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Discussion Starter #1
I have almost 1000 miles on a rebuilt engine and until recently everything was nice and dry.

Now I appear to have an oil leak on the passenger side that appears to be coming (hard to tell) from the seal that is installed in the timing chain cover for the vibration damper. I replaced the seal when I did the rebuild but that seams to be the only logical source. I did not replace the crankshaft bolt when I did the rebuild, is it possible the bolt is not holding the damper securely? I did torque it but the best I could achieve was the base 74 lb-ft plus a small angle - nowhere near the recommended 30 deg plus 15 deg.

I am just looking for alternatives before I pull it apart and replace the seal again in case I am missing something.
 

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I’m not really sure if it’s the same case. But I did a timing chain set on an F150 a few months back. I noticed the crankshaft damper bolt had silicone sealant on it, the truck had never been apart. So this was original. Also noticed when I removed a little oil came out.

Did you noticed any sealant on the bolt or washer? It is also possible that the dampener is worn right where the seal is against it. I sometimes find a groove worn into them and they don’t want to seal up. Same with the rear main seal, but when it’s on the crankshaft end, sometimes a sleeve can be installed. They make one for the front of the crankshaft also, but I’m not really sure if it goes on the dampener or the crank itself. I see them available but I’m not really sure why they aren’t sold with the seal. It looks like they are supposed to work with a standard sized seal.

I doubt the crankshaft dampener is too loose, but it’s possible. They are usually made to not unloosen due to the engine rotation direction. It’s not highly recommended, although most mechanics will do it. But I’ll usually use an impact to snug the crank bolt up. The thing to do is not hammer the crap out of it. But to stop when it seats. Someone might keep the impact hammering and damage the threads or break the bolt off. But that’s the difference that knowing when to stop after doing this for many years. The right way is using a torque wrench. You really can’t get the dampener on offset or anything, it lines itself up when it’s being installed and really won’t go on wrong most of the time.

I have occasionally seen the seal go bad. Usually you’re using a good quality seal though. Sometimes they’ll go bad if they weren’t originally lubricated when the dampener was installed. You should used some grease before installing
 

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Discussion Starter #4
I didn't see any sealant on the threads when I took it apart.

The service manual does say to replace the bolt when it is removed but doesn't say anything about sealant on the bolt when installing.

I originally torqued the bolt as indicated but today I also hit it with an impact to see if it moved (it didn't seem to).

I am going to get a new bolt and seal so that when I take it apart I have a reasonable chance of putting it back together right away. I do have a second damper if the current one appears damaged in the seal area when it is removed.

I guess the good news is the damper is pretty easy to access on this vehicle, just take off the belt and the passenger front wheel.
 

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Discussion Starter #5
Still waiting on the new bolt but decided to remove the damper to confirm that was where the leak was. When I removed the damper the seal basically came with it so it clearly was not pressed into the front cover any longer.

Has anyone else had problems with the front cover seal not be retained by the press fit? I am using a FelPro seal (a brand I trust) and didn't think there was anything that would push the seal out of the cover. I am 95% sure I pressed the seal into the correct depth when I replaced it as part of the engine rebuild. I am considering adding a few stakes to the cover after the replacement seal is pressed in place but don't want to create more of a problem than I am fixing.

Any insight would be appreciated.
 

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Most of the seals come with a rubberized coating to seal against the cover. But sometimes I do like to spread a little bit of grey RTV on the metal part of the seal. Also a little grease on the rubber. I think I mentioned that.

Did you clean the oil off with some degreaser or a power washer first to make sure you can see the oil leak clearly. I always wash the area to find the leak more easily.
 

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Discussion Starter #8
The seal has a rubberized coating, given that it is a press (but light) into the cover I am not sure if sealant on the OD will do much other than get wiped into the engine when pressing the seal in.

I did clean the area with brake cleaner and tried to determine the source of the leak (stationary - engine off and on) without success. A short drive later the crankshaft pulley was dripping with oil and of course oil had been sprayed all over the area. I am 95% sure that the seal had moved out as far as the pulley would allow letting oil seep past the OD of the seal.

