[64speed]

Can anyone recommend a good dye to use to find an oil leak? NAPA and Advance here don’t have any and there are a million brands with wide reviews on Amazon. I have a leak at the front of the engine that as best I can tell is not coming from around the pan or seal. Everything dry up front in that area but after a 10 mile drive I am getting a fairly decent size stain on the driveway that seems to be in the middle of the engine. There are a few drops hanging off the block plate/bellhousing but that’s it. In 555 miles it still shows full but it’s significant enough where I wouldn’t want to park it on someone’s driveway or anything.

[steve25]

The only other 3 places up front where it could be coming from then would be the timing cover gasket , the front crank seal , the fuel pump gaskets or it’s bolts.

The fuel pump bolt holes in the timing cover are not blind , so the fix might be as easy as backing them out one at a time and applying sealer to clean and dry threads.

If you have no mechanical pump on the motor but a block off plate then the threads could still be a issue.

Take a close look on that pump side of the cover, because if it looks dry then do not bother getting any dye to add to the motor because at that point your pulling the timing cover no matter what to fix the leak.

I have seen front crank seals not driven in perpendicular to the cover and that will make for a leak.

Also are you sure it’s engine oil?

If you have transmission lines going into the rad it could be a small leak from those fittings.

Is your fan showing signs of oil

[i82much]

i have tried a few, they all work great. just pick one.

[NeighborsComplaint]

Check your oil pan bolts. They should be snung but not overtightened.

Rear pan gasket or (horrors) rear main seal are the usual suspects if you're spot aligns with the bellhousing but oil can travel some-what. A rear pan gasket or rear main seal leak can run down the back of the block and surface tension allows it to run along the oil pan rails and drip to the ground a from the pan bolt heads when parked.

The dye is one way to determine the source, another is to park the car, remove the inspection plate and stuff a rag up between the flywheel and crank and place clean cardboard under the engine. let it sit overnight and check in the morning.

[64speed]

If it’s the rear main I’ll just let er drip . If it’s something else then I’ll deal with it. I don’t have an inspection cover. It’s a QuickTime scattershield. I THINK it’s forward of that. I am gonna pressure wash the underside when I’m able and start fresh. Nothing but the flat of the pan has any droplets I can see but I’m only a week Post Op so I can’t get under it. Nothing under the car is really greasy yet so I don’t think it could be anything major spraying oil. It sure as hell isn’t like the cracked filter housing. I appreciate you guys help.

[geeteeohguy]

Rear main leaks will baste the underside of the car from the rear of the pan back to the rear bumper. If you have a mid-engine leak it can be the timing cover, valve covers, switch locations, or valley pan cover or bolts. My gut is telling me, from your description, it is not the rear main. Wishing you better luck on this. You've hit every bump on the road with this one.

[Don 79 TA]

I'm trying to remember where i bought the dye/light kit from
i dont recall if it was summit or autozone
i think the main thing i saw in the kits was the light, that is what will help you the most
they dye, if i am not mistaken is about the same
after using it in my friends shop and seeing how helpful it is, especially for AC leaks, of course he had a master kit that had an amazing light, i bought one to help find a leak
that leak drove me bat ch!t nutz
turns out it was an oil breather cap i bought that leak underneath it, and the way it traversed around was mind boggling
i want to say the kit i got had like a small led type of light that took i think 2 AAs and had the glasses and all
wasn't much, but man o man i wish i had that before all the work i did thinking the seals were shot, me not installing them right, etc...
or, perhaps a smoke machine, that's another thing i'd love to have
think how handy that tool is

[64speed]

Yeah it’s pissing me off, I don’t think it’s the chain cover but maybe I’m wrong. I know the seal and pan at least up front cause that’s all dry as a bone. I’ll figure it out unless it’s the rest main. I just can’t go thru all that **** again for a long time. It runs too good. It’ll just have to get parked on gravel or in the grass. My driveway is ruined in the spot where it sits from all the work over the last SEVEN (lol) years but I don’t want to burn bridges ruining other peoples

[jhein]

My previous RAIII motor had a front main seal leak. The previous owner had the motor rebuilt and it had a leak. They replaced the seal and when I got the car there was no leak. After I changed the oil, the leak started again. I'm guessing they still had the leak after the new seal but maybe used some type of anti-leak additive in the oil. The PO blamed it on "cheap overseas parts" but I'm thinking maybe a worn crank snout?

[64speed]

Everything but my block is new forged parts. I just checked my valve cover studs and one had backed off a little so I tightened it and when I can I’m going to thread seal the fuel pump bolts cause that seems reasonable. After that if it doesn’t stop I’ll put Lucas stop leak in it.

