover, even with a tight-fitting silicone hose. 

 

Spray it all down with brake-cleaner to get everything bone-dry, drive it around the block, and see what looks wet. 

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15 minutes ago, 2002Scoob said:

bolt back there that requires a special crush washer

 

It's actually a seal that looks like a thick washer, but Scoob is right, that could be the source. Also, the distributor gasket may be leaking from the bottom. You'll need a mirror to see the bottom and backside of the housing.  Super easy to replace the seal and the gasket all at the same time.

 

Brake cleaner rocks!  Remove all the oil in the area and do the drive around the block.

 

Veteran opinions please:

 

If you determine that the HG is leaking on the back edge, maybe a head bolt re-torque could help.  At 87K it can't hurt to tighten the head bolts a bit, right?  What say the pros?

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10 minutes ago, PaulTWinterton said:

It's actually a seal that looks like a thick washer,

Ahhh yah! You're right, now I remember.

 

That's one of the first things I had to do when I got my car, was replace the dist. housing seal and that little washer-piece-and was the source of most of my oil on the back of the motor.  

 

It's a metal cylinder with a little rubber flange dealie inside, yah?

 

 

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37 minutes ago, 2002Scoob said:

I wouldn't jump to HG so quickly.

 

The distributor housings are pretty common leak points, and there's a bolt back there that requires a special crush washer you shouldn't reuse (but can...unless it leaks when you do).

 

Oil can also get blown down the length of the motor from wind/ the radiator fan and pool in the back, so it could be coming from a poorly sealed, or failing seal on your upper timing cover. 

 

Mine weeps a bit from the breather-hose on the valve-cover, even with a tight-fitting silicone hose. 

 

Spray it all down with brake-cleaner to get everything bone-dry, drive it around the block, and see what looks wet. 

I like the thinking here, but here are tests I've done. Wipe the oil from the block and underneath. Test drive and come back to find the oil weep like seen in the photo, and putting my hand under the distributor housing on the entire bottom edge, including under the crush washered bolt, no oil on my hand. Then, this morning, I rolled a tshirt into a ball, stuffed it into that corner of the head/block where the oil appears, drove up to operating temp., idled, retested, and there was no fresh oil on the tshirt or the block. But 2 days ago I also did a test drive that came back dry, only to leak the next day. I think the upper timing chain cover was replaced in the past 2 years. I'll look into that. The valve cover hose was not clamped when I first got the car 2 weeks ago. But it has been clamped for the past week of leaks. Crazy.

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If you determine that the HG is leaking on the back edge, maybe a head bolt re-torque could help.  At 87K it can't hurt to tighten the head bolts a bit, right?  What say the pros?

I had a head gasket leak water once when I retorqued it after umpteen years.  I don't, anymore.  But that happened once.

 

So here's the deal- the only place the oil touches the head gasket is marked.  The red's high pressure oil up to the cam

and rockers, and green's unpressurized drains .  Blue is water- this is a Cometic gasket, so yours will have slightly different

water restriction passages, but they'll be in the same places.

 

So it's really unlikely oil's coming out of the gasket where you're seeing it.  It MIGHT be coming out somewhere else, and running

back.  But it's so much more likely that the front cover's leaking, the valve cover's leaking, or the distributor's leaking from

either the housing, the o- ring around its base, or out of the distributor itself. 

Those little mirrors- on- a- stick are invaluable for this, as are tiny LED lights that

you can wedge up in there at odd angles.  I have a tiny camera that sometimes helps, too. 

Sometimes not, tho.

 

Worst comes to worst, you could buy that UV dye, and a UV light source (cheap LED version from ePay)

and try that.  In your shoes, I'd keep at it with the wad of t- shirt rag.  But do have some way to extinguish it

if it manages to set itself on fire on the manifold.

 

hth

 

t

 

head gasket color.jpg

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3 minutes ago, TobyB said:

I had a head gasket leak water once when I retorqued it after umpteen years.  I don't, anymore.  But that happened once.

 

So here's the deal- the only place the oil touches the head gasket is marked.  The red's high pressure oil up to the cam

and rockers, and green's unpressurized drains .  Blue is water- this is a Cometic gasket, so yours will have slightly different

water restriction passages, but they'll be in the same places.

 

So it's really unlikely oil's coming out of the gasket where you're seeing it.  It MIGHT be coming out somewhere else, and running

back.  But it's so much more likely that the front cover's leaking, the valve cover's leaking, or the distributor's leaking from

either the housing, the o- ring around its base, or out of the distributor itself. 

Those little mirrors- on- a- stick are invaluable for this, as are tiny LED lights that

you can wedge up in there at odd angles.  I have a tiny camera that sometimes helps, too. 