The new crankshaft bolt is expected today so I plan to install the new seal with sealant on the OD. When I install the pulley I will make sure to grease the lip of the seal and/or pulley to ease installation. I also plan to do my best to torque the bolt per the service manual although it is hard to hold the engine from rotating while also generating the toque required to get the additional 125 degrees of rotation required in the second step.
 

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Yeah it’s really difficult unless the car has a manual transmission. Unless you take the starter out and have someone hold it with a pry bars or something.
 

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Discussion Starter #10
Installed the new seal with additional sealant on the OD, cleaned excess after seal was pressed in place. I did a small stake in three places around the OD of the seal just to prevent the seal from backing out again. Installed the damper with grease on the nose where it engages the seal and the new bolt.

I made a fixture, basically a long straight metal bar, to attach to the taped holes in the pulley that rotated against the suspension as a lock to allow me to toque the bolt per the shop manual.

Will monitor but assume that this problem is now resolved.
 

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So, was it the right solution for this issue? I just do not understand why did this happen, I mean, you would not actually get an oil leak in such a case. I mean, surely some oil will be dropping, however it would not be a leak that you would avtually mention it. Recently, I had a real oil leak on my e92 m3 recently. The gasket that seals the two metal components in the engine actually broke down. So I had a really terrible oil leak, I had to visit the dealer so they fix this one up. Now it is ok, however I am having another problem, I do not know what kind of oil to choose, supertech or mobil 1. After reading this article 🥇Super Tech vs Mobil1 ★ December 2020 - UPDATED Real Comparison, I think that Mobil 1 is better, however I am really sure, which one are you using?
 

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Supertech, I’d pass unless you’re car is just pissing oil. It’s cheap, but for a little more you can buy Castrol in a synthetic, like the Magnatec I have started using. It wasn’t expensive, at Walmart anyways. About $10 cheaper there than at a parts store. Mobil 1 is good, but in my experience, it has a higher burn off rate than Castrol products. The most expensive stuff like Royal Purple gave me the highest rate of oil consumption when I used it in my Subaru Legacy that was a little modified.

My Cobalt was using more oil before. I had been using Valvoline at first when I bought the car. Then started using Castrol GTX high mileage semi-synthetic. Now using Castrol Magnatec with a little Lucas added. It’s reduced my oil leak and consumption noticeably. I’m sure the Lucas has really helped a bit more than the oil alone. Still gotta fix the rear main seal though.
 

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Yes, no additional leakage problems.
Just a small note on seals. Some manufacturers are now using Teflon coated seals (at the lip area) and these are NOT TO BE LUBRICATED at installation -- such as we have done for years with the lips of conventional seals. Don't know if the Cobalt front seal is like this but it's worth some further research perhaps.
RB
 

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I’ve looked for those and haven’t found any with the Teflon coating, yet. Although I haven’t looked too far past the well know companies like AC Delco, Victor Reinz, Mahle, Fel-Pro, Timken, National, just to name a few.
 

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FYI: The May 2020 issue of the MOTOR Magazine has a "Troubleshooter Column" article on the issues with PTFE (or Teflon) oil seals and the correct installation techniques associated with them. Apparently, the usage of these type of seals has been widespread for a number of years -- especially on GM products -- and many technicians (and DIY ers) are not aware of the special requirements for working with them. I would think that this article would be available in the MOTOR Magazine archives section. If not, maybe I could do some research and post it if anybody is interested.

RB
 

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Didn’t realize PTFE was the same as Teflon. I suppose Teflon is actually the name brand then. In that case, was the crank’s front seal always PTFE? From what I see the oem is. Also many Ford seals I’ve used are the same material. Not only that but most oem seals I have used have been prelubricated, mostly Ford and GM is what I’ve been working on. Never really paid much attention to the Euro stuff though as that was what I worked on a lot before.

I can’t say I’ve ever had a seal leak after installation unless the sealing surface was badly grooved, like on an axle shaft or crankshaft. I currently need to get to doing the rear main seal on my Cobalt. But finding time is hard. Always having customers cars coming first. I’m probably repeating myself. That should be really fun having to pull the transmission.
 
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