Too Much Blood on My Pans [UPDATED]

"Urambo Tauro" (urambotauro)
08/18/2016 at 20:01 • Filed to: wrenching, blog, discussion

What makes Mustangs so bloodthirsty? Could it be that they don’t have enough blood of their own, a condition known as hypovolemia ?

Wikipedia defines !!!error: Indecipherable SUB-paragraph formatting!!! as “a state of decreased blood volume” “characterized by salt depletion”. Alas, after more more than twenty years on the road, salt has indeed depleted the outer integrity of my car’s oil pan. The result? A gradual loss of my dear 302's lifeblood.

It started slow, maybe a quart every oil change. But in the past couple of months, it’s become a weekly maintenance item. The bottom of the pan is constantly wet, and the dripping leaves stains on the ground. Last week, I tightened the drain plug, hoping that it was merely loose, and cleaned the area. But it’s still leaking, which is both good news and bad. The good news is, I must have tightened it properly during its last oil change. The bad news is, fixing the leak just got a bit more complicated...

I crawled back underneath and picked away bits of flaking paint. As you might expect, a disconcerting amount fell away from the rusted steel surface. I scraped and brushed all that loose material, and wiped away the dust and oil from the surface. Suddenly, right on the side of the pan I noticed some fresh weepage. Oil, that is. Black brown gold. Texas tea.

In theory, the job is simple: unbolt the oil pan, and put a new one on with a fresh gasket. Shouldn’t be more than $100 in parts. In reality, the saddle-shaped pan is nestled over the K-member, which means dropping the entire front suspension, or pulling the engine out from above to access the pan. All for an itty-bitty oil leak.

Even though a new pan is guaranteed to keep the oil on the inside, that’s an awful lot of trouble to go through. So instead, I’d like to try patching this one in place. Don’t get me wrong: I dislike the idea of taking a chance on a patch that may or may not hold. I’ve only ever tried doing such a thing once, wrapping a glob of J-B Weld around a leaking steel section of power steering line. (It didn’t last long.)

But the oil pan is not subject to that kind of hydraulic pressure. I believe that if I can prep the surface well enough, and seal it with something that can handle temperature changes and oil contact, this would be the practical way to go.

The leak is on the passenger side of the pan, on a flat vertical section. A quick Google search for “oil pan repair” reminded me of one of Torch’s articles from a few years ago: !!!error: Indecipherable SUB-paragraph formatting!!!

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I’ve already drained the oil, and am seriously thinking about (after prepping the surface) smearing a bit of RTV over the pinhole, and using that to glue a coin per Jason’s technique.

What do you think? What are your experiences with patching up leaks? If it was your car, how much of a hassle would pan replacement have to be before you would attempt something like this?

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08/18/2016 UPDATE:

Thanks for the suggestions! I took a chance on epoxy after all.

I prepped the surface real good and coated the front, sides, and bottom of the main hump. After sanding, painting with engine paint and re-filling with oil, I found that it was now leaking in the oil level sensor dimple. I must have disturbed some loose rust and uncovered a new leak.

So I had to start all over again. Re-drain, re-prep, re-coat, re-sand, re-clean, re-paint, re-fill... Only now can I report no leaks!

We’ll see how long it lasts.

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12/22/2016 UPDATE:

The very edge of the repair where the epoxy was thinnest broke through, probably due in part to winter’s more extreme temperature fluctuations. See post !!!error: Indecipherable SUB-paragraph formatting!!! .

DISCUSSION (11)

Expo2k > Urambo Tauro
07/27/2016 at 22:21

I had some luck with liquid steel epoxy (the runnier JB Weld type stuff) on my E30 325i’s aluminum pan. The prep is the most important part: I made sure all the oil was drained, scuffed it up good with a 200 grit sanding sponge, cleaned it with brake cleaner, and applied a LARGE 6"x6" patch around the curb-induced crack. IIRC it held for four years, but then again it didn’t have rust. You’d likely need to remove that.

Urambo Tauro > Expo2k
07/27/2016 at 22:33

Prep is absolutely key; I want to ensure a good bond.

I really like the idea of using an epoxy that I could sand like body filler and paint over. That would allow me to refinish other areas that are probably rusted thin but haven’t broken through yet. However, I’m still a bit nervous about how it would handle heat cycling. I’ll have to visit the store and check the specs on what they have available.

The thing that I like about RTV is that it’s flexible, and Permatex lists heat ranges for the different compounds. The fact that it claims to resist oil is a plus, too.

Urambo Tauro > Expo2k
07/27/2016 at 22:34

IIRC it held for four years, but then again it didn’t have rust.

What happened after four years? Did you get rid of the car? Did the repair actually fail? Or are you still driving it, and that’s how long it’s been so far?

Expo2k > Urambo Tauro
07/28/2016 at 04:47

Gave it to my brother and it started leaking again after some time during his ownership about 4 years later.

MontegoMan562 is a Capri RS Owner > Urambo Tauro
08/11/2016 at 15:15

I took our Jeep Commander to the shop to get it’s oil pan replaced (PREMATURELY I MIGHT ADD YOU RUST PRONE JEEPS) because I realized the same problem of engine up or suspension down. They took care of it real easy and it was worth just paying them to do it.

Urambo Tauro > MontegoMan562 is a Capri RS Owner
08/11/2016 at 15:23

I honestly hadn’t even considered taking it to a shop. But with the tools and equipment they have at their disposal, it might not take as many labor-hours as it would in my garage...

At any rate, I’m in the middle of patching it now. If that doesn’t hold, I’ll see what they would charge. I’ll update this post soon (probably this weekend).

MontegoMan562 is a Capri RS Owner > Urambo Tauro
08/11/2016 at 15:41

Yeah it normally comes down to - “do I have the equipment/tools to complete this job?” I spent probably 3-4 hours trying to get the oil pan out on the Jeep. It didn’t work out so I dropped it at the shop it took them only a couple hours. He only charges me about 60-65 an hour I should have just started with taking it to them.

e36Jeff now drives a ZHP > Urambo Tauro
08/18/2016 at 20:17

If its so badly rusted that it has started leaking oil, its only a matter of time until things get really bad, a minor road strike could easily puncture it. I’d suck it up and go for a replacement pan.

Urambo Tauro > e36Jeff now drives a ZHP
08/18/2016 at 20:25

I’m preparing myself for exactly that, for the next time it starts leaking. And I consider that to be a when , not an if . I might even take it to a shop as MontegoMan suggested.

At any rate, this is kind of an experiment. I’ll be satisfied if it lasts a couple of months. But I feel pretty good about my prep-work, so I might get luckier than that.

At any rate, I’m glad that it has an oil level sensor, so if I ever see that indicator light up, I can shut it off immediately and get a tow.

e36Jeff now drives a ZHP > Urambo Tauro
08/18/2016 at 20:32

Well, if we are doing this as an experiment, coat the bottom of the pan in this . It sacrifices some heat resistance for max oil resistance, but since it’s still good to 500F, which is likely at or above your oil’s flashpoint, if it ever gets that hot, you’ll have greater issues(like the car being engulfed in flames).

Urambo Tauro > e36Jeff now drives a ZHP
08/18/2016 at 20:42

I would like to try that. But the epoxy idea appealed to me more, and I’m serious about biting the bullet on a new pan when this repair fails. Maybe if someone else reads this they’ll give the RTV a shot...