Lower pan pulled and bolts were loose!

[Petebee]

Plan to pull my lower pan and check out the upper pan bolt situation this weekend. Do I need to use any gasket sealant on the new gasket? If so what type? Just a few dabs on the pan surface and use it to hold gasket in place, or something else?

If I have some loose or dropped bolts in the pan should I use thread tape or loctite when I reinstall them? If loctite what color?

BTW just replaced my rear CV axle on the passengers side. My first "real" E30 project. Woo hoo! Plan to drain and replace coolant this weekend to.

[JHZR2]

I used high-temperature thread sealant for the job... though none of my bolts had come out, a couple were looser than the others.  I removed and re-torqued all of them.

Thread sealant (hi-temp, available from all the auto parts stores) doesnt perform the explicit 'locking' function that loctite blue will, however, it is specifically designed for up to 450F temperatures, is designed to prevent threaded items from vibration loosening, and is readily removable.  It cures slower, so it is a bit more of a pain, but I felt it was the right product for the job.

Loctite red is rated for high temperatures, but the removal torque required to break it is past the yield strength of those little bolts.  Loctite blue surely works good, but given the thermal cycling that such a part of the engine goes through, and the potential peak temperatures that it might see, I felt the thread sealant was the best choice.

I used a bit of gasket sealant on the pan, so that it held the gasket in place.  I used it very sparingly, because I had it and it makes things a bit easier... its really not necessary though, IMO, so long as you clean up everything properly beforehand, torque evenly, etc.  

That said, my OE gasket was stuck on with something, likely gasket sealant.

For coolant, be sure to use BMW blue (G-48) or a G-05 chemistry (Zerex G-05 is good stuff).  G-05 is VERY close to the recommended blue G-48.

JMH

[Petebee]

I used high-temperature thread sealant for the job... though none of my bolts had come out, a couple were looser than the others.  I removed and re-torqued all of them.

Thread sealant (hi-temp, available from all the auto parts stores) doesnt perform the explicit 'locking' function that loctite blue will, however, it is specifically designed for up to 450F temperatures, is designed to prevent threaded items from vibration loosening, and is readily removable.  It cures slower, so it is a bit more of a pain, but I felt it was the right product for the job.

Loctite red is rated for high temperatures, but the removal torque required to break it is past the yield strength of those little bolts.  Loctite blue surely works good, but given the thermal cycling that such a part of the engine goes through, and the potential peak temperatures that it might see, I felt the thread sealant was the best choice.

I used a bit of gasket sealant on the pan, so that it held the gasket in place.  I used it very sparingly, because I had it and it makes things a bit easier... its really not necessary though, IMO, so long as you clean up everything properly beforehand, torque evenly, etc.  

That said, my OE gasket was stuck on with something, likely gasket sealant.

For coolant, be sure to use BMW blue (G-48) or a G-05 chemistry (Zerex G-05 is good stuff).  G-05 is VERY close to the recommended blue G-48.

JMH

Thanks for the tips. Bought the BMW coolant, so I should be all set there. I'll get the high temp thread sealant and torque appropriately for the bolts on the inside. Couple of dabs of gasket sealant sounds like the plan for the lower pan gasket.

[Petebee]

Well I just finished pulling the lower pan and I had one bolt in the sump and three others finger tight! I removed all bolts except the one hiding next to the dipstick tube. I couldn't get my torque wrench to fit so I just snugged that one with a ratchet.

All others got high temp thread sealant. They "cured" for at least two hours before I started / drove the car...hope I didn't mess them up.

I ran an engine flush before dropping everything and didn't find anything in the pan, except for the bolt. No metal flakes or metal chunks and no pieces of plastic either.

Remember my sprockets are pretty worn on the cam ends, but I don't see any reason to do the sprocket/timing chain overhaul yet since I didn't have any metal in the pan. The belt whirrs, but it doesn't rattle. What do you guys think about leaving things as is for now? Car has 119K miles, and was very well maintained by the previous owner.

[sheepdog]

Remember my sprockets are pretty worn on the cam ends, but I don't see any reason to do the sprocket/timing chain overhaul yet since I didn't have any metal in the pan. The belt whirrs, but it doesn't rattle. What do you guys think about leaving things as is for now? Car has 119K miles, and was very well maintained by the previous owner.

I would begin saving for a change. It is only a matter of time before you start tossing bits of chain. I would aim to replace it all within 10-20k.

[DZick]

I agree with sheepdog, he had it happen to him and also saw it happen to me
 
My car was babied (didnt see past 5k) its whole life. I made it to 120,xxx and my timing chain tensioner went out. When that happened i skipped time and went approx 180 out, broke the guide rails, etc. I Couldnt even start it, after 2 months of working on it (when i had time) i finally got it i guess you could say "running"..........
 
well to make a long a little story short when i skipped time a valve hit a piston and bent it... not much i still have approx 130 compression, but with all of the cranking and trying to get it running I starved the engine of oil and now i have a terrrrrible knock and cannot hold oil pressure.... i am now done with the m42, and i will be taking it out this spring.
 
I guess there is one good thing to come out of it... three letters... s50
 
Words of advice
 
DONT LET A $45 EASY FIX COST YOU ~$600 ON NEW PARTS JUST TO FIND OUT YOUR ENGINE IS TOAST

[Petebee]

Okay you guys have convinced me. I'll order a tensioner tonight and get the timing chain parts when I get taxes figured out.