Lower Oil pan

[djohnson64]

I'm planning to replace the lower oil pan, and wanted to check with you guys fisrt to minimize the chance of me screwing up.
1- If the old gasket is stuck, should I use Liquid Wrench to loosen it up prior to some gentle scraping? What would be the best way to scrape w/o damaging the aluminum upper pan?
2- Any need to use sealant on the new gasket?
3- The torque for the bolts is 7-9 N-M?
4- Lastly, a local Indy told me to use only genuine MB pan and gasket because of concern regarding leaking (gasket not perfect fit and the pan too thin) Any truth to this?
5- Is there anything else that I should work on while I'm down there?
Thanks.
David
83 300 DT

[Hit Man X]

That's a penetrant, I'd use something for removing crap like Brake Cleaner or something of that nature. Be warned... Brake Cleaner burns a lot more in the eye than PB Blaster does. I seem to get that in my eye when not working on vehicles.

Gasket I'd do dry unless ya know there are some deviations in the mating surfaces, then I'd use a thin film of RTV on it.

My Haynes manual reads different for the torque specs on the Nm end, so I'd ask around...

Typically OE parts are better than aftermarket, but that doesn't always hold true. Gasket sure I could go for but the pan, eh I'd probably go aftermarket. The only way it'd bend and leak is if you mistorqued it.



Be smart and safe down there, motor oil in your eye burns like hell and rust hurts also. Stuff from years ago when I thought safety was for chumps. Ramps if you do or jackstands, use wheel chocks. I got pinned under a 4x4 truck when it came off the ramps and took me for a ride. Mad road rash, tore muscles in my lower back, etc. Not good.

Use a cool fluorescent, not an incandescent... they get very hot when 18" from your head. Rubber gloves are nice to have too.

[dannym]

Hey,
I always use penetrating oil on gaskets.
I would at least try that first before moving to brake cleaner.

You should be able to scrape the cast without disfiguring it.

Danny

[zaffo]

I did this on my 240D and it was a breeze. Had the pan off for about 2 weeks and it was still dripping oil. Pan and lower end clean as a whistle with 314k miles.

I used brake cleaner after scraping with a razor. Used Hylomar on the gasket and it sealed like a poem.

[SD Blue]

When I changed mine, I used penetrating oil because it seem to linger longer to soften the gasket. Most of the gasket came off very easily and a putty knife took care of the rest.

I installed the gasket dry and definitely would recommend it since it has worked so well for mine. With the new gasket materials available, dry is actually recommended. A torque wrench is one of the best gasket "sealers".

[mj_sid]

I've done this a couple of times on the SD's or D's. I would recommend using only MBZ gaskets with no RTV. If you are going to use a non MBZ gasket use RTV. It's not so bad to do; the only hard part is at the end when you want to hurry up and get done but you have to bolt in the million bolts that hold it in.

Happy wrenching,
Matt

[djohnson64]

Originally Posted by mj_sid

If you are going to use a non MBZ gasket use RTV. Matt

Thanks guys.
I'm a newbie at this: What's the RTV?
David

[mj_sid]

RTV is a glue like object that helps to ensure that you get a great seal. It is difficult to use because it's really easy to use too much or too little. The problem with using to much is that it can bleed out on the sides and gunk up what your working with (the oil in this case). If you use to little it will create gaps that the oil can leak out of. RTV comes in different forms; there is a kind that stays pliable that is really cool to work with. For this project I would recommend using a good gasket and forgoing the RTV. When you get the gasket make sure that it is flat in the package; I’ve gotten non MBZ parts that were folded up. When I installed them they never really seemed to work, they always leaked, it's worth the extra $$$ so you don’t have to do it over and over again. If any members have a better definition or corrections please let us know.

--Matt

[djohnson64]

Thanks, Matt.
Sounds like time to go the stealership for the gasket.
David

I would personally use a little permatex "Form-A-Gasket"
Its black glue and is amazing stuff. If your gasket needs changing, chances are that it will fall right off or peel off by hand. I had no problems getting mine off in once chunk (they get stiff).
I layed each side of the new one with this permatex stuff and it is working good. I wouldn't use silicone because (as any VW engine rebuilder knows) you barely EVER use silicone. I think this joint is submerged under the oil inside the pan so it gets a lot of attacking (when I used silicone the first time it leaked)
The other stuff worked great.
Also don't cross thread any of those bolts...they are easy to accidentally get in the wrong way.

Clean your pan out good while you are in there and take a gander up into your engine...expect drips...there are no ways around it.

Make sure you pull the oil filter BEFORE you remove the pan...that thing holds lots of oil in its housing.

[t walgamuth]

actually the joint i believe although the oil obviously flows over it is not submersed in it. the silicone gasket forma gasket stuff if too much is used will break loose and plug the oil pickup.... so if you use that be careful. i would use a standard gasket if it were me and i had timet o get one.

Originally Posted by t walgamuth

actually the joint i believe although the oil obviously flows over it is not submersed in it. the silicone gasket forma gasket stuff if too much is used will break loose and plug the oil pickup.... so if you use that be careful. i would use a standard gasket if it were me and i had timet o get one.

Yeah a very thin coating is all that is required. Of course the way most people use silicone as well it can be just as dangerous. I dislike nothing more than finding spooged out silicone resulting in oil leaks...

RTV
Room
Tempature
Vulcanizing
At least that is what it was called a few years back. Can be hazardous to your oil pump. Once in a very long while it will break a chunk off and that will not disolve and can end up jammed in your oil pump.
Don't ask how I know this.

Also a good fact about the permatex (for those who haven't used it)
It has a pretty thick consistancy however you lay it on real thin. This helps when dealing with the whole "getting in the oil system" problem...Its nice in the fact that you can control it (unlike the sometimes unweildly RTV silicone).

[SD Blue]

I would recommend, as will many others here and the manufacturer, that you avoid RTV sealant. The reason is a diesel uses oil jets for cooling the bottom of pistons, etc... If one little blob breaks off inside, it can cause major problems. Save that RTV for caulking your bathtub or something. It is just not worth risking damage to your engine.

If you are installing a new pan and gasket, with good clean surfaces, there should be no reason to use any kind of sealant. In fact, if you do a little research on new gasket materials, you will find that a sealant can actually be detrimental and cause leaks sooner than they would normally occur.

Try it without sealant, as I did, and I think you will be pleasantly surprised.