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Oil Leak on Freshly Rebuilt 2.5 (Page 1/1) |
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Riney
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DEC 10, 07:11 PM
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I just did a complete rebuilt my 2.5 Iron Duke on a 1984 Fiero that I have owned for 37 years. The machine shop did their part and I am the one that put it back together. The machine shop advised on not using any of the gaskets and to use RTV as that was how the factory built it and my research on the forum confirmed this information so I used the Permatex Ultra Gray. I had a small leak that was coming from the rear of the pan directly under the rear one piece seal. I drove the car for about 150 miles kept evaluating it and decided (hoped) it was the oil pan. The oil was dripping from the lowest point directly under the seal. There was no oil being slung on the flywheel. More research showed that i should have put a bigger bead of silicone around the rear main cap. I dropped the pan with it in the engine in the car (automatic transmission, yes it can be done and is a pain just like this forum says). The pan showed silicone touching the rear cap all the way around but in one spot it was only about 3/16" wide. I left the pan off for several weeks so oil would quit dripping, cleaned everything with brake clean multiple times, got the Permatex Ultra Gray back out and resealed the pan, this time with a bigger bead around the front and rear of the pan. I left the car set for a couple more weeks before adding oil and firing it up. I drove it about 25 miles this time and still have a small leak at the rear of the pan. The car has been sitting for weeks (I am currently rebuilding the entire front suspension while I contemplate dropping the engine back out) and it has a slight drip from the rear of the pan. it drips on the transmission then the oil makes its way around the automatic transmission gasket to a low point on the rear of the car before it hits the ground. The leak seems better but i really have not driven it enough to verify, after sitting for several weeks the spot on the floor is about half the size of a dollar bill.
I do not want to live with this small leak as it did not leak before and I am doing a complete rebuild on everything (engine, transmission, suspension, seats, etc.) sand blasting, painting, and detailing every nut and bolt that comes off. So I am positive I need to drop the cradle and pull the engine back off the transmission.
FYI, this whole project started because the fiber timing gear went out. I now have way more money in this that the car is or ever will be worth, I have more in parts than what I paid for the car 37 years ago.
Does anyone think this oil leak could be something other than the pan like an oil galley plug at the rear of the engine, cam plate at the rear, or rear main seal?
------------------ Riney
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82-T/A [At Work]
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DEC 10, 07:50 PM
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Hey Riney... my daughter just rebuilt her motor a few months ago, and we had the same problem, but luckily discovered it before we put it in the car.
This is Part 1 - https://www.youtube.com/watch?v=nNN-6h3WotI This is Part 2 - https://www.youtube.com/watch?v=h5C_7epwKeo
At 6:08 in the first video, my daughter shows that you're supposed to put some high-compression RTV sealant between the rear main bearing cap, and the engine block, because oil will seep past there and drain down. It could be that that's where it's coming from.
One of the things we did though, before putting it in the car, she assembled the motor completely, kept it on the engine stand, filled it up with oil, and then turned the engine completely sideways... both ways. She'd leave it sideways for a couple of days to see if any oil leaked out anywhere. Three times we caught an oil leak, and were able to fix it before putting the engine into the car. The first time it was the lifter galley cover leaking, then it was the valve cover leaking (and we switched from cork to neoprene), and then finally, the worst one (worst as in hardest to fix) was the one in the front, which was where the oil pan meets the timing cover. She had to pull the entire timing cover off, and re-apply the RTV sealant again.
Hope that helps... and also... I totally get it. My daugther has spent close to $20 grand already in restoration parts (of my money) to restore this car... but we're considering it an education more than anything...
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Dukesterpro
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DEC 11, 11:24 AM
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20 GRAND?!?!
You must love your child! However, from what I have heard, she's always doing her best to earn it! Neat update about rotating the engine, thats creative!