[Dragncar]

Originally Posted by jhein

My previous RAIII motor had a front main seal leak. The previous owner had the motor rebuilt and it had a leak. They replaced the seal and when I got the car there was no leak. After I changed the oil, the leak started again. I'm guessing they still had the leak after the new seal but maybe used some type of anti-leak additive in the oil. The PO blamed it on "cheap overseas parts" but I'm thinking maybe a worn crank snout?

The seal does not ride on the crank. The balancer is the contact point.
Many of the factory balancers ended up with a pressed on sleeve where the seal rubbed. When I sent my old factory balancer to Whitmore so he could degree mark it is came back with one of those sleeves.
The OP might consider a vacuum pump. Its a lot harder for a engine to leak if you have negative crankcase pressure.
This engine I recently fired up had one leak around one of the 2 bolts at the front of the oil pan. I pulled them out, carb cleaned them and the bolt holes and put them back in with Ultra Gray on the threads and the engine is dry as a bone.
Steffs aluminum pan so the outer front pan bolts are deleted. And no pan gaskets since I rave a duel scrapper the front pan gasket was also deleted.
Just RTV.

[jhein]

Originally Posted by Dragncar

The seal does not ride on the crank. The balancer is the contact point.
Many of the factory balancers ended up with a pressed on sleeve where the seal rubbed. When I sent my old factory balancer to Whitmore so he could degree mark it is came back with one of those sleeves.

Thanks, I did not know that. What's even stranger is that when I talked to a machinist/engine builder (not the guy who built my stroker) about the leak, he's the one who mentioned the possibility of a worn crank snout, and I'm sure he wasn't talking about the balancer. I guess it's a good thing I didn't use him.

[geeteeohguy]

Originally Posted by 64speed

Everything but my block is new forged parts. I just checked my valve cover studs and one had backed off a little so I tightened it and when I can I’m going to thread seal the fuel pump bolts cause that seems reasonable. After that if it doesn’t stop I’ll put Lucas stop leak in it.

I would not use stop leak in a new engine build. It works by softening the old, hard rubber seals. Not something you want in a new engine, which already has soft seals in good shape. It will tend to degrade them faster. It works in old tired engines as a stop-gap prior to an overhaul, but in your case, best to fix the leak.

[gtorich]

Originally Posted by geeteeohguy

I would not use stop leak in a new engine build. It works by softening the old, hard rubber seals. Not something you want in a new engine, which already has soft seals in good shape. It will tend to degrade them faster. It works in old tired engines as a stop-gap prior to an overhaul, but in your case, best to fix the leak.

Curious about this statment, if your new soft seals are already leaking , what harm can the stop leak really do anyways...........i get it might degrade them faster, but seems your already in trouble leak wise.....................just trying to learn from this.

Rich

[64speed]

When I was young and stupid and had money burning a hole in my pocket fresh out of the service I moved back in with my parents and built a 20x40 shop with a lift etc. I thought they would live forever I guess. Fast forward, dad has passed, mother moved to a smaller house. I sold my lift and all my real goodies but hand tools to my father in law. 20 plus years on and the lift is still at my disposal but it’s not “mine”. From paint there is dust and overspray under the car plus crap that has just been picked up along the way. If it was still my shop I’d just put down plastic, pressure wash the **** out of every inch and start fresh but he would have a stroke.

[mgarblik]

If the leak is really upsetting you, and it sounds like it is, buy or borrow an evap. smoke machine. You will find the source of the leak in 2 minutes tops. Much easier and cleaner than the dye route. To use dye, everything has to be very clean and dry before you begin. BTW, I have found "liquid band-aids" for leaks to not be very effective.

[Verdoro 68]

Originally Posted by mgarblik

If the leak is really upsetting you, and it sounds like it is, buy or borrow an evap. smoke machine. You will find the source of the leak in 2 minutes tops. Much easier and cleaner than the dye route. To use dye, everything has to be very clean and dry before you begin. BTW, I have found "liquid band-aids" for leaks to not be very effective.

Having used both the dye and the smoke to find a leak, I concur that smoke is the way to go.

[64speed]

I guess it is upsetting. So much money and the last thing I was is spots in the driveway

[Verdoro 68]

In context of what you've been through with your build, this is just a little blip. It's frustrating, but don't let it get you down. Much easier to solve than what you've already fixed.

[mchell]

Originally Posted by 64speed

I guess it is upsetting. So much money and the last thing I was is spots in the driveway

It’s an old Pontiac….there WILL always be something dripping…

As mentioned by someone else, check the pan bolts. You’d be surprised how much they can loosen up after a build…