Replacing *new* profile gasket, what did I do wrong?

[jaredmac11]

Post swap pic for prosperity.
I resealed my M42 not that long ago, in miles, back in end of year 2018. I think about 3-6 months after the install I noticed the top of the oil pan was getting a bit oily and I knew my timing case was weepy. As of this year, Im getting oil on my driveway so I have to do something. Shes just a project car and has gotten maybe 200-300 miles since I built her 2 years ago.

Oil is definitely seeping from the profile gasket, right (exhaust) side where the engine leans. Upper timing case is brand new and dry, lower timing case and sump is oily.

I recall putting gasket maker on the groove of the lower timing case and on the back edges of the gasket, but no dice apparently.
I do think where I failed was I installed the gasket in the winter and didnt warm up the gasket.
However, I want to make certain Im doing this right (and I dont wanna pull the head).

This guide:
https://www.newtis.info/tisv2/a/en/e...pk0SeCSZiVcVuE
is fairly straight forward, but are the special tools essential? If I warm up the gasket and press the timing case down while I reattach it, would that be enough?
also what exactly is going on with the step "Cut off seal at cutting lines." ? What am I cutting? If I recall correctly, the seal isnt sandwiched by the head, just by the timing case, right? so what am I cutting?

I know a lot of people have this issue but surprisingly this forums search and google isnt pulling up too much. I just wanna get it right this time and for all.

Thanks
Jared

[roguetoaster]

Well, there are loads of things that can go wrong with T case sealing on an M42, anything from designed gaps that need goop leaking to oil seeping past bolts. For me, it's been about a 75% success rate with that rubber gasket or the area immediately around it sealing on the first try. So, I'd suggest just doing it again.

Do remember that just because the part (which isn't the profile gasket, but just some other unnamed gasket in that area) you installed was new to you doesn't mean it hadn't been on a shelf for a decade prior.

When the directions reference cutting it seems that they mean the paper gaskets in some way.

[bmwman91]

Yeah, the seals which it says need cutting are the paper ones (or metal if M44). The idea is to have the rubber profile gaskets butt up against the other profile gasket, with sealant gooped in at the butt joints. I am not sure how much the temperature of the part during installation matters either. I have had a leaky joint right above the chain tensioner as well after doing everything "by the book" in warm CA weather. I sort of wonder if the procedure of clamping everything down while the sealant is wet is wrong...you definitely don't tighten covers and stuff down on engines where they use RTV instead of gaskets, you apply it, mate the parts, finger-tighten fasteners and then fully tighten them after a full cure. Tightening them right away forces all of the RTV out.

In the case of the M42 though, I am not sure if you will ever get the upper timing case cover flush with the top of the head if you wait for the sealant to cure, so as roguetoaster says, you have to get the sealant in there, assemble it and accept the less-than-100% of a perfect seal, and repeat if needed. It sure is annoying!

[RotCaboy]

If anyone is ever looking this up due to a leaky timing case... What I did was use Toyota/Lexus FIPG on every like metal to like metal seal on the entire engine. So my M42 rebuild used the thick rubber profile and valve cover gaskets, and the (improved) metal timing to block gasket (since I swapped to the 95 case). I also used the stock replacement upper oil pan gasket since the block and the pan are different metals, they need to be able to expand at different rates and sort of slide. On all other seals (lower pan, all timing case seals, water pump, oil filter housing) I used the FIPG. So far it's been almost 2 years and not a single leak.