Oil leak - 1978 124

[scottmercer]

Hi,

Can someone be so kind as to let me know what bolt/gasket is leaking in this photo? The leak appears to be behind the curved pipe. The view is looking up from the ground towards to the distributor.

https://drive.google.com/file/d/0B7zl-4 ... sp=sharing

Thanks in advance!!!

[So Cal Mark]

I'm betting you have more than 1 leak, but I'd say the distributor seal is leaking for one

[scottmercer]

I just fixed the distributor seal. Next?

[RRoller123]

The rear of the Cam Box looks like it was epoxy patched for some reason (in 2 locations). There seems to be some evidence of fluid leaking at the rear patch. The head gasket under #4 exhaust looks like it has a fluid leak, but this could easily be coming from the distributor above.

[scottmercer]

Thanks guys! Looks like I need to clean up the area, better isolate where the leak is coming from. I suspect the #4 exhaust but will take Mark's advice on ruling out the distributor as that would be easiest, and most logical since I just finished working on it.

I may ask for some more advice in a bit.

[scottmercer]

Hi,

I will be retightening the exhaust manifold bolts due to the leak in this picture:

https://drive.google.com/file/d/0B7zl-4 ... sp=sharing

What should I know before doing this? I just want to do it correctly. I am mainly wondering about:

1. Is there a gasket behind the manifold?

2. Can someone clarify this exchange from a previous thread:

Question: So far I only see oil dripping from the first manifold stud, the one that is neatest the number one cylinder.
Answer: Double nut the stud, remove it, clean it, thread seal it, and reinsert (torque to 18 lbs).
Clarification: does this mean that I would remove the actual threaded stud from the engine?

3. Do I put Permatex on the thread going into the engine, or on the thread visible in my picture above?

4. There was talk on another thread about the flange (where the bolt affixes on the head?) not being flat. How do I go about flattening it?

5. Would it be advisable to sandblast the manifold to get rid of the rust and oil stains?

6. Any other advice or tips/tricks?

Thanks in advance!

[blazingspider]

In response to your questions:

1: Yes, there is a gasket between the exhaust manifold and the head but it's job is just to keep exhaust gases contained and has nothing to do with holding oil back.

2: Yes, the quote refers to removing the stud from the head by double nutting it and then smearing the threads that go back into the head with a sealant. IIRC the 2nd and the 4th stud holes (when counting from the front) are tapped into the oil drainbacks molded in the cambox and could leak oil if the hole was stripped and helicoiled, if the studs have been replaced with the wrong kind (no shoulder) or the shoulder on the original stud does not seal the hole when fully tightened. When encountering this problem you may be able to remove the stud, smear it with a sealant, red RTV for example, tighten it and let the sealant dry before running the car. That may fix the problem.

3: See above

4: You would have to remove the manifold and have some material removed from it.

5: You can if you want or use a drill and a wire wheel, some degreaser, then coat with a good high temp paint.

6: If you're chasing oil leaks in that area check the back of the cambox. There's a seal between the back cambox cover and the cambox that will leak oil when it gets old and brittle. Also the cambox to head gasket is another area where leaks likely develop. and finally the head gasket itself can leak back there by #4.

If I were you I would be most concerned with why the PO smeared all that epoxy in those 2 spots on the cambox. If there are cracks or chunks of material missing there you are more than likely going to have some oil leaking from those areas. Remember that the cams ride in an oil bath and oil is splashing everywhere inside when running.

Good luck

[blazingspider]

Let me clarify one of my statements above. Regarding the 2nd and 4th exhaust manifold stud holes; they are tapped into the oil passageways in the head that receive oil from the molded oil drainbacks on the cambox.

[scottmercer]

Thanks, blazingspider. The PO says this was the from the PPO (previous previous owner). Supposing I dove into this, would it be feasible to just replace with a new cam box? From what I am seeing, it doesn't seem to costly.

[joelittel]

It'll cost you in time, but not too much money.

You'll need to take the timing belt off to replace a cam tower and the research involved in learning how to do it correctly will cost you a little time.

The hardest part for me was getting the cam pulleys off, I highly recommend an impact wrench. You'll also need a torque wrench, and might as well renew the gaskets and seals "while you're in there."

[scottmercer]

So it turns out that I need to repair a crack in the metal of the cam cover (the one above the exhaust manifold). I will require removing the cam box because the crack in near the firewall and inaccessible. Isn't this just a matter of removing the cam wheel, then cam cover, making the repair, and then putting it back together with a new gasket making sure the camwheel position remains the same? Maybe I am oversimplifying it...if so, is there a resource I can review to prepare for the job? Thanks!

[scottmercer]

Addition:

If I am just removing the upper cam cover, do I still have to remove the timing belt? Thanks!

[RRoller123]

I think we may be confused by whether you are talking about the valve cover or the cam boxes or both? The valve cover comes off independently with no real consequence. There is a rubber gasket and just keep things clean. If the cam box itself (which holds the camshaft running down through its center) needs to come off, that is detailed enough that, as stated earlier, a bit of research is needed to do it correctly. The timing belt has to come off, and the cam wheel/gear and camshaft as well, in order to remove/clean and repair the box. In putting it back together, the timing (rotational position) of the cam(s), is critical. Can you post a picture of what needs repair?

Good used Cam boxes are widely available at a reasonable price here, and it is likely that the repair is not worth the effort versus replacement.

Pete

[scottmercer]

Definitely the cam box. It is the RTV repair on the left in the picture.

https://drive.google.com/file/d/0B7zl-4 ... sp=sharing

Also have the leak on video here:

http://www.tubechop.com/watch/7672888

I have already replaced the inner distributor seal and exterior O -ring.

One initial question I have is:
- Is the the exhaust side cambox (so I sound like I know what I am talking about)?
- How much pressure is there in this part of the cambox. Not much as RTV repair was workable for a long long time?

Things I am confident in doing for the repair:
- I can line up the camwheel mark and the auxilary wheel mark as seen here:
https://drive.google.com/file/d/0B7zl-4 ... sp=sharing
- Orient distributor rotor for timing purposes.
- Use chopstick in #1 plug hole to determine if engine is at top of stroke. (clarification: recognizing that this could be the compression or exhaust stroke, aren't I at TDC as long as the cam wheel is lined up? Car is in running condition currently.

Hesitations I have:
- I do not see a mark on the crank pulley. As long as I am at TDC with the cam pulley marks lined up, can't I just make a new mark on the crank pulley? I am petrified of screwing up and ruining engine...but I feel confident as long as I have all the marks I need to reset the engine when I put it back together.

Thanks for any advice on proceeding. As soon as I get some more clarification of what marks I need to ensure I can get my engine back to true TDC no matter what, then I am confident in getting through the rest of the repair.

Thanks!