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82-T/A [At Work]
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DEC 11, 01:38 PM
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quote | Originally posted by Dukesterpro:
20 GRAND?!?!
You must love your child! However, from what I have heard, she's always doing her best to earn it! Neat update about rotating the engine, thats creative! |
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Yeah... long story. She's going to a school that's in a wealthy area. All the neighbors kids are getting Mini Coopers, BMWs, big trucks, or Jeeps (mostly Jeeps). Like... everyone has a Jeep... half the parking lot are Jeeps (seriously). I want to get her something that's nice, but I made a deal with her that I'll only buy her a car, if she's willing to learn how to fix it up. It's coincidental, honestly... that she has a Fiero. I had one on the screen (she had never seen mind at that point) and fell in love with it. So we bought it. Well... to make a 35 year old car run and drive like a brand new car... where everything... I mean, EVERYTHING has been restored... yeah, $20k is about what you can expect. And that was with me being somewhat frugal.
I'm keeping track of everything (though I stopped entering stuff into the spreadsheet like a few months ago), but I expect it to top out around 23-24k... if it's less, I'll be surprised. But at that point, the car will basically be brand new. I think you've seen the videos... if we don't outright replace something, then she cleans, sands, paints, and re-installs.
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Dukesterpro
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DEC 12, 12:43 PM
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Oh you two have done a excellent job, no doubt about it. Im a avid follower on Gen Z garage being a Zoomer myself. (older zoomer, 23 now)
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Riney
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DEC 12, 02:10 PM
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Watched the videos and was very impressed. Good job on getting your daughter involved in repairs and restoration. While assembling the engine i wondered what would keep the the oil from leaking around the bearing cap but I did not find anything in my Pontiac Fiero Service Manual or the Haynes Manual that said anything about sealant on the cap. It did not appear to have any sealant when i disassembled. I should have done more research. It does appear I have a seep at the timing cover as well, this may have to do with pulling the pan and reinstalling. Since I will be pulling things apart i will go ahead and pull the timing cover and get new front and rear seals. It appears to me that the timing cover should be installed at the same time as the oil pan so the RTV will be continuous and not have a possible place for a leak where it meets the timing cover.
It also appears to me that the rear seal should be installed before torqueing down the rear main cap as this would avoid the possibility of damaging the seal lip or distorting the metal casing while driving it in. Do you think this is correct?
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82-T/A [At Work]
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DEC 12, 03:15 PM
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quote | Originally posted by Riney: Watched the videos and was very impressed. Good job on getting your daughter involved in repairs and restoration. While assembling the engine i wondered what would keep the the oil from leaking around the bearing cap but I did not find anything in my Pontiac Fiero Service Manual or the Haynes Manual that said anything about sealant on the cap. It did not appear to have any sealant when i disassembled. I should have done more research. It does appear I have a seep at the timing cover as well, this may have to do with pulling the pan and reinstalling. Since I will be pulling things apart i will go ahead and pull the timing cover and get new front and rear seals. It appears to me that the timing cover should be installed at the same time as the oil pan so the RTV will be continuous and not have a possible place for a leak where it meets the timing cover.
It also appears to me that the rear seal should be installed before torqueing down the rear main cap as this would avoid the possibility of damaging the seal lip or distorting the metal casing while driving it in. Do you think this is correct? |
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I think the only reason we put a little but of "high compression RTV sealant" under the rear main cap (at that spot), is because I've seen it done so many times on so many of the car shows where they rebuild an engine. But I do recall seeing it somewhere, either in the Haynes manual, or the factory service manual... but I just can't remember.
Double check where the leak is on the timing cover... we had a leak initially where it mates with the oil pan (as I menntioned), but another place it often can leak from is the front seal. Apparently (and we did this wrong the first time, but just got lucky), you're supposed to "center" the timing cover. So, for example... you've got all the RTV sealant on the pan, ready to go, and you install it. Before bolting it down completely, you put just a couple of bolts in loose. You then install the crank pulley... thing... I forget what it's called, what the pulley connects to. You then move the timing cover around slightly (with the RTV sealant still went) until you can tell that the front seal is properly equidistant all the way around... and THEN tighten down the rest of the bolts.
You don't need to remove the oil pan if there are no leaks there... just make sure you load up on RTV sealant at all the corners.
But yeah, it's a pain. I learned so much doing this with my daughter...
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