Sometimes not, tho.

 

Worst comes to worst, you could buy that UV dye, and a UV light source (cheap LED version from ePay)

and try that.  In your shoes, I'd keep at it with the wad of t- shirt rag.  But do have some way to extinguish it

if it manages to set itself on fire on the manifold.

 

hth

 

t

 

head gasket color.jpg

Thanks for the insight, and it's so funny you say that. I actually left the hood unlatched in case I had to open it in a hurry! Ha!

I will use a mirror to look further, but it just seems like when I get back from a drive, and there is fresh oil on the block as seen in the photo, I should be able to get some on my hand when I run it around the distributor housing or valve cover if that's where it leaks. More later.

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Also check under the fuel pump if it's leaking the oil will run down to the head gasket and the fan will blow it to the rear.

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I checked with a mirror, got under it, etc. Cleaned it with some brake cleaner, and drove it. Here is a clear picture of the leak after my drive. So, I re-cleaned, figured I had nothing to lose, and gave each bolt on the distributor housing a little tug. Test drove again and I did not see a leak. I have been fooled before, so time will tell. More later.

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Drove it for 30 minutes. Leaked. Walking away from it for a couple days. 

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3 hours ago, gregp553 said:

Drove it for 30 minutes. Leaked. Walking away from it for a couple days. 

I have learned to live with oil leaks.  I swear I have never owned a car that didn't leak.  Some much worse than others, but none the less all had leaks.  I am kinda gun shy when it comes to getting a new motor, as my expectations is that there isn't leaks.. and there will be... and I will get mad and resentful..... and that isn't nice, so no new motor for me until I learn to behave. 

 

Also I suck at fixing them.  I took my oil pan off three times, and still I think it weeps a little.  Rear seal replaced last year... leaks (second one).  Front crank seal replaced... leaks.  Upper timing cover... leaks.    None of them a lot, they sorta weep,  but just enough to not bother to clean your engine bay. 

 

 

 

 

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I'm pretty sure at least one of the rear head bolts shafts has oil in it from the rocker shafts. The shafts have a little passage in the notches that align with the head bolts, and I'm assuming oil goes through that hole since the shafts have oil in them.

 

 

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1 hour ago, aventari said:

I'm pretty sure at least one of the rear head bolts shafts has oil in it from the rocker shafts. The shafts have a little passage in the notches that align with the head bolts, and I'm assuming oil goes through that hole since the shafts have oil in them.

 

 

 

This is true. The rear bolt on the exhaust side of the engine. If you flip or swap the hardened head bolt washer when you have the head off and it doesn’t cleanly fit back into the dimple in the aluminium head it can leak oil from the bolt. I had this once and undid the bolt a few threads (so oil doesn’t get into the hole in the block) and added some sealant under the washer. I then re-torqued the bolt. No leak and no issues. 

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On 8/14/2019 at 12:55 PM, TobyB said:

I had a head gasket leak water once when I retorqued it after umpteen years.  I don't, anymore.  But that happened once.

 

So here's the deal- the only place the oil touches the head gasket is marked.  The red's high pressure oil up to the cam

and rockers, and green's unpressurized drains .  Blue is water- this is a Cometic gasket, so yours will have slightly different

water restriction passages, but they'll be in the same places.

 

So it's really unlikely oil's coming out of the gasket where you're seeing it.  It MIGHT be coming out somewhere else, and running

back.  But it's so much more likely that the front cover's leaking, the valve cover's leaking, or the distributor's leaking from

either the housing, the o- ring around its base, or out of the distributor itself. 

Those little mirrors- on- a- stick are invaluable for this, as are tiny LED lights that

you can wedge up in there at odd angles.  I have a tiny camera that sometimes helps, too. 

Sometimes not, tho.

 

Worst comes to worst, you could buy that UV dye, and a UV light source (cheap LED version from ePay)

and try that.  In your shoes, I'd keep at it with the wad of t- shirt rag.  But do have some way to extinguish it

if it manages to set itself on fire on the manifold.

 

hth

 

t

 

head gasket color.jpg

I removed the air filter housing and got the best view yet of all the places oil could be leaking from the timing chain cover back. That's not it. The distributor housing is not leaking. The valve cover is not leaking. I wadded up a small 3" cotton medical pad and stuffed it right next to the base of the head exactly where the wet spot appears in my photo above. After a drive, the pad was full of oil, at least it looked like and smelled like oil. Seems hard to believe it's water/anti-freeze based on the visual of it. So, as impossible as it seems for oil to leak there from the head gasket, I'm stumped. I'm going on a 50 mile drive tomorrow for the Woodward Dream Cruise with a few thousand muscle cars, and it's either going to be fine or not so fine. Wish me luck.

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