Silicon Vs Anaerobic sealant on engines?

[buzzer]

for years I have used Loctite Plastic Gasket when I have built engines. Its an Anerobic so any that squashes out from a joint can be wiped off on the outside, and the small amount on the inside gets washed off with the oil. I have stripped engines down years after and found no evidence of sealant blockage. for me its good stuff.

a while go I stripped down a Lotus Twincam engine and inside was full of strings of silicon where it has squashed out the joints (they had put loads on) and it had partially blocked the oil pickup pipe. even when you put just a smear on, it still leaves a tiny string of sealant which washes off when hard.

In the next few weeks I have to seal the engine breather and valve covers on my SLK55 AMG, and In notice that it recommends using a silicon sealant as there are no gaskets on the joints.... Its a very common area on the engine to leak.

Question is, why silicon when better products seem to be available... what am I missing, and can I use an anaerobic sealant in place of a silicone one?

[steveo3002]

im far from an expert but doesnt the silicone type fill larger gaps where the other one relies on fairly tight fitting surfaces?

[buzzer]

steveo3002 said:

im far from an expert but doesnt the silicone type fill larger gaps where the other one relies on fairly tight fitting surfaces?

I think you are right...I used some Silicon on a pressed tin primary chain case on a motorbike as it was a bit distorted, sealed a treat, but I was not worried about a bit of silicon around the chain and clutch area.

But most engine components are close fitting, certainly the AMG covers are, and I cant understand why they recommend silicon?

[Boosted LS1]

Anerobics are especially useful for tight flat joints, timing covers, rear main bearing caps etc. I can't stand that stringy silicon stuff and I'm not a fan of hylomar either. For sumps I like the black loctite that's oil/petrol resistant. It forms a really good bond much like the OE goo.

[buzzer]

Boosted LS1 said:

Anerobics are especially useful for tight flat joints, timing covers, rear main bearing caps etc. I can't stand that stringy silicon stuff and I'm not a fan of hylomar either. For sumps I like the black loctite that's oil/petrol resistant. It forms a really good bond much like the OE goo.

Thanks, you got a link or a number on the black stuff?

[Boosted LS1]

buzzer said:

Thanks, you got a link or a number on the black stuff?

halfords sell it, loctite 5922 iirc.